Merge branch 'kvm-late-6.1' into HEAD

[linux-block.git] / arch / x86 / kvm / x86.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Kernel-based Virtual Machine driver for Linux
 *
 * derived from drivers/kvm/kvm_main.c
 *
 * Copyright (C) 2006 Qumranet, Inc.
 * Copyright (C) 2008 Qumranet, Inc.
 * Copyright IBM Corporation, 2008
 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
 *
 * Authors:
 *   Avi Kivity   <avi@qumranet.com>
 *   Yaniv Kamay  <yaniv@qumranet.com>
 *   Amit Shah    <amit.shah@qumranet.com>
 *   Ben-Ami Yassour <benami@il.ibm.com>
 */

#include <linux/kvm_host.h>
#include "irq.h"
#include "ioapic.h"
#include "mmu.h"
#include "i8254.h"
#include "tss.h"
#include "kvm_cache_regs.h"
#include "kvm_emulate.h"
#include "x86.h"
#include "cpuid.h"
#include "pmu.h"
#include "hyperv.h"
#include "lapic.h"
#include "xen.h"
#include "smm.h"

#include <linux/clocksource.h>
#include <linux/interrupt.h>
#include <linux/kvm.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <linux/moduleparam.h>
#include <linux/mman.h>
#include <linux/highmem.h>
#include <linux/iommu.h>
#include <linux/cpufreq.h>
#include <linux/user-return-notifier.h>
#include <linux/srcu.h>
#include <linux/slab.h>
#include <linux/perf_event.h>
#include <linux/uaccess.h>
#include <linux/hash.h>
#include <linux/pci.h>
#include <linux/timekeeper_internal.h>
#include <linux/pvclock_gtod.h>
#include <linux/kvm_irqfd.h>
#include <linux/irqbypass.h>
#include <linux/sched/stat.h>
#include <linux/sched/isolation.h>
#include <linux/mem_encrypt.h>
#include <linux/entry-kvm.h>
#include <linux/suspend.h>

#include <trace/events/kvm.h>

#include <asm/debugreg.h>
#include <asm/msr.h>
#include <asm/desc.h>
#include <asm/mce.h>
#include <asm/pkru.h>
#include <linux/kernel_stat.h>
#include <asm/fpu/api.h>
#include <asm/fpu/xcr.h>
#include <asm/fpu/xstate.h>
#include <asm/pvclock.h>
#include <asm/div64.h>
#include <asm/irq_remapping.h>
#include <asm/mshyperv.h>
#include <asm/hypervisor.h>
#include <asm/tlbflush.h>
#include <asm/intel_pt.h>
#include <asm/emulate_prefix.h>
#include <asm/sgx.h>
#include <clocksource/hyperv_timer.h>

#define CREATE_TRACE_POINTS
#include "trace.h"

#define MAX_IO_MSRS 256
#define KVM_MAX_MCE_BANKS 32

struct kvm_caps kvm_caps __read_mostly = {
        .supported_mce_cap = MCG_CTL_P | MCG_SER_P,
};
EXPORT_SYMBOL_GPL(kvm_caps);

#define  ERR_PTR_USR(e)  ((void __user *)ERR_PTR(e))

#define emul_to_vcpu(ctxt) \
        ((struct kvm_vcpu *)(ctxt)->vcpu)

/* EFER defaults:
 * - enable syscall per default because its emulated by KVM
 * - enable LME and LMA per default on 64 bit KVM
 */
#ifdef CONFIG_X86_64
static
u64 __read_mostly efer_reserved_bits = ~((u64)(EFER_SCE | EFER_LME | EFER_LMA));
#else
static u64 __read_mostly efer_reserved_bits = ~((u64)EFER_SCE);
#endif

static u64 __read_mostly cr4_reserved_bits = CR4_RESERVED_BITS;

#define KVM_EXIT_HYPERCALL_VALID_MASK (1 << KVM_HC_MAP_GPA_RANGE)

#define KVM_CAP_PMU_VALID_MASK KVM_PMU_CAP_DISABLE

#define KVM_X2APIC_API_VALID_FLAGS (KVM_X2APIC_API_USE_32BIT_IDS | \
                                    KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)

static void update_cr8_intercept(struct kvm_vcpu *vcpu);
static void process_nmi(struct kvm_vcpu *vcpu);
static void __kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags);
static void store_regs(struct kvm_vcpu *vcpu);
static int sync_regs(struct kvm_vcpu *vcpu);
static int kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu);

static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2);
static void __get_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2);

struct kvm_x86_ops kvm_x86_ops __read_mostly;

#define KVM_X86_OP(func)                                             \
        DEFINE_STATIC_CALL_NULL(kvm_x86_##func,                      \
                                *(((struct kvm_x86_ops *)0)->func));
#define KVM_X86_OP_OPTIONAL KVM_X86_OP
#define KVM_X86_OP_OPTIONAL_RET0 KVM_X86_OP
#include <asm/kvm-x86-ops.h>
EXPORT_STATIC_CALL_GPL(kvm_x86_get_cs_db_l_bits);
EXPORT_STATIC_CALL_GPL(kvm_x86_cache_reg);

static bool __read_mostly ignore_msrs = 0;
module_param(ignore_msrs, bool, S_IRUGO | S_IWUSR);

bool __read_mostly report_ignored_msrs = true;
module_param(report_ignored_msrs, bool, S_IRUGO | S_IWUSR);
EXPORT_SYMBOL_GPL(report_ignored_msrs);

unsigned int min_timer_period_us = 200;
module_param(min_timer_period_us, uint, S_IRUGO | S_IWUSR);

static bool __read_mostly kvmclock_periodic_sync = true;
module_param(kvmclock_periodic_sync, bool, S_IRUGO);

/* tsc tolerance in parts per million - default to 1/2 of the NTP threshold */
static u32 __read_mostly tsc_tolerance_ppm = 250;
module_param(tsc_tolerance_ppm, uint, S_IRUGO | S_IWUSR);

/*
 * lapic timer advance (tscdeadline mode only) in nanoseconds.  '-1' enables
 * adaptive tuning starting from default advancement of 1000ns.  '0' disables
 * advancement entirely.  Any other value is used as-is and disables adaptive
 * tuning, i.e. allows privileged userspace to set an exact advancement time.
 */
static int __read_mostly lapic_timer_advance_ns = -1;
module_param(lapic_timer_advance_ns, int, S_IRUGO | S_IWUSR);

static bool __read_mostly vector_hashing = true;
module_param(vector_hashing, bool, S_IRUGO);

bool __read_mostly enable_vmware_backdoor = false;
module_param(enable_vmware_backdoor, bool, S_IRUGO);
EXPORT_SYMBOL_GPL(enable_vmware_backdoor);

/*
 * Flags to manipulate forced emulation behavior (any non-zero value will
 * enable forced emulation).
 */
#define KVM_FEP_CLEAR_RFLAGS_RF BIT(1)
static int __read_mostly force_emulation_prefix;
module_param(force_emulation_prefix, int, 0644);

int __read_mostly pi_inject_timer = -1;
module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR);

/* Enable/disable PMU virtualization */
bool __read_mostly enable_pmu = true;
EXPORT_SYMBOL_GPL(enable_pmu);
module_param(enable_pmu, bool, 0444);

bool __read_mostly eager_page_split = true;
module_param(eager_page_split, bool, 0644);

/*
 * Restoring the host value for MSRs that are only consumed when running in
 * usermode, e.g. SYSCALL MSRs and TSC_AUX, can be deferred until the CPU
 * returns to userspace, i.e. the kernel can run with the guest's value.
 */
#define KVM_MAX_NR_USER_RETURN_MSRS 16

struct kvm_user_return_msrs {
        struct user_return_notifier urn;
        bool registered;
        struct kvm_user_return_msr_values {
                u64 host;
                u64 curr;
        } values[KVM_MAX_NR_USER_RETURN_MSRS];
};

u32 __read_mostly kvm_nr_uret_msrs;
EXPORT_SYMBOL_GPL(kvm_nr_uret_msrs);
static u32 __read_mostly kvm_uret_msrs_list[KVM_MAX_NR_USER_RETURN_MSRS];
static struct kvm_user_return_msrs __percpu *user_return_msrs;

#define KVM_SUPPORTED_XCR0     (XFEATURE_MASK_FP | XFEATURE_MASK_SSE \
                                | XFEATURE_MASK_YMM | XFEATURE_MASK_BNDREGS \
                                | XFEATURE_MASK_BNDCSR | XFEATURE_MASK_AVX512 \
                                | XFEATURE_MASK_PKRU | XFEATURE_MASK_XTILE)

u64 __read_mostly host_efer;
EXPORT_SYMBOL_GPL(host_efer);

bool __read_mostly allow_smaller_maxphyaddr = 0;
EXPORT_SYMBOL_GPL(allow_smaller_maxphyaddr);

bool __read_mostly enable_apicv = true;
EXPORT_SYMBOL_GPL(enable_apicv);

u64 __read_mostly host_xss;
EXPORT_SYMBOL_GPL(host_xss);

const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
        KVM_GENERIC_VM_STATS(),
        STATS_DESC_COUNTER(VM, mmu_shadow_zapped),
        STATS_DESC_COUNTER(VM, mmu_pte_write),
        STATS_DESC_COUNTER(VM, mmu_pde_zapped),
        STATS_DESC_COUNTER(VM, mmu_flooded),
        STATS_DESC_COUNTER(VM, mmu_recycled),
        STATS_DESC_COUNTER(VM, mmu_cache_miss),
        STATS_DESC_ICOUNTER(VM, mmu_unsync),
        STATS_DESC_ICOUNTER(VM, pages_4k),
        STATS_DESC_ICOUNTER(VM, pages_2m),
        STATS_DESC_ICOUNTER(VM, pages_1g),
        STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
        STATS_DESC_PCOUNTER(VM, max_mmu_rmap_size),
        STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
};

const struct kvm_stats_header kvm_vm_stats_header = {
        .name_size = KVM_STATS_NAME_SIZE,
        .num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
        .id_offset = sizeof(struct kvm_stats_header),
        .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
        .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
                       sizeof(kvm_vm_stats_desc),
};

const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
        KVM_GENERIC_VCPU_STATS(),
        STATS_DESC_COUNTER(VCPU, pf_taken),
        STATS_DESC_COUNTER(VCPU, pf_fixed),
        STATS_DESC_COUNTER(VCPU, pf_emulate),
        STATS_DESC_COUNTER(VCPU, pf_spurious),
        STATS_DESC_COUNTER(VCPU, pf_fast),
        STATS_DESC_COUNTER(VCPU, pf_mmio_spte_created),
        STATS_DESC_COUNTER(VCPU, pf_guest),
        STATS_DESC_COUNTER(VCPU, tlb_flush),
        STATS_DESC_COUNTER(VCPU, invlpg),
        STATS_DESC_COUNTER(VCPU, exits),
        STATS_DESC_COUNTER(VCPU, io_exits),
        STATS_DESC_COUNTER(VCPU, mmio_exits),
        STATS_DESC_COUNTER(VCPU, signal_exits),
        STATS_DESC_COUNTER(VCPU, irq_window_exits),
        STATS_DESC_COUNTER(VCPU, nmi_window_exits),
        STATS_DESC_COUNTER(VCPU, l1d_flush),
        STATS_DESC_COUNTER(VCPU, halt_exits),
        STATS_DESC_COUNTER(VCPU, request_irq_exits),
        STATS_DESC_COUNTER(VCPU, irq_exits),
        STATS_DESC_COUNTER(VCPU, host_state_reload),
        STATS_DESC_COUNTER(VCPU, fpu_reload),
        STATS_DESC_COUNTER(VCPU, insn_emulation),
        STATS_DESC_COUNTER(VCPU, insn_emulation_fail),
        STATS_DESC_COUNTER(VCPU, hypercalls),
        STATS_DESC_COUNTER(VCPU, irq_injections),
        STATS_DESC_COUNTER(VCPU, nmi_injections),
        STATS_DESC_COUNTER(VCPU, req_event),
        STATS_DESC_COUNTER(VCPU, nested_run),
        STATS_DESC_COUNTER(VCPU, directed_yield_attempted),
        STATS_DESC_COUNTER(VCPU, directed_yield_successful),
        STATS_DESC_COUNTER(VCPU, preemption_reported),
        STATS_DESC_COUNTER(VCPU, preemption_other),
        STATS_DESC_IBOOLEAN(VCPU, guest_mode),
        STATS_DESC_COUNTER(VCPU, notify_window_exits),
};

const struct kvm_stats_header kvm_vcpu_stats_header = {
        .name_size = KVM_STATS_NAME_SIZE,
        .num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
        .id_offset = sizeof(struct kvm_stats_header),
        .desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
        .data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
                       sizeof(kvm_vcpu_stats_desc),
};

u64 __read_mostly host_xcr0;

static struct kmem_cache *x86_emulator_cache;

/*
 * When called, it means the previous get/set msr reached an invalid msr.
 * Return true if we want to ignore/silent this failed msr access.
 */
static bool kvm_msr_ignored_check(u32 msr, u64 data, bool write)
{
        const char *op = write ? "wrmsr" : "rdmsr";

        if (ignore_msrs) {
                if (report_ignored_msrs)
                        kvm_pr_unimpl("ignored %s: 0x%x data 0x%llx\n",
                                      op, msr, data);
                /* Mask the error */
                return true;
        } else {
                kvm_debug_ratelimited("unhandled %s: 0x%x data 0x%llx\n",
                                      op, msr, data);
                return false;
        }
}

static struct kmem_cache *kvm_alloc_emulator_cache(void)
{
        unsigned int useroffset = offsetof(struct x86_emulate_ctxt, src);
        unsigned int size = sizeof(struct x86_emulate_ctxt);

        return kmem_cache_create_usercopy("x86_emulator", size,
                                          __alignof__(struct x86_emulate_ctxt),
                                          SLAB_ACCOUNT, useroffset,
                                          size - useroffset, NULL);
}

static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt);

static inline void kvm_async_pf_hash_reset(struct kvm_vcpu *vcpu)
{
        int i;
        for (i = 0; i < ASYNC_PF_PER_VCPU; i++)
                vcpu->arch.apf.gfns[i] = ~0;
}

static void kvm_on_user_return(struct user_return_notifier *urn)
{
        unsigned slot;
        struct kvm_user_return_msrs *msrs
                = container_of(urn, struct kvm_user_return_msrs, urn);
        struct kvm_user_return_msr_values *values;
        unsigned long flags;

        /*
         * Disabling irqs at this point since the following code could be
         * interrupted and executed through kvm_arch_hardware_disable()
         */
        local_irq_save(flags);
        if (msrs->registered) {
                msrs->registered = false;
                user_return_notifier_unregister(urn);
        }
        local_irq_restore(flags);
        for (slot = 0; slot < kvm_nr_uret_msrs; ++slot) {
                values = &msrs->values[slot];
                if (values->host != values->curr) {
                        wrmsrl(kvm_uret_msrs_list[slot], values->host);
                        values->curr = values->host;
                }
        }
}

static int kvm_probe_user_return_msr(u32 msr)
{
        u64 val;
        int ret;

        preempt_disable();
        ret = rdmsrl_safe(msr, &val);
        if (ret)
                goto out;
        ret = wrmsrl_safe(msr, val);
out:
        preempt_enable();
        return ret;
}

int kvm_add_user_return_msr(u32 msr)
{
        BUG_ON(kvm_nr_uret_msrs >= KVM_MAX_NR_USER_RETURN_MSRS);

        if (kvm_probe_user_return_msr(msr))
                return -1;

        kvm_uret_msrs_list[kvm_nr_uret_msrs] = msr;
        return kvm_nr_uret_msrs++;
}
EXPORT_SYMBOL_GPL(kvm_add_user_return_msr);

int kvm_find_user_return_msr(u32 msr)
{
        int i;

        for (i = 0; i < kvm_nr_uret_msrs; ++i) {
                if (kvm_uret_msrs_list[i] == msr)
                        return i;
        }
        return -1;
}
EXPORT_SYMBOL_GPL(kvm_find_user_return_msr);

static void kvm_user_return_msr_cpu_online(void)
{
        unsigned int cpu = smp_processor_id();
        struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);
        u64 value;
        int i;

        for (i = 0; i < kvm_nr_uret_msrs; ++i) {
                rdmsrl_safe(kvm_uret_msrs_list[i], &value);
                msrs->values[i].host = value;
                msrs->values[i].curr = value;
        }
}

int kvm_set_user_return_msr(unsigned slot, u64 value, u64 mask)
{
        unsigned int cpu = smp_processor_id();
        struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);
        int err;

        value = (value & mask) | (msrs->values[slot].host & ~mask);
        if (value == msrs->values[slot].curr)
                return 0;
        err = wrmsrl_safe(kvm_uret_msrs_list[slot], value);
        if (err)
                return 1;

        msrs->values[slot].curr = value;
        if (!msrs->registered) {
                msrs->urn.on_user_return = kvm_on_user_return;
                user_return_notifier_register(&msrs->urn);
                msrs->registered = true;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_user_return_msr);

static void drop_user_return_notifiers(void)
{
        unsigned int cpu = smp_processor_id();
        struct kvm_user_return_msrs *msrs = per_cpu_ptr(user_return_msrs, cpu);

        if (msrs->registered)
                kvm_on_user_return(&msrs->urn);
}

u64 kvm_get_apic_base(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.apic_base;
}

enum lapic_mode kvm_get_apic_mode(struct kvm_vcpu *vcpu)
{
        return kvm_apic_mode(kvm_get_apic_base(vcpu));
}
EXPORT_SYMBOL_GPL(kvm_get_apic_mode);

int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
        enum lapic_mode old_mode = kvm_get_apic_mode(vcpu);
        enum lapic_mode new_mode = kvm_apic_mode(msr_info->data);
        u64 reserved_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu) | 0x2ff |
                (guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE);

        if ((msr_info->data & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID)
                return 1;
        if (!msr_info->host_initiated) {
                if (old_mode == LAPIC_MODE_X2APIC && new_mode == LAPIC_MODE_XAPIC)
                        return 1;
                if (old_mode == LAPIC_MODE_DISABLED && new_mode == LAPIC_MODE_X2APIC)
                        return 1;
        }

        kvm_lapic_set_base(vcpu, msr_info->data);
        kvm_recalculate_apic_map(vcpu->kvm);
        return 0;
}

/*
 * Handle a fault on a hardware virtualization (VMX or SVM) instruction.
 *
 * Hardware virtualization extension instructions may fault if a reboot turns
 * off virtualization while processes are running.  Usually after catching the
 * fault we just panic; during reboot instead the instruction is ignored.
 */
noinstr void kvm_spurious_fault(void)
{
        /* Fault while not rebooting.  We want the trace. */
        BUG_ON(!kvm_rebooting);
}
EXPORT_SYMBOL_GPL(kvm_spurious_fault);

#define EXCPT_BENIGN            0
#define EXCPT_CONTRIBUTORY      1
#define EXCPT_PF                2

static int exception_class(int vector)
{
        switch (vector) {
        case PF_VECTOR:
                return EXCPT_PF;
        case DE_VECTOR:
        case TS_VECTOR:
        case NP_VECTOR:
        case SS_VECTOR:
        case GP_VECTOR:
                return EXCPT_CONTRIBUTORY;
        default:
                break;
        }
        return EXCPT_BENIGN;
}

#define EXCPT_FAULT             0
#define EXCPT_TRAP              1
#define EXCPT_ABORT             2
#define EXCPT_INTERRUPT         3
#define EXCPT_DB                4

static int exception_type(int vector)
{
        unsigned int mask;

        if (WARN_ON(vector > 31 || vector == NMI_VECTOR))
                return EXCPT_INTERRUPT;

        mask = 1 << vector;

        /*
         * #DBs can be trap-like or fault-like, the caller must check other CPU
         * state, e.g. DR6, to determine whether a #DB is a trap or fault.
         */
        if (mask & (1 << DB_VECTOR))
                return EXCPT_DB;

        if (mask & ((1 << BP_VECTOR) | (1 << OF_VECTOR)))
                return EXCPT_TRAP;

        if (mask & ((1 << DF_VECTOR) | (1 << MC_VECTOR)))
                return EXCPT_ABORT;

        /* Reserved exceptions will result in fault */
        return EXCPT_FAULT;
}

void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu,
                                   struct kvm_queued_exception *ex)
{
        if (!ex->has_payload)
                return;

        switch (ex->vector) {
        case DB_VECTOR:
                /*
                 * "Certain debug exceptions may clear bit 0-3.  The
                 * remaining contents of the DR6 register are never
                 * cleared by the processor".
                 */
                vcpu->arch.dr6 &= ~DR_TRAP_BITS;
                /*
                 * In order to reflect the #DB exception payload in guest
                 * dr6, three components need to be considered: active low
                 * bit, FIXED_1 bits and active high bits (e.g. DR6_BD,
                 * DR6_BS and DR6_BT)
                 * DR6_ACTIVE_LOW contains the FIXED_1 and active low bits.
                 * In the target guest dr6:
                 * FIXED_1 bits should always be set.
                 * Active low bits should be cleared if 1-setting in payload.
                 * Active high bits should be set if 1-setting in payload.
                 *
                 * Note, the payload is compatible with the pending debug
                 * exceptions/exit qualification under VMX, that active_low bits
                 * are active high in payload.
                 * So they need to be flipped for DR6.
                 */
                vcpu->arch.dr6 |= DR6_ACTIVE_LOW;
                vcpu->arch.dr6 |= ex->payload;
                vcpu->arch.dr6 ^= ex->payload & DR6_ACTIVE_LOW;

                /*
                 * The #DB payload is defined as compatible with the 'pending
                 * debug exceptions' field under VMX, not DR6. While bit 12 is
                 * defined in the 'pending debug exceptions' field (enabled
                 * breakpoint), it is reserved and must be zero in DR6.
                 */
                vcpu->arch.dr6 &= ~BIT(12);
                break;
        case PF_VECTOR:
                vcpu->arch.cr2 = ex->payload;
                break;
        }

        ex->has_payload = false;
        ex->payload = 0;
}
EXPORT_SYMBOL_GPL(kvm_deliver_exception_payload);

static void kvm_queue_exception_vmexit(struct kvm_vcpu *vcpu, unsigned int vector,
                                       bool has_error_code, u32 error_code,
                                       bool has_payload, unsigned long payload)
{
        struct kvm_queued_exception *ex = &vcpu->arch.exception_vmexit;

        ex->vector = vector;
        ex->injected = false;
        ex->pending = true;
        ex->has_error_code = has_error_code;
        ex->error_code = error_code;
        ex->has_payload = has_payload;
        ex->payload = payload;
}

/* Forcibly leave the nested mode in cases like a vCPU reset */
static void kvm_leave_nested(struct kvm_vcpu *vcpu)
{
        kvm_x86_ops.nested_ops->leave_nested(vcpu);
}

static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
                unsigned nr, bool has_error, u32 error_code,
                bool has_payload, unsigned long payload, bool reinject)
{
        u32 prev_nr;
        int class1, class2;

        kvm_make_request(KVM_REQ_EVENT, vcpu);

        /*
         * If the exception is destined for L2 and isn't being reinjected,
         * morph it to a VM-Exit if L1 wants to intercept the exception.  A
         * previously injected exception is not checked because it was checked
         * when it was original queued, and re-checking is incorrect if _L1_
         * injected the exception, in which case it's exempt from interception.
         */
        if (!reinject && is_guest_mode(vcpu) &&
            kvm_x86_ops.nested_ops->is_exception_vmexit(vcpu, nr, error_code)) {
                kvm_queue_exception_vmexit(vcpu, nr, has_error, error_code,
                                           has_payload, payload);
                return;
        }

        if (!vcpu->arch.exception.pending && !vcpu->arch.exception.injected) {
        queue:
                if (reinject) {
                        /*
                         * On VM-Entry, an exception can be pending if and only
                         * if event injection was blocked by nested_run_pending.
                         * In that case, however, vcpu_enter_guest() requests an
                         * immediate exit, and the guest shouldn't proceed far
                         * enough to need reinjection.
                         */
                        WARN_ON_ONCE(kvm_is_exception_pending(vcpu));
                        vcpu->arch.exception.injected = true;
                        if (WARN_ON_ONCE(has_payload)) {
                                /*
                                 * A reinjected event has already
                                 * delivered its payload.
                                 */
                                has_payload = false;
                                payload = 0;
                        }
                } else {
                        vcpu->arch.exception.pending = true;
                        vcpu->arch.exception.injected = false;
                }
                vcpu->arch.exception.has_error_code = has_error;
                vcpu->arch.exception.vector = nr;
                vcpu->arch.exception.error_code = error_code;
                vcpu->arch.exception.has_payload = has_payload;
                vcpu->arch.exception.payload = payload;
                if (!is_guest_mode(vcpu))
                        kvm_deliver_exception_payload(vcpu,
                                                      &vcpu->arch.exception);
                return;
        }

        /* to check exception */
        prev_nr = vcpu->arch.exception.vector;
        if (prev_nr == DF_VECTOR) {
                /* triple fault -> shutdown */
                kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                return;
        }
        class1 = exception_class(prev_nr);
        class2 = exception_class(nr);
        if ((class1 == EXCPT_CONTRIBUTORY && class2 == EXCPT_CONTRIBUTORY) ||
            (class1 == EXCPT_PF && class2 != EXCPT_BENIGN)) {
                /*
                 * Synthesize #DF.  Clear the previously injected or pending
                 * exception so as not to incorrectly trigger shutdown.
                 */
                vcpu->arch.exception.injected = false;
                vcpu->arch.exception.pending = false;

                kvm_queue_exception_e(vcpu, DF_VECTOR, 0);
        } else {
                /* replace previous exception with a new one in a hope
                   that instruction re-execution will regenerate lost
                   exception */
                goto queue;
        }
}

void kvm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
        kvm_multiple_exception(vcpu, nr, false, 0, false, 0, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception);

void kvm_requeue_exception(struct kvm_vcpu *vcpu, unsigned nr)
{
        kvm_multiple_exception(vcpu, nr, false, 0, false, 0, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception);

void kvm_queue_exception_p(struct kvm_vcpu *vcpu, unsigned nr,
                           unsigned long payload)
{
        kvm_multiple_exception(vcpu, nr, false, 0, true, payload, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception_p);

static void kvm_queue_exception_e_p(struct kvm_vcpu *vcpu, unsigned nr,
                                    u32 error_code, unsigned long payload)
{
        kvm_multiple_exception(vcpu, nr, true, error_code,
                               true, payload, false);
}

int kvm_complete_insn_gp(struct kvm_vcpu *vcpu, int err)
{
        if (err)
                kvm_inject_gp(vcpu, 0);
        else
                return kvm_skip_emulated_instruction(vcpu);

        return 1;
}
EXPORT_SYMBOL_GPL(kvm_complete_insn_gp);

static int complete_emulated_insn_gp(struct kvm_vcpu *vcpu, int err)
{
        if (err) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        return kvm_emulate_instruction(vcpu, EMULTYPE_NO_DECODE | EMULTYPE_SKIP |
                                       EMULTYPE_COMPLETE_USER_EXIT);
}

void kvm_inject_page_fault(struct kvm_vcpu *vcpu, struct x86_exception *fault)
{
        ++vcpu->stat.pf_guest;

        /*
         * Async #PF in L2 is always forwarded to L1 as a VM-Exit regardless of
         * whether or not L1 wants to intercept "regular" #PF.
         */
        if (is_guest_mode(vcpu) && fault->async_page_fault)
                kvm_queue_exception_vmexit(vcpu, PF_VECTOR,
                                           true, fault->error_code,
                                           true, fault->address);
        else
                kvm_queue_exception_e_p(vcpu, PF_VECTOR, fault->error_code,
                                        fault->address);
}

void kvm_inject_emulated_page_fault(struct kvm_vcpu *vcpu,
                                    struct x86_exception *fault)
{
        struct kvm_mmu *fault_mmu;
        WARN_ON_ONCE(fault->vector != PF_VECTOR);

        fault_mmu = fault->nested_page_fault ? vcpu->arch.mmu :
                                               vcpu->arch.walk_mmu;

        /*
         * Invalidate the TLB entry for the faulting address, if it exists,
         * else the access will fault indefinitely (and to emulate hardware).
         */
        if ((fault->error_code & PFERR_PRESENT_MASK) &&
            !(fault->error_code & PFERR_RSVD_MASK))
                kvm_mmu_invalidate_gva(vcpu, fault_mmu, fault->address,
                                       fault_mmu->root.hpa);

        fault_mmu->inject_page_fault(vcpu, fault);
}
EXPORT_SYMBOL_GPL(kvm_inject_emulated_page_fault);

void kvm_inject_nmi(struct kvm_vcpu *vcpu)
{
        atomic_inc(&vcpu->arch.nmi_queued);
        kvm_make_request(KVM_REQ_NMI, vcpu);
}

void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
        kvm_multiple_exception(vcpu, nr, true, error_code, false, 0, false);
}
EXPORT_SYMBOL_GPL(kvm_queue_exception_e);

void kvm_requeue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code)
{
        kvm_multiple_exception(vcpu, nr, true, error_code, false, 0, true);
}
EXPORT_SYMBOL_GPL(kvm_requeue_exception_e);

/*
 * Checks if cpl <= required_cpl; if true, return true.  Otherwise queue
 * a #GP and return false.
 */
bool kvm_require_cpl(struct kvm_vcpu *vcpu, int required_cpl)
{
        if (static_call(kvm_x86_get_cpl)(vcpu) <= required_cpl)
                return true;
        kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
        return false;
}

bool kvm_require_dr(struct kvm_vcpu *vcpu, int dr)
{
        if ((dr != 4 && dr != 5) || !kvm_read_cr4_bits(vcpu, X86_CR4_DE))
                return true;

        kvm_queue_exception(vcpu, UD_VECTOR);
        return false;
}
EXPORT_SYMBOL_GPL(kvm_require_dr);

static inline u64 pdptr_rsvd_bits(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.reserved_gpa_bits | rsvd_bits(5, 8) | rsvd_bits(1, 2);
}

/*
 * Load the pae pdptrs.  Return 1 if they are all valid, 0 otherwise.
 */
int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
        gfn_t pdpt_gfn = cr3 >> PAGE_SHIFT;
        gpa_t real_gpa;
        int i;
        int ret;
        u64 pdpte[ARRAY_SIZE(mmu->pdptrs)];

        /*
         * If the MMU is nested, CR3 holds an L2 GPA and needs to be translated
         * to an L1 GPA.
         */
        real_gpa = kvm_translate_gpa(vcpu, mmu, gfn_to_gpa(pdpt_gfn),
                                     PFERR_USER_MASK | PFERR_WRITE_MASK, NULL);
        if (real_gpa == INVALID_GPA)
                return 0;

        /* Note the offset, PDPTRs are 32 byte aligned when using PAE paging. */
        ret = kvm_vcpu_read_guest_page(vcpu, gpa_to_gfn(real_gpa), pdpte,
                                       cr3 & GENMASK(11, 5), sizeof(pdpte));
        if (ret < 0)
                return 0;

        for (i = 0; i < ARRAY_SIZE(pdpte); ++i) {
                if ((pdpte[i] & PT_PRESENT_MASK) &&
                    (pdpte[i] & pdptr_rsvd_bits(vcpu))) {
                        return 0;
                }
        }

        /*
         * Marking VCPU_EXREG_PDPTR dirty doesn't work for !tdp_enabled.
         * Shadow page roots need to be reconstructed instead.
         */
        if (!tdp_enabled && memcmp(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs)))
                kvm_mmu_free_roots(vcpu->kvm, mmu, KVM_MMU_ROOT_CURRENT);

        memcpy(mmu->pdptrs, pdpte, sizeof(mmu->pdptrs));
        kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
        kvm_make_request(KVM_REQ_LOAD_MMU_PGD, vcpu);
        vcpu->arch.pdptrs_from_userspace = false;

        return 1;
}
EXPORT_SYMBOL_GPL(load_pdptrs);

void kvm_post_set_cr0(struct kvm_vcpu *vcpu, unsigned long old_cr0, unsigned long cr0)
{
        if ((cr0 ^ old_cr0) & X86_CR0_PG) {
                kvm_clear_async_pf_completion_queue(vcpu);
                kvm_async_pf_hash_reset(vcpu);

                /*
                 * Clearing CR0.PG is defined to flush the TLB from the guest's
                 * perspective.
                 */
                if (!(cr0 & X86_CR0_PG))
                        kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
        }

        if ((cr0 ^ old_cr0) & KVM_MMU_CR0_ROLE_BITS)
                kvm_mmu_reset_context(vcpu);

        if (((cr0 ^ old_cr0) & X86_CR0_CD) &&
            kvm_arch_has_noncoherent_dma(vcpu->kvm) &&
            !kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED))
                kvm_zap_gfn_range(vcpu->kvm, 0, ~0ULL);
}
EXPORT_SYMBOL_GPL(kvm_post_set_cr0);

int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
{
        unsigned long old_cr0 = kvm_read_cr0(vcpu);

        cr0 |= X86_CR0_ET;

#ifdef CONFIG_X86_64
        if (cr0 & 0xffffffff00000000UL)
                return 1;
#endif

        cr0 &= ~CR0_RESERVED_BITS;

        if ((cr0 & X86_CR0_NW) && !(cr0 & X86_CR0_CD))
                return 1;

        if ((cr0 & X86_CR0_PG) && !(cr0 & X86_CR0_PE))
                return 1;

#ifdef CONFIG_X86_64
        if ((vcpu->arch.efer & EFER_LME) && !is_paging(vcpu) &&
            (cr0 & X86_CR0_PG)) {
                int cs_db, cs_l;

                if (!is_pae(vcpu))
                        return 1;
                static_call(kvm_x86_get_cs_db_l_bits)(vcpu, &cs_db, &cs_l);
                if (cs_l)
                        return 1;
        }
#endif
        if (!(vcpu->arch.efer & EFER_LME) && (cr0 & X86_CR0_PG) &&
            is_pae(vcpu) && ((cr0 ^ old_cr0) & X86_CR0_PDPTR_BITS) &&
            !load_pdptrs(vcpu, kvm_read_cr3(vcpu)))
                return 1;

        if (!(cr0 & X86_CR0_PG) &&
            (is_64_bit_mode(vcpu) || kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE)))
                return 1;

        static_call(kvm_x86_set_cr0)(vcpu, cr0);

        kvm_post_set_cr0(vcpu, old_cr0, cr0);

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr0);

void kvm_lmsw(struct kvm_vcpu *vcpu, unsigned long msw)
{
        (void)kvm_set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~0x0eul) | (msw & 0x0f));
}
EXPORT_SYMBOL_GPL(kvm_lmsw);

void kvm_load_guest_xsave_state(struct kvm_vcpu *vcpu)
{
        if (vcpu->arch.guest_state_protected)
                return;

        if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) {

                if (vcpu->arch.xcr0 != host_xcr0)
                        xsetbv(XCR_XFEATURE_ENABLED_MASK, vcpu->arch.xcr0);

                if (vcpu->arch.xsaves_enabled &&
                    vcpu->arch.ia32_xss != host_xss)
                        wrmsrl(MSR_IA32_XSS, vcpu->arch.ia32_xss);
        }

#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
        if (static_cpu_has(X86_FEATURE_PKU) &&
            vcpu->arch.pkru != vcpu->arch.host_pkru &&
            ((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
             kvm_read_cr4_bits(vcpu, X86_CR4_PKE)))
                write_pkru(vcpu->arch.pkru);
#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */
}
EXPORT_SYMBOL_GPL(kvm_load_guest_xsave_state);

void kvm_load_host_xsave_state(struct kvm_vcpu *vcpu)
{
        if (vcpu->arch.guest_state_protected)
                return;

#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
        if (static_cpu_has(X86_FEATURE_PKU) &&
            ((vcpu->arch.xcr0 & XFEATURE_MASK_PKRU) ||
             kvm_read_cr4_bits(vcpu, X86_CR4_PKE))) {
                vcpu->arch.pkru = rdpkru();
                if (vcpu->arch.pkru != vcpu->arch.host_pkru)
                        write_pkru(vcpu->arch.host_pkru);
        }
#endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */

        if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) {

                if (vcpu->arch.xcr0 != host_xcr0)
                        xsetbv(XCR_XFEATURE_ENABLED_MASK, host_xcr0);

                if (vcpu->arch.xsaves_enabled &&
                    vcpu->arch.ia32_xss != host_xss)
                        wrmsrl(MSR_IA32_XSS, host_xss);
        }

}
EXPORT_SYMBOL_GPL(kvm_load_host_xsave_state);

#ifdef CONFIG_X86_64
static inline u64 kvm_guest_supported_xfd(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.guest_supported_xcr0 & XFEATURE_MASK_USER_DYNAMIC;
}
#endif

static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr)
{
        u64 xcr0 = xcr;
        u64 old_xcr0 = vcpu->arch.xcr0;
        u64 valid_bits;

        /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now  */
        if (index != XCR_XFEATURE_ENABLED_MASK)
                return 1;
        if (!(xcr0 & XFEATURE_MASK_FP))
                return 1;
        if ((xcr0 & XFEATURE_MASK_YMM) && !(xcr0 & XFEATURE_MASK_SSE))
                return 1;

        /*
         * Do not allow the guest to set bits that we do not support
         * saving.  However, xcr0 bit 0 is always set, even if the
         * emulated CPU does not support XSAVE (see kvm_vcpu_reset()).
         */
        valid_bits = vcpu->arch.guest_supported_xcr0 | XFEATURE_MASK_FP;
        if (xcr0 & ~valid_bits)
                return 1;

        if ((!(xcr0 & XFEATURE_MASK_BNDREGS)) !=
            (!(xcr0 & XFEATURE_MASK_BNDCSR)))
                return 1;

        if (xcr0 & XFEATURE_MASK_AVX512) {
                if (!(xcr0 & XFEATURE_MASK_YMM))
                        return 1;
                if ((xcr0 & XFEATURE_MASK_AVX512) != XFEATURE_MASK_AVX512)
                        return 1;
        }

        if ((xcr0 & XFEATURE_MASK_XTILE) &&
            ((xcr0 & XFEATURE_MASK_XTILE) != XFEATURE_MASK_XTILE))
                return 1;

        vcpu->arch.xcr0 = xcr0;

        if ((xcr0 ^ old_xcr0) & XFEATURE_MASK_EXTEND)
                kvm_update_cpuid_runtime(vcpu);
        return 0;
}

int kvm_emulate_xsetbv(struct kvm_vcpu *vcpu)
{
        /* Note, #UD due to CR4.OSXSAVE=0 has priority over the intercept. */
        if (static_call(kvm_x86_get_cpl)(vcpu) != 0 ||
            __kvm_set_xcr(vcpu, kvm_rcx_read(vcpu), kvm_read_edx_eax(vcpu))) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        return kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_xsetbv);

bool __kvm_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
        if (cr4 & cr4_reserved_bits)
                return false;

        if (cr4 & vcpu->arch.cr4_guest_rsvd_bits)
                return false;

        return true;
}
EXPORT_SYMBOL_GPL(__kvm_is_valid_cr4);

static bool kvm_is_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
        return __kvm_is_valid_cr4(vcpu, cr4) &&
               static_call(kvm_x86_is_valid_cr4)(vcpu, cr4);
}

void kvm_post_set_cr4(struct kvm_vcpu *vcpu, unsigned long old_cr4, unsigned long cr4)
{
        if ((cr4 ^ old_cr4) & KVM_MMU_CR4_ROLE_BITS)
                kvm_mmu_reset_context(vcpu);

        /*
         * If CR4.PCIDE is changed 0 -> 1, there is no need to flush the TLB
         * according to the SDM; however, stale prev_roots could be reused
         * incorrectly in the future after a MOV to CR3 with NOFLUSH=1, so we
         * free them all.  This is *not* a superset of KVM_REQ_TLB_FLUSH_GUEST
         * or KVM_REQ_TLB_FLUSH_CURRENT, because the hardware TLB is not flushed,
         * so fall through.
         */
        if (!tdp_enabled &&
            (cr4 & X86_CR4_PCIDE) && !(old_cr4 & X86_CR4_PCIDE))
                kvm_mmu_unload(vcpu);

        /*
         * The TLB has to be flushed for all PCIDs if any of the following
         * (architecturally required) changes happen:
         * - CR4.PCIDE is changed from 1 to 0
         * - CR4.PGE is toggled
         *
         * This is a superset of KVM_REQ_TLB_FLUSH_CURRENT.
         */
        if (((cr4 ^ old_cr4) & X86_CR4_PGE) ||
            (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
                kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);

        /*
         * The TLB has to be flushed for the current PCID if any of the
         * following (architecturally required) changes happen:
         * - CR4.SMEP is changed from 0 to 1
         * - CR4.PAE is toggled
         */
        else if (((cr4 ^ old_cr4) & X86_CR4_PAE) ||
                 ((cr4 & X86_CR4_SMEP) && !(old_cr4 & X86_CR4_SMEP)))
                kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu);

}
EXPORT_SYMBOL_GPL(kvm_post_set_cr4);

int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
        unsigned long old_cr4 = kvm_read_cr4(vcpu);

        if (!kvm_is_valid_cr4(vcpu, cr4))
                return 1;

        if (is_long_mode(vcpu)) {
                if (!(cr4 & X86_CR4_PAE))
                        return 1;
                if ((cr4 ^ old_cr4) & X86_CR4_LA57)
                        return 1;
        } else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE)
                   && ((cr4 ^ old_cr4) & X86_CR4_PDPTR_BITS)
                   && !load_pdptrs(vcpu, kvm_read_cr3(vcpu)))
                return 1;

        if ((cr4 & X86_CR4_PCIDE) && !(old_cr4 & X86_CR4_PCIDE)) {
                if (!guest_cpuid_has(vcpu, X86_FEATURE_PCID))
                        return 1;

                /* PCID can not be enabled when cr3[11:0]!=000H or EFER.LMA=0 */
                if ((kvm_read_cr3(vcpu) & X86_CR3_PCID_MASK) || !is_long_mode(vcpu))
                        return 1;
        }

        static_call(kvm_x86_set_cr4)(vcpu, cr4);

        kvm_post_set_cr4(vcpu, old_cr4, cr4);

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr4);

static void kvm_invalidate_pcid(struct kvm_vcpu *vcpu, unsigned long pcid)
{
        struct kvm_mmu *mmu = vcpu->arch.mmu;
        unsigned long roots_to_free = 0;
        int i;

        /*
         * MOV CR3 and INVPCID are usually not intercepted when using TDP, but
         * this is reachable when running EPT=1 and unrestricted_guest=0,  and
         * also via the emulator.  KVM's TDP page tables are not in the scope of
         * the invalidation, but the guest's TLB entries need to be flushed as
         * the CPU may have cached entries in its TLB for the target PCID.
         */
        if (unlikely(tdp_enabled)) {
                kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
                return;
        }

        /*
         * If neither the current CR3 nor any of the prev_roots use the given
         * PCID, then nothing needs to be done here because a resync will
         * happen anyway before switching to any other CR3.
         */
        if (kvm_get_active_pcid(vcpu) == pcid) {
                kvm_make_request(KVM_REQ_MMU_SYNC, vcpu);
                kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu);
        }

        /*
         * If PCID is disabled, there is no need to free prev_roots even if the
         * PCIDs for them are also 0, because MOV to CR3 always flushes the TLB
         * with PCIDE=0.
         */
        if (!kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE))
                return;

        for (i = 0; i < KVM_MMU_NUM_PREV_ROOTS; i++)
                if (kvm_get_pcid(vcpu, mmu->prev_roots[i].pgd) == pcid)
                        roots_to_free |= KVM_MMU_ROOT_PREVIOUS(i);

        kvm_mmu_free_roots(vcpu->kvm, mmu, roots_to_free);
}

int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
        bool skip_tlb_flush = false;
        unsigned long pcid = 0;
#ifdef CONFIG_X86_64
        bool pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE);

        if (pcid_enabled) {
                skip_tlb_flush = cr3 & X86_CR3_PCID_NOFLUSH;
                cr3 &= ~X86_CR3_PCID_NOFLUSH;
                pcid = cr3 & X86_CR3_PCID_MASK;
        }
#endif

        /* PDPTRs are always reloaded for PAE paging. */
        if (cr3 == kvm_read_cr3(vcpu) && !is_pae_paging(vcpu))
                goto handle_tlb_flush;

        /*
         * Do not condition the GPA check on long mode, this helper is used to
         * stuff CR3, e.g. for RSM emulation, and there is no guarantee that
         * the current vCPU mode is accurate.
         */
        if (kvm_vcpu_is_illegal_gpa(vcpu, cr3))
                return 1;

        if (is_pae_paging(vcpu) && !load_pdptrs(vcpu, cr3))
                return 1;

        if (cr3 != kvm_read_cr3(vcpu))
                kvm_mmu_new_pgd(vcpu, cr3);

        vcpu->arch.cr3 = cr3;
        kvm_register_mark_dirty(vcpu, VCPU_EXREG_CR3);
        /* Do not call post_set_cr3, we do not get here for confidential guests.  */

handle_tlb_flush:
        /*
         * A load of CR3 that flushes the TLB flushes only the current PCID,
         * even if PCID is disabled, in which case PCID=0 is flushed.  It's a
         * moot point in the end because _disabling_ PCID will flush all PCIDs,
         * and it's impossible to use a non-zero PCID when PCID is disabled,
         * i.e. only PCID=0 can be relevant.
         */
        if (!skip_tlb_flush)
                kvm_invalidate_pcid(vcpu, pcid);

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr3);

int kvm_set_cr8(struct kvm_vcpu *vcpu, unsigned long cr8)
{
        if (cr8 & CR8_RESERVED_BITS)
                return 1;
        if (lapic_in_kernel(vcpu))
                kvm_lapic_set_tpr(vcpu, cr8);
        else
                vcpu->arch.cr8 = cr8;
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_cr8);

unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu)
{
        if (lapic_in_kernel(vcpu))
                return kvm_lapic_get_cr8(vcpu);
        else
                return vcpu->arch.cr8;
}
EXPORT_SYMBOL_GPL(kvm_get_cr8);

static void kvm_update_dr0123(struct kvm_vcpu *vcpu)
{
        int i;

        if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
                for (i = 0; i < KVM_NR_DB_REGS; i++)
                        vcpu->arch.eff_db[i] = vcpu->arch.db[i];
        }
}

void kvm_update_dr7(struct kvm_vcpu *vcpu)
{
        unsigned long dr7;

        if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
                dr7 = vcpu->arch.guest_debug_dr7;
        else
                dr7 = vcpu->arch.dr7;
        static_call(kvm_x86_set_dr7)(vcpu, dr7);
        vcpu->arch.switch_db_regs &= ~KVM_DEBUGREG_BP_ENABLED;
        if (dr7 & DR7_BP_EN_MASK)
                vcpu->arch.switch_db_regs |= KVM_DEBUGREG_BP_ENABLED;
}
EXPORT_SYMBOL_GPL(kvm_update_dr7);

static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
{
        u64 fixed = DR6_FIXED_1;

        if (!guest_cpuid_has(vcpu, X86_FEATURE_RTM))
                fixed |= DR6_RTM;

        if (!guest_cpuid_has(vcpu, X86_FEATURE_BUS_LOCK_DETECT))
                fixed |= DR6_BUS_LOCK;
        return fixed;
}

int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
        size_t size = ARRAY_SIZE(vcpu->arch.db);

        switch (dr) {
        case 0 ... 3:
                vcpu->arch.db[array_index_nospec(dr, size)] = val;
                if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
                        vcpu->arch.eff_db[dr] = val;
                break;
        case 4:
        case 6:
                if (!kvm_dr6_valid(val))
                        return 1; /* #GP */
                vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu);
                break;
        case 5:
        default: /* 7 */
                if (!kvm_dr7_valid(val))
                        return 1; /* #GP */
                vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
                kvm_update_dr7(vcpu);
                break;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_dr);

void kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
{
        size_t size = ARRAY_SIZE(vcpu->arch.db);

        switch (dr) {
        case 0 ... 3:
                *val = vcpu->arch.db[array_index_nospec(dr, size)];
                break;
        case 4:
        case 6:
                *val = vcpu->arch.dr6;
                break;
        case 5:
        default: /* 7 */
                *val = vcpu->arch.dr7;
                break;
        }
}
EXPORT_SYMBOL_GPL(kvm_get_dr);

int kvm_emulate_rdpmc(struct kvm_vcpu *vcpu)
{
        u32 ecx = kvm_rcx_read(vcpu);
        u64 data;

        if (kvm_pmu_rdpmc(vcpu, ecx, &data)) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        kvm_rax_write(vcpu, (u32)data);
        kvm_rdx_write(vcpu, data >> 32);
        return kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_rdpmc);

/*
 * List of msr numbers which we expose to userspace through KVM_GET_MSRS
 * and KVM_SET_MSRS, and KVM_GET_MSR_INDEX_LIST.
 *
 * The three MSR lists(msrs_to_save, emulated_msrs, msr_based_features)
 * extract the supported MSRs from the related const lists.
 * msrs_to_save is selected from the msrs_to_save_all to reflect the
 * capabilities of the host cpu. This capabilities test skips MSRs that are
 * kvm-specific. Those are put in emulated_msrs_all; filtering of emulated_msrs
 * may depend on host virtualization features rather than host cpu features.
 */

static const u32 msrs_to_save_all[] = {
        MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
        MSR_STAR,
#ifdef CONFIG_X86_64
        MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
        MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
        MSR_IA32_FEAT_CTL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
        MSR_IA32_SPEC_CTRL,
        MSR_IA32_RTIT_CTL, MSR_IA32_RTIT_STATUS, MSR_IA32_RTIT_CR3_MATCH,
        MSR_IA32_RTIT_OUTPUT_BASE, MSR_IA32_RTIT_OUTPUT_MASK,
        MSR_IA32_RTIT_ADDR0_A, MSR_IA32_RTIT_ADDR0_B,
        MSR_IA32_RTIT_ADDR1_A, MSR_IA32_RTIT_ADDR1_B,
        MSR_IA32_RTIT_ADDR2_A, MSR_IA32_RTIT_ADDR2_B,
        MSR_IA32_RTIT_ADDR3_A, MSR_IA32_RTIT_ADDR3_B,
        MSR_IA32_UMWAIT_CONTROL,

        MSR_ARCH_PERFMON_FIXED_CTR0, MSR_ARCH_PERFMON_FIXED_CTR1,
        MSR_ARCH_PERFMON_FIXED_CTR0 + 2,
        MSR_CORE_PERF_FIXED_CTR_CTRL, MSR_CORE_PERF_GLOBAL_STATUS,
        MSR_CORE_PERF_GLOBAL_CTRL, MSR_CORE_PERF_GLOBAL_OVF_CTRL,
        MSR_IA32_PEBS_ENABLE, MSR_IA32_DS_AREA, MSR_PEBS_DATA_CFG,

        /* This part of MSRs should match KVM_INTEL_PMC_MAX_GENERIC. */
        MSR_ARCH_PERFMON_PERFCTR0, MSR_ARCH_PERFMON_PERFCTR1,
        MSR_ARCH_PERFMON_PERFCTR0 + 2, MSR_ARCH_PERFMON_PERFCTR0 + 3,
        MSR_ARCH_PERFMON_PERFCTR0 + 4, MSR_ARCH_PERFMON_PERFCTR0 + 5,
        MSR_ARCH_PERFMON_PERFCTR0 + 6, MSR_ARCH_PERFMON_PERFCTR0 + 7,
        MSR_ARCH_PERFMON_EVENTSEL0, MSR_ARCH_PERFMON_EVENTSEL1,
        MSR_ARCH_PERFMON_EVENTSEL0 + 2, MSR_ARCH_PERFMON_EVENTSEL0 + 3,
        MSR_ARCH_PERFMON_EVENTSEL0 + 4, MSR_ARCH_PERFMON_EVENTSEL0 + 5,
        MSR_ARCH_PERFMON_EVENTSEL0 + 6, MSR_ARCH_PERFMON_EVENTSEL0 + 7,

        MSR_K7_EVNTSEL0, MSR_K7_EVNTSEL1, MSR_K7_EVNTSEL2, MSR_K7_EVNTSEL3,
        MSR_K7_PERFCTR0, MSR_K7_PERFCTR1, MSR_K7_PERFCTR2, MSR_K7_PERFCTR3,

        /* This part of MSRs should match KVM_AMD_PMC_MAX_GENERIC. */
        MSR_F15H_PERF_CTL0, MSR_F15H_PERF_CTL1, MSR_F15H_PERF_CTL2,
        MSR_F15H_PERF_CTL3, MSR_F15H_PERF_CTL4, MSR_F15H_PERF_CTL5,
        MSR_F15H_PERF_CTR0, MSR_F15H_PERF_CTR1, MSR_F15H_PERF_CTR2,
        MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5,

        MSR_IA32_XFD, MSR_IA32_XFD_ERR,
};

static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_all)];
static unsigned num_msrs_to_save;

static const u32 emulated_msrs_all[] = {
        MSR_KVM_SYSTEM_TIME, MSR_KVM_WALL_CLOCK,
        MSR_KVM_SYSTEM_TIME_NEW, MSR_KVM_WALL_CLOCK_NEW,
        HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
        HV_X64_MSR_TIME_REF_COUNT, HV_X64_MSR_REFERENCE_TSC,
        HV_X64_MSR_TSC_FREQUENCY, HV_X64_MSR_APIC_FREQUENCY,
        HV_X64_MSR_CRASH_P0, HV_X64_MSR_CRASH_P1, HV_X64_MSR_CRASH_P2,
        HV_X64_MSR_CRASH_P3, HV_X64_MSR_CRASH_P4, HV_X64_MSR_CRASH_CTL,
        HV_X64_MSR_RESET,
        HV_X64_MSR_VP_INDEX,
        HV_X64_MSR_VP_RUNTIME,
        HV_X64_MSR_SCONTROL,
        HV_X64_MSR_STIMER0_CONFIG,
        HV_X64_MSR_VP_ASSIST_PAGE,
        HV_X64_MSR_REENLIGHTENMENT_CONTROL, HV_X64_MSR_TSC_EMULATION_CONTROL,
        HV_X64_MSR_TSC_EMULATION_STATUS, HV_X64_MSR_TSC_INVARIANT_CONTROL,
        HV_X64_MSR_SYNDBG_OPTIONS,
        HV_X64_MSR_SYNDBG_CONTROL, HV_X64_MSR_SYNDBG_STATUS,
        HV_X64_MSR_SYNDBG_SEND_BUFFER, HV_X64_MSR_SYNDBG_RECV_BUFFER,
        HV_X64_MSR_SYNDBG_PENDING_BUFFER,

        MSR_KVM_ASYNC_PF_EN, MSR_KVM_STEAL_TIME,
        MSR_KVM_PV_EOI_EN, MSR_KVM_ASYNC_PF_INT, MSR_KVM_ASYNC_PF_ACK,

        MSR_IA32_TSC_ADJUST,
        MSR_IA32_TSC_DEADLINE,
        MSR_IA32_ARCH_CAPABILITIES,
        MSR_IA32_PERF_CAPABILITIES,
        MSR_IA32_MISC_ENABLE,
        MSR_IA32_MCG_STATUS,
        MSR_IA32_MCG_CTL,
        MSR_IA32_MCG_EXT_CTL,
        MSR_IA32_SMBASE,
        MSR_SMI_COUNT,
        MSR_PLATFORM_INFO,
        MSR_MISC_FEATURES_ENABLES,
        MSR_AMD64_VIRT_SPEC_CTRL,
        MSR_AMD64_TSC_RATIO,
        MSR_IA32_POWER_CTL,
        MSR_IA32_UCODE_REV,

        /*
         * The following list leaves out MSRs whose values are determined
         * by arch/x86/kvm/vmx/nested.c based on CPUID or other MSRs.
         * We always support the "true" VMX control MSRs, even if the host
         * processor does not, so I am putting these registers here rather
         * than in msrs_to_save_all.
         */
        MSR_IA32_VMX_BASIC,
        MSR_IA32_VMX_TRUE_PINBASED_CTLS,
        MSR_IA32_VMX_TRUE_PROCBASED_CTLS,
        MSR_IA32_VMX_TRUE_EXIT_CTLS,
        MSR_IA32_VMX_TRUE_ENTRY_CTLS,
        MSR_IA32_VMX_MISC,
        MSR_IA32_VMX_CR0_FIXED0,
        MSR_IA32_VMX_CR4_FIXED0,
        MSR_IA32_VMX_VMCS_ENUM,
        MSR_IA32_VMX_PROCBASED_CTLS2,
        MSR_IA32_VMX_EPT_VPID_CAP,
        MSR_IA32_VMX_VMFUNC,

        MSR_K7_HWCR,
        MSR_KVM_POLL_CONTROL,
};

static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_all)];
static unsigned num_emulated_msrs;

/*
 * List of msr numbers which are used to expose MSR-based features that
 * can be used by a hypervisor to validate requested CPU features.
 */
static const u32 msr_based_features_all[] = {
        MSR_IA32_VMX_BASIC,
        MSR_IA32_VMX_TRUE_PINBASED_CTLS,
        MSR_IA32_VMX_PINBASED_CTLS,
        MSR_IA32_VMX_TRUE_PROCBASED_CTLS,
        MSR_IA32_VMX_PROCBASED_CTLS,
        MSR_IA32_VMX_TRUE_EXIT_CTLS,
        MSR_IA32_VMX_EXIT_CTLS,
        MSR_IA32_VMX_TRUE_ENTRY_CTLS,
        MSR_IA32_VMX_ENTRY_CTLS,
        MSR_IA32_VMX_MISC,
        MSR_IA32_VMX_CR0_FIXED0,
        MSR_IA32_VMX_CR0_FIXED1,
        MSR_IA32_VMX_CR4_FIXED0,
        MSR_IA32_VMX_CR4_FIXED1,
        MSR_IA32_VMX_VMCS_ENUM,
        MSR_IA32_VMX_PROCBASED_CTLS2,
        MSR_IA32_VMX_EPT_VPID_CAP,
        MSR_IA32_VMX_VMFUNC,

        MSR_AMD64_DE_CFG,
        MSR_IA32_UCODE_REV,
        MSR_IA32_ARCH_CAPABILITIES,
        MSR_IA32_PERF_CAPABILITIES,
};

static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all)];
static unsigned int num_msr_based_features;

/*
 * Some IA32_ARCH_CAPABILITIES bits have dependencies on MSRs that KVM
 * does not yet virtualize. These include:
 *   10 - MISC_PACKAGE_CTRLS
 *   11 - ENERGY_FILTERING_CTL
 *   12 - DOITM
 *   18 - FB_CLEAR_CTRL
 *   21 - XAPIC_DISABLE_STATUS
 *   23 - OVERCLOCKING_STATUS
 */

#define KVM_SUPPORTED_ARCH_CAP \
        (ARCH_CAP_RDCL_NO | ARCH_CAP_IBRS_ALL | ARCH_CAP_RSBA | \
         ARCH_CAP_SKIP_VMENTRY_L1DFLUSH | ARCH_CAP_SSB_NO | ARCH_CAP_MDS_NO | \
         ARCH_CAP_PSCHANGE_MC_NO | ARCH_CAP_TSX_CTRL_MSR | ARCH_CAP_TAA_NO | \
         ARCH_CAP_SBDR_SSDP_NO | ARCH_CAP_FBSDP_NO | ARCH_CAP_PSDP_NO | \
         ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO)

static u64 kvm_get_arch_capabilities(void)
{
        u64 data = 0;

        if (boot_cpu_has(X86_FEATURE_ARCH_CAPABILITIES)) {
                rdmsrl(MSR_IA32_ARCH_CAPABILITIES, data);
                data &= KVM_SUPPORTED_ARCH_CAP;
        }

        /*
         * If nx_huge_pages is enabled, KVM's shadow paging will ensure that
         * the nested hypervisor runs with NX huge pages.  If it is not,
         * L1 is anyway vulnerable to ITLB_MULTIHIT exploits from other
         * L1 guests, so it need not worry about its own (L2) guests.
         */
        data |= ARCH_CAP_PSCHANGE_MC_NO;

        /*
         * If we're doing cache flushes (either "always" or "cond")
         * we will do one whenever the guest does a vmlaunch/vmresume.
         * If an outer hypervisor is doing the cache flush for us
         * (VMENTER_L1D_FLUSH_NESTED_VM), we can safely pass that
         * capability to the guest too, and if EPT is disabled we're not
         * vulnerable.  Overall, only VMENTER_L1D_FLUSH_NEVER will
         * require a nested hypervisor to do a flush of its own.
         */
        if (l1tf_vmx_mitigation != VMENTER_L1D_FLUSH_NEVER)
                data |= ARCH_CAP_SKIP_VMENTRY_L1DFLUSH;

        if (!boot_cpu_has_bug(X86_BUG_CPU_MELTDOWN))
                data |= ARCH_CAP_RDCL_NO;
        if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS))
                data |= ARCH_CAP_SSB_NO;
        if (!boot_cpu_has_bug(X86_BUG_MDS))
                data |= ARCH_CAP_MDS_NO;

        if (!boot_cpu_has(X86_FEATURE_RTM)) {
                /*
                 * If RTM=0 because the kernel has disabled TSX, the host might
                 * have TAA_NO or TSX_CTRL.  Clear TAA_NO (the guest sees RTM=0
                 * and therefore knows that there cannot be TAA) but keep
                 * TSX_CTRL: some buggy userspaces leave it set on tsx=on hosts,
                 * and we want to allow migrating those guests to tsx=off hosts.
                 */
                data &= ~ARCH_CAP_TAA_NO;
        } else if (!boot_cpu_has_bug(X86_BUG_TAA)) {
                data |= ARCH_CAP_TAA_NO;
        } else {
                /*
                 * Nothing to do here; we emulate TSX_CTRL if present on the
                 * host so the guest can choose between disabling TSX or
                 * using VERW to clear CPU buffers.
                 */
        }

        return data;
}

static int kvm_get_msr_feature(struct kvm_msr_entry *msr)
{
        switch (msr->index) {
        case MSR_IA32_ARCH_CAPABILITIES:
                msr->data = kvm_get_arch_capabilities();
                break;
        case MSR_IA32_PERF_CAPABILITIES:
                msr->data = kvm_caps.supported_perf_cap;
                break;
        case MSR_IA32_UCODE_REV:
                rdmsrl_safe(msr->index, &msr->data);
                break;
        default:
                return static_call(kvm_x86_get_msr_feature)(msr);
        }
        return 0;
}

static int do_get_msr_feature(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
        struct kvm_msr_entry msr;
        int r;

        msr.index = index;
        r = kvm_get_msr_feature(&msr);

        if (r == KVM_MSR_RET_INVALID) {
                /* Unconditionally clear the output for simplicity */
                *data = 0;
                if (kvm_msr_ignored_check(index, 0, false))
                        r = 0;
        }

        if (r)
                return r;

        *data = msr.data;

        return 0;
}

static bool __kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
{
        if (efer & EFER_FFXSR && !guest_cpuid_has(vcpu, X86_FEATURE_FXSR_OPT))
                return false;

        if (efer & EFER_SVME && !guest_cpuid_has(vcpu, X86_FEATURE_SVM))
                return false;

        if (efer & (EFER_LME | EFER_LMA) &&
            !guest_cpuid_has(vcpu, X86_FEATURE_LM))
                return false;

        if (efer & EFER_NX && !guest_cpuid_has(vcpu, X86_FEATURE_NX))
                return false;

        return true;

}
bool kvm_valid_efer(struct kvm_vcpu *vcpu, u64 efer)
{
        if (efer & efer_reserved_bits)
                return false;

        return __kvm_valid_efer(vcpu, efer);
}
EXPORT_SYMBOL_GPL(kvm_valid_efer);

static int set_efer(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
        u64 old_efer = vcpu->arch.efer;
        u64 efer = msr_info->data;
        int r;

        if (efer & efer_reserved_bits)
                return 1;

        if (!msr_info->host_initiated) {
                if (!__kvm_valid_efer(vcpu, efer))
                        return 1;

                if (is_paging(vcpu) &&
                    (vcpu->arch.efer & EFER_LME) != (efer & EFER_LME))
                        return 1;
        }

        efer &= ~EFER_LMA;
        efer |= vcpu->arch.efer & EFER_LMA;

        r = static_call(kvm_x86_set_efer)(vcpu, efer);
        if (r) {
                WARN_ON(r > 0);
                return r;
        }

        if ((efer ^ old_efer) & KVM_MMU_EFER_ROLE_BITS)
                kvm_mmu_reset_context(vcpu);

        return 0;
}

void kvm_enable_efer_bits(u64 mask)
{
       efer_reserved_bits &= ~mask;
}
EXPORT_SYMBOL_GPL(kvm_enable_efer_bits);

bool kvm_msr_allowed(struct kvm_vcpu *vcpu, u32 index, u32 type)
{
        struct kvm_x86_msr_filter *msr_filter;
        struct msr_bitmap_range *ranges;
        struct kvm *kvm = vcpu->kvm;
        bool allowed;
        int idx;
        u32 i;

        /* x2APIC MSRs do not support filtering. */
        if (index >= 0x800 && index <= 0x8ff)
                return true;

        idx = srcu_read_lock(&kvm->srcu);

        msr_filter = srcu_dereference(kvm->arch.msr_filter, &kvm->srcu);
        if (!msr_filter) {
                allowed = true;
                goto out;
        }

        allowed = msr_filter->default_allow;
        ranges = msr_filter->ranges;

        for (i = 0; i < msr_filter->count; i++) {
                u32 start = ranges[i].base;
                u32 end = start + ranges[i].nmsrs;
                u32 flags = ranges[i].flags;
                unsigned long *bitmap = ranges[i].bitmap;

                if ((index >= start) && (index < end) && (flags & type)) {
                        allowed = !!test_bit(index - start, bitmap);
                        break;
                }
        }

out:
        srcu_read_unlock(&kvm->srcu, idx);

        return allowed;
}
EXPORT_SYMBOL_GPL(kvm_msr_allowed);

/*
 * Write @data into the MSR specified by @index.  Select MSR specific fault
 * checks are bypassed if @host_initiated is %true.
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
static int __kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data,
                         bool host_initiated)
{
        struct msr_data msr;

        switch (index) {
        case MSR_FS_BASE:
        case MSR_GS_BASE:
        case MSR_KERNEL_GS_BASE:
        case MSR_CSTAR:
        case MSR_LSTAR:
                if (is_noncanonical_address(data, vcpu))
                        return 1;
                break;
        case MSR_IA32_SYSENTER_EIP:
        case MSR_IA32_SYSENTER_ESP:
                /*
                 * IA32_SYSENTER_ESP and IA32_SYSENTER_EIP cause #GP if
                 * non-canonical address is written on Intel but not on
                 * AMD (which ignores the top 32-bits, because it does
                 * not implement 64-bit SYSENTER).
                 *
                 * 64-bit code should hence be able to write a non-canonical
                 * value on AMD.  Making the address canonical ensures that
                 * vmentry does not fail on Intel after writing a non-canonical
                 * value, and that something deterministic happens if the guest
                 * invokes 64-bit SYSENTER.
                 */
                data = __canonical_address(data, vcpu_virt_addr_bits(vcpu));
                break;
        case MSR_TSC_AUX:
                if (!kvm_is_supported_user_return_msr(MSR_TSC_AUX))
                        return 1;

                if (!host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_RDPID))
                        return 1;

                /*
                 * Per Intel's SDM, bits 63:32 are reserved, but AMD's APM has
                 * incomplete and conflicting architectural behavior.  Current
                 * AMD CPUs completely ignore bits 63:32, i.e. they aren't
                 * reserved and always read as zeros.  Enforce Intel's reserved
                 * bits check if and only if the guest CPU is Intel, and clear
                 * the bits in all other cases.  This ensures cross-vendor
                 * migration will provide consistent behavior for the guest.
                 */
                if (guest_cpuid_is_intel(vcpu) && (data >> 32) != 0)
                        return 1;

                data = (u32)data;
                break;
        }

        msr.data = data;
        msr.index = index;
        msr.host_initiated = host_initiated;

        return static_call(kvm_x86_set_msr)(vcpu, &msr);
}

static int kvm_set_msr_ignored_check(struct kvm_vcpu *vcpu,
                                     u32 index, u64 data, bool host_initiated)
{
        int ret = __kvm_set_msr(vcpu, index, data, host_initiated);

        if (ret == KVM_MSR_RET_INVALID)
                if (kvm_msr_ignored_check(index, data, true))
                        ret = 0;

        return ret;
}

/*
 * Read the MSR specified by @index into @data.  Select MSR specific fault
 * checks are bypassed if @host_initiated is %true.
 * Returns 0 on success, non-0 otherwise.
 * Assumes vcpu_load() was already called.
 */
int __kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data,
                  bool host_initiated)
{
        struct msr_data msr;
        int ret;

        switch (index) {
        case MSR_TSC_AUX:
                if (!kvm_is_supported_user_return_msr(MSR_TSC_AUX))
                        return 1;

                if (!host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_RDPID))
                        return 1;
                break;
        }

        msr.index = index;
        msr.host_initiated = host_initiated;

        ret = static_call(kvm_x86_get_msr)(vcpu, &msr);
        if (!ret)
                *data = msr.data;
        return ret;
}

static int kvm_get_msr_ignored_check(struct kvm_vcpu *vcpu,
                                     u32 index, u64 *data, bool host_initiated)
{
        int ret = __kvm_get_msr(vcpu, index, data, host_initiated);

        if (ret == KVM_MSR_RET_INVALID) {
                /* Unconditionally clear *data for simplicity */
                *data = 0;
                if (kvm_msr_ignored_check(index, 0, false))
                        ret = 0;
        }

        return ret;
}

static int kvm_get_msr_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 *data)
{
        if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_READ))
                return KVM_MSR_RET_FILTERED;
        return kvm_get_msr_ignored_check(vcpu, index, data, false);
}

static int kvm_set_msr_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 data)
{
        if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_WRITE))
                return KVM_MSR_RET_FILTERED;
        return kvm_set_msr_ignored_check(vcpu, index, data, false);
}

int kvm_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data)
{
        return kvm_get_msr_ignored_check(vcpu, index, data, false);
}
EXPORT_SYMBOL_GPL(kvm_get_msr);

int kvm_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data)
{
        return kvm_set_msr_ignored_check(vcpu, index, data, false);
}
EXPORT_SYMBOL_GPL(kvm_set_msr);

static void complete_userspace_rdmsr(struct kvm_vcpu *vcpu)
{
        if (!vcpu->run->msr.error) {
                kvm_rax_write(vcpu, (u32)vcpu->run->msr.data);
                kvm_rdx_write(vcpu, vcpu->run->msr.data >> 32);
        }
}

static int complete_emulated_msr_access(struct kvm_vcpu *vcpu)
{
        return complete_emulated_insn_gp(vcpu, vcpu->run->msr.error);
}

static int complete_emulated_rdmsr(struct kvm_vcpu *vcpu)
{
        complete_userspace_rdmsr(vcpu);
        return complete_emulated_msr_access(vcpu);
}

static int complete_fast_msr_access(struct kvm_vcpu *vcpu)
{
        return static_call(kvm_x86_complete_emulated_msr)(vcpu, vcpu->run->msr.error);
}

static int complete_fast_rdmsr(struct kvm_vcpu *vcpu)
{
        complete_userspace_rdmsr(vcpu);
        return complete_fast_msr_access(vcpu);
}

static u64 kvm_msr_reason(int r)
{
        switch (r) {
        case KVM_MSR_RET_INVALID:
                return KVM_MSR_EXIT_REASON_UNKNOWN;
        case KVM_MSR_RET_FILTERED:
                return KVM_MSR_EXIT_REASON_FILTER;
        default:
                return KVM_MSR_EXIT_REASON_INVAL;
        }
}

static int kvm_msr_user_space(struct kvm_vcpu *vcpu, u32 index,
                              u32 exit_reason, u64 data,
                              int (*completion)(struct kvm_vcpu *vcpu),
                              int r)
{
        u64 msr_reason = kvm_msr_reason(r);

        /* Check if the user wanted to know about this MSR fault */
        if (!(vcpu->kvm->arch.user_space_msr_mask & msr_reason))
                return 0;

        vcpu->run->exit_reason = exit_reason;
        vcpu->run->msr.error = 0;
        memset(vcpu->run->msr.pad, 0, sizeof(vcpu->run->msr.pad));
        vcpu->run->msr.reason = msr_reason;
        vcpu->run->msr.index = index;
        vcpu->run->msr.data = data;
        vcpu->arch.complete_userspace_io = completion;

        return 1;
}

int kvm_emulate_rdmsr(struct kvm_vcpu *vcpu)
{
        u32 ecx = kvm_rcx_read(vcpu);
        u64 data;
        int r;

        r = kvm_get_msr_with_filter(vcpu, ecx, &data);

        if (!r) {
                trace_kvm_msr_read(ecx, data);

                kvm_rax_write(vcpu, data & -1u);
                kvm_rdx_write(vcpu, (data >> 32) & -1u);
        } else {
                /* MSR read failed? See if we should ask user space */
                if (kvm_msr_user_space(vcpu, ecx, KVM_EXIT_X86_RDMSR, 0,
                                       complete_fast_rdmsr, r))
                        return 0;
                trace_kvm_msr_read_ex(ecx);
        }

        return static_call(kvm_x86_complete_emulated_msr)(vcpu, r);
}
EXPORT_SYMBOL_GPL(kvm_emulate_rdmsr);

int kvm_emulate_wrmsr(struct kvm_vcpu *vcpu)
{
        u32 ecx = kvm_rcx_read(vcpu);
        u64 data = kvm_read_edx_eax(vcpu);
        int r;

        r = kvm_set_msr_with_filter(vcpu, ecx, data);

        if (!r) {
                trace_kvm_msr_write(ecx, data);
        } else {
                /* MSR write failed? See if we should ask user space */
                if (kvm_msr_user_space(vcpu, ecx, KVM_EXIT_X86_WRMSR, data,
                                       complete_fast_msr_access, r))
                        return 0;
                /* Signal all other negative errors to userspace */
                if (r < 0)
                        return r;
                trace_kvm_msr_write_ex(ecx, data);
        }

        return static_call(kvm_x86_complete_emulated_msr)(vcpu, r);
}
EXPORT_SYMBOL_GPL(kvm_emulate_wrmsr);

int kvm_emulate_as_nop(struct kvm_vcpu *vcpu)
{
        return kvm_skip_emulated_instruction(vcpu);
}

int kvm_emulate_invd(struct kvm_vcpu *vcpu)
{
        /* Treat an INVD instruction as a NOP and just skip it. */
        return kvm_emulate_as_nop(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_invd);

int kvm_handle_invalid_op(struct kvm_vcpu *vcpu)
{
        kvm_queue_exception(vcpu, UD_VECTOR);
        return 1;
}
EXPORT_SYMBOL_GPL(kvm_handle_invalid_op);


static int kvm_emulate_monitor_mwait(struct kvm_vcpu *vcpu, const char *insn)
{
        if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MWAIT_NEVER_UD_FAULTS) &&
            !guest_cpuid_has(vcpu, X86_FEATURE_MWAIT))
                return kvm_handle_invalid_op(vcpu);

        pr_warn_once("kvm: %s instruction emulated as NOP!\n", insn);
        return kvm_emulate_as_nop(vcpu);
}
int kvm_emulate_mwait(struct kvm_vcpu *vcpu)
{
        return kvm_emulate_monitor_mwait(vcpu, "MWAIT");
}
EXPORT_SYMBOL_GPL(kvm_emulate_mwait);

int kvm_emulate_monitor(struct kvm_vcpu *vcpu)
{
        return kvm_emulate_monitor_mwait(vcpu, "MONITOR");
}
EXPORT_SYMBOL_GPL(kvm_emulate_monitor);

static inline bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu)
{
        xfer_to_guest_mode_prepare();
        return vcpu->mode == EXITING_GUEST_MODE || kvm_request_pending(vcpu) ||
                xfer_to_guest_mode_work_pending();
}

/*
 * The fast path for frequent and performance sensitive wrmsr emulation,
 * i.e. the sending of IPI, sending IPI early in the VM-Exit flow reduces
 * the latency of virtual IPI by avoiding the expensive bits of transitioning
 * from guest to host, e.g. reacquiring KVM's SRCU lock. In contrast to the
 * other cases which must be called after interrupts are enabled on the host.
 */
static int handle_fastpath_set_x2apic_icr_irqoff(struct kvm_vcpu *vcpu, u64 data)
{
        if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(vcpu->arch.apic))
                return 1;

        if (((data & APIC_SHORT_MASK) == APIC_DEST_NOSHORT) &&
            ((data & APIC_DEST_MASK) == APIC_DEST_PHYSICAL) &&
            ((data & APIC_MODE_MASK) == APIC_DM_FIXED) &&
            ((u32)(data >> 32) != X2APIC_BROADCAST))
                return kvm_x2apic_icr_write(vcpu->arch.apic, data);

        return 1;
}

static int handle_fastpath_set_tscdeadline(struct kvm_vcpu *vcpu, u64 data)
{
        if (!kvm_can_use_hv_timer(vcpu))
                return 1;

        kvm_set_lapic_tscdeadline_msr(vcpu, data);
        return 0;
}

fastpath_t handle_fastpath_set_msr_irqoff(struct kvm_vcpu *vcpu)
{
        u32 msr = kvm_rcx_read(vcpu);
        u64 data;
        fastpath_t ret = EXIT_FASTPATH_NONE;

        switch (msr) {
        case APIC_BASE_MSR + (APIC_ICR >> 4):
                data = kvm_read_edx_eax(vcpu);
                if (!handle_fastpath_set_x2apic_icr_irqoff(vcpu, data)) {
                        kvm_skip_emulated_instruction(vcpu);
                        ret = EXIT_FASTPATH_EXIT_HANDLED;
                }
                break;
        case MSR_IA32_TSC_DEADLINE:
                data = kvm_read_edx_eax(vcpu);
                if (!handle_fastpath_set_tscdeadline(vcpu, data)) {
                        kvm_skip_emulated_instruction(vcpu);
                        ret = EXIT_FASTPATH_REENTER_GUEST;
                }
                break;
        default:
                break;
        }

        if (ret != EXIT_FASTPATH_NONE)
                trace_kvm_msr_write(msr, data);

        return ret;
}
EXPORT_SYMBOL_GPL(handle_fastpath_set_msr_irqoff);

/*
 * Adapt set_msr() to msr_io()'s calling convention
 */
static int do_get_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
        return kvm_get_msr_ignored_check(vcpu, index, data, true);
}

static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
{
        return kvm_set_msr_ignored_check(vcpu, index, *data, true);
}

#ifdef CONFIG_X86_64
struct pvclock_clock {
        int vclock_mode;
        u64 cycle_last;
        u64 mask;
        u32 mult;
        u32 shift;
        u64 base_cycles;
        u64 offset;
};

struct pvclock_gtod_data {
        seqcount_t      seq;

        struct pvclock_clock clock; /* extract of a clocksource struct */
        struct pvclock_clock raw_clock; /* extract of a clocksource struct */

        ktime_t         offs_boot;
        u64             wall_time_sec;
};

static struct pvclock_gtod_data pvclock_gtod_data;

static void update_pvclock_gtod(struct timekeeper *tk)
{
        struct pvclock_gtod_data *vdata = &pvclock_gtod_data;

        write_seqcount_begin(&vdata->seq);

        /* copy pvclock gtod data */
        vdata->clock.vclock_mode        = tk->tkr_mono.clock->vdso_clock_mode;
        vdata->clock.cycle_last         = tk->tkr_mono.cycle_last;
        vdata->clock.mask               = tk->tkr_mono.mask;
        vdata->clock.mult               = tk->tkr_mono.mult;
        vdata->clock.shift              = tk->tkr_mono.shift;
        vdata->clock.base_cycles        = tk->tkr_mono.xtime_nsec;
        vdata->clock.offset             = tk->tkr_mono.base;

        vdata->raw_clock.vclock_mode    = tk->tkr_raw.clock->vdso_clock_mode;
        vdata->raw_clock.cycle_last     = tk->tkr_raw.cycle_last;
        vdata->raw_clock.mask           = tk->tkr_raw.mask;
        vdata->raw_clock.mult           = tk->tkr_raw.mult;
        vdata->raw_clock.shift          = tk->tkr_raw.shift;
        vdata->raw_clock.base_cycles    = tk->tkr_raw.xtime_nsec;
        vdata->raw_clock.offset         = tk->tkr_raw.base;

        vdata->wall_time_sec            = tk->xtime_sec;

        vdata->offs_boot                = tk->offs_boot;

        write_seqcount_end(&vdata->seq);
}

static s64 get_kvmclock_base_ns(void)
{
        /* Count up from boot time, but with the frequency of the raw clock.  */
        return ktime_to_ns(ktime_add(ktime_get_raw(), pvclock_gtod_data.offs_boot));
}
#else
static s64 get_kvmclock_base_ns(void)
{
        /* Master clock not used, so we can just use CLOCK_BOOTTIME.  */
        return ktime_get_boottime_ns();
}
#endif

static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs)
{
        int version;
        int r;
        struct pvclock_wall_clock wc;
        u32 wc_sec_hi;
        u64 wall_nsec;

        if (!wall_clock)
                return;

        r = kvm_read_guest(kvm, wall_clock, &version, sizeof(version));
        if (r)
                return;

        if (version & 1)
                ++version;  /* first time write, random junk */

        ++version;

        if (kvm_write_guest(kvm, wall_clock, &version, sizeof(version)))
                return;

        /*
         * The guest calculates current wall clock time by adding
         * system time (updated by kvm_guest_time_update below) to the
         * wall clock specified here.  We do the reverse here.
         */
        wall_nsec = ktime_get_real_ns() - get_kvmclock_ns(kvm);

        wc.nsec = do_div(wall_nsec, 1000000000);
        wc.sec = (u32)wall_nsec; /* overflow in 2106 guest time */
        wc.version = version;

        kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc));

        if (sec_hi_ofs) {
                wc_sec_hi = wall_nsec >> 32;
                kvm_write_guest(kvm, wall_clock + sec_hi_ofs,
                                &wc_sec_hi, sizeof(wc_sec_hi));
        }

        version++;
        kvm_write_guest(kvm, wall_clock, &version, sizeof(version));
}

static void kvm_write_system_time(struct kvm_vcpu *vcpu, gpa_t system_time,
                                  bool old_msr, bool host_initiated)
{
        struct kvm_arch *ka = &vcpu->kvm->arch;

        if (vcpu->vcpu_id == 0 && !host_initiated) {
                if (ka->boot_vcpu_runs_old_kvmclock != old_msr)
                        kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);

                ka->boot_vcpu_runs_old_kvmclock = old_msr;
        }

        vcpu->arch.time = system_time;
        kvm_make_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu);

        /* we verify if the enable bit is set... */
        if (system_time & 1)
                kvm_gpc_activate(&vcpu->arch.pv_time, system_time & ~1ULL,
                                 sizeof(struct pvclock_vcpu_time_info));
        else
                kvm_gpc_deactivate(&vcpu->arch.pv_time);

        return;
}

static uint32_t div_frac(uint32_t dividend, uint32_t divisor)
{
        do_shl32_div32(dividend, divisor);
        return dividend;
}

static void kvm_get_time_scale(uint64_t scaled_hz, uint64_t base_hz,
                               s8 *pshift, u32 *pmultiplier)
{
        uint64_t scaled64;
        int32_t  shift = 0;
        uint64_t tps64;
        uint32_t tps32;

        tps64 = base_hz;
        scaled64 = scaled_hz;
        while (tps64 > scaled64*2 || tps64 & 0xffffffff00000000ULL) {
                tps64 >>= 1;
                shift--;
        }

        tps32 = (uint32_t)tps64;
        while (tps32 <= scaled64 || scaled64 & 0xffffffff00000000ULL) {
                if (scaled64 & 0xffffffff00000000ULL || tps32 & 0x80000000)
                        scaled64 >>= 1;
                else
                        tps32 <<= 1;
                shift++;
        }

        *pshift = shift;
        *pmultiplier = div_frac(scaled64, tps32);
}

#ifdef CONFIG_X86_64
static atomic_t kvm_guest_has_master_clock = ATOMIC_INIT(0);
#endif

static DEFINE_PER_CPU(unsigned long, cpu_tsc_khz);
static unsigned long max_tsc_khz;

static u32 adjust_tsc_khz(u32 khz, s32 ppm)
{
        u64 v = (u64)khz * (1000000 + ppm);
        do_div(v, 1000000);
        return v;
}

static void kvm_vcpu_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 l1_multiplier);

static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
{
        u64 ratio;

        /* Guest TSC same frequency as host TSC? */
        if (!scale) {
                kvm_vcpu_write_tsc_multiplier(vcpu, kvm_caps.default_tsc_scaling_ratio);
                return 0;
        }

        /* TSC scaling supported? */
        if (!kvm_caps.has_tsc_control) {
                if (user_tsc_khz > tsc_khz) {
                        vcpu->arch.tsc_catchup = 1;
                        vcpu->arch.tsc_always_catchup = 1;
                        return 0;
                } else {
                        pr_warn_ratelimited("user requested TSC rate below hardware speed\n");
                        return -1;
                }
        }

        /* TSC scaling required  - calculate ratio */
        ratio = mul_u64_u32_div(1ULL << kvm_caps.tsc_scaling_ratio_frac_bits,
                                user_tsc_khz, tsc_khz);

        if (ratio == 0 || ratio >= kvm_caps.max_tsc_scaling_ratio) {
                pr_warn_ratelimited("Invalid TSC scaling ratio - virtual-tsc-khz=%u\n",
                                    user_tsc_khz);
                return -1;
        }

        kvm_vcpu_write_tsc_multiplier(vcpu, ratio);
        return 0;
}

static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz)
{
        u32 thresh_lo, thresh_hi;
        int use_scaling = 0;

        /* tsc_khz can be zero if TSC calibration fails */
        if (user_tsc_khz == 0) {
                /* set tsc_scaling_ratio to a safe value */
                kvm_vcpu_write_tsc_multiplier(vcpu, kvm_caps.default_tsc_scaling_ratio);
                return -1;
        }

        /* Compute a scale to convert nanoseconds in TSC cycles */
        kvm_get_time_scale(user_tsc_khz * 1000LL, NSEC_PER_SEC,
                           &vcpu->arch.virtual_tsc_shift,
                           &vcpu->arch.virtual_tsc_mult);
        vcpu->arch.virtual_tsc_khz = user_tsc_khz;

        /*
         * Compute the variation in TSC rate which is acceptable
         * within the range of tolerance and decide if the
         * rate being applied is within that bounds of the hardware
         * rate.  If so, no scaling or compensation need be done.
         */
        thresh_lo = adjust_tsc_khz(tsc_khz, -tsc_tolerance_ppm);
        thresh_hi = adjust_tsc_khz(tsc_khz, tsc_tolerance_ppm);
        if (user_tsc_khz < thresh_lo || user_tsc_khz > thresh_hi) {
                pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", user_tsc_khz, thresh_lo, thresh_hi);
                use_scaling = 1;
        }
        return set_tsc_khz(vcpu, user_tsc_khz, use_scaling);
}

static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
{
        u64 tsc = pvclock_scale_delta(kernel_ns-vcpu->arch.this_tsc_nsec,
                                      vcpu->arch.virtual_tsc_mult,
                                      vcpu->arch.virtual_tsc_shift);
        tsc += vcpu->arch.this_tsc_write;
        return tsc;
}

#ifdef CONFIG_X86_64
static inline int gtod_is_based_on_tsc(int mode)
{
        return mode == VDSO_CLOCKMODE_TSC || mode == VDSO_CLOCKMODE_HVCLOCK;
}
#endif

static void kvm_track_tsc_matching(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_X86_64
        bool vcpus_matched;
        struct kvm_arch *ka = &vcpu->kvm->arch;
        struct pvclock_gtod_data *gtod = &pvclock_gtod_data;

        vcpus_matched = (ka->nr_vcpus_matched_tsc + 1 ==
                         atomic_read(&vcpu->kvm->online_vcpus));

        /*
         * Once the masterclock is enabled, always perform request in
         * order to update it.
         *
         * In order to enable masterclock, the host clocksource must be TSC
         * and the vcpus need to have matched TSCs.  When that happens,
         * perform request to enable masterclock.
         */
        if (ka->use_master_clock ||
            (gtod_is_based_on_tsc(gtod->clock.vclock_mode) && vcpus_matched))
                kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);

        trace_kvm_track_tsc(vcpu->vcpu_id, ka->nr_vcpus_matched_tsc,
                            atomic_read(&vcpu->kvm->online_vcpus),
                            ka->use_master_clock, gtod->clock.vclock_mode);
#endif
}

/*
 * Multiply tsc by a fixed point number represented by ratio.
 *
 * The most significant 64-N bits (mult) of ratio represent the
 * integral part of the fixed point number; the remaining N bits
 * (frac) represent the fractional part, ie. ratio represents a fixed
 * point number (mult + frac * 2^(-N)).
 *
 * N equals to kvm_caps.tsc_scaling_ratio_frac_bits.
 */
static inline u64 __scale_tsc(u64 ratio, u64 tsc)
{
        return mul_u64_u64_shr(tsc, ratio, kvm_caps.tsc_scaling_ratio_frac_bits);
}

u64 kvm_scale_tsc(u64 tsc, u64 ratio)
{
        u64 _tsc = tsc;

        if (ratio != kvm_caps.default_tsc_scaling_ratio)
                _tsc = __scale_tsc(ratio, tsc);

        return _tsc;
}

static u64 kvm_compute_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
{
        u64 tsc;

        tsc = kvm_scale_tsc(rdtsc(), vcpu->arch.l1_tsc_scaling_ratio);

        return target_tsc - tsc;
}

u64 kvm_read_l1_tsc(struct kvm_vcpu *vcpu, u64 host_tsc)
{
        return vcpu->arch.l1_tsc_offset +
                kvm_scale_tsc(host_tsc, vcpu->arch.l1_tsc_scaling_ratio);
}
EXPORT_SYMBOL_GPL(kvm_read_l1_tsc);

u64 kvm_calc_nested_tsc_offset(u64 l1_offset, u64 l2_offset, u64 l2_multiplier)
{
        u64 nested_offset;

        if (l2_multiplier == kvm_caps.default_tsc_scaling_ratio)
                nested_offset = l1_offset;
        else
                nested_offset = mul_s64_u64_shr((s64) l1_offset, l2_multiplier,
                                                kvm_caps.tsc_scaling_ratio_frac_bits);

        nested_offset += l2_offset;
        return nested_offset;
}
EXPORT_SYMBOL_GPL(kvm_calc_nested_tsc_offset);

u64 kvm_calc_nested_tsc_multiplier(u64 l1_multiplier, u64 l2_multiplier)
{
        if (l2_multiplier != kvm_caps.default_tsc_scaling_ratio)
                return mul_u64_u64_shr(l1_multiplier, l2_multiplier,
                                       kvm_caps.tsc_scaling_ratio_frac_bits);

        return l1_multiplier;
}
EXPORT_SYMBOL_GPL(kvm_calc_nested_tsc_multiplier);

static void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 l1_offset)
{
        trace_kvm_write_tsc_offset(vcpu->vcpu_id,
                                   vcpu->arch.l1_tsc_offset,
                                   l1_offset);

        vcpu->arch.l1_tsc_offset = l1_offset;

        /*
         * If we are here because L1 chose not to trap WRMSR to TSC then
         * according to the spec this should set L1's TSC (as opposed to
         * setting L1's offset for L2).
         */
        if (is_guest_mode(vcpu))
                vcpu->arch.tsc_offset = kvm_calc_nested_tsc_offset(
                        l1_offset,
                        static_call(kvm_x86_get_l2_tsc_offset)(vcpu),
                        static_call(kvm_x86_get_l2_tsc_multiplier)(vcpu));
        else
                vcpu->arch.tsc_offset = l1_offset;

        static_call(kvm_x86_write_tsc_offset)(vcpu, vcpu->arch.tsc_offset);
}

static void kvm_vcpu_write_tsc_multiplier(struct kvm_vcpu *vcpu, u64 l1_multiplier)
{
        vcpu->arch.l1_tsc_scaling_ratio = l1_multiplier;

        /* Userspace is changing the multiplier while L2 is active */
        if (is_guest_mode(vcpu))
                vcpu->arch.tsc_scaling_ratio = kvm_calc_nested_tsc_multiplier(
                        l1_multiplier,
                        static_call(kvm_x86_get_l2_tsc_multiplier)(vcpu));
        else
                vcpu->arch.tsc_scaling_ratio = l1_multiplier;

        if (kvm_caps.has_tsc_control)
                static_call(kvm_x86_write_tsc_multiplier)(
                        vcpu, vcpu->arch.tsc_scaling_ratio);
}

static inline bool kvm_check_tsc_unstable(void)
{
#ifdef CONFIG_X86_64
        /*
         * TSC is marked unstable when we're running on Hyper-V,
         * 'TSC page' clocksource is good.
         */
        if (pvclock_gtod_data.clock.vclock_mode == VDSO_CLOCKMODE_HVCLOCK)
                return false;
#endif
        return check_tsc_unstable();
}

/*
 * Infers attempts to synchronize the guest's tsc from host writes. Sets the
 * offset for the vcpu and tracks the TSC matching generation that the vcpu
 * participates in.
 */
static void __kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 offset, u64 tsc,
                                  u64 ns, bool matched)
{
        struct kvm *kvm = vcpu->kvm;

        lockdep_assert_held(&kvm->arch.tsc_write_lock);

        /*
         * We also track th most recent recorded KHZ, write and time to
         * allow the matching interval to be extended at each write.
         */
        kvm->arch.last_tsc_nsec = ns;
        kvm->arch.last_tsc_write = tsc;
        kvm->arch.last_tsc_khz = vcpu->arch.virtual_tsc_khz;
        kvm->arch.last_tsc_offset = offset;

        vcpu->arch.last_guest_tsc = tsc;

        kvm_vcpu_write_tsc_offset(vcpu, offset);

        if (!matched) {
                /*
                 * We split periods of matched TSC writes into generations.
                 * For each generation, we track the original measured
                 * nanosecond time, offset, and write, so if TSCs are in
                 * sync, we can match exact offset, and if not, we can match
                 * exact software computation in compute_guest_tsc()
                 *
                 * These values are tracked in kvm->arch.cur_xxx variables.
                 */
                kvm->arch.cur_tsc_generation++;
                kvm->arch.cur_tsc_nsec = ns;
                kvm->arch.cur_tsc_write = tsc;
                kvm->arch.cur_tsc_offset = offset;
                kvm->arch.nr_vcpus_matched_tsc = 0;
        } else if (vcpu->arch.this_tsc_generation != kvm->arch.cur_tsc_generation) {
                kvm->arch.nr_vcpus_matched_tsc++;
        }

        /* Keep track of which generation this VCPU has synchronized to */
        vcpu->arch.this_tsc_generation = kvm->arch.cur_tsc_generation;
        vcpu->arch.this_tsc_nsec = kvm->arch.cur_tsc_nsec;
        vcpu->arch.this_tsc_write = kvm->arch.cur_tsc_write;

        kvm_track_tsc_matching(vcpu);
}

static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data)
{
        struct kvm *kvm = vcpu->kvm;
        u64 offset, ns, elapsed;
        unsigned long flags;
        bool matched = false;
        bool synchronizing = false;

        raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
        offset = kvm_compute_l1_tsc_offset(vcpu, data);
        ns = get_kvmclock_base_ns();
        elapsed = ns - kvm->arch.last_tsc_nsec;

        if (vcpu->arch.virtual_tsc_khz) {
                if (data == 0) {
                        /*
                         * detection of vcpu initialization -- need to sync
                         * with other vCPUs. This particularly helps to keep
                         * kvm_clock stable after CPU hotplug
                         */
                        synchronizing = true;
                } else {
                        u64 tsc_exp = kvm->arch.last_tsc_write +
                                                nsec_to_cycles(vcpu, elapsed);
                        u64 tsc_hz = vcpu->arch.virtual_tsc_khz * 1000LL;
                        /*
                         * Special case: TSC write with a small delta (1 second)
                         * of virtual cycle time against real time is
                         * interpreted as an attempt to synchronize the CPU.
                         */
                        synchronizing = data < tsc_exp + tsc_hz &&
                                        data + tsc_hz > tsc_exp;
                }
        }

        /*
         * For a reliable TSC, we can match TSC offsets, and for an unstable
         * TSC, we add elapsed time in this computation.  We could let the
         * compensation code attempt to catch up if we fall behind, but
         * it's better to try to match offsets from the beginning.
         */
        if (synchronizing &&
            vcpu->arch.virtual_tsc_khz == kvm->arch.last_tsc_khz) {
                if (!kvm_check_tsc_unstable()) {
                        offset = kvm->arch.cur_tsc_offset;
                } else {
                        u64 delta = nsec_to_cycles(vcpu, elapsed);
                        data += delta;
                        offset = kvm_compute_l1_tsc_offset(vcpu, data);
                }
                matched = true;
        }

        __kvm_synchronize_tsc(vcpu, offset, data, ns, matched);
        raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
}

static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
                                           s64 adjustment)
{
        u64 tsc_offset = vcpu->arch.l1_tsc_offset;
        kvm_vcpu_write_tsc_offset(vcpu, tsc_offset + adjustment);
}

static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment)
{
        if (vcpu->arch.l1_tsc_scaling_ratio != kvm_caps.default_tsc_scaling_ratio)
                WARN_ON(adjustment < 0);
        adjustment = kvm_scale_tsc((u64) adjustment,
                                   vcpu->arch.l1_tsc_scaling_ratio);
        adjust_tsc_offset_guest(vcpu, adjustment);
}

#ifdef CONFIG_X86_64

static u64 read_tsc(void)
{
        u64 ret = (u64)rdtsc_ordered();
        u64 last = pvclock_gtod_data.clock.cycle_last;

        if (likely(ret >= last))
                return ret;

        /*
         * GCC likes to generate cmov here, but this branch is extremely
         * predictable (it's just a function of time and the likely is
         * very likely) and there's a data dependence, so force GCC
         * to generate a branch instead.  I don't barrier() because
         * we don't actually need a barrier, and if this function
         * ever gets inlined it will generate worse code.
         */
        asm volatile ("");
        return last;
}

static inline u64 vgettsc(struct pvclock_clock *clock, u64 *tsc_timestamp,
                          int *mode)
{
        long v;
        u64 tsc_pg_val;

        switch (clock->vclock_mode) {
        case VDSO_CLOCKMODE_HVCLOCK:
                tsc_pg_val = hv_read_tsc_page_tsc(hv_get_tsc_page(),
                                                  tsc_timestamp);
                if (tsc_pg_val != U64_MAX) {
                        /* TSC page valid */
                        *mode = VDSO_CLOCKMODE_HVCLOCK;
                        v = (tsc_pg_val - clock->cycle_last) &
                                clock->mask;
                } else {
                        /* TSC page invalid */
                        *mode = VDSO_CLOCKMODE_NONE;
                }
                break;
        case VDSO_CLOCKMODE_TSC:
                *mode = VDSO_CLOCKMODE_TSC;
                *tsc_timestamp = read_tsc();
                v = (*tsc_timestamp - clock->cycle_last) &
                        clock->mask;
                break;
        default:
                *mode = VDSO_CLOCKMODE_NONE;
        }

        if (*mode == VDSO_CLOCKMODE_NONE)
                *tsc_timestamp = v = 0;

        return v * clock->mult;
}

static int do_monotonic_raw(s64 *t, u64 *tsc_timestamp)
{
        struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
        unsigned long seq;
        int mode;
        u64 ns;

        do {
                seq = read_seqcount_begin(&gtod->seq);
                ns = gtod->raw_clock.base_cycles;
                ns += vgettsc(&gtod->raw_clock, tsc_timestamp, &mode);
                ns >>= gtod->raw_clock.shift;
                ns += ktime_to_ns(ktime_add(gtod->raw_clock.offset, gtod->offs_boot));
        } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));
        *t = ns;

        return mode;
}

static int do_realtime(struct timespec64 *ts, u64 *tsc_timestamp)
{
        struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
        unsigned long seq;
        int mode;
        u64 ns;

        do {
                seq = read_seqcount_begin(&gtod->seq);
                ts->tv_sec = gtod->wall_time_sec;
                ns = gtod->clock.base_cycles;
                ns += vgettsc(&gtod->clock, tsc_timestamp, &mode);
                ns >>= gtod->clock.shift;
        } while (unlikely(read_seqcount_retry(&gtod->seq, seq)));

        ts->tv_sec += __iter_div_u64_rem(ns, NSEC_PER_SEC, &ns);
        ts->tv_nsec = ns;

        return mode;
}

/* returns true if host is using TSC based clocksource */
static bool kvm_get_time_and_clockread(s64 *kernel_ns, u64 *tsc_timestamp)
{
        /* checked again under seqlock below */
        if (!gtod_is_based_on_tsc(pvclock_gtod_data.clock.vclock_mode))
                return false;

        return gtod_is_based_on_tsc(do_monotonic_raw(kernel_ns,
                                                      tsc_timestamp));
}

/* returns true if host is using TSC based clocksource */
static bool kvm_get_walltime_and_clockread(struct timespec64 *ts,
                                           u64 *tsc_timestamp)
{
        /* checked again under seqlock below */
        if (!gtod_is_based_on_tsc(pvclock_gtod_data.clock.vclock_mode))
                return false;

        return gtod_is_based_on_tsc(do_realtime(ts, tsc_timestamp));
}
#endif

/*
 *
 * Assuming a stable TSC across physical CPUS, and a stable TSC
 * across virtual CPUs, the following condition is possible.
 * Each numbered line represents an event visible to both
 * CPUs at the next numbered event.
 *
 * "timespecX" represents host monotonic time. "tscX" represents
 * RDTSC value.
 *
 *              VCPU0 on CPU0           |       VCPU1 on CPU1
 *
 * 1.  read timespec0,tsc0
 * 2.                                   | timespec1 = timespec0 + N
 *                                      | tsc1 = tsc0 + M
 * 3. transition to guest               | transition to guest
 * 4. ret0 = timespec0 + (rdtsc - tsc0) |
 * 5.                                   | ret1 = timespec1 + (rdtsc - tsc1)
 *                                      | ret1 = timespec0 + N + (rdtsc - (tsc0 + M))
 *
 * Since ret0 update is visible to VCPU1 at time 5, to obey monotonicity:
 *
 *      - ret0 < ret1
 *      - timespec0 + (rdtsc - tsc0) < timespec0 + N + (rdtsc - (tsc0 + M))
 *              ...
 *      - 0 < N - M => M < N
 *
 * That is, when timespec0 != timespec1, M < N. Unfortunately that is not
 * always the case (the difference between two distinct xtime instances
 * might be smaller then the difference between corresponding TSC reads,
 * when updating guest vcpus pvclock areas).
 *
 * To avoid that problem, do not allow visibility of distinct
 * system_timestamp/tsc_timestamp values simultaneously: use a master
 * copy of host monotonic time values. Update that master copy
 * in lockstep.
 *
 * Rely on synchronization of host TSCs and guest TSCs for monotonicity.
 *
 */

static void pvclock_update_vm_gtod_copy(struct kvm *kvm)
{
#ifdef CONFIG_X86_64
        struct kvm_arch *ka = &kvm->arch;
        int vclock_mode;
        bool host_tsc_clocksource, vcpus_matched;

        lockdep_assert_held(&kvm->arch.tsc_write_lock);
        vcpus_matched = (ka->nr_vcpus_matched_tsc + 1 ==
                        atomic_read(&kvm->online_vcpus));

        /*
         * If the host uses TSC clock, then passthrough TSC as stable
         * to the guest.
         */
        host_tsc_clocksource = kvm_get_time_and_clockread(
                                        &ka->master_kernel_ns,
                                        &ka->master_cycle_now);

        ka->use_master_clock = host_tsc_clocksource && vcpus_matched
                                && !ka->backwards_tsc_observed
                                && !ka->boot_vcpu_runs_old_kvmclock;

        if (ka->use_master_clock)
                atomic_set(&kvm_guest_has_master_clock, 1);

        vclock_mode = pvclock_gtod_data.clock.vclock_mode;
        trace_kvm_update_master_clock(ka->use_master_clock, vclock_mode,
                                        vcpus_matched);
#endif
}

static void kvm_make_mclock_inprogress_request(struct kvm *kvm)
{
        kvm_make_all_cpus_request(kvm, KVM_REQ_MCLOCK_INPROGRESS);
}

static void __kvm_start_pvclock_update(struct kvm *kvm)
{
        raw_spin_lock_irq(&kvm->arch.tsc_write_lock);
        write_seqcount_begin(&kvm->arch.pvclock_sc);
}

static void kvm_start_pvclock_update(struct kvm *kvm)
{
        kvm_make_mclock_inprogress_request(kvm);

        /* no guest entries from this point */
        __kvm_start_pvclock_update(kvm);
}

static void kvm_end_pvclock_update(struct kvm *kvm)
{
        struct kvm_arch *ka = &kvm->arch;
        struct kvm_vcpu *vcpu;
        unsigned long i;

        write_seqcount_end(&ka->pvclock_sc);
        raw_spin_unlock_irq(&ka->tsc_write_lock);
        kvm_for_each_vcpu(i, vcpu, kvm)
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);

        /* guest entries allowed */
        kvm_for_each_vcpu(i, vcpu, kvm)
                kvm_clear_request(KVM_REQ_MCLOCK_INPROGRESS, vcpu);
}

static void kvm_update_masterclock(struct kvm *kvm)
{
        kvm_hv_request_tsc_page_update(kvm);
        kvm_start_pvclock_update(kvm);
        pvclock_update_vm_gtod_copy(kvm);
        kvm_end_pvclock_update(kvm);
}

/*
 * Use the kernel's tsc_khz directly if the TSC is constant, otherwise use KVM's
 * per-CPU value (which may be zero if a CPU is going offline).  Note, tsc_khz
 * can change during boot even if the TSC is constant, as it's possible for KVM
 * to be loaded before TSC calibration completes.  Ideally, KVM would get a
 * notification when calibration completes, but practically speaking calibration
 * will complete before userspace is alive enough to create VMs.
 */
static unsigned long get_cpu_tsc_khz(void)
{
        if (static_cpu_has(X86_FEATURE_CONSTANT_TSC))
                return tsc_khz;
        else
                return __this_cpu_read(cpu_tsc_khz);
}

/* Called within read_seqcount_begin/retry for kvm->pvclock_sc.  */
static void __get_kvmclock(struct kvm *kvm, struct kvm_clock_data *data)
{
        struct kvm_arch *ka = &kvm->arch;
        struct pvclock_vcpu_time_info hv_clock;

        /* both __this_cpu_read() and rdtsc() should be on the same cpu */
        get_cpu();

        data->flags = 0;
        if (ka->use_master_clock &&
            (static_cpu_has(X86_FEATURE_CONSTANT_TSC) || __this_cpu_read(cpu_tsc_khz))) {
#ifdef CONFIG_X86_64
                struct timespec64 ts;

                if (kvm_get_walltime_and_clockread(&ts, &data->host_tsc)) {
                        data->realtime = ts.tv_nsec + NSEC_PER_SEC * ts.tv_sec;
                        data->flags |= KVM_CLOCK_REALTIME | KVM_CLOCK_HOST_TSC;
                } else
#endif
                data->host_tsc = rdtsc();

                data->flags |= KVM_CLOCK_TSC_STABLE;
                hv_clock.tsc_timestamp = ka->master_cycle_now;
                hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset;
                kvm_get_time_scale(NSEC_PER_SEC, get_cpu_tsc_khz() * 1000LL,
                                   &hv_clock.tsc_shift,
                                   &hv_clock.tsc_to_system_mul);
                data->clock = __pvclock_read_cycles(&hv_clock, data->host_tsc);
        } else {
                data->clock = get_kvmclock_base_ns() + ka->kvmclock_offset;
        }

        put_cpu();
}

static void get_kvmclock(struct kvm *kvm, struct kvm_clock_data *data)
{
        struct kvm_arch *ka = &kvm->arch;
        unsigned seq;

        do {
                seq = read_seqcount_begin(&ka->pvclock_sc);
                __get_kvmclock(kvm, data);
        } while (read_seqcount_retry(&ka->pvclock_sc, seq));
}

u64 get_kvmclock_ns(struct kvm *kvm)
{
        struct kvm_clock_data data;

        get_kvmclock(kvm, &data);
        return data.clock;
}

static void kvm_setup_guest_pvclock(struct kvm_vcpu *v,
                                    struct gfn_to_pfn_cache *gpc,
                                    unsigned int offset)
{
        struct kvm_vcpu_arch *vcpu = &v->arch;
        struct pvclock_vcpu_time_info *guest_hv_clock;
        unsigned long flags;

        read_lock_irqsave(&gpc->lock, flags);
        while (!kvm_gpc_check(gpc, offset + sizeof(*guest_hv_clock))) {
                read_unlock_irqrestore(&gpc->lock, flags);

                if (kvm_gpc_refresh(gpc, offset + sizeof(*guest_hv_clock)))
                        return;

                read_lock_irqsave(&gpc->lock, flags);
        }

        guest_hv_clock = (void *)(gpc->khva + offset);

        /*
         * This VCPU is paused, but it's legal for a guest to read another
         * VCPU's kvmclock, so we really have to follow the specification where
         * it says that version is odd if data is being modified, and even after
         * it is consistent.
         */

        guest_hv_clock->version = vcpu->hv_clock.version = (guest_hv_clock->version + 1) | 1;
        smp_wmb();

        /* retain PVCLOCK_GUEST_STOPPED if set in guest copy */
        vcpu->hv_clock.flags |= (guest_hv_clock->flags & PVCLOCK_GUEST_STOPPED);

        if (vcpu->pvclock_set_guest_stopped_request) {
                vcpu->hv_clock.flags |= PVCLOCK_GUEST_STOPPED;
                vcpu->pvclock_set_guest_stopped_request = false;
        }

        memcpy(guest_hv_clock, &vcpu->hv_clock, sizeof(*guest_hv_clock));
        smp_wmb();

        guest_hv_clock->version = ++vcpu->hv_clock.version;

        mark_page_dirty_in_slot(v->kvm, gpc->memslot, gpc->gpa >> PAGE_SHIFT);
        read_unlock_irqrestore(&gpc->lock, flags);

        trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock);
}

static int kvm_guest_time_update(struct kvm_vcpu *v)
{
        unsigned long flags, tgt_tsc_khz;
        unsigned seq;
        struct kvm_vcpu_arch *vcpu = &v->arch;
        struct kvm_arch *ka = &v->kvm->arch;
        s64 kernel_ns;
        u64 tsc_timestamp, host_tsc;
        u8 pvclock_flags;
        bool use_master_clock;

        kernel_ns = 0;
        host_tsc = 0;

        /*
         * If the host uses TSC clock, then passthrough TSC as stable
         * to the guest.
         */
        do {
                seq = read_seqcount_begin(&ka->pvclock_sc);
                use_master_clock = ka->use_master_clock;
                if (use_master_clock) {
                        host_tsc = ka->master_cycle_now;
                        kernel_ns = ka->master_kernel_ns;
                }
        } while (read_seqcount_retry(&ka->pvclock_sc, seq));

        /* Keep irq disabled to prevent changes to the clock */
        local_irq_save(flags);
        tgt_tsc_khz = get_cpu_tsc_khz();
        if (unlikely(tgt_tsc_khz == 0)) {
                local_irq_restore(flags);
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
                return 1;
        }
        if (!use_master_clock) {
                host_tsc = rdtsc();
                kernel_ns = get_kvmclock_base_ns();
        }

        tsc_timestamp = kvm_read_l1_tsc(v, host_tsc);

        /*
         * We may have to catch up the TSC to match elapsed wall clock
         * time for two reasons, even if kvmclock is used.
         *   1) CPU could have been running below the maximum TSC rate
         *   2) Broken TSC compensation resets the base at each VCPU
         *      entry to avoid unknown leaps of TSC even when running
         *      again on the same CPU.  This may cause apparent elapsed
         *      time to disappear, and the guest to stand still or run
         *      very slowly.
         */
        if (vcpu->tsc_catchup) {
                u64 tsc = compute_guest_tsc(v, kernel_ns);
                if (tsc > tsc_timestamp) {
                        adjust_tsc_offset_guest(v, tsc - tsc_timestamp);
                        tsc_timestamp = tsc;
                }
        }

        local_irq_restore(flags);

        /* With all the info we got, fill in the values */

        if (kvm_caps.has_tsc_control)
                tgt_tsc_khz = kvm_scale_tsc(tgt_tsc_khz,
                                            v->arch.l1_tsc_scaling_ratio);

        if (unlikely(vcpu->hw_tsc_khz != tgt_tsc_khz)) {
                kvm_get_time_scale(NSEC_PER_SEC, tgt_tsc_khz * 1000LL,
                                   &vcpu->hv_clock.tsc_shift,
                                   &vcpu->hv_clock.tsc_to_system_mul);
                vcpu->hw_tsc_khz = tgt_tsc_khz;
        }

        vcpu->hv_clock.tsc_timestamp = tsc_timestamp;
        vcpu->hv_clock.system_time = kernel_ns + v->kvm->arch.kvmclock_offset;
        vcpu->last_guest_tsc = tsc_timestamp;

        /* If the host uses TSC clocksource, then it is stable */
        pvclock_flags = 0;
        if (use_master_clock)
                pvclock_flags |= PVCLOCK_TSC_STABLE_BIT;

        vcpu->hv_clock.flags = pvclock_flags;

        if (vcpu->pv_time.active)
                kvm_setup_guest_pvclock(v, &vcpu->pv_time, 0);
        if (vcpu->xen.vcpu_info_cache.active)
                kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_info_cache,
                                        offsetof(struct compat_vcpu_info, time));
        if (vcpu->xen.vcpu_time_info_cache.active)
                kvm_setup_guest_pvclock(v, &vcpu->xen.vcpu_time_info_cache, 0);
        kvm_hv_setup_tsc_page(v->kvm, &vcpu->hv_clock);
        return 0;
}

/*
 * kvmclock updates which are isolated to a given vcpu, such as
 * vcpu->cpu migration, should not allow system_timestamp from
 * the rest of the vcpus to remain static. Otherwise ntp frequency
 * correction applies to one vcpu's system_timestamp but not
 * the others.
 *
 * So in those cases, request a kvmclock update for all vcpus.
 * We need to rate-limit these requests though, as they can
 * considerably slow guests that have a large number of vcpus.
 * The time for a remote vcpu to update its kvmclock is bound
 * by the delay we use to rate-limit the updates.
 */

#define KVMCLOCK_UPDATE_DELAY msecs_to_jiffies(100)

static void kvmclock_update_fn(struct work_struct *work)
{
        unsigned long i;
        struct delayed_work *dwork = to_delayed_work(work);
        struct kvm_arch *ka = container_of(dwork, struct kvm_arch,
                                           kvmclock_update_work);
        struct kvm *kvm = container_of(ka, struct kvm, arch);
        struct kvm_vcpu *vcpu;

        kvm_for_each_vcpu(i, vcpu, kvm) {
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
                kvm_vcpu_kick(vcpu);
        }
}

static void kvm_gen_kvmclock_update(struct kvm_vcpu *v)
{
        struct kvm *kvm = v->kvm;

        kvm_make_request(KVM_REQ_CLOCK_UPDATE, v);
        schedule_delayed_work(&kvm->arch.kvmclock_update_work,
                                        KVMCLOCK_UPDATE_DELAY);
}

#define KVMCLOCK_SYNC_PERIOD (300 * HZ)

static void kvmclock_sync_fn(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct kvm_arch *ka = container_of(dwork, struct kvm_arch,
                                           kvmclock_sync_work);
        struct kvm *kvm = container_of(ka, struct kvm, arch);

        if (!kvmclock_periodic_sync)
                return;

        schedule_delayed_work(&kvm->arch.kvmclock_update_work, 0);
        schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
                                        KVMCLOCK_SYNC_PERIOD);
}

/* These helpers are safe iff @msr is known to be an MCx bank MSR. */
static bool is_mci_control_msr(u32 msr)
{
        return (msr & 3) == 0;
}
static bool is_mci_status_msr(u32 msr)
{
        return (msr & 3) == 1;
}

/*
 * On AMD, HWCR[McStatusWrEn] controls whether setting MCi_STATUS results in #GP.
 */
static bool can_set_mci_status(struct kvm_vcpu *vcpu)
{
        /* McStatusWrEn enabled? */
        if (guest_cpuid_is_amd_or_hygon(vcpu))
                return !!(vcpu->arch.msr_hwcr & BIT_ULL(18));

        return false;
}

static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
        u64 mcg_cap = vcpu->arch.mcg_cap;
        unsigned bank_num = mcg_cap & 0xff;
        u32 msr = msr_info->index;
        u64 data = msr_info->data;
        u32 offset, last_msr;

        switch (msr) {
        case MSR_IA32_MCG_STATUS:
                vcpu->arch.mcg_status = data;
                break;
        case MSR_IA32_MCG_CTL:
                if (!(mcg_cap & MCG_CTL_P) &&
                    (data || !msr_info->host_initiated))
                        return 1;
                if (data != 0 && data != ~(u64)0)
                        return 1;
                vcpu->arch.mcg_ctl = data;
                break;
        case MSR_IA32_MC0_CTL2 ... MSR_IA32_MCx_CTL2(KVM_MAX_MCE_BANKS) - 1:
                last_msr = MSR_IA32_MCx_CTL2(bank_num) - 1;
                if (msr > last_msr)
                        return 1;

                if (!(mcg_cap & MCG_CMCI_P) && (data || !msr_info->host_initiated))
                        return 1;
                /* An attempt to write a 1 to a reserved bit raises #GP */
                if (data & ~(MCI_CTL2_CMCI_EN | MCI_CTL2_CMCI_THRESHOLD_MASK))
                        return 1;
                offset = array_index_nospec(msr - MSR_IA32_MC0_CTL2,
                                            last_msr + 1 - MSR_IA32_MC0_CTL2);
                vcpu->arch.mci_ctl2_banks[offset] = data;
                break;
        case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
                last_msr = MSR_IA32_MCx_CTL(bank_num) - 1;
                if (msr > last_msr)
                        return 1;

                /*
                 * Only 0 or all 1s can be written to IA32_MCi_CTL, all other
                 * values are architecturally undefined.  But, some Linux
                 * kernels clear bit 10 in bank 4 to workaround a BIOS/GART TLB
                 * issue on AMD K8s, allow bit 10 to be clear when setting all
                 * other bits in order to avoid an uncaught #GP in the guest.
                 *
                 * UNIXWARE clears bit 0 of MC1_CTL to ignore correctable,
                 * single-bit ECC data errors.
                 */
                if (is_mci_control_msr(msr) &&
                    data != 0 && (data | (1 << 10) | 1) != ~(u64)0)
                        return 1;

                /*
                 * All CPUs allow writing 0 to MCi_STATUS MSRs to clear the MSR.
                 * AMD-based CPUs allow non-zero values, but if and only if
                 * HWCR[McStatusWrEn] is set.
                 */
                if (!msr_info->host_initiated && is_mci_status_msr(msr) &&
                    data != 0 && !can_set_mci_status(vcpu))
                        return 1;

                offset = array_index_nospec(msr - MSR_IA32_MC0_CTL,
                                            last_msr + 1 - MSR_IA32_MC0_CTL);
                vcpu->arch.mce_banks[offset] = data;
                break;
        default:
                return 1;
        }
        return 0;
}

static inline bool kvm_pv_async_pf_enabled(struct kvm_vcpu *vcpu)
{
        u64 mask = KVM_ASYNC_PF_ENABLED | KVM_ASYNC_PF_DELIVERY_AS_INT;

        return (vcpu->arch.apf.msr_en_val & mask) == mask;
}

static int kvm_pv_enable_async_pf(struct kvm_vcpu *vcpu, u64 data)
{
        gpa_t gpa = data & ~0x3f;

        /* Bits 4:5 are reserved, Should be zero */
        if (data & 0x30)
                return 1;

        if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_VMEXIT) &&
            (data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT))
                return 1;

        if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT) &&
            (data & KVM_ASYNC_PF_DELIVERY_AS_INT))
                return 1;

        if (!lapic_in_kernel(vcpu))
                return data ? 1 : 0;

        vcpu->arch.apf.msr_en_val = data;

        if (!kvm_pv_async_pf_enabled(vcpu)) {
                kvm_clear_async_pf_completion_queue(vcpu);
                kvm_async_pf_hash_reset(vcpu);
                return 0;
        }

        if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apf.data, gpa,
                                        sizeof(u64)))
                return 1;

        vcpu->arch.apf.send_user_only = !(data & KVM_ASYNC_PF_SEND_ALWAYS);
        vcpu->arch.apf.delivery_as_pf_vmexit = data & KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;

        kvm_async_pf_wakeup_all(vcpu);

        return 0;
}

static int kvm_pv_enable_async_pf_int(struct kvm_vcpu *vcpu, u64 data)
{
        /* Bits 8-63 are reserved */
        if (data >> 8)
                return 1;

        if (!lapic_in_kernel(vcpu))
                return 1;

        vcpu->arch.apf.msr_int_val = data;

        vcpu->arch.apf.vec = data & KVM_ASYNC_PF_VEC_MASK;

        return 0;
}

static void kvmclock_reset(struct kvm_vcpu *vcpu)
{
        kvm_gpc_deactivate(&vcpu->arch.pv_time);
        vcpu->arch.time = 0;
}

static void kvm_vcpu_flush_tlb_all(struct kvm_vcpu *vcpu)
{
        ++vcpu->stat.tlb_flush;
        static_call(kvm_x86_flush_tlb_all)(vcpu);

        /* Flushing all ASIDs flushes the current ASID... */
        kvm_clear_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu);
}

static void kvm_vcpu_flush_tlb_guest(struct kvm_vcpu *vcpu)
{
        ++vcpu->stat.tlb_flush;

        if (!tdp_enabled) {
                /*
                 * A TLB flush on behalf of the guest is equivalent to
                 * INVPCID(all), toggling CR4.PGE, etc., which requires
                 * a forced sync of the shadow page tables.  Ensure all the
                 * roots are synced and the guest TLB in hardware is clean.
                 */
                kvm_mmu_sync_roots(vcpu);
                kvm_mmu_sync_prev_roots(vcpu);
        }

        static_call(kvm_x86_flush_tlb_guest)(vcpu);

        /*
         * Flushing all "guest" TLB is always a superset of Hyper-V's fine
         * grained flushing.
         */
        kvm_hv_vcpu_purge_flush_tlb(vcpu);
}


static inline void kvm_vcpu_flush_tlb_current(struct kvm_vcpu *vcpu)
{
        ++vcpu->stat.tlb_flush;
        static_call(kvm_x86_flush_tlb_current)(vcpu);
}

/*
 * Service "local" TLB flush requests, which are specific to the current MMU
 * context.  In addition to the generic event handling in vcpu_enter_guest(),
 * TLB flushes that are targeted at an MMU context also need to be serviced
 * prior before nested VM-Enter/VM-Exit.
 */
void kvm_service_local_tlb_flush_requests(struct kvm_vcpu *vcpu)
{
        if (kvm_check_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu))
                kvm_vcpu_flush_tlb_current(vcpu);

        if (kvm_check_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu))
                kvm_vcpu_flush_tlb_guest(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_service_local_tlb_flush_requests);

static void record_steal_time(struct kvm_vcpu *vcpu)
{
        struct gfn_to_hva_cache *ghc = &vcpu->arch.st.cache;
        struct kvm_steal_time __user *st;
        struct kvm_memslots *slots;
        gpa_t gpa = vcpu->arch.st.msr_val & KVM_STEAL_VALID_BITS;
        u64 steal;
        u32 version;

        if (kvm_xen_msr_enabled(vcpu->kvm)) {
                kvm_xen_runstate_set_running(vcpu);
                return;
        }

        if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
                return;

        if (WARN_ON_ONCE(current->mm != vcpu->kvm->mm))
                return;

        slots = kvm_memslots(vcpu->kvm);

        if (unlikely(slots->generation != ghc->generation ||
                     gpa != ghc->gpa ||
                     kvm_is_error_hva(ghc->hva) || !ghc->memslot)) {
                /* We rely on the fact that it fits in a single page. */
                BUILD_BUG_ON((sizeof(*st) - 1) & KVM_STEAL_VALID_BITS);

                if (kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, gpa, sizeof(*st)) ||
                    kvm_is_error_hva(ghc->hva) || !ghc->memslot)
                        return;
        }

        st = (struct kvm_steal_time __user *)ghc->hva;
        /*
         * Doing a TLB flush here, on the guest's behalf, can avoid
         * expensive IPIs.
         */
        if (guest_pv_has(vcpu, KVM_FEATURE_PV_TLB_FLUSH)) {
                u8 st_preempted = 0;
                int err = -EFAULT;

                if (!user_access_begin(st, sizeof(*st)))
                        return;

                asm volatile("1: xchgb %0, %2\n"
                             "xor %1, %1\n"
                             "2:\n"
                             _ASM_EXTABLE_UA(1b, 2b)
                             : "+q" (st_preempted),
                               "+&r" (err),
                               "+m" (st->preempted));
                if (err)
                        goto out;

                user_access_end();

                vcpu->arch.st.preempted = 0;

                trace_kvm_pv_tlb_flush(vcpu->vcpu_id,
                                       st_preempted & KVM_VCPU_FLUSH_TLB);
                if (st_preempted & KVM_VCPU_FLUSH_TLB)
                        kvm_vcpu_flush_tlb_guest(vcpu);

                if (!user_access_begin(st, sizeof(*st)))
                        goto dirty;
        } else {
                if (!user_access_begin(st, sizeof(*st)))
                        return;

                unsafe_put_user(0, &st->preempted, out);
                vcpu->arch.st.preempted = 0;
        }

        unsafe_get_user(version, &st->version, out);
        if (version & 1)
                version += 1;  /* first time write, random junk */

        version += 1;
        unsafe_put_user(version, &st->version, out);

        smp_wmb();

        unsafe_get_user(steal, &st->steal, out);
        steal += current->sched_info.run_delay -
                vcpu->arch.st.last_steal;
        vcpu->arch.st.last_steal = current->sched_info.run_delay;
        unsafe_put_user(steal, &st->steal, out);

        version += 1;
        unsafe_put_user(version, &st->version, out);

 out:
        user_access_end();
 dirty:
        mark_page_dirty_in_slot(vcpu->kvm, ghc->memslot, gpa_to_gfn(ghc->gpa));
}

int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
        bool pr = false;
        u32 msr = msr_info->index;
        u64 data = msr_info->data;

        if (msr && msr == vcpu->kvm->arch.xen_hvm_config.msr)
                return kvm_xen_write_hypercall_page(vcpu, data);

        switch (msr) {
        case MSR_AMD64_NB_CFG:
        case MSR_IA32_UCODE_WRITE:
        case MSR_VM_HSAVE_PA:
        case MSR_AMD64_PATCH_LOADER:
        case MSR_AMD64_BU_CFG2:
        case MSR_AMD64_DC_CFG:
        case MSR_F15H_EX_CFG:
                break;

        case MSR_IA32_UCODE_REV:
                if (msr_info->host_initiated)
                        vcpu->arch.microcode_version = data;
                break;
        case MSR_IA32_ARCH_CAPABILITIES:
                if (!msr_info->host_initiated)
                        return 1;
                vcpu->arch.arch_capabilities = data;
                break;
        case MSR_IA32_PERF_CAPABILITIES:
                if (!msr_info->host_initiated)
                        return 1;
                if (data & ~kvm_caps.supported_perf_cap)
                        return 1;

                vcpu->arch.perf_capabilities = data;
                kvm_pmu_refresh(vcpu);
                return 0;
        case MSR_EFER:
                return set_efer(vcpu, msr_info);
        case MSR_K7_HWCR:
                data &= ~(u64)0x40;     /* ignore flush filter disable */
                data &= ~(u64)0x100;    /* ignore ignne emulation enable */
                data &= ~(u64)0x8;      /* ignore TLB cache disable */

                /* Handle McStatusWrEn */
                if (data == BIT_ULL(18)) {
                        vcpu->arch.msr_hwcr = data;
                } else if (data != 0) {
                        vcpu_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
                                    data);
                        return 1;
                }
                break;
        case MSR_FAM10H_MMIO_CONF_BASE:
                if (data != 0) {
                        vcpu_unimpl(vcpu, "unimplemented MMIO_CONF_BASE wrmsr: "
                                    "0x%llx\n", data);
                        return 1;
                }
                break;
        case 0x200 ... MSR_IA32_MC0_CTL2 - 1:
        case MSR_IA32_MCx_CTL2(KVM_MAX_MCE_BANKS) ... 0x2ff:
                return kvm_mtrr_set_msr(vcpu, msr, data);
        case MSR_IA32_APICBASE:
                return kvm_set_apic_base(vcpu, msr_info);
        case APIC_BASE_MSR ... APIC_BASE_MSR + 0xff:
                return kvm_x2apic_msr_write(vcpu, msr, data);
        case MSR_IA32_TSC_DEADLINE:
                kvm_set_lapic_tscdeadline_msr(vcpu, data);
                break;
        case MSR_IA32_TSC_ADJUST:
                if (guest_cpuid_has(vcpu, X86_FEATURE_TSC_ADJUST)) {
                        if (!msr_info->host_initiated) {
                                s64 adj = data - vcpu->arch.ia32_tsc_adjust_msr;
                                adjust_tsc_offset_guest(vcpu, adj);
                                /* Before back to guest, tsc_timestamp must be adjusted
                                 * as well, otherwise guest's percpu pvclock time could jump.
                                 */
                                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
                        }
                        vcpu->arch.ia32_tsc_adjust_msr = data;
                }
                break;
        case MSR_IA32_MISC_ENABLE: {
                u64 old_val = vcpu->arch.ia32_misc_enable_msr;

                if (!msr_info->host_initiated) {
                        /* RO bits */
                        if ((old_val ^ data) & MSR_IA32_MISC_ENABLE_PMU_RO_MASK)
                                return 1;

                        /* R bits, i.e. writes are ignored, but don't fault. */
                        data = data & ~MSR_IA32_MISC_ENABLE_EMON;
                        data |= old_val & MSR_IA32_MISC_ENABLE_EMON;
                }

                if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT) &&
                    ((old_val ^ data)  & MSR_IA32_MISC_ENABLE_MWAIT)) {
                        if (!guest_cpuid_has(vcpu, X86_FEATURE_XMM3))
                                return 1;
                        vcpu->arch.ia32_misc_enable_msr = data;
                        kvm_update_cpuid_runtime(vcpu);
                } else {
                        vcpu->arch.ia32_misc_enable_msr = data;
                }
                break;
        }
        case MSR_IA32_SMBASE:
                if (!IS_ENABLED(CONFIG_KVM_SMM) || !msr_info->host_initiated)
                        return 1;
                vcpu->arch.smbase = data;
                break;
        case MSR_IA32_POWER_CTL:
                vcpu->arch.msr_ia32_power_ctl = data;
                break;
        case MSR_IA32_TSC:
                if (msr_info->host_initiated) {
                        kvm_synchronize_tsc(vcpu, data);
                } else {
                        u64 adj = kvm_compute_l1_tsc_offset(vcpu, data) - vcpu->arch.l1_tsc_offset;
                        adjust_tsc_offset_guest(vcpu, adj);
                        vcpu->arch.ia32_tsc_adjust_msr += adj;
                }
                break;
        case MSR_IA32_XSS:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
                        return 1;
                /*
                 * KVM supports exposing PT to the guest, but does not support
                 * IA32_XSS[bit 8]. Guests have to use RDMSR/WRMSR rather than
                 * XSAVES/XRSTORS to save/restore PT MSRs.
                 */
                if (data & ~kvm_caps.supported_xss)
                        return 1;
                vcpu->arch.ia32_xss = data;
                kvm_update_cpuid_runtime(vcpu);
                break;
        case MSR_SMI_COUNT:
                if (!msr_info->host_initiated)
                        return 1;
                vcpu->arch.smi_count = data;
                break;
        case MSR_KVM_WALL_CLOCK_NEW:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))
                        return 1;

                vcpu->kvm->arch.wall_clock = data;
                kvm_write_wall_clock(vcpu->kvm, data, 0);
                break;
        case MSR_KVM_WALL_CLOCK:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE))
                        return 1;

                vcpu->kvm->arch.wall_clock = data;
                kvm_write_wall_clock(vcpu->kvm, data, 0);
                break;
        case MSR_KVM_SYSTEM_TIME_NEW:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))
                        return 1;

                kvm_write_system_time(vcpu, data, false, msr_info->host_initiated);
                break;
        case MSR_KVM_SYSTEM_TIME:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE))
                        return 1;

                kvm_write_system_time(vcpu, data, true,  msr_info->host_initiated);
                break;
        case MSR_KVM_ASYNC_PF_EN:
                if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF))
                        return 1;

                if (kvm_pv_enable_async_pf(vcpu, data))
                        return 1;
                break;
        case MSR_KVM_ASYNC_PF_INT:
                if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT))
                        return 1;

                if (kvm_pv_enable_async_pf_int(vcpu, data))
                        return 1;
                break;
        case MSR_KVM_ASYNC_PF_ACK:
                if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT))
                        return 1;
                if (data & 0x1) {
                        vcpu->arch.apf.pageready_pending = false;
                        kvm_check_async_pf_completion(vcpu);
                }
                break;
        case MSR_KVM_STEAL_TIME:
                if (!guest_pv_has(vcpu, KVM_FEATURE_STEAL_TIME))
                        return 1;

                if (unlikely(!sched_info_on()))
                        return 1;

                if (data & KVM_STEAL_RESERVED_MASK)
                        return 1;

                vcpu->arch.st.msr_val = data;

                if (!(data & KVM_MSR_ENABLED))
                        break;

                kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);

                break;
        case MSR_KVM_PV_EOI_EN:
                if (!guest_pv_has(vcpu, KVM_FEATURE_PV_EOI))
                        return 1;

                if (kvm_lapic_set_pv_eoi(vcpu, data, sizeof(u8)))
                        return 1;
                break;

        case MSR_KVM_POLL_CONTROL:
                if (!guest_pv_has(vcpu, KVM_FEATURE_POLL_CONTROL))
                        return 1;

                /* only enable bit supported */
                if (data & (-1ULL << 1))
                        return 1;

                vcpu->arch.msr_kvm_poll_control = data;
                break;

        case MSR_IA32_MCG_CTL:
        case MSR_IA32_MCG_STATUS:
        case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
        case MSR_IA32_MC0_CTL2 ... MSR_IA32_MCx_CTL2(KVM_MAX_MCE_BANKS) - 1:
                return set_msr_mce(vcpu, msr_info);

        case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
        case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1:
                pr = true;
                fallthrough;
        case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
        case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL1:
                if (kvm_pmu_is_valid_msr(vcpu, msr))
                        return kvm_pmu_set_msr(vcpu, msr_info);

                if (pr || data != 0)
                        vcpu_unimpl(vcpu, "disabled perfctr wrmsr: "
                                    "0x%x data 0x%llx\n", msr, data);
                break;
        case MSR_K7_CLK_CTL:
                /*
                 * Ignore all writes to this no longer documented MSR.
                 * Writes are only relevant for old K7 processors,
                 * all pre-dating SVM, but a recommended workaround from
                 * AMD for these chips. It is possible to specify the
                 * affected processor models on the command line, hence
                 * the need to ignore the workaround.
                 */
                break;
        case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
        case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
        case HV_X64_MSR_SYNDBG_OPTIONS:
        case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
        case HV_X64_MSR_CRASH_CTL:
        case HV_X64_MSR_STIMER0_CONFIG ... HV_X64_MSR_STIMER3_COUNT:
        case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
        case HV_X64_MSR_TSC_EMULATION_CONTROL:
        case HV_X64_MSR_TSC_EMULATION_STATUS:
        case HV_X64_MSR_TSC_INVARIANT_CONTROL:
                return kvm_hv_set_msr_common(vcpu, msr, data,
                                             msr_info->host_initiated);
        case MSR_IA32_BBL_CR_CTL3:
                /* Drop writes to this legacy MSR -- see rdmsr
                 * counterpart for further detail.
                 */
                if (report_ignored_msrs)
                        vcpu_unimpl(vcpu, "ignored wrmsr: 0x%x data 0x%llx\n",
                                msr, data);
                break;
        case MSR_AMD64_OSVW_ID_LENGTH:
                if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
                        return 1;
                vcpu->arch.osvw.length = data;
                break;
        case MSR_AMD64_OSVW_STATUS:
                if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
                        return 1;
                vcpu->arch.osvw.status = data;
                break;
        case MSR_PLATFORM_INFO:
                if (!msr_info->host_initiated ||
                    (!(data & MSR_PLATFORM_INFO_CPUID_FAULT) &&
                     cpuid_fault_enabled(vcpu)))
                        return 1;
                vcpu->arch.msr_platform_info = data;
                break;
        case MSR_MISC_FEATURES_ENABLES:
                if (data & ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT ||
                    (data & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT &&
                     !supports_cpuid_fault(vcpu)))
                        return 1;
                vcpu->arch.msr_misc_features_enables = data;
                break;
#ifdef CONFIG_X86_64
        case MSR_IA32_XFD:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_XFD))
                        return 1;

                if (data & ~kvm_guest_supported_xfd(vcpu))
                        return 1;

                fpu_update_guest_xfd(&vcpu->arch.guest_fpu, data);
                break;
        case MSR_IA32_XFD_ERR:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_XFD))
                        return 1;

                if (data & ~kvm_guest_supported_xfd(vcpu))
                        return 1;

                vcpu->arch.guest_fpu.xfd_err = data;
                break;
#endif
        case MSR_IA32_PEBS_ENABLE:
        case MSR_IA32_DS_AREA:
        case MSR_PEBS_DATA_CFG:
        case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:
                if (kvm_pmu_is_valid_msr(vcpu, msr))
                        return kvm_pmu_set_msr(vcpu, msr_info);
                /*
                 * Userspace is allowed to write '0' to MSRs that KVM reports
                 * as to-be-saved, even if an MSRs isn't fully supported.
                 */
                return !msr_info->host_initiated || data;
        default:
                if (kvm_pmu_is_valid_msr(vcpu, msr))
                        return kvm_pmu_set_msr(vcpu, msr_info);
                return KVM_MSR_RET_INVALID;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_set_msr_common);

static int get_msr_mce(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, bool host)
{
        u64 data;
        u64 mcg_cap = vcpu->arch.mcg_cap;
        unsigned bank_num = mcg_cap & 0xff;
        u32 offset, last_msr;

        switch (msr) {
        case MSR_IA32_P5_MC_ADDR:
        case MSR_IA32_P5_MC_TYPE:
                data = 0;
                break;
        case MSR_IA32_MCG_CAP:
                data = vcpu->arch.mcg_cap;
                break;
        case MSR_IA32_MCG_CTL:
                if (!(mcg_cap & MCG_CTL_P) && !host)
                        return 1;
                data = vcpu->arch.mcg_ctl;
                break;
        case MSR_IA32_MCG_STATUS:
                data = vcpu->arch.mcg_status;
                break;
        case MSR_IA32_MC0_CTL2 ... MSR_IA32_MCx_CTL2(KVM_MAX_MCE_BANKS) - 1:
                last_msr = MSR_IA32_MCx_CTL2(bank_num) - 1;
                if (msr > last_msr)
                        return 1;

                if (!(mcg_cap & MCG_CMCI_P) && !host)
                        return 1;
                offset = array_index_nospec(msr - MSR_IA32_MC0_CTL2,
                                            last_msr + 1 - MSR_IA32_MC0_CTL2);
                data = vcpu->arch.mci_ctl2_banks[offset];
                break;
        case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
                last_msr = MSR_IA32_MCx_CTL(bank_num) - 1;
                if (msr > last_msr)
                        return 1;

                offset = array_index_nospec(msr - MSR_IA32_MC0_CTL,
                                            last_msr + 1 - MSR_IA32_MC0_CTL);
                data = vcpu->arch.mce_banks[offset];
                break;
        default:
                return 1;
        }
        *pdata = data;
        return 0;
}

int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
        switch (msr_info->index) {
        case MSR_IA32_PLATFORM_ID:
        case MSR_IA32_EBL_CR_POWERON:
        case MSR_IA32_LASTBRANCHFROMIP:
        case MSR_IA32_LASTBRANCHTOIP:
        case MSR_IA32_LASTINTFROMIP:
        case MSR_IA32_LASTINTTOIP:
        case MSR_AMD64_SYSCFG:
        case MSR_K8_TSEG_ADDR:
        case MSR_K8_TSEG_MASK:
        case MSR_VM_HSAVE_PA:
        case MSR_K8_INT_PENDING_MSG:
        case MSR_AMD64_NB_CFG:
        case MSR_FAM10H_MMIO_CONF_BASE:
        case MSR_AMD64_BU_CFG2:
        case MSR_IA32_PERF_CTL:
        case MSR_AMD64_DC_CFG:
        case MSR_F15H_EX_CFG:
        /*
         * Intel Sandy Bridge CPUs must support the RAPL (running average power
         * limit) MSRs. Just return 0, as we do not want to expose the host
         * data here. Do not conditionalize this on CPUID, as KVM does not do
         * so for existing CPU-specific MSRs.
         */
        case MSR_RAPL_POWER_UNIT:
        case MSR_PP0_ENERGY_STATUS:     /* Power plane 0 (core) */
        case MSR_PP1_ENERGY_STATUS:     /* Power plane 1 (graphics uncore) */
        case MSR_PKG_ENERGY_STATUS:     /* Total package */
        case MSR_DRAM_ENERGY_STATUS:    /* DRAM controller */
                msr_info->data = 0;
                break;
        case MSR_IA32_PEBS_ENABLE:
        case MSR_IA32_DS_AREA:
        case MSR_PEBS_DATA_CFG:
        case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:
                if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
                        return kvm_pmu_get_msr(vcpu, msr_info);
                /*
                 * Userspace is allowed to read MSRs that KVM reports as
                 * to-be-saved, even if an MSR isn't fully supported.
                 */
                if (!msr_info->host_initiated)
                        return 1;
                msr_info->data = 0;
                break;
        case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
        case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
        case MSR_P6_PERFCTR0 ... MSR_P6_PERFCTR1:
        case MSR_P6_EVNTSEL0 ... MSR_P6_EVNTSEL1:
                if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
                        return kvm_pmu_get_msr(vcpu, msr_info);
                msr_info->data = 0;
                break;
        case MSR_IA32_UCODE_REV:
                msr_info->data = vcpu->arch.microcode_version;
                break;
        case MSR_IA32_ARCH_CAPABILITIES:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES))
                        return 1;
                msr_info->data = vcpu->arch.arch_capabilities;
                break;
        case MSR_IA32_PERF_CAPABILITIES:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_PDCM))
                        return 1;
                msr_info->data = vcpu->arch.perf_capabilities;
                break;
        case MSR_IA32_POWER_CTL:
                msr_info->data = vcpu->arch.msr_ia32_power_ctl;
                break;
        case MSR_IA32_TSC: {
                /*
                 * Intel SDM states that MSR_IA32_TSC read adds the TSC offset
                 * even when not intercepted. AMD manual doesn't explicitly
                 * state this but appears to behave the same.
                 *
                 * On userspace reads and writes, however, we unconditionally
                 * return L1's TSC value to ensure backwards-compatible
                 * behavior for migration.
                 */
                u64 offset, ratio;

                if (msr_info->host_initiated) {
                        offset = vcpu->arch.l1_tsc_offset;
                        ratio = vcpu->arch.l1_tsc_scaling_ratio;
                } else {
                        offset = vcpu->arch.tsc_offset;
                        ratio = vcpu->arch.tsc_scaling_ratio;
                }

                msr_info->data = kvm_scale_tsc(rdtsc(), ratio) + offset;
                break;
        }
        case MSR_MTRRcap:
        case 0x200 ... MSR_IA32_MC0_CTL2 - 1:
        case MSR_IA32_MCx_CTL2(KVM_MAX_MCE_BANKS) ... 0x2ff:
                return kvm_mtrr_get_msr(vcpu, msr_info->index, &msr_info->data);
        case 0xcd: /* fsb frequency */
                msr_info->data = 3;
                break;
                /*
                 * MSR_EBC_FREQUENCY_ID
                 * Conservative value valid for even the basic CPU models.
                 * Models 0,1: 000 in bits 23:21 indicating a bus speed of
                 * 100MHz, model 2 000 in bits 18:16 indicating 100MHz,
                 * and 266MHz for model 3, or 4. Set Core Clock
                 * Frequency to System Bus Frequency Ratio to 1 (bits
                 * 31:24) even though these are only valid for CPU
                 * models > 2, however guests may end up dividing or
                 * multiplying by zero otherwise.
                 */
        case MSR_EBC_FREQUENCY_ID:
                msr_info->data = 1 << 24;
                break;
        case MSR_IA32_APICBASE:
                msr_info->data = kvm_get_apic_base(vcpu);
                break;
        case APIC_BASE_MSR ... APIC_BASE_MSR + 0xff:
                return kvm_x2apic_msr_read(vcpu, msr_info->index, &msr_info->data);
        case MSR_IA32_TSC_DEADLINE:
                msr_info->data = kvm_get_lapic_tscdeadline_msr(vcpu);
                break;
        case MSR_IA32_TSC_ADJUST:
                msr_info->data = (u64)vcpu->arch.ia32_tsc_adjust_msr;
                break;
        case MSR_IA32_MISC_ENABLE:
                msr_info->data = vcpu->arch.ia32_misc_enable_msr;
                break;
        case MSR_IA32_SMBASE:
                if (!IS_ENABLED(CONFIG_KVM_SMM) || !msr_info->host_initiated)
                        return 1;
                msr_info->data = vcpu->arch.smbase;
                break;
        case MSR_SMI_COUNT:
                msr_info->data = vcpu->arch.smi_count;
                break;
        case MSR_IA32_PERF_STATUS:
                /* TSC increment by tick */
                msr_info->data = 1000ULL;
                /* CPU multiplier */
                msr_info->data |= (((uint64_t)4ULL) << 40);
                break;
        case MSR_EFER:
                msr_info->data = vcpu->arch.efer;
                break;
        case MSR_KVM_WALL_CLOCK:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE))
                        return 1;

                msr_info->data = vcpu->kvm->arch.wall_clock;
                break;
        case MSR_KVM_WALL_CLOCK_NEW:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))
                        return 1;

                msr_info->data = vcpu->kvm->arch.wall_clock;
                break;
        case MSR_KVM_SYSTEM_TIME:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE))
                        return 1;

                msr_info->data = vcpu->arch.time;
                break;
        case MSR_KVM_SYSTEM_TIME_NEW:
                if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2))
                        return 1;

                msr_info->data = vcpu->arch.time;
                break;
        case MSR_KVM_ASYNC_PF_EN:
                if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF))
                        return 1;

                msr_info->data = vcpu->arch.apf.msr_en_val;
                break;
        case MSR_KVM_ASYNC_PF_INT:
                if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT))
                        return 1;

                msr_info->data = vcpu->arch.apf.msr_int_val;
                break;
        case MSR_KVM_ASYNC_PF_ACK:
                if (!guest_pv_has(vcpu, KVM_FEATURE_ASYNC_PF_INT))
                        return 1;

                msr_info->data = 0;
                break;
        case MSR_KVM_STEAL_TIME:
                if (!guest_pv_has(vcpu, KVM_FEATURE_STEAL_TIME))
                        return 1;

                msr_info->data = vcpu->arch.st.msr_val;
                break;
        case MSR_KVM_PV_EOI_EN:
                if (!guest_pv_has(vcpu, KVM_FEATURE_PV_EOI))
                        return 1;

                msr_info->data = vcpu->arch.pv_eoi.msr_val;
                break;
        case MSR_KVM_POLL_CONTROL:
                if (!guest_pv_has(vcpu, KVM_FEATURE_POLL_CONTROL))
                        return 1;

                msr_info->data = vcpu->arch.msr_kvm_poll_control;
                break;
        case MSR_IA32_P5_MC_ADDR:
        case MSR_IA32_P5_MC_TYPE:
        case MSR_IA32_MCG_CAP:
        case MSR_IA32_MCG_CTL:
        case MSR_IA32_MCG_STATUS:
        case MSR_IA32_MC0_CTL ... MSR_IA32_MCx_CTL(KVM_MAX_MCE_BANKS) - 1:
        case MSR_IA32_MC0_CTL2 ... MSR_IA32_MCx_CTL2(KVM_MAX_MCE_BANKS) - 1:
                return get_msr_mce(vcpu, msr_info->index, &msr_info->data,
                                   msr_info->host_initiated);
        case MSR_IA32_XSS:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_XSAVES))
                        return 1;
                msr_info->data = vcpu->arch.ia32_xss;
                break;
        case MSR_K7_CLK_CTL:
                /*
                 * Provide expected ramp-up count for K7. All other
                 * are set to zero, indicating minimum divisors for
                 * every field.
                 *
                 * This prevents guest kernels on AMD host with CPU
                 * type 6, model 8 and higher from exploding due to
                 * the rdmsr failing.
                 */
                msr_info->data = 0x20000000;
                break;
        case HV_X64_MSR_GUEST_OS_ID ... HV_X64_MSR_SINT15:
        case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER:
        case HV_X64_MSR_SYNDBG_OPTIONS:
        case HV_X64_MSR_CRASH_P0 ... HV_X64_MSR_CRASH_P4:
        case HV_X64_MSR_CRASH_CTL:
        case HV_X64_MSR_STIMER0_CONFIG ... HV_X64_MSR_STIMER3_COUNT:
        case HV_X64_MSR_REENLIGHTENMENT_CONTROL:
        case HV_X64_MSR_TSC_EMULATION_CONTROL:
        case HV_X64_MSR_TSC_EMULATION_STATUS:
        case HV_X64_MSR_TSC_INVARIANT_CONTROL:
                return kvm_hv_get_msr_common(vcpu,
                                             msr_info->index, &msr_info->data,
                                             msr_info->host_initiated);
        case MSR_IA32_BBL_CR_CTL3:
                /* This legacy MSR exists but isn't fully documented in current
                 * silicon.  It is however accessed by winxp in very narrow
                 * scenarios where it sets bit #19, itself documented as
                 * a "reserved" bit.  Best effort attempt to source coherent
                 * read data here should the balance of the register be
                 * interpreted by the guest:
                 *
                 * L2 cache control register 3: 64GB range, 256KB size,
                 * enabled, latency 0x1, configured
                 */
                msr_info->data = 0xbe702111;
                break;
        case MSR_AMD64_OSVW_ID_LENGTH:
                if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
                        return 1;
                msr_info->data = vcpu->arch.osvw.length;
                break;
        case MSR_AMD64_OSVW_STATUS:
                if (!guest_cpuid_has(vcpu, X86_FEATURE_OSVW))
                        return 1;
                msr_info->data = vcpu->arch.osvw.status;
                break;
        case MSR_PLATFORM_INFO:
                if (!msr_info->host_initiated &&
                    !vcpu->kvm->arch.guest_can_read_msr_platform_info)
                        return 1;
                msr_info->data = vcpu->arch.msr_platform_info;
                break;
        case MSR_MISC_FEATURES_ENABLES:
                msr_info->data = vcpu->arch.msr_misc_features_enables;
                break;
        case MSR_K7_HWCR:
                msr_info->data = vcpu->arch.msr_hwcr;
                break;
#ifdef CONFIG_X86_64
        case MSR_IA32_XFD:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_XFD))
                        return 1;

                msr_info->data = vcpu->arch.guest_fpu.fpstate->xfd;
                break;
        case MSR_IA32_XFD_ERR:
                if (!msr_info->host_initiated &&
                    !guest_cpuid_has(vcpu, X86_FEATURE_XFD))
                        return 1;

                msr_info->data = vcpu->arch.guest_fpu.xfd_err;
                break;
#endif
        default:
                if (kvm_pmu_is_valid_msr(vcpu, msr_info->index))
                        return kvm_pmu_get_msr(vcpu, msr_info);
                return KVM_MSR_RET_INVALID;
        }
        return 0;
}
EXPORT_SYMBOL_GPL(kvm_get_msr_common);

/*
 * Read or write a bunch of msrs. All parameters are kernel addresses.
 *
 * @return number of msrs set successfully.
 */
static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
                    struct kvm_msr_entry *entries,
                    int (*do_msr)(struct kvm_vcpu *vcpu,
                                  unsigned index, u64 *data))
{
        int i;

        for (i = 0; i < msrs->nmsrs; ++i)
                if (do_msr(vcpu, entries[i].index, &entries[i].data))
                        break;

        return i;
}

/*
 * Read or write a bunch of msrs. Parameters are user addresses.
 *
 * @return number of msrs set successfully.
 */
static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
                  int (*do_msr)(struct kvm_vcpu *vcpu,
                                unsigned index, u64 *data),
                  int writeback)
{
        struct kvm_msrs msrs;
        struct kvm_msr_entry *entries;
        int r, n;
        unsigned size;

        r = -EFAULT;
        if (copy_from_user(&msrs, user_msrs, sizeof(msrs)))
                goto out;

        r = -E2BIG;
        if (msrs.nmsrs >= MAX_IO_MSRS)
                goto out;

        size = sizeof(struct kvm_msr_entry) * msrs.nmsrs;
        entries = memdup_user(user_msrs->entries, size);
        if (IS_ERR(entries)) {
                r = PTR_ERR(entries);
                goto out;
        }

        r = n = __msr_io(vcpu, &msrs, entries, do_msr);
        if (r < 0)
                goto out_free;

        r = -EFAULT;
        if (writeback && copy_to_user(user_msrs->entries, entries, size))
                goto out_free;

        r = n;

out_free:
        kfree(entries);
out:
        return r;
}

static inline bool kvm_can_mwait_in_guest(void)
{
        return boot_cpu_has(X86_FEATURE_MWAIT) &&
                !boot_cpu_has_bug(X86_BUG_MONITOR) &&
                boot_cpu_has(X86_FEATURE_ARAT);
}

static int kvm_ioctl_get_supported_hv_cpuid(struct kvm_vcpu *vcpu,
                                            struct kvm_cpuid2 __user *cpuid_arg)
{
        struct kvm_cpuid2 cpuid;
        int r;

        r = -EFAULT;
        if (copy_from_user(&cpuid, cpuid_arg, sizeof(cpuid)))
                return r;

        r = kvm_get_hv_cpuid(vcpu, &cpuid, cpuid_arg->entries);
        if (r)
                return r;

        r = -EFAULT;
        if (copy_to_user(cpuid_arg, &cpuid, sizeof(cpuid)))
                return r;

        return 0;
}

int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
        int r = 0;

        switch (ext) {
        case KVM_CAP_IRQCHIP:
        case KVM_CAP_HLT:
        case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
        case KVM_CAP_SET_TSS_ADDR:
        case KVM_CAP_EXT_CPUID:
        case KVM_CAP_EXT_EMUL_CPUID:
        case KVM_CAP_CLOCKSOURCE:
        case KVM_CAP_PIT:
        case KVM_CAP_NOP_IO_DELAY:
        case KVM_CAP_MP_STATE:
        case KVM_CAP_SYNC_MMU:
        case KVM_CAP_USER_NMI:
        case KVM_CAP_REINJECT_CONTROL:
        case KVM_CAP_IRQ_INJECT_STATUS:
        case KVM_CAP_IOEVENTFD:
        case KVM_CAP_IOEVENTFD_NO_LENGTH:
        case KVM_CAP_PIT2:
        case KVM_CAP_PIT_STATE2:
        case KVM_CAP_SET_IDENTITY_MAP_ADDR:
        case KVM_CAP_VCPU_EVENTS:
        case KVM_CAP_HYPERV:
        case KVM_CAP_HYPERV_VAPIC:
        case KVM_CAP_HYPERV_SPIN:
        case KVM_CAP_HYPERV_SYNIC:
        case KVM_CAP_HYPERV_SYNIC2:
        case KVM_CAP_HYPERV_VP_INDEX:
        case KVM_CAP_HYPERV_EVENTFD:
        case KVM_CAP_HYPERV_TLBFLUSH:
        case KVM_CAP_HYPERV_SEND_IPI:
        case KVM_CAP_HYPERV_CPUID:
        case KVM_CAP_HYPERV_ENFORCE_CPUID:
        case KVM_CAP_SYS_HYPERV_CPUID:
        case KVM_CAP_PCI_SEGMENT:
        case KVM_CAP_DEBUGREGS:
        case KVM_CAP_X86_ROBUST_SINGLESTEP:
        case KVM_CAP_XSAVE:
        case KVM_CAP_ASYNC_PF:
        case KVM_CAP_ASYNC_PF_INT:
        case KVM_CAP_GET_TSC_KHZ:
        case KVM_CAP_KVMCLOCK_CTRL:
        case KVM_CAP_READONLY_MEM:
        case KVM_CAP_HYPERV_TIME:
        case KVM_CAP_IOAPIC_POLARITY_IGNORED:
        case KVM_CAP_TSC_DEADLINE_TIMER:
        case KVM_CAP_DISABLE_QUIRKS:
        case KVM_CAP_SET_BOOT_CPU_ID:
        case KVM_CAP_SPLIT_IRQCHIP:
        case KVM_CAP_IMMEDIATE_EXIT:
        case KVM_CAP_PMU_EVENT_FILTER:
        case KVM_CAP_GET_MSR_FEATURES:
        case KVM_CAP_MSR_PLATFORM_INFO:
        case KVM_CAP_EXCEPTION_PAYLOAD:
        case KVM_CAP_X86_TRIPLE_FAULT_EVENT:
        case KVM_CAP_SET_GUEST_DEBUG:
        case KVM_CAP_LAST_CPU:
        case KVM_CAP_X86_USER_SPACE_MSR:
        case KVM_CAP_X86_MSR_FILTER:
        case KVM_CAP_ENFORCE_PV_FEATURE_CPUID:
#ifdef CONFIG_X86_SGX_KVM
        case KVM_CAP_SGX_ATTRIBUTE:
#endif
        case KVM_CAP_VM_COPY_ENC_CONTEXT_FROM:
        case KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM:
        case KVM_CAP_SREGS2:
        case KVM_CAP_EXIT_ON_EMULATION_FAILURE:
        case KVM_CAP_VCPU_ATTRIBUTES:
        case KVM_CAP_SYS_ATTRIBUTES:
        case KVM_CAP_VAPIC:
        case KVM_CAP_ENABLE_CAP:
        case KVM_CAP_VM_DISABLE_NX_HUGE_PAGES:
                r = 1;
                break;
        case KVM_CAP_EXIT_HYPERCALL:
                r = KVM_EXIT_HYPERCALL_VALID_MASK;
                break;
        case KVM_CAP_SET_GUEST_DEBUG2:
                return KVM_GUESTDBG_VALID_MASK;
#ifdef CONFIG_KVM_XEN
        case KVM_CAP_XEN_HVM:
                r = KVM_XEN_HVM_CONFIG_HYPERCALL_MSR |
                    KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL |
                    KVM_XEN_HVM_CONFIG_SHARED_INFO |
                    KVM_XEN_HVM_CONFIG_EVTCHN_2LEVEL |
                    KVM_XEN_HVM_CONFIG_EVTCHN_SEND;
                if (sched_info_on())
                        r |= KVM_XEN_HVM_CONFIG_RUNSTATE |
                             KVM_XEN_HVM_CONFIG_RUNSTATE_UPDATE_FLAG;
                break;
#endif
        case KVM_CAP_SYNC_REGS:
                r = KVM_SYNC_X86_VALID_FIELDS;
                break;
        case KVM_CAP_ADJUST_CLOCK:
                r = KVM_CLOCK_VALID_FLAGS;
                break;
        case KVM_CAP_X86_DISABLE_EXITS:
                r |=  KVM_X86_DISABLE_EXITS_HLT | KVM_X86_DISABLE_EXITS_PAUSE |
                      KVM_X86_DISABLE_EXITS_CSTATE;
                if(kvm_can_mwait_in_guest())
                        r |= KVM_X86_DISABLE_EXITS_MWAIT;
                break;
        case KVM_CAP_X86_SMM:
                if (!IS_ENABLED(CONFIG_KVM_SMM))
                        break;

                /* SMBASE is usually relocated above 1M on modern chipsets,
                 * and SMM handlers might indeed rely on 4G segment limits,
                 * so do not report SMM to be available if real mode is
                 * emulated via vm86 mode.  Still, do not go to great lengths
                 * to avoid userspace's usage of the feature, because it is a
                 * fringe case that is not enabled except via specific settings
                 * of the module parameters.
                 */
                r = static_call(kvm_x86_has_emulated_msr)(kvm, MSR_IA32_SMBASE);
                break;
        case KVM_CAP_NR_VCPUS:
                r = min_t(unsigned int, num_online_cpus(), KVM_MAX_VCPUS);
                break;
        case KVM_CAP_MAX_VCPUS:
                r = KVM_MAX_VCPUS;
                break;
        case KVM_CAP_MAX_VCPU_ID:
                r = KVM_MAX_VCPU_IDS;
                break;
        case KVM_CAP_PV_MMU:    /* obsolete */
                r = 0;
                break;
        case KVM_CAP_MCE:
                r = KVM_MAX_MCE_BANKS;
                break;
        case KVM_CAP_XCRS:
                r = boot_cpu_has(X86_FEATURE_XSAVE);
                break;
        case KVM_CAP_TSC_CONTROL:
        case KVM_CAP_VM_TSC_CONTROL:
                r = kvm_caps.has_tsc_control;
                break;
        case KVM_CAP_X2APIC_API:
                r = KVM_X2APIC_API_VALID_FLAGS;
                break;
        case KVM_CAP_NESTED_STATE:
                r = kvm_x86_ops.nested_ops->get_state ?
                        kvm_x86_ops.nested_ops->get_state(NULL, NULL, 0) : 0;
                break;
        case KVM_CAP_HYPERV_DIRECT_TLBFLUSH:
                r = kvm_x86_ops.enable_l2_tlb_flush != NULL;
                break;
        case KVM_CAP_HYPERV_ENLIGHTENED_VMCS:
                r = kvm_x86_ops.nested_ops->enable_evmcs != NULL;
                break;
        case KVM_CAP_SMALLER_MAXPHYADDR:
                r = (int) allow_smaller_maxphyaddr;
                break;
        case KVM_CAP_STEAL_TIME:
                r = sched_info_on();
                break;
        case KVM_CAP_X86_BUS_LOCK_EXIT:
                if (kvm_caps.has_bus_lock_exit)
                        r = KVM_BUS_LOCK_DETECTION_OFF |
                            KVM_BUS_LOCK_DETECTION_EXIT;
                else
                        r = 0;
                break;
        case KVM_CAP_XSAVE2: {
                u64 guest_perm = xstate_get_guest_group_perm();

                r = xstate_required_size(kvm_caps.supported_xcr0 & guest_perm, false);
                if (r < sizeof(struct kvm_xsave))
                        r = sizeof(struct kvm_xsave);
                break;
        }
        case KVM_CAP_PMU_CAPABILITY:
                r = enable_pmu ? KVM_CAP_PMU_VALID_MASK : 0;
                break;
        case KVM_CAP_DISABLE_QUIRKS2:
                r = KVM_X86_VALID_QUIRKS;
                break;
        case KVM_CAP_X86_NOTIFY_VMEXIT:
                r = kvm_caps.has_notify_vmexit;
                break;
        default:
                break;
        }
        return r;
}

static inline void __user *kvm_get_attr_addr(struct kvm_device_attr *attr)
{
        void __user *uaddr = (void __user*)(unsigned long)attr->addr;

        if ((u64)(unsigned long)uaddr != attr->addr)
                return ERR_PTR_USR(-EFAULT);
        return uaddr;
}

static int kvm_x86_dev_get_attr(struct kvm_device_attr *attr)
{
        u64 __user *uaddr = kvm_get_attr_addr(attr);

        if (attr->group)
                return -ENXIO;

        if (IS_ERR(uaddr))
                return PTR_ERR(uaddr);

        switch (attr->attr) {
        case KVM_X86_XCOMP_GUEST_SUPP:
                if (put_user(kvm_caps.supported_xcr0, uaddr))
                        return -EFAULT;
                return 0;
        default:
                return -ENXIO;
                break;
        }
}

static int kvm_x86_dev_has_attr(struct kvm_device_attr *attr)
{
        if (attr->group)
                return -ENXIO;

        switch (attr->attr) {
        case KVM_X86_XCOMP_GUEST_SUPP:
                return 0;
        default:
                return -ENXIO;
        }
}

long kvm_arch_dev_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        long r;

        switch (ioctl) {
        case KVM_GET_MSR_INDEX_LIST: {
                struct kvm_msr_list __user *user_msr_list = argp;
                struct kvm_msr_list msr_list;
                unsigned n;

                r = -EFAULT;
                if (copy_from_user(&msr_list, user_msr_list, sizeof(msr_list)))
                        goto out;
                n = msr_list.nmsrs;
                msr_list.nmsrs = num_msrs_to_save + num_emulated_msrs;
                if (copy_to_user(user_msr_list, &msr_list, sizeof(msr_list)))
                        goto out;
                r = -E2BIG;
                if (n < msr_list.nmsrs)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(user_msr_list->indices, &msrs_to_save,
                                 num_msrs_to_save * sizeof(u32)))
                        goto out;
                if (copy_to_user(user_msr_list->indices + num_msrs_to_save,
                                 &emulated_msrs,
                                 num_emulated_msrs * sizeof(u32)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_GET_SUPPORTED_CPUID:
        case KVM_GET_EMULATED_CPUID: {
                struct kvm_cpuid2 __user *cpuid_arg = argp;
                struct kvm_cpuid2 cpuid;

                r = -EFAULT;
                if (copy_from_user(&cpuid, cpuid_arg, sizeof(cpuid)))
                        goto out;

                r = kvm_dev_ioctl_get_cpuid(&cpuid, cpuid_arg->entries,
                                            ioctl);
                if (r)
                        goto out;

                r = -EFAULT;
                if (copy_to_user(cpuid_arg, &cpuid, sizeof(cpuid)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_X86_GET_MCE_CAP_SUPPORTED:
                r = -EFAULT;
                if (copy_to_user(argp, &kvm_caps.supported_mce_cap,
                                 sizeof(kvm_caps.supported_mce_cap)))
                        goto out;
                r = 0;
                break;
        case KVM_GET_MSR_FEATURE_INDEX_LIST: {
                struct kvm_msr_list __user *user_msr_list = argp;
                struct kvm_msr_list msr_list;
                unsigned int n;

                r = -EFAULT;
                if (copy_from_user(&msr_list, user_msr_list, sizeof(msr_list)))
                        goto out;
                n = msr_list.nmsrs;
                msr_list.nmsrs = num_msr_based_features;
                if (copy_to_user(user_msr_list, &msr_list, sizeof(msr_list)))
                        goto out;
                r = -E2BIG;
                if (n < msr_list.nmsrs)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(user_msr_list->indices, &msr_based_features,
                                 num_msr_based_features * sizeof(u32)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_GET_MSRS:
                r = msr_io(NULL, argp, do_get_msr_feature, 1);
                break;
        case KVM_GET_SUPPORTED_HV_CPUID:
                r = kvm_ioctl_get_supported_hv_cpuid(NULL, argp);
                break;
        case KVM_GET_DEVICE_ATTR: {
                struct kvm_device_attr attr;
                r = -EFAULT;
                if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
                        break;
                r = kvm_x86_dev_get_attr(&attr);
                break;
        }
        case KVM_HAS_DEVICE_ATTR: {
                struct kvm_device_attr attr;
                r = -EFAULT;
                if (copy_from_user(&attr, (void __user *)arg, sizeof(attr)))
                        break;
                r = kvm_x86_dev_has_attr(&attr);
                break;
        }
        default:
                r = -EINVAL;
                break;
        }
out:
        return r;
}

static void wbinvd_ipi(void *garbage)
{
        wbinvd();
}

static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu)
{
        return kvm_arch_has_noncoherent_dma(vcpu->kvm);
}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
        /* Address WBINVD may be executed by guest */
        if (need_emulate_wbinvd(vcpu)) {
                if (static_call(kvm_x86_has_wbinvd_exit)())
                        cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
                else if (vcpu->cpu != -1 && vcpu->cpu != cpu)
                        smp_call_function_single(vcpu->cpu,
                                        wbinvd_ipi, NULL, 1);
        }

        static_call(kvm_x86_vcpu_load)(vcpu, cpu);

        /* Save host pkru register if supported */
        vcpu->arch.host_pkru = read_pkru();

        /* Apply any externally detected TSC adjustments (due to suspend) */
        if (unlikely(vcpu->arch.tsc_offset_adjustment)) {
                adjust_tsc_offset_host(vcpu, vcpu->arch.tsc_offset_adjustment);
                vcpu->arch.tsc_offset_adjustment = 0;
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
        }

        if (unlikely(vcpu->cpu != cpu) || kvm_check_tsc_unstable()) {
                s64 tsc_delta = !vcpu->arch.last_host_tsc ? 0 :
                                rdtsc() - vcpu->arch.last_host_tsc;
                if (tsc_delta < 0)
                        mark_tsc_unstable("KVM discovered backwards TSC");

                if (kvm_check_tsc_unstable()) {
                        u64 offset = kvm_compute_l1_tsc_offset(vcpu,
                                                vcpu->arch.last_guest_tsc);
                        kvm_vcpu_write_tsc_offset(vcpu, offset);
                        vcpu->arch.tsc_catchup = 1;
                }

                if (kvm_lapic_hv_timer_in_use(vcpu))
                        kvm_lapic_restart_hv_timer(vcpu);

                /*
                 * On a host with synchronized TSC, there is no need to update
                 * kvmclock on vcpu->cpu migration
                 */
                if (!vcpu->kvm->arch.use_master_clock || vcpu->cpu == -1)
                        kvm_make_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu);
                if (vcpu->cpu != cpu)
                        kvm_make_request(KVM_REQ_MIGRATE_TIMER, vcpu);
                vcpu->cpu = cpu;
        }

        kvm_make_request(KVM_REQ_STEAL_UPDATE, vcpu);
}

static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
{
        struct gfn_to_hva_cache *ghc = &vcpu->arch.st.cache;
        struct kvm_steal_time __user *st;
        struct kvm_memslots *slots;
        static const u8 preempted = KVM_VCPU_PREEMPTED;
        gpa_t gpa = vcpu->arch.st.msr_val & KVM_STEAL_VALID_BITS;

        /*
         * The vCPU can be marked preempted if and only if the VM-Exit was on
         * an instruction boundary and will not trigger guest emulation of any
         * kind (see vcpu_run).  Vendor specific code controls (conservatively)
         * when this is true, for example allowing the vCPU to be marked
         * preempted if and only if the VM-Exit was due to a host interrupt.
         */
        if (!vcpu->arch.at_instruction_boundary) {
                vcpu->stat.preemption_other++;
                return;
        }

        vcpu->stat.preemption_reported++;
        if (!(vcpu->arch.st.msr_val & KVM_MSR_ENABLED))
                return;

        if (vcpu->arch.st.preempted)
                return;

        /* This happens on process exit */
        if (unlikely(current->mm != vcpu->kvm->mm))
                return;

        slots = kvm_memslots(vcpu->kvm);

        if (unlikely(slots->generation != ghc->generation ||
                     gpa != ghc->gpa ||
                     kvm_is_error_hva(ghc->hva) || !ghc->memslot))
                return;

        st = (struct kvm_steal_time __user *)ghc->hva;
        BUILD_BUG_ON(sizeof(st->preempted) != sizeof(preempted));

        if (!copy_to_user_nofault(&st->preempted, &preempted, sizeof(preempted)))
                vcpu->arch.st.preempted = KVM_VCPU_PREEMPTED;

        mark_page_dirty_in_slot(vcpu->kvm, ghc->memslot, gpa_to_gfn(ghc->gpa));
}

void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
        int idx;

        if (vcpu->preempted) {
                if (!vcpu->arch.guest_state_protected)
                        vcpu->arch.preempted_in_kernel = !static_call(kvm_x86_get_cpl)(vcpu);

                /*
                 * Take the srcu lock as memslots will be accessed to check the gfn
                 * cache generation against the memslots generation.
                 */
                idx = srcu_read_lock(&vcpu->kvm->srcu);
                if (kvm_xen_msr_enabled(vcpu->kvm))
                        kvm_xen_runstate_set_preempted(vcpu);
                else
                        kvm_steal_time_set_preempted(vcpu);
                srcu_read_unlock(&vcpu->kvm->srcu, idx);
        }

        static_call(kvm_x86_vcpu_put)(vcpu);
        vcpu->arch.last_host_tsc = rdtsc();
}

static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
                                    struct kvm_lapic_state *s)
{
        static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu);

        return kvm_apic_get_state(vcpu, s);
}

static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
                                    struct kvm_lapic_state *s)
{
        int r;

        r = kvm_apic_set_state(vcpu, s);
        if (r)
                return r;
        update_cr8_intercept(vcpu);

        return 0;
}

static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu)
{
        /*
         * We can accept userspace's request for interrupt injection
         * as long as we have a place to store the interrupt number.
         * The actual injection will happen when the CPU is able to
         * deliver the interrupt.
         */
        if (kvm_cpu_has_extint(vcpu))
                return false;

        /* Acknowledging ExtINT does not happen if LINT0 is masked.  */
        return (!lapic_in_kernel(vcpu) ||
                kvm_apic_accept_pic_intr(vcpu));
}

static int kvm_vcpu_ready_for_interrupt_injection(struct kvm_vcpu *vcpu)
{
        /*
         * Do not cause an interrupt window exit if an exception
         * is pending or an event needs reinjection; userspace
         * might want to inject the interrupt manually using KVM_SET_REGS
         * or KVM_SET_SREGS.  For that to work, we must be at an
         * instruction boundary and with no events half-injected.
         */
        return (kvm_arch_interrupt_allowed(vcpu) &&
                kvm_cpu_accept_dm_intr(vcpu) &&
                !kvm_event_needs_reinjection(vcpu) &&
                !kvm_is_exception_pending(vcpu));
}

static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
                                    struct kvm_interrupt *irq)
{
        if (irq->irq >= KVM_NR_INTERRUPTS)
                return -EINVAL;

        if (!irqchip_in_kernel(vcpu->kvm)) {
                kvm_queue_interrupt(vcpu, irq->irq, false);
                kvm_make_request(KVM_REQ_EVENT, vcpu);
                return 0;
        }

        /*
         * With in-kernel LAPIC, we only use this to inject EXTINT, so
         * fail for in-kernel 8259.
         */
        if (pic_in_kernel(vcpu->kvm))
                return -ENXIO;

        if (vcpu->arch.pending_external_vector != -1)
                return -EEXIST;

        vcpu->arch.pending_external_vector = irq->irq;
        kvm_make_request(KVM_REQ_EVENT, vcpu);
        return 0;
}

static int kvm_vcpu_ioctl_nmi(struct kvm_vcpu *vcpu)
{
        kvm_inject_nmi(vcpu);

        return 0;
}

static int vcpu_ioctl_tpr_access_reporting(struct kvm_vcpu *vcpu,
                                           struct kvm_tpr_access_ctl *tac)
{
        if (tac->flags)
                return -EINVAL;
        vcpu->arch.tpr_access_reporting = !!tac->enabled;
        return 0;
}

static int kvm_vcpu_ioctl_x86_setup_mce(struct kvm_vcpu *vcpu,
                                        u64 mcg_cap)
{
        int r;
        unsigned bank_num = mcg_cap & 0xff, bank;

        r = -EINVAL;
        if (!bank_num || bank_num > KVM_MAX_MCE_BANKS)
                goto out;
        if (mcg_cap & ~(kvm_caps.supported_mce_cap | 0xff | 0xff0000))
                goto out;
        r = 0;
        vcpu->arch.mcg_cap = mcg_cap;
        /* Init IA32_MCG_CTL to all 1s */
        if (mcg_cap & MCG_CTL_P)
                vcpu->arch.mcg_ctl = ~(u64)0;
        /* Init IA32_MCi_CTL to all 1s, IA32_MCi_CTL2 to all 0s */
        for (bank = 0; bank < bank_num; bank++) {
                vcpu->arch.mce_banks[bank*4] = ~(u64)0;
                if (mcg_cap & MCG_CMCI_P)
                        vcpu->arch.mci_ctl2_banks[bank] = 0;
        }

        kvm_apic_after_set_mcg_cap(vcpu);

        static_call(kvm_x86_setup_mce)(vcpu);
out:
        return r;
}

/*
 * Validate this is an UCNA (uncorrectable no action) error by checking the
 * MCG_STATUS and MCi_STATUS registers:
 * - none of the bits for Machine Check Exceptions are set
 * - both the VAL (valid) and UC (uncorrectable) bits are set
 * MCI_STATUS_PCC - Processor Context Corrupted
 * MCI_STATUS_S - Signaled as a Machine Check Exception
 * MCI_STATUS_AR - Software recoverable Action Required
 */
static bool is_ucna(struct kvm_x86_mce *mce)
{
        return  !mce->mcg_status &&
                !(mce->status & (MCI_STATUS_PCC | MCI_STATUS_S | MCI_STATUS_AR)) &&
                (mce->status & MCI_STATUS_VAL) &&
                (mce->status & MCI_STATUS_UC);
}

static int kvm_vcpu_x86_set_ucna(struct kvm_vcpu *vcpu, struct kvm_x86_mce *mce, u64* banks)
{
        u64 mcg_cap = vcpu->arch.mcg_cap;

        banks[1] = mce->status;
        banks[2] = mce->addr;
        banks[3] = mce->misc;
        vcpu->arch.mcg_status = mce->mcg_status;

        if (!(mcg_cap & MCG_CMCI_P) ||
            !(vcpu->arch.mci_ctl2_banks[mce->bank] & MCI_CTL2_CMCI_EN))
                return 0;

        if (lapic_in_kernel(vcpu))
                kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTCMCI);

        return 0;
}

static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
                                      struct kvm_x86_mce *mce)
{
        u64 mcg_cap = vcpu->arch.mcg_cap;
        unsigned bank_num = mcg_cap & 0xff;
        u64 *banks = vcpu->arch.mce_banks;

        if (mce->bank >= bank_num || !(mce->status & MCI_STATUS_VAL))
                return -EINVAL;

        banks += array_index_nospec(4 * mce->bank, 4 * bank_num);

        if (is_ucna(mce))
                return kvm_vcpu_x86_set_ucna(vcpu, mce, banks);

        /*
         * if IA32_MCG_CTL is not all 1s, the uncorrected error
         * reporting is disabled
         */
        if ((mce->status & MCI_STATUS_UC) && (mcg_cap & MCG_CTL_P) &&
            vcpu->arch.mcg_ctl != ~(u64)0)
                return 0;
        /*
         * if IA32_MCi_CTL is not all 1s, the uncorrected error
         * reporting is disabled for the bank
         */
        if ((mce->status & MCI_STATUS_UC) && banks[0] != ~(u64)0)
                return 0;
        if (mce->status & MCI_STATUS_UC) {
                if ((vcpu->arch.mcg_status & MCG_STATUS_MCIP) ||
                    !kvm_read_cr4_bits(vcpu, X86_CR4_MCE)) {
                        kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                        return 0;
                }
                if (banks[1] & MCI_STATUS_VAL)
                        mce->status |= MCI_STATUS_OVER;
                banks[2] = mce->addr;
                banks[3] = mce->misc;
                vcpu->arch.mcg_status = mce->mcg_status;
                banks[1] = mce->status;
                kvm_queue_exception(vcpu, MC_VECTOR);
        } else if (!(banks[1] & MCI_STATUS_VAL)
                   || !(banks[1] & MCI_STATUS_UC)) {
                if (banks[1] & MCI_STATUS_VAL)
                        mce->status |= MCI_STATUS_OVER;
                banks[2] = mce->addr;
                banks[3] = mce->misc;
                banks[1] = mce->status;
        } else
                banks[1] |= MCI_STATUS_OVER;
        return 0;
}

static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
                                               struct kvm_vcpu_events *events)
{
        struct kvm_queued_exception *ex;

        process_nmi(vcpu);

#ifdef CONFIG_KVM_SMM
        if (kvm_check_request(KVM_REQ_SMI, vcpu))
                process_smi(vcpu);
#endif

        /*
         * KVM's ABI only allows for one exception to be migrated.  Luckily,
         * the only time there can be two queued exceptions is if there's a
         * non-exiting _injected_ exception, and a pending exiting exception.
         * In that case, ignore the VM-Exiting exception as it's an extension
         * of the injected exception.
         */
        if (vcpu->arch.exception_vmexit.pending &&
            !vcpu->arch.exception.pending &&
            !vcpu->arch.exception.injected)
                ex = &vcpu->arch.exception_vmexit;
        else
                ex = &vcpu->arch.exception;

        /*
         * In guest mode, payload delivery should be deferred if the exception
         * will be intercepted by L1, e.g. KVM should not modifying CR2 if L1
         * intercepts #PF, ditto for DR6 and #DBs.  If the per-VM capability,
         * KVM_CAP_EXCEPTION_PAYLOAD, is not set, userspace may or may not
         * propagate the payload and so it cannot be safely deferred.  Deliver
         * the payload if the capability hasn't been requested.
         */
        if (!vcpu->kvm->arch.exception_payload_enabled &&
            ex->pending && ex->has_payload)
                kvm_deliver_exception_payload(vcpu, ex);

        memset(events, 0, sizeof(*events));

        /*
         * The API doesn't provide the instruction length for software
         * exceptions, so don't report them. As long as the guest RIP
         * isn't advanced, we should expect to encounter the exception
         * again.
         */
        if (!kvm_exception_is_soft(ex->vector)) {
                events->exception.injected = ex->injected;
                events->exception.pending = ex->pending;
                /*
                 * For ABI compatibility, deliberately conflate
                 * pending and injected exceptions when
                 * KVM_CAP_EXCEPTION_PAYLOAD isn't enabled.
                 */
                if (!vcpu->kvm->arch.exception_payload_enabled)
                        events->exception.injected |= ex->pending;
        }
        events->exception.nr = ex->vector;
        events->exception.has_error_code = ex->has_error_code;
        events->exception.error_code = ex->error_code;
        events->exception_has_payload = ex->has_payload;
        events->exception_payload = ex->payload;

        events->interrupt.injected =
                vcpu->arch.interrupt.injected && !vcpu->arch.interrupt.soft;
        events->interrupt.nr = vcpu->arch.interrupt.nr;
        events->interrupt.shadow = static_call(kvm_x86_get_interrupt_shadow)(vcpu);

        events->nmi.injected = vcpu->arch.nmi_injected;
        events->nmi.pending = vcpu->arch.nmi_pending != 0;
        events->nmi.masked = static_call(kvm_x86_get_nmi_mask)(vcpu);

        /* events->sipi_vector is never valid when reporting to user space */

#ifdef CONFIG_KVM_SMM
        events->smi.smm = is_smm(vcpu);
        events->smi.pending = vcpu->arch.smi_pending;
        events->smi.smm_inside_nmi =
                !!(vcpu->arch.hflags & HF_SMM_INSIDE_NMI_MASK);
#endif
        events->smi.latched_init = kvm_lapic_latched_init(vcpu);

        events->flags = (KVM_VCPUEVENT_VALID_NMI_PENDING
                         | KVM_VCPUEVENT_VALID_SHADOW
                         | KVM_VCPUEVENT_VALID_SMM);
        if (vcpu->kvm->arch.exception_payload_enabled)
                events->flags |= KVM_VCPUEVENT_VALID_PAYLOAD;
        if (vcpu->kvm->arch.triple_fault_event) {
                events->triple_fault.pending = kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                events->flags |= KVM_VCPUEVENT_VALID_TRIPLE_FAULT;
        }
}

static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
                                              struct kvm_vcpu_events *events)
{
        if (events->flags & ~(KVM_VCPUEVENT_VALID_NMI_PENDING
                              | KVM_VCPUEVENT_VALID_SIPI_VECTOR
                              | KVM_VCPUEVENT_VALID_SHADOW
                              | KVM_VCPUEVENT_VALID_SMM
                              | KVM_VCPUEVENT_VALID_PAYLOAD
                              | KVM_VCPUEVENT_VALID_TRIPLE_FAULT))
                return -EINVAL;

        if (events->flags & KVM_VCPUEVENT_VALID_PAYLOAD) {
                if (!vcpu->kvm->arch.exception_payload_enabled)
                        return -EINVAL;
                if (events->exception.pending)
                        events->exception.injected = 0;
                else
                        events->exception_has_payload = 0;
        } else {
                events->exception.pending = 0;
                events->exception_has_payload = 0;
        }

        if ((events->exception.injected || events->exception.pending) &&
            (events->exception.nr > 31 || events->exception.nr == NMI_VECTOR))
                return -EINVAL;

        /* INITs are latched while in SMM */
        if (events->flags & KVM_VCPUEVENT_VALID_SMM &&
            (events->smi.smm || events->smi.pending) &&
            vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED)
                return -EINVAL;

        process_nmi(vcpu);

        /*
         * Flag that userspace is stuffing an exception, the next KVM_RUN will
         * morph the exception to a VM-Exit if appropriate.  Do this only for
         * pending exceptions, already-injected exceptions are not subject to
         * intercpetion.  Note, userspace that conflates pending and injected
         * is hosed, and will incorrectly convert an injected exception into a
         * pending exception, which in turn may cause a spurious VM-Exit.
         */
        vcpu->arch.exception_from_userspace = events->exception.pending;

        vcpu->arch.exception_vmexit.pending = false;

        vcpu->arch.exception.injected = events->exception.injected;
        vcpu->arch.exception.pending = events->exception.pending;
        vcpu->arch.exception.vector = events->exception.nr;
        vcpu->arch.exception.has_error_code = events->exception.has_error_code;
        vcpu->arch.exception.error_code = events->exception.error_code;
        vcpu->arch.exception.has_payload = events->exception_has_payload;
        vcpu->arch.exception.payload = events->exception_payload;

        vcpu->arch.interrupt.injected = events->interrupt.injected;
        vcpu->arch.interrupt.nr = events->interrupt.nr;
        vcpu->arch.interrupt.soft = events->interrupt.soft;
        if (events->flags & KVM_VCPUEVENT_VALID_SHADOW)
                static_call(kvm_x86_set_interrupt_shadow)(vcpu,
                                                events->interrupt.shadow);

        vcpu->arch.nmi_injected = events->nmi.injected;
        if (events->flags & KVM_VCPUEVENT_VALID_NMI_PENDING)
                vcpu->arch.nmi_pending = events->nmi.pending;
        static_call(kvm_x86_set_nmi_mask)(vcpu, events->nmi.masked);

        if (events->flags & KVM_VCPUEVENT_VALID_SIPI_VECTOR &&
            lapic_in_kernel(vcpu))
                vcpu->arch.apic->sipi_vector = events->sipi_vector;

        if (events->flags & KVM_VCPUEVENT_VALID_SMM) {
#ifdef CONFIG_KVM_SMM
                if (!!(vcpu->arch.hflags & HF_SMM_MASK) != events->smi.smm) {
                        kvm_leave_nested(vcpu);
                        kvm_smm_changed(vcpu, events->smi.smm);
                }

                vcpu->arch.smi_pending = events->smi.pending;

                if (events->smi.smm) {
                        if (events->smi.smm_inside_nmi)
                                vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK;
                        else
                                vcpu->arch.hflags &= ~HF_SMM_INSIDE_NMI_MASK;
                }

#else
                if (events->smi.smm || events->smi.pending ||
                    events->smi.smm_inside_nmi)
                        return -EINVAL;
#endif

                if (lapic_in_kernel(vcpu)) {
                        if (events->smi.latched_init)
                                set_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
                        else
                                clear_bit(KVM_APIC_INIT, &vcpu->arch.apic->pending_events);
                }
        }

        if (events->flags & KVM_VCPUEVENT_VALID_TRIPLE_FAULT) {
                if (!vcpu->kvm->arch.triple_fault_event)
                        return -EINVAL;
                if (events->triple_fault.pending)
                        kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
                else
                        kvm_clear_request(KVM_REQ_TRIPLE_FAULT, vcpu);
        }

        kvm_make_request(KVM_REQ_EVENT, vcpu);

        return 0;
}

static void kvm_vcpu_ioctl_x86_get_debugregs(struct kvm_vcpu *vcpu,
                                             struct kvm_debugregs *dbgregs)
{
        unsigned long val;

        memcpy(dbgregs->db, vcpu->arch.db, sizeof(vcpu->arch.db));
        kvm_get_dr(vcpu, 6, &val);
        dbgregs->dr6 = val;
        dbgregs->dr7 = vcpu->arch.dr7;
        dbgregs->flags = 0;
        memset(&dbgregs->reserved, 0, sizeof(dbgregs->reserved));
}

static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
                                            struct kvm_debugregs *dbgregs)
{
        if (dbgregs->flags)
                return -EINVAL;

        if (!kvm_dr6_valid(dbgregs->dr6))
                return -EINVAL;
        if (!kvm_dr7_valid(dbgregs->dr7))
                return -EINVAL;

        memcpy(vcpu->arch.db, dbgregs->db, sizeof(vcpu->arch.db));
        kvm_update_dr0123(vcpu);
        vcpu->arch.dr6 = dbgregs->dr6;
        vcpu->arch.dr7 = dbgregs->dr7;
        kvm_update_dr7(vcpu);

        return 0;
}

static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
                                         struct kvm_xsave *guest_xsave)
{
        if (fpstate_is_confidential(&vcpu->arch.guest_fpu))
                return;

        fpu_copy_guest_fpstate_to_uabi(&vcpu->arch.guest_fpu,
                                       guest_xsave->region,
                                       sizeof(guest_xsave->region),
                                       vcpu->arch.pkru);
}

static void kvm_vcpu_ioctl_x86_get_xsave2(struct kvm_vcpu *vcpu,
                                          u8 *state, unsigned int size)
{
        if (fpstate_is_confidential(&vcpu->arch.guest_fpu))
                return;

        fpu_copy_guest_fpstate_to_uabi(&vcpu->arch.guest_fpu,
                                       state, size, vcpu->arch.pkru);
}

static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
                                        struct kvm_xsave *guest_xsave)
{
        if (fpstate_is_confidential(&vcpu->arch.guest_fpu))
                return 0;

        return fpu_copy_uabi_to_guest_fpstate(&vcpu->arch.guest_fpu,
                                              guest_xsave->region,
                                              kvm_caps.supported_xcr0,
                                              &vcpu->arch.pkru);
}

static void kvm_vcpu_ioctl_x86_get_xcrs(struct kvm_vcpu *vcpu,
                                        struct kvm_xcrs *guest_xcrs)
{
        if (!boot_cpu_has(X86_FEATURE_XSAVE)) {
                guest_xcrs->nr_xcrs = 0;
                return;
        }

        guest_xcrs->nr_xcrs = 1;
        guest_xcrs->flags = 0;
        guest_xcrs->xcrs[0].xcr = XCR_XFEATURE_ENABLED_MASK;
        guest_xcrs->xcrs[0].value = vcpu->arch.xcr0;
}

static int kvm_vcpu_ioctl_x86_set_xcrs(struct kvm_vcpu *vcpu,
                                       struct kvm_xcrs *guest_xcrs)
{
        int i, r = 0;

        if (!boot_cpu_has(X86_FEATURE_XSAVE))
                return -EINVAL;

        if (guest_xcrs->nr_xcrs > KVM_MAX_XCRS || guest_xcrs->flags)
                return -EINVAL;

        for (i = 0; i < guest_xcrs->nr_xcrs; i++)
                /* Only support XCR0 currently */
                if (guest_xcrs->xcrs[i].xcr == XCR_XFEATURE_ENABLED_MASK) {
                        r = __kvm_set_xcr(vcpu, XCR_XFEATURE_ENABLED_MASK,
                                guest_xcrs->xcrs[i].value);
                        break;
                }
        if (r)
                r = -EINVAL;
        return r;
}

/*
 * kvm_set_guest_paused() indicates to the guest kernel that it has been
 * stopped by the hypervisor.  This function will be called from the host only.
 * EINVAL is returned when the host attempts to set the flag for a guest that
 * does not support pv clocks.
 */
static int kvm_set_guest_paused(struct kvm_vcpu *vcpu)
{
        if (!vcpu->arch.pv_time.active)
                return -EINVAL;
        vcpu->arch.pvclock_set_guest_stopped_request = true;
        kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
        return 0;
}

static int kvm_arch_tsc_has_attr(struct kvm_vcpu *vcpu,
                                 struct kvm_device_attr *attr)
{
        int r;

        switch (attr->attr) {
        case KVM_VCPU_TSC_OFFSET:
                r = 0;
                break;
        default:
                r = -ENXIO;
        }

        return r;
}

static int kvm_arch_tsc_get_attr(struct kvm_vcpu *vcpu,
                                 struct kvm_device_attr *attr)
{
        u64 __user *uaddr = kvm_get_attr_addr(attr);
        int r;

        if (IS_ERR(uaddr))
                return PTR_ERR(uaddr);

        switch (attr->attr) {
        case KVM_VCPU_TSC_OFFSET:
                r = -EFAULT;
                if (put_user(vcpu->arch.l1_tsc_offset, uaddr))
                        break;
                r = 0;
                break;
        default:
                r = -ENXIO;
        }

        return r;
}

static int kvm_arch_tsc_set_attr(struct kvm_vcpu *vcpu,
                                 struct kvm_device_attr *attr)
{
        u64 __user *uaddr = kvm_get_attr_addr(attr);
        struct kvm *kvm = vcpu->kvm;
        int r;

        if (IS_ERR(uaddr))
                return PTR_ERR(uaddr);

        switch (attr->attr) {
        case KVM_VCPU_TSC_OFFSET: {
                u64 offset, tsc, ns;
                unsigned long flags;
                bool matched;

                r = -EFAULT;
                if (get_user(offset, uaddr))
                        break;

                raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);

                matched = (vcpu->arch.virtual_tsc_khz &&
                           kvm->arch.last_tsc_khz == vcpu->arch.virtual_tsc_khz &&
                           kvm->arch.last_tsc_offset == offset);

                tsc = kvm_scale_tsc(rdtsc(), vcpu->arch.l1_tsc_scaling_ratio) + offset;
                ns = get_kvmclock_base_ns();

                __kvm_synchronize_tsc(vcpu, offset, tsc, ns, matched);
                raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);

                r = 0;
                break;
        }
        default:
                r = -ENXIO;
        }

        return r;
}

static int kvm_vcpu_ioctl_device_attr(struct kvm_vcpu *vcpu,
                                      unsigned int ioctl,
                                      void __user *argp)
{
        struct kvm_device_attr attr;
        int r;

        if (copy_from_user(&attr, argp, sizeof(attr)))
                return -EFAULT;

        if (attr.group != KVM_VCPU_TSC_CTRL)
                return -ENXIO;

        switch (ioctl) {
        case KVM_HAS_DEVICE_ATTR:
                r = kvm_arch_tsc_has_attr(vcpu, &attr);
                break;
        case KVM_GET_DEVICE_ATTR:
                r = kvm_arch_tsc_get_attr(vcpu, &attr);
                break;
        case KVM_SET_DEVICE_ATTR:
                r = kvm_arch_tsc_set_attr(vcpu, &attr);
                break;
        }

        return r;
}

static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
                                     struct kvm_enable_cap *cap)
{
        int r;
        uint16_t vmcs_version;
        void __user *user_ptr;

        if (cap->flags)
                return -EINVAL;

        switch (cap->cap) {
        case KVM_CAP_HYPERV_SYNIC2:
                if (cap->args[0])
                        return -EINVAL;
                fallthrough;

        case KVM_CAP_HYPERV_SYNIC:
                if (!irqchip_in_kernel(vcpu->kvm))
                        return -EINVAL;
                return kvm_hv_activate_synic(vcpu, cap->cap ==
                                             KVM_CAP_HYPERV_SYNIC2);
        case KVM_CAP_HYPERV_ENLIGHTENED_VMCS:
                if (!kvm_x86_ops.nested_ops->enable_evmcs)
                        return -ENOTTY;
                r = kvm_x86_ops.nested_ops->enable_evmcs(vcpu, &vmcs_version);
                if (!r) {
                        user_ptr = (void __user *)(uintptr_t)cap->args[0];
                        if (copy_to_user(user_ptr, &vmcs_version,
                                         sizeof(vmcs_version)))
                                r = -EFAULT;
                }
                return r;
        case KVM_CAP_HYPERV_DIRECT_TLBFLUSH:
                if (!kvm_x86_ops.enable_l2_tlb_flush)
                        return -ENOTTY;

                return static_call(kvm_x86_enable_l2_tlb_flush)(vcpu);

        case KVM_CAP_HYPERV_ENFORCE_CPUID:
                return kvm_hv_set_enforce_cpuid(vcpu, cap->args[0]);

        case KVM_CAP_ENFORCE_PV_FEATURE_CPUID:
                vcpu->arch.pv_cpuid.enforce = cap->args[0];
                if (vcpu->arch.pv_cpuid.enforce)
                        kvm_update_pv_runtime(vcpu);

                return 0;
        default:
                return -EINVAL;
        }
}

long kvm_arch_vcpu_ioctl(struct file *filp,
                         unsigned int ioctl, unsigned long arg)
{
        struct kvm_vcpu *vcpu = filp->private_data;
        void __user *argp = (void __user *)arg;
        int r;
        union {
                struct kvm_sregs2 *sregs2;
                struct kvm_lapic_state *lapic;
                struct kvm_xsave *xsave;
                struct kvm_xcrs *xcrs;
                void *buffer;
        } u;

        vcpu_load(vcpu);

        u.buffer = NULL;
        switch (ioctl) {
        case KVM_GET_LAPIC: {
                r = -EINVAL;
                if (!lapic_in_kernel(vcpu))
                        goto out;
                u.lapic = kzalloc(sizeof(struct kvm_lapic_state),
                                GFP_KERNEL_ACCOUNT);

                r = -ENOMEM;
                if (!u.lapic)
                        goto out;
                r = kvm_vcpu_ioctl_get_lapic(vcpu, u.lapic);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, u.lapic, sizeof(struct kvm_lapic_state)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_LAPIC: {
                r = -EINVAL;
                if (!lapic_in_kernel(vcpu))
                        goto out;
                u.lapic = memdup_user(argp, sizeof(*u.lapic));
                if (IS_ERR(u.lapic)) {
                        r = PTR_ERR(u.lapic);
                        goto out_nofree;
                }

                r = kvm_vcpu_ioctl_set_lapic(vcpu, u.lapic);
                break;
        }
        case KVM_INTERRUPT: {
                struct kvm_interrupt irq;

                r = -EFAULT;
                if (copy_from_user(&irq, argp, sizeof(irq)))
                        goto out;
                r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
                break;
        }
        case KVM_NMI: {
                r = kvm_vcpu_ioctl_nmi(vcpu);
                break;
        }
        case KVM_SMI: {
                r = kvm_inject_smi(vcpu);
                break;
        }
        case KVM_SET_CPUID: {
                struct kvm_cpuid __user *cpuid_arg = argp;
                struct kvm_cpuid cpuid;

                r = -EFAULT;
                if (copy_from_user(&cpuid, cpuid_arg, sizeof(cpuid)))
                        goto out;
                r = kvm_vcpu_ioctl_set_cpuid(vcpu, &cpuid, cpuid_arg->entries);
                break;
        }
        case KVM_SET_CPUID2: {
                struct kvm_cpuid2 __user *cpuid_arg = argp;
                struct kvm_cpuid2 cpuid;

                r = -EFAULT;
                if (copy_from_user(&cpuid, cpuid_arg, sizeof(cpuid)))
                        goto out;
                r = kvm_vcpu_ioctl_set_cpuid2(vcpu, &cpuid,
                                              cpuid_arg->entries);
                break;
        }
        case KVM_GET_CPUID2: {
                struct kvm_cpuid2 __user *cpuid_arg = argp;
                struct kvm_cpuid2 cpuid;

                r = -EFAULT;
                if (copy_from_user(&cpuid, cpuid_arg, sizeof(cpuid)))
                        goto out;
                r = kvm_vcpu_ioctl_get_cpuid2(vcpu, &cpuid,
                                              cpuid_arg->entries);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(cpuid_arg, &cpuid, sizeof(cpuid)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_GET_MSRS: {
                int idx = srcu_read_lock(&vcpu->kvm->srcu);
                r = msr_io(vcpu, argp, do_get_msr, 1);
                srcu_read_unlock(&vcpu->kvm->srcu, idx);
                break;
        }
        case KVM_SET_MSRS: {
                int idx = srcu_read_lock(&vcpu->kvm->srcu);
                r = msr_io(vcpu, argp, do_set_msr, 0);
                srcu_read_unlock(&vcpu->kvm->srcu, idx);
                break;
        }
        case KVM_TPR_ACCESS_REPORTING: {
                struct kvm_tpr_access_ctl tac;

                r = -EFAULT;
                if (copy_from_user(&tac, argp, sizeof(tac)))
                        goto out;
                r = vcpu_ioctl_tpr_access_reporting(vcpu, &tac);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &tac, sizeof(tac)))
                        goto out;
                r = 0;
                break;
        };
        case KVM_SET_VAPIC_ADDR: {
                struct kvm_vapic_addr va;
                int idx;

                r = -EINVAL;
                if (!lapic_in_kernel(vcpu))
                        goto out;
                r = -EFAULT;
                if (copy_from_user(&va, argp, sizeof(va)))
                        goto out;
                idx = srcu_read_lock(&vcpu->kvm->srcu);
                r = kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);
                srcu_read_unlock(&vcpu->kvm->srcu, idx);
                break;
        }
        case KVM_X86_SETUP_MCE: {
                u64 mcg_cap;

                r = -EFAULT;
                if (copy_from_user(&mcg_cap, argp, sizeof(mcg_cap)))
                        goto out;
                r = kvm_vcpu_ioctl_x86_setup_mce(vcpu, mcg_cap);
                break;
        }
        case KVM_X86_SET_MCE: {
                struct kvm_x86_mce mce;

                r = -EFAULT;
                if (copy_from_user(&mce, argp, sizeof(mce)))
                        goto out;
                r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
                break;
        }
        case KVM_GET_VCPU_EVENTS: {
                struct kvm_vcpu_events events;

                kvm_vcpu_ioctl_x86_get_vcpu_events(vcpu, &events);

                r = -EFAULT;
                if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events)))
                        break;
                r = 0;
                break;
        }
        case KVM_SET_VCPU_EVENTS: {
                struct kvm_vcpu_events events;

                r = -EFAULT;
                if (copy_from_user(&events, argp, sizeof(struct kvm_vcpu_events)))
                        break;

                r = kvm_vcpu_ioctl_x86_set_vcpu_events(vcpu, &events);
                break;
        }
        case KVM_GET_DEBUGREGS: {
                struct kvm_debugregs dbgregs;

                kvm_vcpu_ioctl_x86_get_debugregs(vcpu, &dbgregs);

                r = -EFAULT;
                if (copy_to_user(argp, &dbgregs,
                                 sizeof(struct kvm_debugregs)))
                        break;
                r = 0;
                break;
        }
        case KVM_SET_DEBUGREGS: {
                struct kvm_debugregs dbgregs;

                r = -EFAULT;
                if (copy_from_user(&dbgregs, argp,
                                   sizeof(struct kvm_debugregs)))
                        break;

                r = kvm_vcpu_ioctl_x86_set_debugregs(vcpu, &dbgregs);
                break;
        }
        case KVM_GET_XSAVE: {
                r = -EINVAL;
                if (vcpu->arch.guest_fpu.uabi_size > sizeof(struct kvm_xsave))
                        break;

                u.xsave = kzalloc(sizeof(struct kvm_xsave), GFP_KERNEL_ACCOUNT);
                r = -ENOMEM;
                if (!u.xsave)
                        break;

                kvm_vcpu_ioctl_x86_get_xsave(vcpu, u.xsave);

                r = -EFAULT;
                if (copy_to_user(argp, u.xsave, sizeof(struct kvm_xsave)))
                        break;
                r = 0;
                break;
        }
        case KVM_SET_XSAVE: {
                int size = vcpu->arch.guest_fpu.uabi_size;

                u.xsave = memdup_user(argp, size);
                if (IS_ERR(u.xsave)) {
                        r = PTR_ERR(u.xsave);
                        goto out_nofree;
                }

                r = kvm_vcpu_ioctl_x86_set_xsave(vcpu, u.xsave);
                break;
        }

        case KVM_GET_XSAVE2: {
                int size = vcpu->arch.guest_fpu.uabi_size;

                u.xsave = kzalloc(size, GFP_KERNEL_ACCOUNT);
                r = -ENOMEM;
                if (!u.xsave)
                        break;

                kvm_vcpu_ioctl_x86_get_xsave2(vcpu, u.buffer, size);

                r = -EFAULT;
                if (copy_to_user(argp, u.xsave, size))
                        break;

                r = 0;
                break;
        }

        case KVM_GET_XCRS: {
                u.xcrs = kzalloc(sizeof(struct kvm_xcrs), GFP_KERNEL_ACCOUNT);
                r = -ENOMEM;
                if (!u.xcrs)
                        break;

                kvm_vcpu_ioctl_x86_get_xcrs(vcpu, u.xcrs);

                r = -EFAULT;
                if (copy_to_user(argp, u.xcrs,
                                 sizeof(struct kvm_xcrs)))
                        break;
                r = 0;
                break;
        }
        case KVM_SET_XCRS: {
                u.xcrs = memdup_user(argp, sizeof(*u.xcrs));
                if (IS_ERR(u.xcrs)) {
                        r = PTR_ERR(u.xcrs);
                        goto out_nofree;
                }

                r = kvm_vcpu_ioctl_x86_set_xcrs(vcpu, u.xcrs);
                break;
        }
        case KVM_SET_TSC_KHZ: {
                u32 user_tsc_khz;

                r = -EINVAL;
                user_tsc_khz = (u32)arg;

                if (kvm_caps.has_tsc_control &&
                    user_tsc_khz >= kvm_caps.max_guest_tsc_khz)
                        goto out;

                if (user_tsc_khz == 0)
                        user_tsc_khz = tsc_khz;

                if (!kvm_set_tsc_khz(vcpu, user_tsc_khz))
                        r = 0;

                goto out;
        }
        case KVM_GET_TSC_KHZ: {
                r = vcpu->arch.virtual_tsc_khz;
                goto out;
        }
        case KVM_KVMCLOCK_CTRL: {
                r = kvm_set_guest_paused(vcpu);
                goto out;
        }
        case KVM_ENABLE_CAP: {
                struct kvm_enable_cap cap;

                r = -EFAULT;
                if (copy_from_user(&cap, argp, sizeof(cap)))
                        goto out;
                r = kvm_vcpu_ioctl_enable_cap(vcpu, &cap);
                break;
        }
        case KVM_GET_NESTED_STATE: {
                struct kvm_nested_state __user *user_kvm_nested_state = argp;
                u32 user_data_size;

                r = -EINVAL;
                if (!kvm_x86_ops.nested_ops->get_state)
                        break;

                BUILD_BUG_ON(sizeof(user_data_size) != sizeof(user_kvm_nested_state->size));
                r = -EFAULT;
                if (get_user(user_data_size, &user_kvm_nested_state->size))
                        break;

                r = kvm_x86_ops.nested_ops->get_state(vcpu, user_kvm_nested_state,
                                                     user_data_size);
                if (r < 0)
                        break;

                if (r > user_data_size) {
                        if (put_user(r, &user_kvm_nested_state->size))
                                r = -EFAULT;
                        else
                                r = -E2BIG;
                        break;
                }

                r = 0;
                break;
        }
        case KVM_SET_NESTED_STATE: {
                struct kvm_nested_state __user *user_kvm_nested_state = argp;
                struct kvm_nested_state kvm_state;
                int idx;

                r = -EINVAL;
                if (!kvm_x86_ops.nested_ops->set_state)
                        break;

                r = -EFAULT;
                if (copy_from_user(&kvm_state, user_kvm_nested_state, sizeof(kvm_state)))
                        break;

                r = -EINVAL;
                if (kvm_state.size < sizeof(kvm_state))
                        break;

                if (kvm_state.flags &
                    ~(KVM_STATE_NESTED_RUN_PENDING | KVM_STATE_NESTED_GUEST_MODE
                      | KVM_STATE_NESTED_EVMCS | KVM_STATE_NESTED_MTF_PENDING
                      | KVM_STATE_NESTED_GIF_SET))
                        break;

                /* nested_run_pending implies guest_mode.  */
                if ((kvm_state.flags & KVM_STATE_NESTED_RUN_PENDING)
                    && !(kvm_state.flags & KVM_STATE_NESTED_GUEST_MODE))
                        break;

                idx = srcu_read_lock(&vcpu->kvm->srcu);
                r = kvm_x86_ops.nested_ops->set_state(vcpu, user_kvm_nested_state, &kvm_state);
                srcu_read_unlock(&vcpu->kvm->srcu, idx);
                break;
        }
        case KVM_GET_SUPPORTED_HV_CPUID:
                r = kvm_ioctl_get_supported_hv_cpuid(vcpu, argp);
                break;
#ifdef CONFIG_KVM_XEN
        case KVM_XEN_VCPU_GET_ATTR: {
                struct kvm_xen_vcpu_attr xva;

                r = -EFAULT;
                if (copy_from_user(&xva, argp, sizeof(xva)))
                        goto out;
                r = kvm_xen_vcpu_get_attr(vcpu, &xva);
                if (!r && copy_to_user(argp, &xva, sizeof(xva)))
                        r = -EFAULT;
                break;
        }
        case KVM_XEN_VCPU_SET_ATTR: {
                struct kvm_xen_vcpu_attr xva;

                r = -EFAULT;
                if (copy_from_user(&xva, argp, sizeof(xva)))
                        goto out;
                r = kvm_xen_vcpu_set_attr(vcpu, &xva);
                break;
        }
#endif
        case KVM_GET_SREGS2: {
                u.sregs2 = kzalloc(sizeof(struct kvm_sregs2), GFP_KERNEL);
                r = -ENOMEM;
                if (!u.sregs2)
                        goto out;
                __get_sregs2(vcpu, u.sregs2);
                r = -EFAULT;
                if (copy_to_user(argp, u.sregs2, sizeof(struct kvm_sregs2)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_SREGS2: {
                u.sregs2 = memdup_user(argp, sizeof(struct kvm_sregs2));
                if (IS_ERR(u.sregs2)) {
                        r = PTR_ERR(u.sregs2);
                        u.sregs2 = NULL;
                        goto out;
                }
                r = __set_sregs2(vcpu, u.sregs2);
                break;
        }
        case KVM_HAS_DEVICE_ATTR:
        case KVM_GET_DEVICE_ATTR:
        case KVM_SET_DEVICE_ATTR:
                r = kvm_vcpu_ioctl_device_attr(vcpu, ioctl, argp);
                break;
        default:
                r = -EINVAL;
        }
out:
        kfree(u.buffer);
out_nofree:
        vcpu_put(vcpu);
        return r;
}

vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
        return VM_FAULT_SIGBUS;
}

static int kvm_vm_ioctl_set_tss_addr(struct kvm *kvm, unsigned long addr)
{
        int ret;

        if (addr > (unsigned int)(-3 * PAGE_SIZE))
                return -EINVAL;
        ret = static_call(kvm_x86_set_tss_addr)(kvm, addr);
        return ret;
}

static int kvm_vm_ioctl_set_identity_map_addr(struct kvm *kvm,
                                              u64 ident_addr)
{
        return static_call(kvm_x86_set_identity_map_addr)(kvm, ident_addr);
}

static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
                                         unsigned long kvm_nr_mmu_pages)
{
        if (kvm_nr_mmu_pages < KVM_MIN_ALLOC_MMU_PAGES)
                return -EINVAL;

        mutex_lock(&kvm->slots_lock);

        kvm_mmu_change_mmu_pages(kvm, kvm_nr_mmu_pages);
        kvm->arch.n_requested_mmu_pages = kvm_nr_mmu_pages;

        mutex_unlock(&kvm->slots_lock);
        return 0;
}

static unsigned long kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm)
{
        return kvm->arch.n_max_mmu_pages;
}

static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
{
        struct kvm_pic *pic = kvm->arch.vpic;
        int r;

        r = 0;
        switch (chip->chip_id) {
        case KVM_IRQCHIP_PIC_MASTER:
                memcpy(&chip->chip.pic, &pic->pics[0],
                        sizeof(struct kvm_pic_state));
                break;
        case KVM_IRQCHIP_PIC_SLAVE:
                memcpy(&chip->chip.pic, &pic->pics[1],
                        sizeof(struct kvm_pic_state));
                break;
        case KVM_IRQCHIP_IOAPIC:
                kvm_get_ioapic(kvm, &chip->chip.ioapic);
                break;
        default:
                r = -EINVAL;
                break;
        }
        return r;
}

static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
{
        struct kvm_pic *pic = kvm->arch.vpic;
        int r;

        r = 0;
        switch (chip->chip_id) {
        case KVM_IRQCHIP_PIC_MASTER:
                spin_lock(&pic->lock);
                memcpy(&pic->pics[0], &chip->chip.pic,
                        sizeof(struct kvm_pic_state));
                spin_unlock(&pic->lock);
                break;
        case KVM_IRQCHIP_PIC_SLAVE:
                spin_lock(&pic->lock);
                memcpy(&pic->pics[1], &chip->chip.pic,
                        sizeof(struct kvm_pic_state));
                spin_unlock(&pic->lock);
                break;
        case KVM_IRQCHIP_IOAPIC:
                kvm_set_ioapic(kvm, &chip->chip.ioapic);
                break;
        default:
                r = -EINVAL;
                break;
        }
        kvm_pic_update_irq(pic);
        return r;
}

static int kvm_vm_ioctl_get_pit(struct kvm *kvm, struct kvm_pit_state *ps)
{
        struct kvm_kpit_state *kps = &kvm->arch.vpit->pit_state;

        BUILD_BUG_ON(sizeof(*ps) != sizeof(kps->channels));

        mutex_lock(&kps->lock);
        memcpy(ps, &kps->channels, sizeof(*ps));
        mutex_unlock(&kps->lock);
        return 0;
}

static int kvm_vm_ioctl_set_pit(struct kvm *kvm, struct kvm_pit_state *ps)
{
        int i;
        struct kvm_pit *pit = kvm->arch.vpit;

        mutex_lock(&pit->pit_state.lock);
        memcpy(&pit->pit_state.channels, ps, sizeof(*ps));
        for (i = 0; i < 3; i++)
                kvm_pit_load_count(pit, i, ps->channels[i].count, 0);
        mutex_unlock(&pit->pit_state.lock);
        return 0;
}

static int kvm_vm_ioctl_get_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
{
        mutex_lock(&kvm->arch.vpit->pit_state.lock);
        memcpy(ps->channels, &kvm->arch.vpit->pit_state.channels,
                sizeof(ps->channels));
        ps->flags = kvm->arch.vpit->pit_state.flags;
        mutex_unlock(&kvm->arch.vpit->pit_state.lock);
        memset(&ps->reserved, 0, sizeof(ps->reserved));
        return 0;
}

static int kvm_vm_ioctl_set_pit2(struct kvm *kvm, struct kvm_pit_state2 *ps)
{
        int start = 0;
        int i;
        u32 prev_legacy, cur_legacy;
        struct kvm_pit *pit = kvm->arch.vpit;

        mutex_lock(&pit->pit_state.lock);
        prev_legacy = pit->pit_state.flags & KVM_PIT_FLAGS_HPET_LEGACY;
        cur_legacy = ps->flags & KVM_PIT_FLAGS_HPET_LEGACY;
        if (!prev_legacy && cur_legacy)
                start = 1;
        memcpy(&pit->pit_state.channels, &ps->channels,
               sizeof(pit->pit_state.channels));
        pit->pit_state.flags = ps->flags;
        for (i = 0; i < 3; i++)
                kvm_pit_load_count(pit, i, pit->pit_state.channels[i].count,
                                   start && i == 0);
        mutex_unlock(&pit->pit_state.lock);
        return 0;
}

static int kvm_vm_ioctl_reinject(struct kvm *kvm,
                                 struct kvm_reinject_control *control)
{
        struct kvm_pit *pit = kvm->arch.vpit;

        /* pit->pit_state.lock was overloaded to prevent userspace from getting
         * an inconsistent state after running multiple KVM_REINJECT_CONTROL
         * ioctls in parallel.  Use a separate lock if that ioctl isn't rare.
         */
        mutex_lock(&pit->pit_state.lock);
        kvm_pit_set_reinject(pit, control->pit_reinject);
        mutex_unlock(&pit->pit_state.lock);

        return 0;
}

void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
{

        /*
         * Flush all CPUs' dirty log buffers to the  dirty_bitmap.  Called
         * before reporting dirty_bitmap to userspace.  KVM flushes the buffers
         * on all VM-Exits, thus we only need to kick running vCPUs to force a
         * VM-Exit.
         */
        struct kvm_vcpu *vcpu;
        unsigned long i;

        kvm_for_each_vcpu(i, vcpu, kvm)
                kvm_vcpu_kick(vcpu);
}

int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_event,
                        bool line_status)
{
        if (!irqchip_in_kernel(kvm))
                return -ENXIO;

        irq_event->status = kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
                                        irq_event->irq, irq_event->level,
                                        line_status);
        return 0;
}

int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
                            struct kvm_enable_cap *cap)
{
        int r;

        if (cap->flags)
                return -EINVAL;

        switch (cap->cap) {
        case KVM_CAP_DISABLE_QUIRKS2:
                r = -EINVAL;
                if (cap->args[0] & ~KVM_X86_VALID_QUIRKS)
                        break;
                fallthrough;
        case KVM_CAP_DISABLE_QUIRKS:
                kvm->arch.disabled_quirks = cap->args[0];
                r = 0;
                break;
        case KVM_CAP_SPLIT_IRQCHIP: {
                mutex_lock(&kvm->lock);
                r = -EINVAL;
                if (cap->args[0] > MAX_NR_RESERVED_IOAPIC_PINS)
                        goto split_irqchip_unlock;
                r = -EEXIST;
                if (irqchip_in_kernel(kvm))
                        goto split_irqchip_unlock;
                if (kvm->created_vcpus)
                        goto split_irqchip_unlock;
                r = kvm_setup_empty_irq_routing(kvm);
                if (r)
                        goto split_irqchip_unlock;
                /* Pairs with irqchip_in_kernel. */
                smp_wmb();
                kvm->arch.irqchip_mode = KVM_IRQCHIP_SPLIT;
                kvm->arch.nr_reserved_ioapic_pins = cap->args[0];
                kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_ABSENT);
                r = 0;
split_irqchip_unlock:
                mutex_unlock(&kvm->lock);
                break;
        }
        case KVM_CAP_X2APIC_API:
                r = -EINVAL;
                if (cap->args[0] & ~KVM_X2APIC_API_VALID_FLAGS)
                        break;

                if (cap->args[0] & KVM_X2APIC_API_USE_32BIT_IDS)
                        kvm->arch.x2apic_format = true;
                if (cap->args[0] & KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK)
                        kvm->arch.x2apic_broadcast_quirk_disabled = true;

                r = 0;
                break;
        case KVM_CAP_X86_DISABLE_EXITS:
                r = -EINVAL;
                if (cap->args[0] & ~KVM_X86_DISABLE_VALID_EXITS)
                        break;

                if ((cap->args[0] & KVM_X86_DISABLE_EXITS_MWAIT) &&
                        kvm_can_mwait_in_guest())
                        kvm->arch.mwait_in_guest = true;
                if (cap->args[0] & KVM_X86_DISABLE_EXITS_HLT)
                        kvm->arch.hlt_in_guest = true;
                if (cap->args[0] & KVM_X86_DISABLE_EXITS_PAUSE)
                        kvm->arch.pause_in_guest = true;
                if (cap->args[0] & KVM_X86_DISABLE_EXITS_CSTATE)
                        kvm->arch.cstate_in_guest = true;
                r = 0;
                break;
        case KVM_CAP_MSR_PLATFORM_INFO:
                kvm->arch.guest_can_read_msr_platform_info = cap->args[0];
                r = 0;
                break;
        case KVM_CAP_EXCEPTION_PAYLOAD:
                kvm->arch.exception_payload_enabled = cap->args[0];
                r = 0;
                break;
        case KVM_CAP_X86_TRIPLE_FAULT_EVENT:
                kvm->arch.triple_fault_event = cap->args[0];
                r = 0;
                break;
        case KVM_CAP_X86_USER_SPACE_MSR:
                r = -EINVAL;
                if (cap->args[0] & ~KVM_MSR_EXIT_REASON_VALID_MASK)
                        break;
                kvm->arch.user_space_msr_mask = cap->args[0];
                r = 0;
                break;
        case KVM_CAP_X86_BUS_LOCK_EXIT:
                r = -EINVAL;
                if (cap->args[0] & ~KVM_BUS_LOCK_DETECTION_VALID_MODE)
                        break;

                if ((cap->args[0] & KVM_BUS_LOCK_DETECTION_OFF) &&
                    (cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT))
                        break;

                if (kvm_caps.has_bus_lock_exit &&
                    cap->args[0] & KVM_BUS_LOCK_DETECTION_EXIT)
                        kvm->arch.bus_lock_detection_enabled = true;
                r = 0;
                break;
#ifdef CONFIG_X86_SGX_KVM
        case KVM_CAP_SGX_ATTRIBUTE: {
                unsigned long allowed_attributes = 0;

                r = sgx_set_attribute(&allowed_attributes, cap->args[0]);
                if (r)
                        break;

                /* KVM only supports the PROVISIONKEY privileged attribute. */
                if ((allowed_attributes & SGX_ATTR_PROVISIONKEY) &&
                    !(allowed_attributes & ~SGX_ATTR_PROVISIONKEY))
                        kvm->arch.sgx_provisioning_allowed = true;
                else
                        r = -EINVAL;
                break;
        }
#endif
        case KVM_CAP_VM_COPY_ENC_CONTEXT_FROM:
                r = -EINVAL;
                if (!kvm_x86_ops.vm_copy_enc_context_from)
                        break;

                r = static_call(kvm_x86_vm_copy_enc_context_from)(kvm, cap->args[0]);
                break;
        case KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM:
                r = -EINVAL;
                if (!kvm_x86_ops.vm_move_enc_context_from)
                        break;

                r = static_call(kvm_x86_vm_move_enc_context_from)(kvm, cap->args[0]);
                break;
        case KVM_CAP_EXIT_HYPERCALL:
                if (cap->args[0] & ~KVM_EXIT_HYPERCALL_VALID_MASK) {
                        r = -EINVAL;
                        break;
                }
                kvm->arch.hypercall_exit_enabled = cap->args[0];
                r = 0;
                break;
        case KVM_CAP_EXIT_ON_EMULATION_FAILURE:
                r = -EINVAL;
                if (cap->args[0] & ~1)
                        break;
                kvm->arch.exit_on_emulation_error = cap->args[0];
                r = 0;
                break;
        case KVM_CAP_PMU_CAPABILITY:
                r = -EINVAL;
                if (!enable_pmu || (cap->args[0] & ~KVM_CAP_PMU_VALID_MASK))
                        break;

                mutex_lock(&kvm->lock);
                if (!kvm->created_vcpus) {
                        kvm->arch.enable_pmu = !(cap->args[0] & KVM_PMU_CAP_DISABLE);
                        r = 0;
                }
                mutex_unlock(&kvm->lock);
                break;
        case KVM_CAP_MAX_VCPU_ID:
                r = -EINVAL;
                if (cap->args[0] > KVM_MAX_VCPU_IDS)
                        break;

                mutex_lock(&kvm->lock);
                if (kvm->arch.max_vcpu_ids == cap->args[0]) {
                        r = 0;
                } else if (!kvm->arch.max_vcpu_ids) {
                        kvm->arch.max_vcpu_ids = cap->args[0];
                        r = 0;
                }
                mutex_unlock(&kvm->lock);
                break;
        case KVM_CAP_X86_NOTIFY_VMEXIT:
                r = -EINVAL;
                if ((u32)cap->args[0] & ~KVM_X86_NOTIFY_VMEXIT_VALID_BITS)
                        break;
                if (!kvm_caps.has_notify_vmexit)
                        break;
                if (!((u32)cap->args[0] & KVM_X86_NOTIFY_VMEXIT_ENABLED))
                        break;
                mutex_lock(&kvm->lock);
                if (!kvm->created_vcpus) {
                        kvm->arch.notify_window = cap->args[0] >> 32;
                        kvm->arch.notify_vmexit_flags = (u32)cap->args[0];
                        r = 0;
                }
                mutex_unlock(&kvm->lock);
                break;
        case KVM_CAP_VM_DISABLE_NX_HUGE_PAGES:
                r = -EINVAL;

                /*
                 * Since the risk of disabling NX hugepages is a guest crashing
                 * the system, ensure the userspace process has permission to
                 * reboot the system.
                 *
                 * Note that unlike the reboot() syscall, the process must have
                 * this capability in the root namespace because exposing
                 * /dev/kvm into a container does not limit the scope of the
                 * iTLB multihit bug to that container. In other words,
                 * this must use capable(), not ns_capable().
                 */
                if (!capable(CAP_SYS_BOOT)) {
                        r = -EPERM;
                        break;
                }

                if (cap->args[0])
                        break;

                mutex_lock(&kvm->lock);
                if (!kvm->created_vcpus) {
                        kvm->arch.disable_nx_huge_pages = true;
                        r = 0;
                }
                mutex_unlock(&kvm->lock);
                break;
        default:
                r = -EINVAL;
                break;
        }
        return r;
}

static struct kvm_x86_msr_filter *kvm_alloc_msr_filter(bool default_allow)
{
        struct kvm_x86_msr_filter *msr_filter;

        msr_filter = kzalloc(sizeof(*msr_filter), GFP_KERNEL_ACCOUNT);
        if (!msr_filter)
                return NULL;

        msr_filter->default_allow = default_allow;
        return msr_filter;
}

static void kvm_free_msr_filter(struct kvm_x86_msr_filter *msr_filter)
{
        u32 i;

        if (!msr_filter)
                return;

        for (i = 0; i < msr_filter->count; i++)
                kfree(msr_filter->ranges[i].bitmap);

        kfree(msr_filter);
}

static int kvm_add_msr_filter(struct kvm_x86_msr_filter *msr_filter,
                              struct kvm_msr_filter_range *user_range)
{
        unsigned long *bitmap = NULL;
        size_t bitmap_size;

        if (!user_range->nmsrs)
                return 0;

        if (user_range->flags & ~KVM_MSR_FILTER_RANGE_VALID_MASK)
                return -EINVAL;

        if (!user_range->flags)
                return -EINVAL;

        bitmap_size = BITS_TO_LONGS(user_range->nmsrs) * sizeof(long);
        if (!bitmap_size || bitmap_size > KVM_MSR_FILTER_MAX_BITMAP_SIZE)
                return -EINVAL;

        bitmap = memdup_user((__user u8*)user_range->bitmap, bitmap_size);
        if (IS_ERR(bitmap))
                return PTR_ERR(bitmap);

        msr_filter->ranges[msr_filter->count] = (struct msr_bitmap_range) {
                .flags = user_range->flags,
                .base = user_range->base,
                .nmsrs = user_range->nmsrs,
                .bitmap = bitmap,
        };

        msr_filter->count++;
        return 0;
}

static int kvm_vm_ioctl_set_msr_filter(struct kvm *kvm,
                                       struct kvm_msr_filter *filter)
{
        struct kvm_x86_msr_filter *new_filter, *old_filter;
        bool default_allow;
        bool empty = true;
        int r = 0;
        u32 i;

        if (filter->flags & ~KVM_MSR_FILTER_VALID_MASK)
                return -EINVAL;

        for (i = 0; i < ARRAY_SIZE(filter->ranges); i++)
                empty &= !filter->ranges[i].nmsrs;

        default_allow = !(filter->flags & KVM_MSR_FILTER_DEFAULT_DENY);
        if (empty && !default_allow)
                return -EINVAL;

        new_filter = kvm_alloc_msr_filter(default_allow);
        if (!new_filter)
                return -ENOMEM;

        for (i = 0; i < ARRAY_SIZE(filter->ranges); i++) {
                r = kvm_add_msr_filter(new_filter, &filter->ranges[i]);
                if (r) {
                        kvm_free_msr_filter(new_filter);
                        return r;
                }
        }

        mutex_lock(&kvm->lock);

        /* The per-VM filter is protected by kvm->lock... */
        old_filter = srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1);

        rcu_assign_pointer(kvm->arch.msr_filter, new_filter);
        synchronize_srcu(&kvm->srcu);

        kvm_free_msr_filter(old_filter);

        kvm_make_all_cpus_request(kvm, KVM_REQ_MSR_FILTER_CHANGED);
        mutex_unlock(&kvm->lock);

        return 0;
}

#ifdef CONFIG_KVM_COMPAT
/* for KVM_X86_SET_MSR_FILTER */
struct kvm_msr_filter_range_compat {
        __u32 flags;
        __u32 nmsrs;
        __u32 base;
        __u32 bitmap;
};

struct kvm_msr_filter_compat {
        __u32 flags;
        struct kvm_msr_filter_range_compat ranges[KVM_MSR_FILTER_MAX_RANGES];
};

#define KVM_X86_SET_MSR_FILTER_COMPAT _IOW(KVMIO, 0xc6, struct kvm_msr_filter_compat)

long kvm_arch_vm_compat_ioctl(struct file *filp, unsigned int ioctl,
                              unsigned long arg)
{
        void __user *argp = (void __user *)arg;
        struct kvm *kvm = filp->private_data;
        long r = -ENOTTY;

        switch (ioctl) {
        case KVM_X86_SET_MSR_FILTER_COMPAT: {
                struct kvm_msr_filter __user *user_msr_filter = argp;
                struct kvm_msr_filter_compat filter_compat;
                struct kvm_msr_filter filter;
                int i;

                if (copy_from_user(&filter_compat, user_msr_filter,
                                   sizeof(filter_compat)))
                        return -EFAULT;

                filter.flags = filter_compat.flags;
                for (i = 0; i < ARRAY_SIZE(filter.ranges); i++) {
                        struct kvm_msr_filter_range_compat *cr;

                        cr = &filter_compat.ranges[i];
                        filter.ranges[i] = (struct kvm_msr_filter_range) {
                                .flags = cr->flags,
                                .nmsrs = cr->nmsrs,
                                .base = cr->base,
                                .bitmap = (__u8 *)(ulong)cr->bitmap,
                        };
                }

                r = kvm_vm_ioctl_set_msr_filter(kvm, &filter);
                break;
        }
        }

        return r;
}
#endif

#ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
static int kvm_arch_suspend_notifier(struct kvm *kvm)
{
        struct kvm_vcpu *vcpu;
        unsigned long i;
        int ret = 0;

        mutex_lock(&kvm->lock);
        kvm_for_each_vcpu(i, vcpu, kvm) {
                if (!vcpu->arch.pv_time.active)
                        continue;

                ret = kvm_set_guest_paused(vcpu);
                if (ret) {
                        kvm_err("Failed to pause guest VCPU%d: %d\n",
                                vcpu->vcpu_id, ret);
                        break;
                }
        }
        mutex_unlock(&kvm->lock);

        return ret ? NOTIFY_BAD : NOTIFY_DONE;
}

int kvm_arch_pm_notifier(struct kvm *kvm, unsigned long state)
{
        switch (state) {
        case PM_HIBERNATION_PREPARE:
        case PM_SUSPEND_PREPARE:
                return kvm_arch_suspend_notifier(kvm);
        }

        return NOTIFY_DONE;
}
#endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */

static int kvm_vm_ioctl_get_clock(struct kvm *kvm, void __user *argp)
{
        struct kvm_clock_data data = { 0 };

        get_kvmclock(kvm, &data);
        if (copy_to_user(argp, &data, sizeof(data)))
                return -EFAULT;

        return 0;
}

static int kvm_vm_ioctl_set_clock(struct kvm *kvm, void __user *argp)
{
        struct kvm_arch *ka = &kvm->arch;
        struct kvm_clock_data data;
        u64 now_raw_ns;

        if (copy_from_user(&data, argp, sizeof(data)))
                return -EFAULT;

        /*
         * Only KVM_CLOCK_REALTIME is used, but allow passing the
         * result of KVM_GET_CLOCK back to KVM_SET_CLOCK.
         */
        if (data.flags & ~KVM_CLOCK_VALID_FLAGS)
                return -EINVAL;

        kvm_hv_request_tsc_page_update(kvm);
        kvm_start_pvclock_update(kvm);
        pvclock_update_vm_gtod_copy(kvm);

        /*
         * This pairs with kvm_guest_time_update(): when masterclock is
         * in use, we use master_kernel_ns + kvmclock_offset to set
         * unsigned 'system_time' so if we use get_kvmclock_ns() (which
         * is slightly ahead) here we risk going negative on unsigned
         * 'system_time' when 'data.clock' is very small.
         */
        if (data.flags & KVM_CLOCK_REALTIME) {
                u64 now_real_ns = ktime_get_real_ns();

                /*
                 * Avoid stepping the kvmclock backwards.
                 */
                if (now_real_ns > data.realtime)
                        data.clock += now_real_ns - data.realtime;
        }

        if (ka->use_master_clock)
                now_raw_ns = ka->master_kernel_ns;
        else
                now_raw_ns = get_kvmclock_base_ns();
        ka->kvmclock_offset = data.clock - now_raw_ns;
        kvm_end_pvclock_update(kvm);
        return 0;
}

long kvm_arch_vm_ioctl(struct file *filp,
                       unsigned int ioctl, unsigned long arg)
{
        struct kvm *kvm = filp->private_data;
        void __user *argp = (void __user *)arg;
        int r = -ENOTTY;
        /*
         * This union makes it completely explicit to gcc-3.x
         * that these two variables' stack usage should be
         * combined, not added together.
         */
        union {
                struct kvm_pit_state ps;
                struct kvm_pit_state2 ps2;
                struct kvm_pit_config pit_config;
        } u;

        switch (ioctl) {
        case KVM_SET_TSS_ADDR:
                r = kvm_vm_ioctl_set_tss_addr(kvm, arg);
                break;
        case KVM_SET_IDENTITY_MAP_ADDR: {
                u64 ident_addr;

                mutex_lock(&kvm->lock);
                r = -EINVAL;
                if (kvm->created_vcpus)
                        goto set_identity_unlock;
                r = -EFAULT;
                if (copy_from_user(&ident_addr, argp, sizeof(ident_addr)))
                        goto set_identity_unlock;
                r = kvm_vm_ioctl_set_identity_map_addr(kvm, ident_addr);
set_identity_unlock:
                mutex_unlock(&kvm->lock);
                break;
        }
        case KVM_SET_NR_MMU_PAGES:
                r = kvm_vm_ioctl_set_nr_mmu_pages(kvm, arg);
                break;
        case KVM_GET_NR_MMU_PAGES:
                r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
                break;
        case KVM_CREATE_IRQCHIP: {
                mutex_lock(&kvm->lock);

                r = -EEXIST;
                if (irqchip_in_kernel(kvm))
                        goto create_irqchip_unlock;

                r = -EINVAL;
                if (kvm->created_vcpus)
                        goto create_irqchip_unlock;

                r = kvm_pic_init(kvm);
                if (r)
                        goto create_irqchip_unlock;

                r = kvm_ioapic_init(kvm);
                if (r) {
                        kvm_pic_destroy(kvm);
                        goto create_irqchip_unlock;
                }

                r = kvm_setup_default_irq_routing(kvm);
                if (r) {
                        kvm_ioapic_destroy(kvm);
                        kvm_pic_destroy(kvm);
                        goto create_irqchip_unlock;
                }
                /* Write kvm->irq_routing before enabling irqchip_in_kernel. */
                smp_wmb();
                kvm->arch.irqchip_mode = KVM_IRQCHIP_KERNEL;
                kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_ABSENT);
        create_irqchip_unlock:
                mutex_unlock(&kvm->lock);
                break;
        }
        case KVM_CREATE_PIT:
                u.pit_config.flags = KVM_PIT_SPEAKER_DUMMY;
                goto create_pit;
        case KVM_CREATE_PIT2:
                r = -EFAULT;
                if (copy_from_user(&u.pit_config, argp,
                                   sizeof(struct kvm_pit_config)))
                        goto out;
        create_pit:
                mutex_lock(&kvm->lock);
                r = -EEXIST;
                if (kvm->arch.vpit)
                        goto create_pit_unlock;
                r = -ENOMEM;
                kvm->arch.vpit = kvm_create_pit(kvm, u.pit_config.flags);
                if (kvm->arch.vpit)
                        r = 0;
        create_pit_unlock:
                mutex_unlock(&kvm->lock);
                break;
        case KVM_GET_IRQCHIP: {
                /* 0: PIC master, 1: PIC slave, 2: IOAPIC */
                struct kvm_irqchip *chip;

                chip = memdup_user(argp, sizeof(*chip));
                if (IS_ERR(chip)) {
                        r = PTR_ERR(chip);
                        goto out;
                }

                r = -ENXIO;
                if (!irqchip_kernel(kvm))
                        goto get_irqchip_out;
                r = kvm_vm_ioctl_get_irqchip(kvm, chip);
                if (r)
                        goto get_irqchip_out;
                r = -EFAULT;
                if (copy_to_user(argp, chip, sizeof(*chip)))
                        goto get_irqchip_out;
                r = 0;
        get_irqchip_out:
                kfree(chip);
                break;
        }
        case KVM_SET_IRQCHIP: {
                /* 0: PIC master, 1: PIC slave, 2: IOAPIC */
                struct kvm_irqchip *chip;

                chip = memdup_user(argp, sizeof(*chip));
                if (IS_ERR(chip)) {
                        r = PTR_ERR(chip);
                        goto out;
                }

                r = -ENXIO;
                if (!irqchip_kernel(kvm))
                        goto set_irqchip_out;
                r = kvm_vm_ioctl_set_irqchip(kvm, chip);
        set_irqchip_out:
                kfree(chip);
                break;
        }
        case KVM_GET_PIT: {
                r = -EFAULT;
                if (copy_from_user(&u.ps, argp, sizeof(struct kvm_pit_state)))
                        goto out;
                r = -ENXIO;
                if (!kvm->arch.vpit)
                        goto out;
                r = kvm_vm_ioctl_get_pit(kvm, &u.ps);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &u.ps, sizeof(struct kvm_pit_state)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_PIT: {
                r = -EFAULT;
                if (copy_from_user(&u.ps, argp, sizeof(u.ps)))
                        goto out;
                mutex_lock(&kvm->lock);
                r = -ENXIO;
                if (!kvm->arch.vpit)
                        goto set_pit_out;
                r = kvm_vm_ioctl_set_pit(kvm, &u.ps);
set_pit_out:
                mutex_unlock(&kvm->lock);
                break;
        }
        case KVM_GET_PIT2: {
                r = -ENXIO;
                if (!kvm->arch.vpit)
                        goto out;
                r = kvm_vm_ioctl_get_pit2(kvm, &u.ps2);
                if (r)
                        goto out;
                r = -EFAULT;
                if (copy_to_user(argp, &u.ps2, sizeof(u.ps2)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_PIT2: {
                r = -EFAULT;
                if (copy_from_user(&u.ps2, argp, sizeof(u.ps2)))
                        goto out;
                mutex_lock(&kvm->lock);
                r = -ENXIO;
                if (!kvm->arch.vpit)
                        goto set_pit2_out;
                r = kvm_vm_ioctl_set_pit2(kvm, &u.ps2);
set_pit2_out:
                mutex_unlock(&kvm->lock);
                break;
        }
        case KVM_REINJECT_CONTROL: {
                struct kvm_reinject_control control;
                r =  -EFAULT;
                if (copy_from_user(&control, argp, sizeof(control)))
                        goto out;
                r = -ENXIO;
                if (!kvm->arch.vpit)
                        goto out;
                r = kvm_vm_ioctl_reinject(kvm, &control);
                break;
        }
        case KVM_SET_BOOT_CPU_ID:
                r = 0;
                mutex_lock(&kvm->lock);
                if (kvm->created_vcpus)
                        r = -EBUSY;
                else
                        kvm->arch.bsp_vcpu_id = arg;
                mutex_unlock(&kvm->lock);
                break;
#ifdef CONFIG_KVM_XEN
        case KVM_XEN_HVM_CONFIG: {
                struct kvm_xen_hvm_config xhc;
                r = -EFAULT;
                if (copy_from_user(&xhc, argp, sizeof(xhc)))
                        goto out;
                r = kvm_xen_hvm_config(kvm, &xhc);
                break;
        }
        case KVM_XEN_HVM_GET_ATTR: {
                struct kvm_xen_hvm_attr xha;

                r = -EFAULT;
                if (copy_from_user(&xha, argp, sizeof(xha)))
                        goto out;
                r = kvm_xen_hvm_get_attr(kvm, &xha);
                if (!r && copy_to_user(argp, &xha, sizeof(xha)))
                        r = -EFAULT;
                break;
        }
        case KVM_XEN_HVM_SET_ATTR: {
                struct kvm_xen_hvm_attr xha;

                r = -EFAULT;
                if (copy_from_user(&xha, argp, sizeof(xha)))
                        goto out;
                r = kvm_xen_hvm_set_attr(kvm, &xha);
                break;
        }
        case KVM_XEN_HVM_EVTCHN_SEND: {
                struct kvm_irq_routing_xen_evtchn uxe;

                r = -EFAULT;
                if (copy_from_user(&uxe, argp, sizeof(uxe)))
                        goto out;
                r = kvm_xen_hvm_evtchn_send(kvm, &uxe);
                break;
        }
#endif
        case KVM_SET_CLOCK:
                r = kvm_vm_ioctl_set_clock(kvm, argp);
                break;
        case KVM_GET_CLOCK:
                r = kvm_vm_ioctl_get_clock(kvm, argp);
                break;
        case KVM_SET_TSC_KHZ: {
                u32 user_tsc_khz;

                r = -EINVAL;
                user_tsc_khz = (u32)arg;

                if (kvm_caps.has_tsc_control &&
                    user_tsc_khz >= kvm_caps.max_guest_tsc_khz)
                        goto out;

                if (user_tsc_khz == 0)
                        user_tsc_khz = tsc_khz;

                WRITE_ONCE(kvm->arch.default_tsc_khz, user_tsc_khz);
                r = 0;

                goto out;
        }
        case KVM_GET_TSC_KHZ: {
                r = READ_ONCE(kvm->arch.default_tsc_khz);
                goto out;
        }
        case KVM_MEMORY_ENCRYPT_OP: {
                r = -ENOTTY;
                if (!kvm_x86_ops.mem_enc_ioctl)
                        goto out;

                r = static_call(kvm_x86_mem_enc_ioctl)(kvm, argp);
                break;
        }
        case KVM_MEMORY_ENCRYPT_REG_REGION: {
                struct kvm_enc_region region;

                r = -EFAULT;
                if (copy_from_user(&region, argp, sizeof(region)))
                        goto out;

                r = -ENOTTY;
                if (!kvm_x86_ops.mem_enc_register_region)
                        goto out;

                r = static_call(kvm_x86_mem_enc_register_region)(kvm, &region);
                break;
        }
        case KVM_MEMORY_ENCRYPT_UNREG_REGION: {
                struct kvm_enc_region region;

                r = -EFAULT;
                if (copy_from_user(&region, argp, sizeof(region)))
                        goto out;

                r = -ENOTTY;
                if (!kvm_x86_ops.mem_enc_unregister_region)
                        goto out;

                r = static_call(kvm_x86_mem_enc_unregister_region)(kvm, &region);
                break;
        }
        case KVM_HYPERV_EVENTFD: {
                struct kvm_hyperv_eventfd hvevfd;

                r = -EFAULT;
                if (copy_from_user(&hvevfd, argp, sizeof(hvevfd)))
                        goto out;
                r = kvm_vm_ioctl_hv_eventfd(kvm, &hvevfd);
                break;
        }
        case KVM_SET_PMU_EVENT_FILTER:
                r = kvm_vm_ioctl_set_pmu_event_filter(kvm, argp);
                break;
        case KVM_X86_SET_MSR_FILTER: {
                struct kvm_msr_filter __user *user_msr_filter = argp;
                struct kvm_msr_filter filter;

                if (copy_from_user(&filter, user_msr_filter, sizeof(filter)))
                        return -EFAULT;

                r = kvm_vm_ioctl_set_msr_filter(kvm, &filter);
                break;
        }
        default:
                r = -ENOTTY;
        }
out:
        return r;
}

static void kvm_init_msr_list(void)
{
        u32 dummy[2];
        unsigned i;

        BUILD_BUG_ON_MSG(KVM_PMC_MAX_FIXED != 3,
                         "Please update the fixed PMCs in msrs_to_saved_all[]");

        num_msrs_to_save = 0;
        num_emulated_msrs = 0;
        num_msr_based_features = 0;

        for (i = 0; i < ARRAY_SIZE(msrs_to_save_all); i++) {
                if (rdmsr_safe(msrs_to_save_all[i], &dummy[0], &dummy[1]) < 0)
                        continue;

                /*
                 * Even MSRs that are valid in the host may not be exposed
                 * to the guests in some cases.
                 */
                switch (msrs_to_save_all[i]) {
                case MSR_IA32_BNDCFGS:
                        if (!kvm_mpx_supported())
                                continue;
                        break;
                case MSR_TSC_AUX:
                        if (!kvm_cpu_cap_has(X86_FEATURE_RDTSCP) &&
                            !kvm_cpu_cap_has(X86_FEATURE_RDPID))
                                continue;
                        break;
                case MSR_IA32_UMWAIT_CONTROL:
                        if (!kvm_cpu_cap_has(X86_FEATURE_WAITPKG))
                                continue;
                        break;
                case MSR_IA32_RTIT_CTL:
                case MSR_IA32_RTIT_STATUS:
                        if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT))
                                continue;
                        break;
                case MSR_IA32_RTIT_CR3_MATCH:
                        if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT) ||
                            !intel_pt_validate_hw_cap(PT_CAP_cr3_filtering))
                                continue;
                        break;
                case MSR_IA32_RTIT_OUTPUT_BASE:
                case MSR_IA32_RTIT_OUTPUT_MASK:
                        if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT) ||
                                (!intel_pt_validate_hw_cap(PT_CAP_topa_output) &&
                                 !intel_pt_validate_hw_cap(PT_CAP_single_range_output)))
                                continue;
                        break;
                case MSR_IA32_RTIT_ADDR0_A ... MSR_IA32_RTIT_ADDR3_B:
                        if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT) ||
                                msrs_to_save_all[i] - MSR_IA32_RTIT_ADDR0_A >=
                                intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2)
                                continue;
                        break;
                case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR_MAX:
                        if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >=
                            min(KVM_INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp))
                                continue;
                        break;
                case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL_MAX:
                        if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >=
                            min(KVM_INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp))
                                continue;
                        break;
                case MSR_IA32_XFD:
                case MSR_IA32_XFD_ERR:
                        if (!kvm_cpu_cap_has(X86_FEATURE_XFD))
                                continue;
                        break;
                default:
                        break;
                }

                msrs_to_save[num_msrs_to_save++] = msrs_to_save_all[i];
        }

        for (i = 0; i < ARRAY_SIZE(emulated_msrs_all); i++) {
                if (!static_call(kvm_x86_has_emulated_msr)(NULL, emulated_msrs_all[i]))
                        continue;

                emulated_msrs[num_emulated_msrs++] = emulated_msrs_all[i];
        }

        for (i = 0; i < ARRAY_SIZE(msr_based_features_all); i++) {
                struct kvm_msr_entry msr;

                msr.index = msr_based_features_all[i];
                if (kvm_get_msr_feature(&msr))
                        continue;

                msr_based_features[num_msr_based_features++] = msr_based_features_all[i];
        }
}

static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len,
                           const void *v)
{
        int handled = 0;
        int n;

        do {
                n = min(len, 8);
                if (!(lapic_in_kernel(vcpu) &&
                      !kvm_iodevice_write(vcpu, &vcpu->arch.apic->dev, addr, n, v))
                    && kvm_io_bus_write(vcpu, KVM_MMIO_BUS, addr, n, v))
                        break;
                handled += n;
                addr += n;
                len -= n;
                v += n;
        } while (len);

        return handled;
}

static int vcpu_mmio_read(struct kvm_vcpu *vcpu, gpa_t addr, int len, void *v)
{
        int handled = 0;
        int n;

        do {
                n = min(len, 8);
                if (!(lapic_in_kernel(vcpu) &&
                      !kvm_iodevice_read(vcpu, &vcpu->arch.apic->dev,
                                         addr, n, v))
                    && kvm_io_bus_read(vcpu, KVM_MMIO_BUS, addr, n, v))
                        break;
                trace_kvm_mmio(KVM_TRACE_MMIO_READ, n, addr, v);
                handled += n;
                addr += n;
                len -= n;
                v += n;
        } while (len);

        return handled;
}

void kvm_set_segment(struct kvm_vcpu *vcpu,
                     struct kvm_segment *var, int seg)
{
        static_call(kvm_x86_set_segment)(vcpu, var, seg);
}

void kvm_get_segment(struct kvm_vcpu *vcpu,
                     struct kvm_segment *var, int seg)
{
        static_call(kvm_x86_get_segment)(vcpu, var, seg);
}

gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u64 access,
                           struct x86_exception *exception)
{
        struct kvm_mmu *mmu = vcpu->arch.mmu;
        gpa_t t_gpa;

        BUG_ON(!mmu_is_nested(vcpu));

        /* NPT walks are always user-walks */
        access |= PFERR_USER_MASK;
        t_gpa  = mmu->gva_to_gpa(vcpu, mmu, gpa, access, exception);

        return t_gpa;
}

gpa_t kvm_mmu_gva_to_gpa_read(struct kvm_vcpu *vcpu, gva_t gva,
                              struct x86_exception *exception)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        u64 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
        return mmu->gva_to_gpa(vcpu, mmu, gva, access, exception);
}
EXPORT_SYMBOL_GPL(kvm_mmu_gva_to_gpa_read);

gpa_t kvm_mmu_gva_to_gpa_write(struct kvm_vcpu *vcpu, gva_t gva,
                               struct x86_exception *exception)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        u64 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
        access |= PFERR_WRITE_MASK;
        return mmu->gva_to_gpa(vcpu, mmu, gva, access, exception);
}
EXPORT_SYMBOL_GPL(kvm_mmu_gva_to_gpa_write);

/* uses this to access any guest's mapped memory without checking CPL */
gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva,
                                struct x86_exception *exception)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;

        return mmu->gva_to_gpa(vcpu, mmu, gva, 0, exception);
}

static int kvm_read_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
                                      struct kvm_vcpu *vcpu, u64 access,
                                      struct x86_exception *exception)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
        void *data = val;
        int r = X86EMUL_CONTINUE;

        while (bytes) {
                gpa_t gpa = mmu->gva_to_gpa(vcpu, mmu, addr, access, exception);
                unsigned offset = addr & (PAGE_SIZE-1);
                unsigned toread = min(bytes, (unsigned)PAGE_SIZE - offset);
                int ret;

                if (gpa == INVALID_GPA)
                        return X86EMUL_PROPAGATE_FAULT;
                ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, data,
                                               offset, toread);
                if (ret < 0) {
                        r = X86EMUL_IO_NEEDED;
                        goto out;
                }

                bytes -= toread;
                data += toread;
                addr += toread;
        }
out:
        return r;
}

/* used for instruction fetching */
static int kvm_fetch_guest_virt(struct x86_emulate_ctxt *ctxt,
                                gva_t addr, void *val, unsigned int bytes,
                                struct x86_exception *exception)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
        u64 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;
        unsigned offset;
        int ret;

        /* Inline kvm_read_guest_virt_helper for speed.  */
        gpa_t gpa = mmu->gva_to_gpa(vcpu, mmu, addr, access|PFERR_FETCH_MASK,
                                    exception);
        if (unlikely(gpa == INVALID_GPA))
                return X86EMUL_PROPAGATE_FAULT;

        offset = addr & (PAGE_SIZE-1);
        if (WARN_ON(offset + bytes > PAGE_SIZE))
                bytes = (unsigned)PAGE_SIZE - offset;
        ret = kvm_vcpu_read_guest_page(vcpu, gpa >> PAGE_SHIFT, val,
                                       offset, bytes);
        if (unlikely(ret < 0))
                return X86EMUL_IO_NEEDED;

        return X86EMUL_CONTINUE;
}

int kvm_read_guest_virt(struct kvm_vcpu *vcpu,
                               gva_t addr, void *val, unsigned int bytes,
                               struct x86_exception *exception)
{
        u64 access = (static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0;

        /*
         * FIXME: this should call handle_emulation_failure if X86EMUL_IO_NEEDED
         * is returned, but our callers are not ready for that and they blindly
         * call kvm_inject_page_fault.  Ensure that they at least do not leak
         * uninitialized kernel stack memory into cr2 and error code.
         */
        memset(exception, 0, sizeof(*exception));
        return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access,
                                          exception);
}
EXPORT_SYMBOL_GPL(kvm_read_guest_virt);

static int emulator_read_std(struct x86_emulate_ctxt *ctxt,
                             gva_t addr, void *val, unsigned int bytes,
                             struct x86_exception *exception, bool system)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        u64 access = 0;

        if (system)
                access |= PFERR_IMPLICIT_ACCESS;
        else if (static_call(kvm_x86_get_cpl)(vcpu) == 3)
                access |= PFERR_USER_MASK;

        return kvm_read_guest_virt_helper(addr, val, bytes, vcpu, access, exception);
}

static int kvm_write_guest_virt_helper(gva_t addr, void *val, unsigned int bytes,
                                      struct kvm_vcpu *vcpu, u64 access,
                                      struct x86_exception *exception)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
        void *data = val;
        int r = X86EMUL_CONTINUE;

        while (bytes) {
                gpa_t gpa = mmu->gva_to_gpa(vcpu, mmu, addr, access, exception);
                unsigned offset = addr & (PAGE_SIZE-1);
                unsigned towrite = min(bytes, (unsigned)PAGE_SIZE - offset);
                int ret;

                if (gpa == INVALID_GPA)
                        return X86EMUL_PROPAGATE_FAULT;
                ret = kvm_vcpu_write_guest(vcpu, gpa, data, towrite);
                if (ret < 0) {
                        r = X86EMUL_IO_NEEDED;
                        goto out;
                }

                bytes -= towrite;
                data += towrite;
                addr += towrite;
        }
out:
        return r;
}

static int emulator_write_std(struct x86_emulate_ctxt *ctxt, gva_t addr, void *val,
                              unsigned int bytes, struct x86_exception *exception,
                              bool system)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        u64 access = PFERR_WRITE_MASK;

        if (system)
                access |= PFERR_IMPLICIT_ACCESS;
        else if (static_call(kvm_x86_get_cpl)(vcpu) == 3)
                access |= PFERR_USER_MASK;

        return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
                                           access, exception);
}

int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
                                unsigned int bytes, struct x86_exception *exception)
{
        /* kvm_write_guest_virt_system can pull in tons of pages. */
        vcpu->arch.l1tf_flush_l1d = true;

        return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
                                           PFERR_WRITE_MASK, exception);
}
EXPORT_SYMBOL_GPL(kvm_write_guest_virt_system);

static int kvm_can_emulate_insn(struct kvm_vcpu *vcpu, int emul_type,
                                void *insn, int insn_len)
{
        return static_call(kvm_x86_can_emulate_instruction)(vcpu, emul_type,
                                                            insn, insn_len);
}

int handle_ud(struct kvm_vcpu *vcpu)
{
        static const char kvm_emulate_prefix[] = { __KVM_EMULATE_PREFIX };
        int fep_flags = READ_ONCE(force_emulation_prefix);
        int emul_type = EMULTYPE_TRAP_UD;
        char sig[5]; /* ud2; .ascii "kvm" */
        struct x86_exception e;

        if (unlikely(!kvm_can_emulate_insn(vcpu, emul_type, NULL, 0)))
                return 1;

        if (fep_flags &&
            kvm_read_guest_virt(vcpu, kvm_get_linear_rip(vcpu),
                                sig, sizeof(sig), &e) == 0 &&
            memcmp(sig, kvm_emulate_prefix, sizeof(sig)) == 0) {
                if (fep_flags & KVM_FEP_CLEAR_RFLAGS_RF)
                        kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) & ~X86_EFLAGS_RF);
                kvm_rip_write(vcpu, kvm_rip_read(vcpu) + sizeof(sig));
                emul_type = EMULTYPE_TRAP_UD_FORCED;
        }

        return kvm_emulate_instruction(vcpu, emul_type);
}
EXPORT_SYMBOL_GPL(handle_ud);

static int vcpu_is_mmio_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
                            gpa_t gpa, bool write)
{
        /* For APIC access vmexit */
        if ((gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
                return 1;

        if (vcpu_match_mmio_gpa(vcpu, gpa)) {
                trace_vcpu_match_mmio(gva, gpa, write, true);
                return 1;
        }

        return 0;
}

static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
                                gpa_t *gpa, struct x86_exception *exception,
                                bool write)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
        u64 access = ((static_call(kvm_x86_get_cpl)(vcpu) == 3) ? PFERR_USER_MASK : 0)
                | (write ? PFERR_WRITE_MASK : 0);

        /*
         * currently PKRU is only applied to ept enabled guest so
         * there is no pkey in EPT page table for L1 guest or EPT
         * shadow page table for L2 guest.
         */
        if (vcpu_match_mmio_gva(vcpu, gva) && (!is_paging(vcpu) ||
            !permission_fault(vcpu, vcpu->arch.walk_mmu,
                              vcpu->arch.mmio_access, 0, access))) {
                *gpa = vcpu->arch.mmio_gfn << PAGE_SHIFT |
                                        (gva & (PAGE_SIZE - 1));
                trace_vcpu_match_mmio(gva, *gpa, write, false);
                return 1;
        }

        *gpa = mmu->gva_to_gpa(vcpu, mmu, gva, access, exception);

        if (*gpa == INVALID_GPA)
                return -1;

        return vcpu_is_mmio_gpa(vcpu, gva, *gpa, write);
}

int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
                        const void *val, int bytes)
{
        int ret;

        ret = kvm_vcpu_write_guest(vcpu, gpa, val, bytes);
        if (ret < 0)
                return 0;
        kvm_page_track_write(vcpu, gpa, val, bytes);
        return 1;
}

struct read_write_emulator_ops {
        int (*read_write_prepare)(struct kvm_vcpu *vcpu, void *val,
                                  int bytes);
        int (*read_write_emulate)(struct kvm_vcpu *vcpu, gpa_t gpa,
                                  void *val, int bytes);
        int (*read_write_mmio)(struct kvm_vcpu *vcpu, gpa_t gpa,
                               int bytes, void *val);
        int (*read_write_exit_mmio)(struct kvm_vcpu *vcpu, gpa_t gpa,
                                    void *val, int bytes);
        bool write;
};

static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes)
{
        if (vcpu->mmio_read_completed) {
                trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes,
                               vcpu->mmio_fragments[0].gpa, val);
                vcpu->mmio_read_completed = 0;
                return 1;
        }

        return 0;
}

static int read_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
                        void *val, int bytes)
{
        return !kvm_vcpu_read_guest(vcpu, gpa, val, bytes);
}

static int write_emulate(struct kvm_vcpu *vcpu, gpa_t gpa,
                         void *val, int bytes)
{
        return emulator_write_phys(vcpu, gpa, val, bytes);
}

static int write_mmio(struct kvm_vcpu *vcpu, gpa_t gpa, int bytes, void *val)
{
        trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, val);
        return vcpu_mmio_write(vcpu, gpa, bytes, val);
}

static int read_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
                          void *val, int bytes)
{
        trace_kvm_mmio(KVM_TRACE_MMIO_READ_UNSATISFIED, bytes, gpa, NULL);
        return X86EMUL_IO_NEEDED;
}

static int write_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
                           void *val, int bytes)
{
        struct kvm_mmio_fragment *frag = &vcpu->mmio_fragments[0];

        memcpy(vcpu->run->mmio.data, frag->data, min(8u, frag->len));
        return X86EMUL_CONTINUE;
}

static const struct read_write_emulator_ops read_emultor = {
        .read_write_prepare = read_prepare,
        .read_write_emulate = read_emulate,
        .read_write_mmio = vcpu_mmio_read,
        .read_write_exit_mmio = read_exit_mmio,
};

static const struct read_write_emulator_ops write_emultor = {
        .read_write_emulate = write_emulate,
        .read_write_mmio = write_mmio,
        .read_write_exit_mmio = write_exit_mmio,
        .write = true,
};

static int emulator_read_write_onepage(unsigned long addr, void *val,
                                       unsigned int bytes,
                                       struct x86_exception *exception,
                                       struct kvm_vcpu *vcpu,
                                       const struct read_write_emulator_ops *ops)
{
        gpa_t gpa;
        int handled, ret;
        bool write = ops->write;
        struct kvm_mmio_fragment *frag;
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;

        /*
         * If the exit was due to a NPF we may already have a GPA.
         * If the GPA is present, use it to avoid the GVA to GPA table walk.
         * Note, this cannot be used on string operations since string
         * operation using rep will only have the initial GPA from the NPF
         * occurred.
         */
        if (ctxt->gpa_available && emulator_can_use_gpa(ctxt) &&
            (addr & ~PAGE_MASK) == (ctxt->gpa_val & ~PAGE_MASK)) {
                gpa = ctxt->gpa_val;
                ret = vcpu_is_mmio_gpa(vcpu, addr, gpa, write);
        } else {
                ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
                if (ret < 0)
                        return X86EMUL_PROPAGATE_FAULT;
        }

        if (!ret && ops->read_write_emulate(vcpu, gpa, val, bytes))
                return X86EMUL_CONTINUE;

        /*
         * Is this MMIO handled locally?
         */
        handled = ops->read_write_mmio(vcpu, gpa, bytes, val);
        if (handled == bytes)
                return X86EMUL_CONTINUE;

        gpa += handled;
        bytes -= handled;
        val += handled;

        WARN_ON(vcpu->mmio_nr_fragments >= KVM_MAX_MMIO_FRAGMENTS);
        frag = &vcpu->mmio_fragments[vcpu->mmio_nr_fragments++];
        frag->gpa = gpa;
        frag->data = val;
        frag->len = bytes;
        return X86EMUL_CONTINUE;
}

static int emulator_read_write(struct x86_emulate_ctxt *ctxt,
                        unsigned long addr,
                        void *val, unsigned int bytes,
                        struct x86_exception *exception,
                        const struct read_write_emulator_ops *ops)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        gpa_t gpa;
        int rc;

        if (ops->read_write_prepare &&
                  ops->read_write_prepare(vcpu, val, bytes))
                return X86EMUL_CONTINUE;

        vcpu->mmio_nr_fragments = 0;

        /* Crossing a page boundary? */
        if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
                int now;

                now = -addr & ~PAGE_MASK;
                rc = emulator_read_write_onepage(addr, val, now, exception,
                                                 vcpu, ops);

                if (rc != X86EMUL_CONTINUE)
                        return rc;
                addr += now;
                if (ctxt->mode != X86EMUL_MODE_PROT64)
                        addr = (u32)addr;
                val += now;
                bytes -= now;
        }

        rc = emulator_read_write_onepage(addr, val, bytes, exception,
                                         vcpu, ops);
        if (rc != X86EMUL_CONTINUE)
                return rc;

        if (!vcpu->mmio_nr_fragments)
                return rc;

        gpa = vcpu->mmio_fragments[0].gpa;

        vcpu->mmio_needed = 1;
        vcpu->mmio_cur_fragment = 0;

        vcpu->run->mmio.len = min(8u, vcpu->mmio_fragments[0].len);
        vcpu->run->mmio.is_write = vcpu->mmio_is_write = ops->write;
        vcpu->run->exit_reason = KVM_EXIT_MMIO;
        vcpu->run->mmio.phys_addr = gpa;

        return ops->read_write_exit_mmio(vcpu, gpa, val, bytes);
}

static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt,
                                  unsigned long addr,
                                  void *val,
                                  unsigned int bytes,
                                  struct x86_exception *exception)
{
        return emulator_read_write(ctxt, addr, val, bytes,
                                   exception, &read_emultor);
}

static int emulator_write_emulated(struct x86_emulate_ctxt *ctxt,
                            unsigned long addr,
                            const void *val,
                            unsigned int bytes,
                            struct x86_exception *exception)
{
        return emulator_read_write(ctxt, addr, (void *)val, bytes,
                                   exception, &write_emultor);
}

#define emulator_try_cmpxchg_user(t, ptr, old, new) \
        (__try_cmpxchg_user((t __user *)(ptr), (t *)(old), *(t *)(new), efault ## t))

static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
                                     unsigned long addr,
                                     const void *old,
                                     const void *new,
                                     unsigned int bytes,
                                     struct x86_exception *exception)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        u64 page_line_mask;
        unsigned long hva;
        gpa_t gpa;
        int r;

        /* guests cmpxchg8b have to be emulated atomically */
        if (bytes > 8 || (bytes & (bytes - 1)))
                goto emul_write;

        gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, NULL);

        if (gpa == INVALID_GPA ||
            (gpa & PAGE_MASK) == APIC_DEFAULT_PHYS_BASE)
                goto emul_write;

        /*
         * Emulate the atomic as a straight write to avoid #AC if SLD is
         * enabled in the host and the access splits a cache line.
         */
        if (boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT))
                page_line_mask = ~(cache_line_size() - 1);
        else
                page_line_mask = PAGE_MASK;

        if (((gpa + bytes - 1) & page_line_mask) != (gpa & page_line_mask))
                goto emul_write;

        hva = kvm_vcpu_gfn_to_hva(vcpu, gpa_to_gfn(gpa));
        if (kvm_is_error_hva(hva))
                goto emul_write;

        hva += offset_in_page(gpa);

        switch (bytes) {
        case 1:
                r = emulator_try_cmpxchg_user(u8, hva, old, new);
                break;
        case 2:
                r = emulator_try_cmpxchg_user(u16, hva, old, new);
                break;
        case 4:
                r = emulator_try_cmpxchg_user(u32, hva, old, new);
                break;
        case 8:
                r = emulator_try_cmpxchg_user(u64, hva, old, new);
                break;
        default:
                BUG();
        }

        if (r < 0)
                return X86EMUL_UNHANDLEABLE;
        if (r)
                return X86EMUL_CMPXCHG_FAILED;

        kvm_page_track_write(vcpu, gpa, new, bytes);

        return X86EMUL_CONTINUE;

emul_write:
        printk_once(KERN_WARNING "kvm: emulating exchange as write\n");

        return emulator_write_emulated(ctxt, addr, new, bytes, exception);
}

static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
                               unsigned short port, void *data,
                               unsigned int count, bool in)
{
        unsigned i;
        int r;

        WARN_ON_ONCE(vcpu->arch.pio.count);
        for (i = 0; i < count; i++) {
                if (in)
                        r = kvm_io_bus_read(vcpu, KVM_PIO_BUS, port, size, data);
                else
                        r = kvm_io_bus_write(vcpu, KVM_PIO_BUS, port, size, data);

                if (r) {
                        if (i == 0)
                                goto userspace_io;

                        /*
                         * Userspace must have unregistered the device while PIO
                         * was running.  Drop writes / read as 0.
                         */
                        if (in)
                                memset(data, 0, size * (count - i));
                        break;
                }

                data += size;
        }
        return 1;

userspace_io:
        vcpu->arch.pio.port = port;
        vcpu->arch.pio.in = in;
        vcpu->arch.pio.count = count;
        vcpu->arch.pio.size = size;

        if (in)
                memset(vcpu->arch.pio_data, 0, size * count);
        else
                memcpy(vcpu->arch.pio_data, data, size * count);

        vcpu->run->exit_reason = KVM_EXIT_IO;
        vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
        vcpu->run->io.size = size;
        vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
        vcpu->run->io.count = count;
        vcpu->run->io.port = port;
        return 0;
}

static int emulator_pio_in(struct kvm_vcpu *vcpu, int size,
                           unsigned short port, void *val, unsigned int count)
{
        int r = emulator_pio_in_out(vcpu, size, port, val, count, true);
        if (r)
                trace_kvm_pio(KVM_PIO_IN, port, size, count, val);

        return r;
}

static void complete_emulator_pio_in(struct kvm_vcpu *vcpu, void *val)
{
        int size = vcpu->arch.pio.size;
        unsigned int count = vcpu->arch.pio.count;
        memcpy(val, vcpu->arch.pio_data, size * count);
        trace_kvm_pio(KVM_PIO_IN, vcpu->arch.pio.port, size, count, vcpu->arch.pio_data);
        vcpu->arch.pio.count = 0;
}

static int emulator_pio_in_emulated(struct x86_emulate_ctxt *ctxt,
                                    int size, unsigned short port, void *val,
                                    unsigned int count)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        if (vcpu->arch.pio.count) {
                /*
                 * Complete a previous iteration that required userspace I/O.
                 * Note, @count isn't guaranteed to match pio.count as userspace
                 * can modify ECX before rerunning the vCPU.  Ignore any such
                 * shenanigans as KVM doesn't support modifying the rep count,
                 * and the emulator ensures @count doesn't overflow the buffer.
                 */
                complete_emulator_pio_in(vcpu, val);
                return 1;
        }

        return emulator_pio_in(vcpu, size, port, val, count);
}

static int emulator_pio_out(struct kvm_vcpu *vcpu, int size,
                            unsigned short port, const void *val,
                            unsigned int count)
{
        trace_kvm_pio(KVM_PIO_OUT, port, size, count, val);
        return emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
}

static int emulator_pio_out_emulated(struct x86_emulate_ctxt *ctxt,
                                     int size, unsigned short port,
                                     const void *val, unsigned int count)
{
        return emulator_pio_out(emul_to_vcpu(ctxt), size, port, val, count);
}

static unsigned long get_segment_base(struct kvm_vcpu *vcpu, int seg)
{
        return static_call(kvm_x86_get_segment_base)(vcpu, seg);
}

static void emulator_invlpg(struct x86_emulate_ctxt *ctxt, ulong address)
{
        kvm_mmu_invlpg(emul_to_vcpu(ctxt), address);
}

static int kvm_emulate_wbinvd_noskip(struct kvm_vcpu *vcpu)
{
        if (!need_emulate_wbinvd(vcpu))
                return X86EMUL_CONTINUE;

        if (static_call(kvm_x86_has_wbinvd_exit)()) {
                int cpu = get_cpu();

                cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
                on_each_cpu_mask(vcpu->arch.wbinvd_dirty_mask,
                                wbinvd_ipi, NULL, 1);
                put_cpu();
                cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
        } else
                wbinvd();
        return X86EMUL_CONTINUE;
}

int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu)
{
        kvm_emulate_wbinvd_noskip(vcpu);
        return kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd);



static void emulator_wbinvd(struct x86_emulate_ctxt *ctxt)
{
        kvm_emulate_wbinvd_noskip(emul_to_vcpu(ctxt));
}

static void emulator_get_dr(struct x86_emulate_ctxt *ctxt, int dr,
                            unsigned long *dest)
{
        kvm_get_dr(emul_to_vcpu(ctxt), dr, dest);
}

static int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr,
                           unsigned long value)
{

        return kvm_set_dr(emul_to_vcpu(ctxt), dr, value);
}

static u64 mk_cr_64(u64 curr_cr, u32 new_val)
{
        return (curr_cr & ~((1ULL << 32) - 1)) | new_val;
}

static unsigned long emulator_get_cr(struct x86_emulate_ctxt *ctxt, int cr)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        unsigned long value;

        switch (cr) {
        case 0:
                value = kvm_read_cr0(vcpu);
                break;
        case 2:
                value = vcpu->arch.cr2;
                break;
        case 3:
                value = kvm_read_cr3(vcpu);
                break;
        case 4:
                value = kvm_read_cr4(vcpu);
                break;
        case 8:
                value = kvm_get_cr8(vcpu);
                break;
        default:
                kvm_err("%s: unexpected cr %u\n", __func__, cr);
                return 0;
        }

        return value;
}

static int emulator_set_cr(struct x86_emulate_ctxt *ctxt, int cr, ulong val)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        int res = 0;

        switch (cr) {
        case 0:
                res = kvm_set_cr0(vcpu, mk_cr_64(kvm_read_cr0(vcpu), val));
                break;
        case 2:
                vcpu->arch.cr2 = val;
                break;
        case 3:
                res = kvm_set_cr3(vcpu, val);
                break;
        case 4:
                res = kvm_set_cr4(vcpu, mk_cr_64(kvm_read_cr4(vcpu), val));
                break;
        case 8:
                res = kvm_set_cr8(vcpu, val);
                break;
        default:
                kvm_err("%s: unexpected cr %u\n", __func__, cr);
                res = -1;
        }

        return res;
}

static int emulator_get_cpl(struct x86_emulate_ctxt *ctxt)
{
        return static_call(kvm_x86_get_cpl)(emul_to_vcpu(ctxt));
}

static void emulator_get_gdt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
        static_call(kvm_x86_get_gdt)(emul_to_vcpu(ctxt), dt);
}

static void emulator_get_idt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
        static_call(kvm_x86_get_idt)(emul_to_vcpu(ctxt), dt);
}

static void emulator_set_gdt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
        static_call(kvm_x86_set_gdt)(emul_to_vcpu(ctxt), dt);
}

static void emulator_set_idt(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt)
{
        static_call(kvm_x86_set_idt)(emul_to_vcpu(ctxt), dt);
}

static unsigned long emulator_get_cached_segment_base(
        struct x86_emulate_ctxt *ctxt, int seg)
{
        return get_segment_base(emul_to_vcpu(ctxt), seg);
}

static bool emulator_get_segment(struct x86_emulate_ctxt *ctxt, u16 *selector,
                                 struct desc_struct *desc, u32 *base3,
                                 int seg)
{
        struct kvm_segment var;

        kvm_get_segment(emul_to_vcpu(ctxt), &var, seg);
        *selector = var.selector;

        if (var.unusable) {
                memset(desc, 0, sizeof(*desc));
                if (base3)
                        *base3 = 0;
                return false;
        }

        if (var.g)
                var.limit >>= 12;
        set_desc_limit(desc, var.limit);
        set_desc_base(desc, (unsigned long)var.base);
#ifdef CONFIG_X86_64
        if (base3)
                *base3 = var.base >> 32;
#endif
        desc->type = var.type;
        desc->s = var.s;
        desc->dpl = var.dpl;
        desc->p = var.present;
        desc->avl = var.avl;
        desc->l = var.l;
        desc->d = var.db;
        desc->g = var.g;

        return true;
}

static void emulator_set_segment(struct x86_emulate_ctxt *ctxt, u16 selector,
                                 struct desc_struct *desc, u32 base3,
                                 int seg)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        struct kvm_segment var;

        var.selector = selector;
        var.base = get_desc_base(desc);
#ifdef CONFIG_X86_64
        var.base |= ((u64)base3) << 32;
#endif
        var.limit = get_desc_limit(desc);
        if (desc->g)
                var.limit = (var.limit << 12) | 0xfff;
        var.type = desc->type;
        var.dpl = desc->dpl;
        var.db = desc->d;
        var.s = desc->s;
        var.l = desc->l;
        var.g = desc->g;
        var.avl = desc->avl;
        var.present = desc->p;
        var.unusable = !var.present;
        var.padding = 0;

        kvm_set_segment(vcpu, &var, seg);
        return;
}

static int emulator_get_msr_with_filter(struct x86_emulate_ctxt *ctxt,
                                        u32 msr_index, u64 *pdata)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        int r;

        r = kvm_get_msr_with_filter(vcpu, msr_index, pdata);
        if (r < 0)
                return X86EMUL_UNHANDLEABLE;

        if (r) {
                if (kvm_msr_user_space(vcpu, msr_index, KVM_EXIT_X86_RDMSR, 0,
                                       complete_emulated_rdmsr, r))
                        return X86EMUL_IO_NEEDED;

                trace_kvm_msr_read_ex(msr_index);
                return X86EMUL_PROPAGATE_FAULT;
        }

        trace_kvm_msr_read(msr_index, *pdata);
        return X86EMUL_CONTINUE;
}

static int emulator_set_msr_with_filter(struct x86_emulate_ctxt *ctxt,
                                        u32 msr_index, u64 data)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        int r;

        r = kvm_set_msr_with_filter(vcpu, msr_index, data);
        if (r < 0)
                return X86EMUL_UNHANDLEABLE;

        if (r) {
                if (kvm_msr_user_space(vcpu, msr_index, KVM_EXIT_X86_WRMSR, data,
                                       complete_emulated_msr_access, r))
                        return X86EMUL_IO_NEEDED;

                trace_kvm_msr_write_ex(msr_index, data);
                return X86EMUL_PROPAGATE_FAULT;
        }

        trace_kvm_msr_write(msr_index, data);
        return X86EMUL_CONTINUE;
}

static int emulator_get_msr(struct x86_emulate_ctxt *ctxt,
                            u32 msr_index, u64 *pdata)
{
        return kvm_get_msr(emul_to_vcpu(ctxt), msr_index, pdata);
}

static int emulator_check_pmc(struct x86_emulate_ctxt *ctxt,
                              u32 pmc)
{
        if (kvm_pmu_is_valid_rdpmc_ecx(emul_to_vcpu(ctxt), pmc))
                return 0;
        return -EINVAL;
}

static int emulator_read_pmc(struct x86_emulate_ctxt *ctxt,
                             u32 pmc, u64 *pdata)
{
        return kvm_pmu_rdpmc(emul_to_vcpu(ctxt), pmc, pdata);
}

static void emulator_halt(struct x86_emulate_ctxt *ctxt)
{
        emul_to_vcpu(ctxt)->arch.halt_request = 1;
}

static int emulator_intercept(struct x86_emulate_ctxt *ctxt,
                              struct x86_instruction_info *info,
                              enum x86_intercept_stage stage)
{
        return static_call(kvm_x86_check_intercept)(emul_to_vcpu(ctxt), info, stage,
                                            &ctxt->exception);
}

static bool emulator_get_cpuid(struct x86_emulate_ctxt *ctxt,
                              u32 *eax, u32 *ebx, u32 *ecx, u32 *edx,
                              bool exact_only)
{
        return kvm_cpuid(emul_to_vcpu(ctxt), eax, ebx, ecx, edx, exact_only);
}

static bool emulator_guest_has_long_mode(struct x86_emulate_ctxt *ctxt)
{
        return guest_cpuid_has(emul_to_vcpu(ctxt), X86_FEATURE_LM);
}

static bool emulator_guest_has_movbe(struct x86_emulate_ctxt *ctxt)
{
        return guest_cpuid_has(emul_to_vcpu(ctxt), X86_FEATURE_MOVBE);
}

static bool emulator_guest_has_fxsr(struct x86_emulate_ctxt *ctxt)
{
        return guest_cpuid_has(emul_to_vcpu(ctxt), X86_FEATURE_FXSR);
}

static bool emulator_guest_has_rdpid(struct x86_emulate_ctxt *ctxt)
{
        return guest_cpuid_has(emul_to_vcpu(ctxt), X86_FEATURE_RDPID);
}

static ulong emulator_read_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg)
{
        return kvm_register_read_raw(emul_to_vcpu(ctxt), reg);
}

static void emulator_write_gpr(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val)
{
        kvm_register_write_raw(emul_to_vcpu(ctxt), reg, val);
}

static void emulator_set_nmi_mask(struct x86_emulate_ctxt *ctxt, bool masked)
{
        static_call(kvm_x86_set_nmi_mask)(emul_to_vcpu(ctxt), masked);
}

static unsigned emulator_get_hflags(struct x86_emulate_ctxt *ctxt)
{
        return emul_to_vcpu(ctxt)->arch.hflags;
}

#ifndef CONFIG_KVM_SMM
static int emulator_leave_smm(struct x86_emulate_ctxt *ctxt)
{
        WARN_ON_ONCE(1);
        return X86EMUL_UNHANDLEABLE;
}
#endif

static void emulator_triple_fault(struct x86_emulate_ctxt *ctxt)
{
        kvm_make_request(KVM_REQ_TRIPLE_FAULT, emul_to_vcpu(ctxt));
}

static int emulator_set_xcr(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr)
{
        return __kvm_set_xcr(emul_to_vcpu(ctxt), index, xcr);
}

static void emulator_vm_bugged(struct x86_emulate_ctxt *ctxt)
{
        struct kvm *kvm = emul_to_vcpu(ctxt)->kvm;

        if (!kvm->vm_bugged)
                kvm_vm_bugged(kvm);
}

static const struct x86_emulate_ops emulate_ops = {
        .vm_bugged           = emulator_vm_bugged,
        .read_gpr            = emulator_read_gpr,
        .write_gpr           = emulator_write_gpr,
        .read_std            = emulator_read_std,
        .write_std           = emulator_write_std,
        .fetch               = kvm_fetch_guest_virt,
        .read_emulated       = emulator_read_emulated,
        .write_emulated      = emulator_write_emulated,
        .cmpxchg_emulated    = emulator_cmpxchg_emulated,
        .invlpg              = emulator_invlpg,
        .pio_in_emulated     = emulator_pio_in_emulated,
        .pio_out_emulated    = emulator_pio_out_emulated,
        .get_segment         = emulator_get_segment,
        .set_segment         = emulator_set_segment,
        .get_cached_segment_base = emulator_get_cached_segment_base,
        .get_gdt             = emulator_get_gdt,
        .get_idt             = emulator_get_idt,
        .set_gdt             = emulator_set_gdt,
        .set_idt             = emulator_set_idt,
        .get_cr              = emulator_get_cr,
        .set_cr              = emulator_set_cr,
        .cpl                 = emulator_get_cpl,
        .get_dr              = emulator_get_dr,
        .set_dr              = emulator_set_dr,
        .set_msr_with_filter = emulator_set_msr_with_filter,
        .get_msr_with_filter = emulator_get_msr_with_filter,
        .get_msr             = emulator_get_msr,
        .check_pmc           = emulator_check_pmc,
        .read_pmc            = emulator_read_pmc,
        .halt                = emulator_halt,
        .wbinvd              = emulator_wbinvd,
        .fix_hypercall       = emulator_fix_hypercall,
        .intercept           = emulator_intercept,
        .get_cpuid           = emulator_get_cpuid,
        .guest_has_long_mode = emulator_guest_has_long_mode,
        .guest_has_movbe     = emulator_guest_has_movbe,
        .guest_has_fxsr      = emulator_guest_has_fxsr,
        .guest_has_rdpid     = emulator_guest_has_rdpid,
        .set_nmi_mask        = emulator_set_nmi_mask,
        .get_hflags          = emulator_get_hflags,
        .leave_smm           = emulator_leave_smm,
        .triple_fault        = emulator_triple_fault,
        .set_xcr             = emulator_set_xcr,
};

static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)
{
        u32 int_shadow = static_call(kvm_x86_get_interrupt_shadow)(vcpu);
        /*
         * an sti; sti; sequence only disable interrupts for the first
         * instruction. So, if the last instruction, be it emulated or
         * not, left the system with the INT_STI flag enabled, it
         * means that the last instruction is an sti. We should not
         * leave the flag on in this case. The same goes for mov ss
         */
        if (int_shadow & mask)
                mask = 0;
        if (unlikely(int_shadow || mask)) {
                static_call(kvm_x86_set_interrupt_shadow)(vcpu, mask);
                if (!mask)
                        kvm_make_request(KVM_REQ_EVENT, vcpu);
        }
}

static void inject_emulated_exception(struct kvm_vcpu *vcpu)
{
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;

        if (ctxt->exception.vector == PF_VECTOR)
                kvm_inject_emulated_page_fault(vcpu, &ctxt->exception);
        else if (ctxt->exception.error_code_valid)
                kvm_queue_exception_e(vcpu, ctxt->exception.vector,
                                      ctxt->exception.error_code);
        else
                kvm_queue_exception(vcpu, ctxt->exception.vector);
}

static struct x86_emulate_ctxt *alloc_emulate_ctxt(struct kvm_vcpu *vcpu)
{
        struct x86_emulate_ctxt *ctxt;

        ctxt = kmem_cache_zalloc(x86_emulator_cache, GFP_KERNEL_ACCOUNT);
        if (!ctxt) {
                pr_err("kvm: failed to allocate vcpu's emulator\n");
                return NULL;
        }

        ctxt->vcpu = vcpu;
        ctxt->ops = &emulate_ops;
        vcpu->arch.emulate_ctxt = ctxt;

        return ctxt;
}

static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
{
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
        int cs_db, cs_l;

        static_call(kvm_x86_get_cs_db_l_bits)(vcpu, &cs_db, &cs_l);

        ctxt->gpa_available = false;
        ctxt->eflags = kvm_get_rflags(vcpu);
        ctxt->tf = (ctxt->eflags & X86_EFLAGS_TF) != 0;

        ctxt->eip = kvm_rip_read(vcpu);
        ctxt->mode = (!is_protmode(vcpu))               ? X86EMUL_MODE_REAL :
                     (ctxt->eflags & X86_EFLAGS_VM)     ? X86EMUL_MODE_VM86 :
                     (cs_l && is_long_mode(vcpu))       ? X86EMUL_MODE_PROT64 :
                     cs_db                              ? X86EMUL_MODE_PROT32 :
                                                          X86EMUL_MODE_PROT16;
        BUILD_BUG_ON(HF_GUEST_MASK != X86EMUL_GUEST_MASK);

        ctxt->interruptibility = 0;
        ctxt->have_exception = false;
        ctxt->exception.vector = -1;
        ctxt->perm_ok = false;

        init_decode_cache(ctxt);
        vcpu->arch.emulate_regs_need_sync_from_vcpu = false;
}

void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip)
{
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
        int ret;

        init_emulate_ctxt(vcpu);

        ctxt->op_bytes = 2;
        ctxt->ad_bytes = 2;
        ctxt->_eip = ctxt->eip + inc_eip;
        ret = emulate_int_real(ctxt, irq);

        if (ret != X86EMUL_CONTINUE) {
                kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
        } else {
                ctxt->eip = ctxt->_eip;
                kvm_rip_write(vcpu, ctxt->eip);
                kvm_set_rflags(vcpu, ctxt->eflags);
        }
}
EXPORT_SYMBOL_GPL(kvm_inject_realmode_interrupt);

static void prepare_emulation_failure_exit(struct kvm_vcpu *vcpu, u64 *data,
                                           u8 ndata, u8 *insn_bytes, u8 insn_size)
{
        struct kvm_run *run = vcpu->run;
        u64 info[5];
        u8 info_start;

        /*
         * Zero the whole array used to retrieve the exit info, as casting to
         * u32 for select entries will leave some chunks uninitialized.
         */
        memset(&info, 0, sizeof(info));

        static_call(kvm_x86_get_exit_info)(vcpu, (u32 *)&info[0], &info[1],
                                           &info[2], (u32 *)&info[3],
                                           (u32 *)&info[4]);

        run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
        run->emulation_failure.suberror = KVM_INTERNAL_ERROR_EMULATION;

        /*
         * There's currently space for 13 entries, but 5 are used for the exit
         * reason and info.  Restrict to 4 to reduce the maintenance burden
         * when expanding kvm_run.emulation_failure in the future.
         */
        if (WARN_ON_ONCE(ndata > 4))
                ndata = 4;

        /* Always include the flags as a 'data' entry. */
        info_start = 1;
        run->emulation_failure.flags = 0;

        if (insn_size) {
                BUILD_BUG_ON((sizeof(run->emulation_failure.insn_size) +
                              sizeof(run->emulation_failure.insn_bytes) != 16));
                info_start += 2;
                run->emulation_failure.flags |=
                        KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES;
                run->emulation_failure.insn_size = insn_size;
                memset(run->emulation_failure.insn_bytes, 0x90,
                       sizeof(run->emulation_failure.insn_bytes));
                memcpy(run->emulation_failure.insn_bytes, insn_bytes, insn_size);
        }

        memcpy(&run->internal.data[info_start], info, sizeof(info));
        memcpy(&run->internal.data[info_start + ARRAY_SIZE(info)], data,
               ndata * sizeof(data[0]));

        run->emulation_failure.ndata = info_start + ARRAY_SIZE(info) + ndata;
}

static void prepare_emulation_ctxt_failure_exit(struct kvm_vcpu *vcpu)
{
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;

        prepare_emulation_failure_exit(vcpu, NULL, 0, ctxt->fetch.data,
                                       ctxt->fetch.end - ctxt->fetch.data);
}

void __kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu, u64 *data,
                                          u8 ndata)
{
        prepare_emulation_failure_exit(vcpu, data, ndata, NULL, 0);
}
EXPORT_SYMBOL_GPL(__kvm_prepare_emulation_failure_exit);

void kvm_prepare_emulation_failure_exit(struct kvm_vcpu *vcpu)
{
        __kvm_prepare_emulation_failure_exit(vcpu, NULL, 0);
}
EXPORT_SYMBOL_GPL(kvm_prepare_emulation_failure_exit);

static int handle_emulation_failure(struct kvm_vcpu *vcpu, int emulation_type)
{
        struct kvm *kvm = vcpu->kvm;

        ++vcpu->stat.insn_emulation_fail;
        trace_kvm_emulate_insn_failed(vcpu);

        if (emulation_type & EMULTYPE_VMWARE_GP) {
                kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
                return 1;
        }

        if (kvm->arch.exit_on_emulation_error ||
            (emulation_type & EMULTYPE_SKIP)) {
                prepare_emulation_ctxt_failure_exit(vcpu);
                return 0;
        }

        kvm_queue_exception(vcpu, UD_VECTOR);

        if (!is_guest_mode(vcpu) && static_call(kvm_x86_get_cpl)(vcpu) == 0) {
                prepare_emulation_ctxt_failure_exit(vcpu);
                return 0;
        }

        return 1;
}

static bool reexecute_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
                                  bool write_fault_to_shadow_pgtable,
                                  int emulation_type)
{
        gpa_t gpa = cr2_or_gpa;
        kvm_pfn_t pfn;

        if (!(emulation_type & EMULTYPE_ALLOW_RETRY_PF))
                return false;

        if (WARN_ON_ONCE(is_guest_mode(vcpu)) ||
            WARN_ON_ONCE(!(emulation_type & EMULTYPE_PF)))
                return false;

        if (!vcpu->arch.mmu->root_role.direct) {
                /*
                 * Write permission should be allowed since only
                 * write access need to be emulated.
                 */
                gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2_or_gpa, NULL);

                /*
                 * If the mapping is invalid in guest, let cpu retry
                 * it to generate fault.
                 */
                if (gpa == INVALID_GPA)
                        return true;
        }

        /*
         * Do not retry the unhandleable instruction if it faults on the
         * readonly host memory, otherwise it will goto a infinite loop:
         * retry instruction -> write #PF -> emulation fail -> retry
         * instruction -> ...
         */
        pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa));

        /*
         * If the instruction failed on the error pfn, it can not be fixed,
         * report the error to userspace.
         */
        if (is_error_noslot_pfn(pfn))
                return false;

        kvm_release_pfn_clean(pfn);

        /* The instructions are well-emulated on direct mmu. */
        if (vcpu->arch.mmu->root_role.direct) {
                unsigned int indirect_shadow_pages;

                write_lock(&vcpu->kvm->mmu_lock);
                indirect_shadow_pages = vcpu->kvm->arch.indirect_shadow_pages;
                write_unlock(&vcpu->kvm->mmu_lock);

                if (indirect_shadow_pages)
                        kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));

                return true;
        }

        /*
         * if emulation was due to access to shadowed page table
         * and it failed try to unshadow page and re-enter the
         * guest to let CPU execute the instruction.
         */
        kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));

        /*
         * If the access faults on its page table, it can not
         * be fixed by unprotecting shadow page and it should
         * be reported to userspace.
         */
        return !write_fault_to_shadow_pgtable;
}

static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
                              gpa_t cr2_or_gpa,  int emulation_type)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        unsigned long last_retry_eip, last_retry_addr, gpa = cr2_or_gpa;

        last_retry_eip = vcpu->arch.last_retry_eip;
        last_retry_addr = vcpu->arch.last_retry_addr;

        /*
         * If the emulation is caused by #PF and it is non-page_table
         * writing instruction, it means the VM-EXIT is caused by shadow
         * page protected, we can zap the shadow page and retry this
         * instruction directly.
         *
         * Note: if the guest uses a non-page-table modifying instruction
         * on the PDE that points to the instruction, then we will unmap
         * the instruction and go to an infinite loop. So, we cache the
         * last retried eip and the last fault address, if we meet the eip
         * and the address again, we can break out of the potential infinite
         * loop.
         */
        vcpu->arch.last_retry_eip = vcpu->arch.last_retry_addr = 0;

        if (!(emulation_type & EMULTYPE_ALLOW_RETRY_PF))
                return false;

        if (WARN_ON_ONCE(is_guest_mode(vcpu)) ||
            WARN_ON_ONCE(!(emulation_type & EMULTYPE_PF)))
                return false;

        if (x86_page_table_writing_insn(ctxt))
                return false;

        if (ctxt->eip == last_retry_eip && last_retry_addr == cr2_or_gpa)
                return false;

        vcpu->arch.last_retry_eip = ctxt->eip;
        vcpu->arch.last_retry_addr = cr2_or_gpa;

        if (!vcpu->arch.mmu->root_role.direct)
                gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2_or_gpa, NULL);

        kvm_mmu_unprotect_page(vcpu->kvm, gpa_to_gfn(gpa));

        return true;
}

static int complete_emulated_mmio(struct kvm_vcpu *vcpu);
static int complete_emulated_pio(struct kvm_vcpu *vcpu);

static int kvm_vcpu_check_hw_bp(unsigned long addr, u32 type, u32 dr7,
                                unsigned long *db)
{
        u32 dr6 = 0;
        int i;
        u32 enable, rwlen;

        enable = dr7;
        rwlen = dr7 >> 16;
        for (i = 0; i < 4; i++, enable >>= 2, rwlen >>= 4)
                if ((enable & 3) && (rwlen & 15) == type && db[i] == addr)
                        dr6 |= (1 << i);
        return dr6;
}

static int kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu)
{
        struct kvm_run *kvm_run = vcpu->run;

        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
                kvm_run->debug.arch.dr6 = DR6_BS | DR6_ACTIVE_LOW;
                kvm_run->debug.arch.pc = kvm_get_linear_rip(vcpu);
                kvm_run->debug.arch.exception = DB_VECTOR;
                kvm_run->exit_reason = KVM_EXIT_DEBUG;
                return 0;
        }
        kvm_queue_exception_p(vcpu, DB_VECTOR, DR6_BS);
        return 1;
}

int kvm_skip_emulated_instruction(struct kvm_vcpu *vcpu)
{
        unsigned long rflags = static_call(kvm_x86_get_rflags)(vcpu);
        int r;

        r = static_call(kvm_x86_skip_emulated_instruction)(vcpu);
        if (unlikely(!r))
                return 0;

        kvm_pmu_trigger_event(vcpu, PERF_COUNT_HW_INSTRUCTIONS);

        /*
         * rflags is the old, "raw" value of the flags.  The new value has
         * not been saved yet.
         *
         * This is correct even for TF set by the guest, because "the
         * processor will not generate this exception after the instruction
         * that sets the TF flag".
         */
        if (unlikely(rflags & X86_EFLAGS_TF))
                r = kvm_vcpu_do_singlestep(vcpu);
        return r;
}
EXPORT_SYMBOL_GPL(kvm_skip_emulated_instruction);

static bool kvm_is_code_breakpoint_inhibited(struct kvm_vcpu *vcpu)
{
        u32 shadow;

        if (kvm_get_rflags(vcpu) & X86_EFLAGS_RF)
                return true;

        /*
         * Intel CPUs inhibit code #DBs when MOV/POP SS blocking is active,
         * but AMD CPUs do not.  MOV/POP SS blocking is rare, check that first
         * to avoid the relatively expensive CPUID lookup.
         */
        shadow = static_call(kvm_x86_get_interrupt_shadow)(vcpu);
        return (shadow & KVM_X86_SHADOW_INT_MOV_SS) &&
               guest_cpuid_is_intel(vcpu);
}

static bool kvm_vcpu_check_code_breakpoint(struct kvm_vcpu *vcpu,
                                           int emulation_type, int *r)
{
        WARN_ON_ONCE(emulation_type & EMULTYPE_NO_DECODE);

        /*
         * Do not check for code breakpoints if hardware has already done the
         * checks, as inferred from the emulation type.  On NO_DECODE and SKIP,
         * the instruction has passed all exception checks, and all intercepted
         * exceptions that trigger emulation have lower priority than code
         * breakpoints, i.e. the fact that the intercepted exception occurred
         * means any code breakpoints have already been serviced.
         *
         * Note, KVM needs to check for code #DBs on EMULTYPE_TRAP_UD_FORCED as
         * hardware has checked the RIP of the magic prefix, but not the RIP of
         * the instruction being emulated.  The intent of forced emulation is
         * to behave as if KVM intercepted the instruction without an exception
         * and without a prefix.
         */
        if (emulation_type & (EMULTYPE_NO_DECODE | EMULTYPE_SKIP |
                              EMULTYPE_TRAP_UD | EMULTYPE_VMWARE_GP | EMULTYPE_PF))
                return false;

        if (unlikely(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) &&
            (vcpu->arch.guest_debug_dr7 & DR7_BP_EN_MASK)) {
                struct kvm_run *kvm_run = vcpu->run;
                unsigned long eip = kvm_get_linear_rip(vcpu);
                u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0,
                                           vcpu->arch.guest_debug_dr7,
                                           vcpu->arch.eff_db);

                if (dr6 != 0) {
                        kvm_run->debug.arch.dr6 = dr6 | DR6_ACTIVE_LOW;
                        kvm_run->debug.arch.pc = eip;
                        kvm_run->debug.arch.exception = DB_VECTOR;
                        kvm_run->exit_reason = KVM_EXIT_DEBUG;
                        *r = 0;
                        return true;
                }
        }

        if (unlikely(vcpu->arch.dr7 & DR7_BP_EN_MASK) &&
            !kvm_is_code_breakpoint_inhibited(vcpu)) {
                unsigned long eip = kvm_get_linear_rip(vcpu);
                u32 dr6 = kvm_vcpu_check_hw_bp(eip, 0,
                                           vcpu->arch.dr7,
                                           vcpu->arch.db);

                if (dr6 != 0) {
                        kvm_queue_exception_p(vcpu, DB_VECTOR, dr6);
                        *r = 1;
                        return true;
                }
        }

        return false;
}

static bool is_vmware_backdoor_opcode(struct x86_emulate_ctxt *ctxt)
{
        switch (ctxt->opcode_len) {
        case 1:
                switch (ctxt->b) {
                case 0xe4:      /* IN */
                case 0xe5:
                case 0xec:
                case 0xed:
                case 0xe6:      /* OUT */
                case 0xe7:
                case 0xee:
                case 0xef:
                case 0x6c:      /* INS */
                case 0x6d:
                case 0x6e:      /* OUTS */
                case 0x6f:
                        return true;
                }
                break;
        case 2:
                switch (ctxt->b) {
                case 0x33:      /* RDPMC */
                        return true;
                }
                break;
        }

        return false;
}

/*
 * Decode an instruction for emulation.  The caller is responsible for handling
 * code breakpoints.  Note, manually detecting code breakpoints is unnecessary
 * (and wrong) when emulating on an intercepted fault-like exception[*], as
 * code breakpoints have higher priority and thus have already been done by
 * hardware.
 *
 * [*] Except #MC, which is higher priority, but KVM should never emulate in
 *     response to a machine check.
 */
int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type,
                                    void *insn, int insn_len)
{
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
        int r;

        init_emulate_ctxt(vcpu);

        r = x86_decode_insn(ctxt, insn, insn_len, emulation_type);

        trace_kvm_emulate_insn_start(vcpu);
        ++vcpu->stat.insn_emulation;

        return r;
}
EXPORT_SYMBOL_GPL(x86_decode_emulated_instruction);

int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
                            int emulation_type, void *insn, int insn_len)
{
        int r;
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
        bool writeback = true;
        bool write_fault_to_spt;

        if (unlikely(!kvm_can_emulate_insn(vcpu, emulation_type, insn, insn_len)))
                return 1;

        vcpu->arch.l1tf_flush_l1d = true;

        /*
         * Clear write_fault_to_shadow_pgtable here to ensure it is
         * never reused.
         */
        write_fault_to_spt = vcpu->arch.write_fault_to_shadow_pgtable;
        vcpu->arch.write_fault_to_shadow_pgtable = false;

        if (!(emulation_type & EMULTYPE_NO_DECODE)) {
                kvm_clear_exception_queue(vcpu);

                /*
                 * Return immediately if RIP hits a code breakpoint, such #DBs
                 * are fault-like and are higher priority than any faults on
                 * the code fetch itself.
                 */
                if (kvm_vcpu_check_code_breakpoint(vcpu, emulation_type, &r))
                        return r;

                r = x86_decode_emulated_instruction(vcpu, emulation_type,
                                                    insn, insn_len);
                if (r != EMULATION_OK)  {
                        if ((emulation_type & EMULTYPE_TRAP_UD) ||
                            (emulation_type & EMULTYPE_TRAP_UD_FORCED)) {
                                kvm_queue_exception(vcpu, UD_VECTOR);
                                return 1;
                        }
                        if (reexecute_instruction(vcpu, cr2_or_gpa,
                                                  write_fault_to_spt,
                                                  emulation_type))
                                return 1;

                        if (ctxt->have_exception &&
                            !(emulation_type & EMULTYPE_SKIP)) {
                                /*
                                 * #UD should result in just EMULATION_FAILED, and trap-like
                                 * exception should not be encountered during decode.
                                 */
                                WARN_ON_ONCE(ctxt->exception.vector == UD_VECTOR ||
                                             exception_type(ctxt->exception.vector) == EXCPT_TRAP);
                                inject_emulated_exception(vcpu);
                                return 1;
                        }
                        return handle_emulation_failure(vcpu, emulation_type);
                }
        }

        if ((emulation_type & EMULTYPE_VMWARE_GP) &&
            !is_vmware_backdoor_opcode(ctxt)) {
                kvm_queue_exception_e(vcpu, GP_VECTOR, 0);
                return 1;
        }

        /*
         * EMULTYPE_SKIP without EMULTYPE_COMPLETE_USER_EXIT is intended for
         * use *only* by vendor callbacks for kvm_skip_emulated_instruction().
         * The caller is responsible for updating interruptibility state and
         * injecting single-step #DBs.
         */
        if (emulation_type & EMULTYPE_SKIP) {
                if (ctxt->mode != X86EMUL_MODE_PROT64)
                        ctxt->eip = (u32)ctxt->_eip;
                else
                        ctxt->eip = ctxt->_eip;

                if (emulation_type & EMULTYPE_COMPLETE_USER_EXIT) {
                        r = 1;
                        goto writeback;
                }

                kvm_rip_write(vcpu, ctxt->eip);
                if (ctxt->eflags & X86_EFLAGS_RF)
                        kvm_set_rflags(vcpu, ctxt->eflags & ~X86_EFLAGS_RF);
                return 1;
        }

        if (retry_instruction(ctxt, cr2_or_gpa, emulation_type))
                return 1;

        /* this is needed for vmware backdoor interface to work since it
           changes registers values  during IO operation */
        if (vcpu->arch.emulate_regs_need_sync_from_vcpu) {
                vcpu->arch.emulate_regs_need_sync_from_vcpu = false;
                emulator_invalidate_register_cache(ctxt);
        }

restart:
        if (emulation_type & EMULTYPE_PF) {
                /* Save the faulting GPA (cr2) in the address field */
                ctxt->exception.address = cr2_or_gpa;

                /* With shadow page tables, cr2 contains a GVA or nGPA. */
                if (vcpu->arch.mmu->root_role.direct) {
                        ctxt->gpa_available = true;
                        ctxt->gpa_val = cr2_or_gpa;
                }
        } else {
                /* Sanitize the address out of an abundance of paranoia. */
                ctxt->exception.address = 0;
        }

        r = x86_emulate_insn(ctxt);

        if (r == EMULATION_INTERCEPTED)
                return 1;

        if (r == EMULATION_FAILED) {
                if (reexecute_instruction(vcpu, cr2_or_gpa, write_fault_to_spt,
                                        emulation_type))
                        return 1;

                return handle_emulation_failure(vcpu, emulation_type);
        }

        if (ctxt->have_exception) {
                r = 1;
                inject_emulated_exception(vcpu);
        } else if (vcpu->arch.pio.count) {
                if (!vcpu->arch.pio.in) {
                        /* FIXME: return into emulator if single-stepping.  */
                        vcpu->arch.pio.count = 0;
                } else {
                        writeback = false;
                        vcpu->arch.complete_userspace_io = complete_emulated_pio;
                }
                r = 0;
        } else if (vcpu->mmio_needed) {
                ++vcpu->stat.mmio_exits;

                if (!vcpu->mmio_is_write)
                        writeback = false;
                r = 0;
                vcpu->arch.complete_userspace_io = complete_emulated_mmio;
        } else if (vcpu->arch.complete_userspace_io) {
                writeback = false;
                r = 0;
        } else if (r == EMULATION_RESTART)
                goto restart;
        else
                r = 1;

writeback:
        if (writeback) {
                unsigned long rflags = static_call(kvm_x86_get_rflags)(vcpu);
                toggle_interruptibility(vcpu, ctxt->interruptibility);
                vcpu->arch.emulate_regs_need_sync_to_vcpu = false;

                /*
                 * Note, EXCPT_DB is assumed to be fault-like as the emulator
                 * only supports code breakpoints and general detect #DB, both
                 * of which are fault-like.
                 */
                if (!ctxt->have_exception ||
                    exception_type(ctxt->exception.vector) == EXCPT_TRAP) {
                        kvm_pmu_trigger_event(vcpu, PERF_COUNT_HW_INSTRUCTIONS);
                        if (ctxt->is_branch)
                                kvm_pmu_trigger_event(vcpu, PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
                        kvm_rip_write(vcpu, ctxt->eip);
                        if (r && (ctxt->tf || (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)))
                                r = kvm_vcpu_do_singlestep(vcpu);
                        static_call_cond(kvm_x86_update_emulated_instruction)(vcpu);
                        __kvm_set_rflags(vcpu, ctxt->eflags);
                }

                /*
                 * For STI, interrupts are shadowed; so KVM_REQ_EVENT will
                 * do nothing, and it will be requested again as soon as
                 * the shadow expires.  But we still need to check here,
                 * because POPF has no interrupt shadow.
                 */
                if (unlikely((ctxt->eflags & ~rflags) & X86_EFLAGS_IF))
                        kvm_make_request(KVM_REQ_EVENT, vcpu);
        } else
                vcpu->arch.emulate_regs_need_sync_to_vcpu = true;

        return r;
}

int kvm_emulate_instruction(struct kvm_vcpu *vcpu, int emulation_type)
{
        return x86_emulate_instruction(vcpu, 0, emulation_type, NULL, 0);
}
EXPORT_SYMBOL_GPL(kvm_emulate_instruction);

int kvm_emulate_instruction_from_buffer(struct kvm_vcpu *vcpu,
                                        void *insn, int insn_len)
{
        return x86_emulate_instruction(vcpu, 0, 0, insn, insn_len);
}
EXPORT_SYMBOL_GPL(kvm_emulate_instruction_from_buffer);

static int complete_fast_pio_out_port_0x7e(struct kvm_vcpu *vcpu)
{
        vcpu->arch.pio.count = 0;
        return 1;
}

static int complete_fast_pio_out(struct kvm_vcpu *vcpu)
{
        vcpu->arch.pio.count = 0;

        if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.pio.linear_rip)))
                return 1;

        return kvm_skip_emulated_instruction(vcpu);
}

static int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size,
                            unsigned short port)
{
        unsigned long val = kvm_rax_read(vcpu);
        int ret = emulator_pio_out(vcpu, size, port, &val, 1);

        if (ret)
                return ret;

        /*
         * Workaround userspace that relies on old KVM behavior of %rip being
         * incremented prior to exiting to userspace to handle "OUT 0x7e".
         */
        if (port == 0x7e &&
            kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_OUT_7E_INC_RIP)) {
                vcpu->arch.complete_userspace_io =
                        complete_fast_pio_out_port_0x7e;
                kvm_skip_emulated_instruction(vcpu);
        } else {
                vcpu->arch.pio.linear_rip = kvm_get_linear_rip(vcpu);
                vcpu->arch.complete_userspace_io = complete_fast_pio_out;
        }
        return 0;
}

static int complete_fast_pio_in(struct kvm_vcpu *vcpu)
{
        unsigned long val;

        /* We should only ever be called with arch.pio.count equal to 1 */
        BUG_ON(vcpu->arch.pio.count != 1);

        if (unlikely(!kvm_is_linear_rip(vcpu, vcpu->arch.pio.linear_rip))) {
                vcpu->arch.pio.count = 0;
                return 1;
        }

        /* For size less than 4 we merge, else we zero extend */
        val = (vcpu->arch.pio.size < 4) ? kvm_rax_read(vcpu) : 0;

        complete_emulator_pio_in(vcpu, &val);
        kvm_rax_write(vcpu, val);

        return kvm_skip_emulated_instruction(vcpu);
}

static int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size,
                           unsigned short port)
{
        unsigned long val;
        int ret;

        /* For size less than 4 we merge, else we zero extend */
        val = (size < 4) ? kvm_rax_read(vcpu) : 0;

        ret = emulator_pio_in(vcpu, size, port, &val, 1);
        if (ret) {
                kvm_rax_write(vcpu, val);
                return ret;
        }

        vcpu->arch.pio.linear_rip = kvm_get_linear_rip(vcpu);
        vcpu->arch.complete_userspace_io = complete_fast_pio_in;

        return 0;
}

int kvm_fast_pio(struct kvm_vcpu *vcpu, int size, unsigned short port, int in)
{
        int ret;

        if (in)
                ret = kvm_fast_pio_in(vcpu, size, port);
        else
                ret = kvm_fast_pio_out(vcpu, size, port);
        return ret && kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_fast_pio);

static int kvmclock_cpu_down_prep(unsigned int cpu)
{
        __this_cpu_write(cpu_tsc_khz, 0);
        return 0;
}

static void tsc_khz_changed(void *data)
{
        struct cpufreq_freqs *freq = data;
        unsigned long khz = 0;

        WARN_ON_ONCE(boot_cpu_has(X86_FEATURE_CONSTANT_TSC));

        if (data)
                khz = freq->new;
        else
                khz = cpufreq_quick_get(raw_smp_processor_id());
        if (!khz)
                khz = tsc_khz;
        __this_cpu_write(cpu_tsc_khz, khz);
}

#ifdef CONFIG_X86_64
static void kvm_hyperv_tsc_notifier(void)
{
        struct kvm *kvm;
        int cpu;

        mutex_lock(&kvm_lock);
        list_for_each_entry(kvm, &vm_list, vm_list)
                kvm_make_mclock_inprogress_request(kvm);

        /* no guest entries from this point */
        hyperv_stop_tsc_emulation();

        /* TSC frequency always matches when on Hyper-V */
        if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
                for_each_present_cpu(cpu)
                        per_cpu(cpu_tsc_khz, cpu) = tsc_khz;
        }
        kvm_caps.max_guest_tsc_khz = tsc_khz;

        list_for_each_entry(kvm, &vm_list, vm_list) {
                __kvm_start_pvclock_update(kvm);
                pvclock_update_vm_gtod_copy(kvm);
                kvm_end_pvclock_update(kvm);
        }

        mutex_unlock(&kvm_lock);
}
#endif

static void __kvmclock_cpufreq_notifier(struct cpufreq_freqs *freq, int cpu)
{
        struct kvm *kvm;
        struct kvm_vcpu *vcpu;
        int send_ipi = 0;
        unsigned long i;

        /*
         * We allow guests to temporarily run on slowing clocks,
         * provided we notify them after, or to run on accelerating
         * clocks, provided we notify them before.  Thus time never
         * goes backwards.
         *
         * However, we have a problem.  We can't atomically update
         * the frequency of a given CPU from this function; it is
         * merely a notifier, which can be called from any CPU.
         * Changing the TSC frequency at arbitrary points in time
         * requires a recomputation of local variables related to
         * the TSC for each VCPU.  We must flag these local variables
         * to be updated and be sure the update takes place with the
         * new frequency before any guests proceed.
         *
         * Unfortunately, the combination of hotplug CPU and frequency
         * change creates an intractable locking scenario; the order
         * of when these callouts happen is undefined with respect to
         * CPU hotplug, and they can race with each other.  As such,
         * merely setting per_cpu(cpu_tsc_khz) = X during a hotadd is
         * undefined; you can actually have a CPU frequency change take
         * place in between the computation of X and the setting of the
         * variable.  To protect against this problem, all updates of
         * the per_cpu tsc_khz variable are done in an interrupt
         * protected IPI, and all callers wishing to update the value
         * must wait for a synchronous IPI to complete (which is trivial
         * if the caller is on the CPU already).  This establishes the
         * necessary total order on variable updates.
         *
         * Note that because a guest time update may take place
         * anytime after the setting of the VCPU's request bit, the
         * correct TSC value must be set before the request.  However,
         * to ensure the update actually makes it to any guest which
         * starts running in hardware virtualization between the set
         * and the acquisition of the spinlock, we must also ping the
         * CPU after setting the request bit.
         *
         */

        smp_call_function_single(cpu, tsc_khz_changed, freq, 1);

        mutex_lock(&kvm_lock);
        list_for_each_entry(kvm, &vm_list, vm_list) {
                kvm_for_each_vcpu(i, vcpu, kvm) {
                        if (vcpu->cpu != cpu)
                                continue;
                        kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
                        if (vcpu->cpu != raw_smp_processor_id())
                                send_ipi = 1;
                }
        }
        mutex_unlock(&kvm_lock);

        if (freq->old < freq->new && send_ipi) {
                /*
                 * We upscale the frequency.  Must make the guest
                 * doesn't see old kvmclock values while running with
                 * the new frequency, otherwise we risk the guest sees
                 * time go backwards.
                 *
                 * In case we update the frequency for another cpu
                 * (which might be in guest context) send an interrupt
                 * to kick the cpu out of guest context.  Next time
                 * guest context is entered kvmclock will be updated,
                 * so the guest will not see stale values.
                 */
                smp_call_function_single(cpu, tsc_khz_changed, freq, 1);
        }
}

static int kvmclock_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                                     void *data)
{
        struct cpufreq_freqs *freq = data;
        int cpu;

        if (val == CPUFREQ_PRECHANGE && freq->old > freq->new)
                return 0;
        if (val == CPUFREQ_POSTCHANGE && freq->old < freq->new)
                return 0;

        for_each_cpu(cpu, freq->policy->cpus)
                __kvmclock_cpufreq_notifier(freq, cpu);

        return 0;
}

static struct notifier_block kvmclock_cpufreq_notifier_block = {
        .notifier_call  = kvmclock_cpufreq_notifier
};

static int kvmclock_cpu_online(unsigned int cpu)
{
        tsc_khz_changed(NULL);
        return 0;
}

static void kvm_timer_init(void)
{
        if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
                max_tsc_khz = tsc_khz;

                if (IS_ENABLED(CONFIG_CPU_FREQ)) {
                        struct cpufreq_policy *policy;
                        int cpu;

                        cpu = get_cpu();
                        policy = cpufreq_cpu_get(cpu);
                        if (policy) {
                                if (policy->cpuinfo.max_freq)
                                        max_tsc_khz = policy->cpuinfo.max_freq;
                                cpufreq_cpu_put(policy);
                        }
                        put_cpu();
                }
                cpufreq_register_notifier(&kvmclock_cpufreq_notifier_block,
                                          CPUFREQ_TRANSITION_NOTIFIER);

                cpuhp_setup_state(CPUHP_AP_X86_KVM_CLK_ONLINE, "x86/kvm/clk:online",
                                  kvmclock_cpu_online, kvmclock_cpu_down_prep);
        }
}

#ifdef CONFIG_X86_64
static void pvclock_gtod_update_fn(struct work_struct *work)
{
        struct kvm *kvm;
        struct kvm_vcpu *vcpu;
        unsigned long i;

        mutex_lock(&kvm_lock);
        list_for_each_entry(kvm, &vm_list, vm_list)
                kvm_for_each_vcpu(i, vcpu, kvm)
                        kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
        atomic_set(&kvm_guest_has_master_clock, 0);
        mutex_unlock(&kvm_lock);
}

static DECLARE_WORK(pvclock_gtod_work, pvclock_gtod_update_fn);

/*
 * Indirection to move queue_work() out of the tk_core.seq write held
 * region to prevent possible deadlocks against time accessors which
 * are invoked with work related locks held.
 */
static void pvclock_irq_work_fn(struct irq_work *w)
{
        queue_work(system_long_wq, &pvclock_gtod_work);
}

static DEFINE_IRQ_WORK(pvclock_irq_work, pvclock_irq_work_fn);

/*
 * Notification about pvclock gtod data update.
 */
static int pvclock_gtod_notify(struct notifier_block *nb, unsigned long unused,
                               void *priv)
{
        struct pvclock_gtod_data *gtod = &pvclock_gtod_data;
        struct timekeeper *tk = priv;

        update_pvclock_gtod(tk);

        /*
         * Disable master clock if host does not trust, or does not use,
         * TSC based clocksource. Delegate queue_work() to irq_work as
         * this is invoked with tk_core.seq write held.
         */
        if (!gtod_is_based_on_tsc(gtod->clock.vclock_mode) &&
            atomic_read(&kvm_guest_has_master_clock) != 0)
                irq_work_queue(&pvclock_irq_work);
        return 0;
}

static struct notifier_block pvclock_gtod_notifier = {
        .notifier_call = pvclock_gtod_notify,
};
#endif

int kvm_arch_init(void *opaque)
{
        struct kvm_x86_init_ops *ops = opaque;
        u64 host_pat;
        int r;

        if (kvm_x86_ops.hardware_enable) {
                pr_err("kvm: already loaded vendor module '%s'\n", kvm_x86_ops.name);
                return -EEXIST;
        }

        if (!ops->cpu_has_kvm_support()) {
                pr_err_ratelimited("kvm: no hardware support for '%s'\n",
                                   ops->runtime_ops->name);
                return -EOPNOTSUPP;
        }
        if (ops->disabled_by_bios()) {
                pr_err_ratelimited("kvm: support for '%s' disabled by bios\n",
                                   ops->runtime_ops->name);
                return -EOPNOTSUPP;
        }

        /*
         * KVM explicitly assumes that the guest has an FPU and
         * FXSAVE/FXRSTOR. For example, the KVM_GET_FPU explicitly casts the
         * vCPU's FPU state as a fxregs_state struct.
         */
        if (!boot_cpu_has(X86_FEATURE_FPU) || !boot_cpu_has(X86_FEATURE_FXSR)) {
                printk(KERN_ERR "kvm: inadequate fpu\n");
                return -EOPNOTSUPP;
        }

        if (IS_ENABLED(CONFIG_PREEMPT_RT) && !boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
                pr_err("RT requires X86_FEATURE_CONSTANT_TSC\n");
                return -EOPNOTSUPP;
        }

        /*
         * KVM assumes that PAT entry '0' encodes WB memtype and simply zeroes
         * the PAT bits in SPTEs.  Bail if PAT[0] is programmed to something
         * other than WB.  Note, EPT doesn't utilize the PAT, but don't bother
         * with an exception.  PAT[0] is set to WB on RESET and also by the
         * kernel, i.e. failure indicates a kernel bug or broken firmware.
         */
        if (rdmsrl_safe(MSR_IA32_CR_PAT, &host_pat) ||
            (host_pat & GENMASK(2, 0)) != 6) {
                pr_err("kvm: host PAT[0] is not WB\n");
                return -EIO;
        }

        x86_emulator_cache = kvm_alloc_emulator_cache();
        if (!x86_emulator_cache) {
                pr_err("kvm: failed to allocate cache for x86 emulator\n");
                return -ENOMEM;
        }

        user_return_msrs = alloc_percpu(struct kvm_user_return_msrs);
        if (!user_return_msrs) {
                printk(KERN_ERR "kvm: failed to allocate percpu kvm_user_return_msrs\n");
                r = -ENOMEM;
                goto out_free_x86_emulator_cache;
        }
        kvm_nr_uret_msrs = 0;

        r = kvm_mmu_vendor_module_init();
        if (r)
                goto out_free_percpu;

        kvm_timer_init();

        if (boot_cpu_has(X86_FEATURE_XSAVE)) {
                host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
                kvm_caps.supported_xcr0 = host_xcr0 & KVM_SUPPORTED_XCR0;
        }

        if (pi_inject_timer == -1)
                pi_inject_timer = housekeeping_enabled(HK_TYPE_TIMER);
#ifdef CONFIG_X86_64
        pvclock_gtod_register_notifier(&pvclock_gtod_notifier);

        if (hypervisor_is_type(X86_HYPER_MS_HYPERV))
                set_hv_tscchange_cb(kvm_hyperv_tsc_notifier);
#endif

        return 0;

out_free_percpu:
        free_percpu(user_return_msrs);
out_free_x86_emulator_cache:
        kmem_cache_destroy(x86_emulator_cache);
        return r;
}

void kvm_arch_exit(void)
{
#ifdef CONFIG_X86_64
        if (hypervisor_is_type(X86_HYPER_MS_HYPERV))
                clear_hv_tscchange_cb();
#endif
        kvm_lapic_exit();

        if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) {
                cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block,
                                            CPUFREQ_TRANSITION_NOTIFIER);
                cpuhp_remove_state_nocalls(CPUHP_AP_X86_KVM_CLK_ONLINE);
        }
#ifdef CONFIG_X86_64
        pvclock_gtod_unregister_notifier(&pvclock_gtod_notifier);
        irq_work_sync(&pvclock_irq_work);
        cancel_work_sync(&pvclock_gtod_work);
#endif
        kvm_x86_ops.hardware_enable = NULL;
        kvm_mmu_vendor_module_exit();
        free_percpu(user_return_msrs);
        kmem_cache_destroy(x86_emulator_cache);
#ifdef CONFIG_KVM_XEN
        static_key_deferred_flush(&kvm_xen_enabled);
        WARN_ON(static_branch_unlikely(&kvm_xen_enabled.key));
#endif
}

static int __kvm_emulate_halt(struct kvm_vcpu *vcpu, int state, int reason)
{
        /*
         * The vCPU has halted, e.g. executed HLT.  Update the run state if the
         * local APIC is in-kernel, the run loop will detect the non-runnable
         * state and halt the vCPU.  Exit to userspace if the local APIC is
         * managed by userspace, in which case userspace is responsible for
         * handling wake events.
         */
        ++vcpu->stat.halt_exits;
        if (lapic_in_kernel(vcpu)) {
                vcpu->arch.mp_state = state;
                return 1;
        } else {
                vcpu->run->exit_reason = reason;
                return 0;
        }
}

int kvm_emulate_halt_noskip(struct kvm_vcpu *vcpu)
{
        return __kvm_emulate_halt(vcpu, KVM_MP_STATE_HALTED, KVM_EXIT_HLT);
}
EXPORT_SYMBOL_GPL(kvm_emulate_halt_noskip);

int kvm_emulate_halt(struct kvm_vcpu *vcpu)
{
        int ret = kvm_skip_emulated_instruction(vcpu);
        /*
         * TODO: we might be squashing a GUESTDBG_SINGLESTEP-triggered
         * KVM_EXIT_DEBUG here.
         */
        return kvm_emulate_halt_noskip(vcpu) && ret;
}
EXPORT_SYMBOL_GPL(kvm_emulate_halt);

int kvm_emulate_ap_reset_hold(struct kvm_vcpu *vcpu)
{
        int ret = kvm_skip_emulated_instruction(vcpu);

        return __kvm_emulate_halt(vcpu, KVM_MP_STATE_AP_RESET_HOLD,
                                        KVM_EXIT_AP_RESET_HOLD) && ret;
}
EXPORT_SYMBOL_GPL(kvm_emulate_ap_reset_hold);

#ifdef CONFIG_X86_64
static int kvm_pv_clock_pairing(struct kvm_vcpu *vcpu, gpa_t paddr,
                                unsigned long clock_type)
{
        struct kvm_clock_pairing clock_pairing;
        struct timespec64 ts;
        u64 cycle;
        int ret;

        if (clock_type != KVM_CLOCK_PAIRING_WALLCLOCK)
                return -KVM_EOPNOTSUPP;

        /*
         * When tsc is in permanent catchup mode guests won't be able to use
         * pvclock_read_retry loop to get consistent view of pvclock
         */
        if (vcpu->arch.tsc_always_catchup)
                return -KVM_EOPNOTSUPP;

        if (!kvm_get_walltime_and_clockread(&ts, &cycle))
                return -KVM_EOPNOTSUPP;

        clock_pairing.sec = ts.tv_sec;
        clock_pairing.nsec = ts.tv_nsec;
        clock_pairing.tsc = kvm_read_l1_tsc(vcpu, cycle);
        clock_pairing.flags = 0;
        memset(&clock_pairing.pad, 0, sizeof(clock_pairing.pad));

        ret = 0;
        if (kvm_write_guest(vcpu->kvm, paddr, &clock_pairing,
                            sizeof(struct kvm_clock_pairing)))
                ret = -KVM_EFAULT;

        return ret;
}
#endif

/*
 * kvm_pv_kick_cpu_op:  Kick a vcpu.
 *
 * @apicid - apicid of vcpu to be kicked.
 */
static void kvm_pv_kick_cpu_op(struct kvm *kvm, int apicid)
{
        /*
         * All other fields are unused for APIC_DM_REMRD, but may be consumed by
         * common code, e.g. for tracing. Defer initialization to the compiler.
         */
        struct kvm_lapic_irq lapic_irq = {
                .delivery_mode = APIC_DM_REMRD,
                .dest_mode = APIC_DEST_PHYSICAL,
                .shorthand = APIC_DEST_NOSHORT,
                .dest_id = apicid,
        };

        kvm_irq_delivery_to_apic(kvm, NULL, &lapic_irq, NULL);
}

bool kvm_apicv_activated(struct kvm *kvm)
{
        return (READ_ONCE(kvm->arch.apicv_inhibit_reasons) == 0);
}
EXPORT_SYMBOL_GPL(kvm_apicv_activated);

bool kvm_vcpu_apicv_activated(struct kvm_vcpu *vcpu)
{
        ulong vm_reasons = READ_ONCE(vcpu->kvm->arch.apicv_inhibit_reasons);
        ulong vcpu_reasons = static_call(kvm_x86_vcpu_get_apicv_inhibit_reasons)(vcpu);

        return (vm_reasons | vcpu_reasons) == 0;
}
EXPORT_SYMBOL_GPL(kvm_vcpu_apicv_activated);

static void set_or_clear_apicv_inhibit(unsigned long *inhibits,
                                       enum kvm_apicv_inhibit reason, bool set)
{
        if (set)
                __set_bit(reason, inhibits);
        else
                __clear_bit(reason, inhibits);

        trace_kvm_apicv_inhibit_changed(reason, set, *inhibits);
}

static void kvm_apicv_init(struct kvm *kvm)
{
        unsigned long *inhibits = &kvm->arch.apicv_inhibit_reasons;

        init_rwsem(&kvm->arch.apicv_update_lock);

        set_or_clear_apicv_inhibit(inhibits, APICV_INHIBIT_REASON_ABSENT, true);

        if (!enable_apicv)
                set_or_clear_apicv_inhibit(inhibits,
                                           APICV_INHIBIT_REASON_DISABLE, true);
}

static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id)
{
        struct kvm_vcpu *target = NULL;
        struct kvm_apic_map *map;

        vcpu->stat.directed_yield_attempted++;

        if (single_task_running())
                goto no_yield;

        rcu_read_lock();
        map = rcu_dereference(vcpu->kvm->arch.apic_map);

        if (likely(map) && dest_id <= map->max_apic_id && map->phys_map[dest_id])
                target = map->phys_map[dest_id]->vcpu;

        rcu_read_unlock();

        if (!target || !READ_ONCE(target->ready))
                goto no_yield;

        /* Ignore requests to yield to self */
        if (vcpu == target)
                goto no_yield;

        if (kvm_vcpu_yield_to(target) <= 0)
                goto no_yield;

        vcpu->stat.directed_yield_successful++;

no_yield:
        return;
}

static int complete_hypercall_exit(struct kvm_vcpu *vcpu)
{
        u64 ret = vcpu->run->hypercall.ret;

        if (!is_64_bit_mode(vcpu))
                ret = (u32)ret;
        kvm_rax_write(vcpu, ret);
        ++vcpu->stat.hypercalls;
        return kvm_skip_emulated_instruction(vcpu);
}

int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
{
        unsigned long nr, a0, a1, a2, a3, ret;
        int op_64_bit;

        if (kvm_xen_hypercall_enabled(vcpu->kvm))
                return kvm_xen_hypercall(vcpu);

        if (kvm_hv_hypercall_enabled(vcpu))
                return kvm_hv_hypercall(vcpu);

        nr = kvm_rax_read(vcpu);
        a0 = kvm_rbx_read(vcpu);
        a1 = kvm_rcx_read(vcpu);
        a2 = kvm_rdx_read(vcpu);
        a3 = kvm_rsi_read(vcpu);

        trace_kvm_hypercall(nr, a0, a1, a2, a3);

        op_64_bit = is_64_bit_hypercall(vcpu);
        if (!op_64_bit) {
                nr &= 0xFFFFFFFF;
                a0 &= 0xFFFFFFFF;
                a1 &= 0xFFFFFFFF;
                a2 &= 0xFFFFFFFF;
                a3 &= 0xFFFFFFFF;
        }

        if (static_call(kvm_x86_get_cpl)(vcpu) != 0) {
                ret = -KVM_EPERM;
                goto out;
        }

        ret = -KVM_ENOSYS;

        switch (nr) {
        case KVM_HC_VAPIC_POLL_IRQ:
                ret = 0;
                break;
        case KVM_HC_KICK_CPU:
                if (!guest_pv_has(vcpu, KVM_FEATURE_PV_UNHALT))
                        break;

                kvm_pv_kick_cpu_op(vcpu->kvm, a1);
                kvm_sched_yield(vcpu, a1);
                ret = 0;
                break;
#ifdef CONFIG_X86_64
        case KVM_HC_CLOCK_PAIRING:
                ret = kvm_pv_clock_pairing(vcpu, a0, a1);
                break;
#endif
        case KVM_HC_SEND_IPI:
                if (!guest_pv_has(vcpu, KVM_FEATURE_PV_SEND_IPI))
                        break;

                ret = kvm_pv_send_ipi(vcpu->kvm, a0, a1, a2, a3, op_64_bit);
                break;
        case KVM_HC_SCHED_YIELD:
                if (!guest_pv_has(vcpu, KVM_FEATURE_PV_SCHED_YIELD))
                        break;

                kvm_sched_yield(vcpu, a0);
                ret = 0;
                break;
        case KVM_HC_MAP_GPA_RANGE: {
                u64 gpa = a0, npages = a1, attrs = a2;

                ret = -KVM_ENOSYS;
                if (!(vcpu->kvm->arch.hypercall_exit_enabled & (1 << KVM_HC_MAP_GPA_RANGE)))
                        break;

                if (!PAGE_ALIGNED(gpa) || !npages ||
                    gpa_to_gfn(gpa) + npages <= gpa_to_gfn(gpa)) {
                        ret = -KVM_EINVAL;
                        break;
                }

                vcpu->run->exit_reason        = KVM_EXIT_HYPERCALL;
                vcpu->run->hypercall.nr       = KVM_HC_MAP_GPA_RANGE;
                vcpu->run->hypercall.args[0]  = gpa;
                vcpu->run->hypercall.args[1]  = npages;
                vcpu->run->hypercall.args[2]  = attrs;
                vcpu->run->hypercall.longmode = op_64_bit;
                vcpu->arch.complete_userspace_io = complete_hypercall_exit;
                return 0;
        }
        default:
                ret = -KVM_ENOSYS;
                break;
        }
out:
        if (!op_64_bit)
                ret = (u32)ret;
        kvm_rax_write(vcpu, ret);

        ++vcpu->stat.hypercalls;
        return kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_hypercall);

static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
{
        struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
        char instruction[3];
        unsigned long rip = kvm_rip_read(vcpu);

        /*
         * If the quirk is disabled, synthesize a #UD and let the guest pick up
         * the pieces.
         */
        if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_FIX_HYPERCALL_INSN)) {
                ctxt->exception.error_code_valid = false;
                ctxt->exception.vector = UD_VECTOR;
                ctxt->have_exception = true;
                return X86EMUL_PROPAGATE_FAULT;
        }

        static_call(kvm_x86_patch_hypercall)(vcpu, instruction);

        return emulator_write_emulated(ctxt, rip, instruction, 3,
                &ctxt->exception);
}

static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
{
        return vcpu->run->request_interrupt_window &&
                likely(!pic_in_kernel(vcpu->kvm));
}

/* Called within kvm->srcu read side.  */
static void post_kvm_run_save(struct kvm_vcpu *vcpu)
{
        struct kvm_run *kvm_run = vcpu->run;

        kvm_run->if_flag = static_call(kvm_x86_get_if_flag)(vcpu);
        kvm_run->cr8 = kvm_get_cr8(vcpu);
        kvm_run->apic_base = kvm_get_apic_base(vcpu);

        kvm_run->ready_for_interrupt_injection =
                pic_in_kernel(vcpu->kvm) ||
                kvm_vcpu_ready_for_interrupt_injection(vcpu);

        if (is_smm(vcpu))
                kvm_run->flags |= KVM_RUN_X86_SMM;
}

static void update_cr8_intercept(struct kvm_vcpu *vcpu)
{
        int max_irr, tpr;

        if (!kvm_x86_ops.update_cr8_intercept)
                return;

        if (!lapic_in_kernel(vcpu))
                return;

        if (vcpu->arch.apic->apicv_active)
                return;

        if (!vcpu->arch.apic->vapic_addr)
                max_irr = kvm_lapic_find_highest_irr(vcpu);
        else
                max_irr = -1;

        if (max_irr != -1)
                max_irr >>= 4;

        tpr = kvm_lapic_get_cr8(vcpu);

        static_call(kvm_x86_update_cr8_intercept)(vcpu, tpr, max_irr);
}


int kvm_check_nested_events(struct kvm_vcpu *vcpu)
{
        if (kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu)) {
                kvm_x86_ops.nested_ops->triple_fault(vcpu);
                return 1;
        }

        return kvm_x86_ops.nested_ops->check_events(vcpu);
}

static void kvm_inject_exception(struct kvm_vcpu *vcpu)
{
        trace_kvm_inj_exception(vcpu->arch.exception.vector,
                                vcpu->arch.exception.has_error_code,
                                vcpu->arch.exception.error_code,
                                vcpu->arch.exception.injected);

        if (vcpu->arch.exception.error_code && !is_protmode(vcpu))
                vcpu->arch.exception.error_code = false;
        static_call(kvm_x86_inject_exception)(vcpu);
}

/*
 * Check for any event (interrupt or exception) that is ready to be injected,
 * and if there is at least one event, inject the event with the highest
 * priority.  This handles both "pending" events, i.e. events that have never
 * been injected into the guest, and "injected" events, i.e. events that were
 * injected as part of a previous VM-Enter, but weren't successfully delivered
 * and need to be re-injected.
 *
 * Note, this is not guaranteed to be invoked on a guest instruction boundary,
 * i.e. doesn't guarantee that there's an event window in the guest.  KVM must
 * be able to inject exceptions in the "middle" of an instruction, and so must
 * also be able to re-inject NMIs and IRQs in the middle of an instruction.
 * I.e. for exceptions and re-injected events, NOT invoking this on instruction
 * boundaries is necessary and correct.
 *
 * For simplicity, KVM uses a single path to inject all events (except events
 * that are injected directly from L1 to L2) and doesn't explicitly track
 * instruction boundaries for asynchronous events.  However, because VM-Exits
 * that can occur during instruction execution typically result in KVM skipping
 * the instruction or injecting an exception, e.g. instruction and exception
 * intercepts, and because pending exceptions have higher priority than pending
 * interrupts, KVM still honors instruction boundaries in most scenarios.
 *
 * But, if a VM-Exit occurs during instruction execution, and KVM does NOT skip
 * the instruction or inject an exception, then KVM can incorrecty inject a new
 * asynchrounous event if the event became pending after the CPU fetched the
 * instruction (in the guest).  E.g. if a page fault (#PF, #NPF, EPT violation)
 * occurs and is resolved by KVM, a coincident NMI, SMI, IRQ, etc... can be
 * injected on the restarted instruction instead of being deferred until the
 * instruction completes.
 *
 * In practice, this virtualization hole is unlikely to be observed by the
 * guest, and even less likely to cause functional problems.  To detect the
 * hole, the guest would have to trigger an event on a side effect of an early
 * phase of instruction execution, e.g. on the instruction fetch from memory.
 * And for it to be a functional problem, the guest would need to depend on the
 * ordering between that side effect, the instruction completing, _and_ the
 * delivery of the asynchronous event.
 */
static int kvm_check_and_inject_events(struct kvm_vcpu *vcpu,
                                       bool *req_immediate_exit)
{
        bool can_inject;
        int r;

        /*
         * Process nested events first, as nested VM-Exit supercedes event
         * re-injection.  If there's an event queued for re-injection, it will
         * be saved into the appropriate vmc{b,s}12 fields on nested VM-Exit.
         */
        if (is_guest_mode(vcpu))
                r = kvm_check_nested_events(vcpu);
        else
                r = 0;

        /*
         * Re-inject exceptions and events *especially* if immediate entry+exit
         * to/from L2 is needed, as any event that has already been injected
         * into L2 needs to complete its lifecycle before injecting a new event.
         *
         * Don't re-inject an NMI or interrupt if there is a pending exception.
         * This collision arises if an exception occurred while vectoring the
         * injected event, KVM intercepted said exception, and KVM ultimately
         * determined the fault belongs to the guest and queues the exception
         * for injection back into the guest.
         *
         * "Injected" interrupts can also collide with pending exceptions if
         * userspace ignores the "ready for injection" flag and blindly queues
         * an interrupt.  In that case, prioritizing the exception is correct,
         * as the exception "occurred" before the exit to userspace.  Trap-like
         * exceptions, e.g. most #DBs, have higher priority than interrupts.
         * And while fault-like exceptions, e.g. #GP and #PF, are the lowest
         * priority, they're only generated (pended) during instruction
         * execution, and interrupts are recognized at instruction boundaries.
         * Thus a pending fault-like exception means the fault occurred on the
         * *previous* instruction and must be serviced prior to recognizing any
         * new events in order to fully complete the previous instruction.
         */
        if (vcpu->arch.exception.injected)
                kvm_inject_exception(vcpu);
        else if (kvm_is_exception_pending(vcpu))
                ; /* see above */
        else if (vcpu->arch.nmi_injected)
                static_call(kvm_x86_inject_nmi)(vcpu);
        else if (vcpu->arch.interrupt.injected)
                static_call(kvm_x86_inject_irq)(vcpu, true);

        /*
         * Exceptions that morph to VM-Exits are handled above, and pending
         * exceptions on top of injected exceptions that do not VM-Exit should
         * either morph to #DF or, sadly, override the injected exception.
         */
        WARN_ON_ONCE(vcpu->arch.exception.injected &&
                     vcpu->arch.exception.pending);

        /*
         * Bail if immediate entry+exit to/from the guest is needed to complete
         * nested VM-Enter or event re-injection so that a different pending
         * event can be serviced (or if KVM needs to exit to userspace).
         *
         * Otherwise, continue processing events even if VM-Exit occurred.  The
         * VM-Exit will have cleared exceptions that were meant for L2, but
         * there may now be events that can be injected into L1.
         */
        if (r < 0)
                goto out;

        /*
         * A pending exception VM-Exit should either result in nested VM-Exit
         * or force an immediate re-entry and exit to/from L2, and exception
         * VM-Exits cannot be injected (flag should _never_ be set).
         */
        WARN_ON_ONCE(vcpu->arch.exception_vmexit.injected ||
                     vcpu->arch.exception_vmexit.pending);

        /*
         * New events, other than exceptions, cannot be injected if KVM needs
         * to re-inject a previous event.  See above comments on re-injecting
         * for why pending exceptions get priority.
         */
        can_inject = !kvm_event_needs_reinjection(vcpu);

        if (vcpu->arch.exception.pending) {
                /*
                 * Fault-class exceptions, except #DBs, set RF=1 in the RFLAGS
                 * value pushed on the stack.  Trap-like exception and all #DBs
                 * leave RF as-is (KVM follows Intel's behavior in this regard;
                 * AMD states that code breakpoint #DBs excplitly clear RF=0).
                 *
                 * Note, most versions of Intel's SDM and AMD's APM incorrectly
                 * describe the behavior of General Detect #DBs, which are
                 * fault-like.  They do _not_ set RF, a la code breakpoints.
                 */
                if (exception_type(vcpu->arch.exception.vector) == EXCPT_FAULT)
                        __kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
                                             X86_EFLAGS_RF);

                if (vcpu->arch.exception.vector == DB_VECTOR) {
                        kvm_deliver_exception_payload(vcpu, &vcpu->arch.exception);
                        if (vcpu->arch.dr7 & DR7_GD) {
                                vcpu->arch.dr7 &= ~DR7_GD;
                                kvm_update_dr7(vcpu);
                        }
                }

                kvm_inject_exception(vcpu);

                vcpu->arch.exception.pending = false;
                vcpu->arch.exception.injected = true;

                can_inject = false;
        }

        /* Don't inject interrupts if the user asked to avoid doing so */
        if (vcpu->guest_debug & KVM_GUESTDBG_BLOCKIRQ)
                return 0;

        /*
         * Finally, inject interrupt events.  If an event cannot be injected
         * due to architectural conditions (e.g. IF=0) a window-open exit
         * will re-request KVM_REQ_EVENT.  Sometimes however an event is pending
         * and can architecturally be injected, but we cannot do it right now:
         * an interrupt could have arrived just now and we have to inject it
         * as a vmexit, or there could already an event in the queue, which is
         * indicated by can_inject.  In that case we request an immediate exit
         * in order to make progress and get back here for another iteration.
         * The kvm_x86_ops hooks communicate this by returning -EBUSY.
         */
#ifdef CONFIG_KVM_SMM
        if (vcpu->arch.smi_pending) {
                r = can_inject ? static_call(kvm_x86_smi_allowed)(vcpu, true) : -EBUSY;
                if (r < 0)
                        goto out;
                if (r) {
                        vcpu->arch.smi_pending = false;
                        ++vcpu->arch.smi_count;
                        enter_smm(vcpu);
                        can_inject = false;
                } else
                        static_call(kvm_x86_enable_smi_window)(vcpu);
        }
#endif

        if (vcpu->arch.nmi_pending) {
                r = can_inject ? static_call(kvm_x86_nmi_allowed)(vcpu, true) : -EBUSY;
                if (r < 0)
                        goto out;
                if (r) {
                        --vcpu->arch.nmi_pending;
                        vcpu->arch.nmi_injected = true;
                        static_call(kvm_x86_inject_nmi)(vcpu);
                        can_inject = false;
                        WARN_ON(static_call(kvm_x86_nmi_allowed)(vcpu, true) < 0);
                }
                if (vcpu->arch.nmi_pending)
                        static_call(kvm_x86_enable_nmi_window)(vcpu);
        }

        if (kvm_cpu_has_injectable_intr(vcpu)) {
                r = can_inject ? static_call(kvm_x86_interrupt_allowed)(vcpu, true) : -EBUSY;
                if (r < 0)
                        goto out;
                if (r) {
                        kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu), false);
                        static_call(kvm_x86_inject_irq)(vcpu, false);
                        WARN_ON(static_call(kvm_x86_interrupt_allowed)(vcpu, true) < 0);
                }
                if (kvm_cpu_has_injectable_intr(vcpu))
                        static_call(kvm_x86_enable_irq_window)(vcpu);
        }

        if (is_guest_mode(vcpu) &&
            kvm_x86_ops.nested_ops->has_events &&
            kvm_x86_ops.nested_ops->has_events(vcpu))
                *req_immediate_exit = true;

        /*
         * KVM must never queue a new exception while injecting an event; KVM
         * is done emulating and should only propagate the to-be-injected event
         * to the VMCS/VMCB.  Queueing a new exception can put the vCPU into an
         * infinite loop as KVM will bail from VM-Enter to inject the pending
         * exception and start the cycle all over.
         *
         * Exempt triple faults as they have special handling and won't put the
         * vCPU into an infinite loop.  Triple fault can be queued when running
         * VMX without unrestricted guest, as that requires KVM to emulate Real
         * Mode events (see kvm_inject_realmode_interrupt()).
         */
        WARN_ON_ONCE(vcpu->arch.exception.pending ||
                     vcpu->arch.exception_vmexit.pending);
        return 0;

out:
        if (r == -EBUSY) {
                *req_immediate_exit = true;
                r = 0;
        }
        return r;
}

static void process_nmi(struct kvm_vcpu *vcpu)
{
        unsigned limit = 2;

        /*
         * x86 is limited to one NMI running, and one NMI pending after it.
         * If an NMI is already in progress, limit further NMIs to just one.
         * Otherwise, allow two (and we'll inject the first one immediately).
         */
        if (static_call(kvm_x86_get_nmi_mask)(vcpu) || vcpu->arch.nmi_injected)
                limit = 1;

        vcpu->arch.nmi_pending += atomic_xchg(&vcpu->arch.nmi_queued, 0);
        vcpu->arch.nmi_pending = min(vcpu->arch.nmi_pending, limit);
        kvm_make_request(KVM_REQ_EVENT, vcpu);
}

void kvm_make_scan_ioapic_request_mask(struct kvm *kvm,
                                       unsigned long *vcpu_bitmap)
{
        kvm_make_vcpus_request_mask(kvm, KVM_REQ_SCAN_IOAPIC, vcpu_bitmap);
}

void kvm_make_scan_ioapic_request(struct kvm *kvm)
{
        kvm_make_all_cpus_request(kvm, KVM_REQ_SCAN_IOAPIC);
}

void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu)
{
        struct kvm_lapic *apic = vcpu->arch.apic;
        bool activate;

        if (!lapic_in_kernel(vcpu))
                return;

        down_read(&vcpu->kvm->arch.apicv_update_lock);
        preempt_disable();

        /* Do not activate APICV when APIC is disabled */
        activate = kvm_vcpu_apicv_activated(vcpu) &&
                   (kvm_get_apic_mode(vcpu) != LAPIC_MODE_DISABLED);

        if (apic->apicv_active == activate)
                goto out;

        apic->apicv_active = activate;
        kvm_apic_update_apicv(vcpu);
        static_call(kvm_x86_refresh_apicv_exec_ctrl)(vcpu);

        /*
         * When APICv gets disabled, we may still have injected interrupts
         * pending. At the same time, KVM_REQ_EVENT may not be set as APICv was
         * still active when the interrupt got accepted. Make sure
         * kvm_check_and_inject_events() is called to check for that.
         */
        if (!apic->apicv_active)
                kvm_make_request(KVM_REQ_EVENT, vcpu);

out:
        preempt_enable();
        up_read(&vcpu->kvm->arch.apicv_update_lock);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_update_apicv);

void __kvm_set_or_clear_apicv_inhibit(struct kvm *kvm,
                                      enum kvm_apicv_inhibit reason, bool set)
{
        unsigned long old, new;

        lockdep_assert_held_write(&kvm->arch.apicv_update_lock);

        if (!static_call(kvm_x86_check_apicv_inhibit_reasons)(reason))
                return;

        old = new = kvm->arch.apicv_inhibit_reasons;

        set_or_clear_apicv_inhibit(&new, reason, set);

        if (!!old != !!new) {
                /*
                 * Kick all vCPUs before setting apicv_inhibit_reasons to avoid
                 * false positives in the sanity check WARN in svm_vcpu_run().
                 * This task will wait for all vCPUs to ack the kick IRQ before
                 * updating apicv_inhibit_reasons, and all other vCPUs will
                 * block on acquiring apicv_update_lock so that vCPUs can't
                 * redo svm_vcpu_run() without seeing the new inhibit state.
                 *
                 * Note, holding apicv_update_lock and taking it in the read
                 * side (handling the request) also prevents other vCPUs from
                 * servicing the request with a stale apicv_inhibit_reasons.
                 */
                kvm_make_all_cpus_request(kvm, KVM_REQ_APICV_UPDATE);
                kvm->arch.apicv_inhibit_reasons = new;
                if (new) {
                        unsigned long gfn = gpa_to_gfn(APIC_DEFAULT_PHYS_BASE);
                        int idx = srcu_read_lock(&kvm->srcu);

                        kvm_zap_gfn_range(kvm, gfn, gfn+1);
                        srcu_read_unlock(&kvm->srcu, idx);
                }
        } else {
                kvm->arch.apicv_inhibit_reasons = new;
        }
}

void kvm_set_or_clear_apicv_inhibit(struct kvm *kvm,
                                    enum kvm_apicv_inhibit reason, bool set)
{
        if (!enable_apicv)
                return;

        down_write(&kvm->arch.apicv_update_lock);
        __kvm_set_or_clear_apicv_inhibit(kvm, reason, set);
        up_write(&kvm->arch.apicv_update_lock);
}
EXPORT_SYMBOL_GPL(kvm_set_or_clear_apicv_inhibit);

static void vcpu_scan_ioapic(struct kvm_vcpu *vcpu)
{
        if (!kvm_apic_present(vcpu))
                return;

        bitmap_zero(vcpu->arch.ioapic_handled_vectors, 256);

        if (irqchip_split(vcpu->kvm))
                kvm_scan_ioapic_routes(vcpu, vcpu->arch.ioapic_handled_vectors);
        else {
                static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu);
                if (ioapic_in_kernel(vcpu->kvm))
                        kvm_ioapic_scan_entry(vcpu, vcpu->arch.ioapic_handled_vectors);
        }

        if (is_guest_mode(vcpu))
                vcpu->arch.load_eoi_exitmap_pending = true;
        else
                kvm_make_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu);
}

static void vcpu_load_eoi_exitmap(struct kvm_vcpu *vcpu)
{
        u64 eoi_exit_bitmap[4];

        if (!kvm_apic_hw_enabled(vcpu->arch.apic))
                return;

        if (to_hv_vcpu(vcpu)) {
                bitmap_or((ulong *)eoi_exit_bitmap,
                          vcpu->arch.ioapic_handled_vectors,
                          to_hv_synic(vcpu)->vec_bitmap, 256);
                static_call_cond(kvm_x86_load_eoi_exitmap)(vcpu, eoi_exit_bitmap);
                return;
        }

        static_call_cond(kvm_x86_load_eoi_exitmap)(
                vcpu, (u64 *)vcpu->arch.ioapic_handled_vectors);
}

void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
                                            unsigned long start, unsigned long end)
{
        unsigned long apic_address;

        /*
         * The physical address of apic access page is stored in the VMCS.
         * Update it when it becomes invalid.
         */
        apic_address = gfn_to_hva(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT);
        if (start <= apic_address && apic_address < end)
                kvm_make_all_cpus_request(kvm, KVM_REQ_APIC_PAGE_RELOAD);
}

void kvm_arch_guest_memory_reclaimed(struct kvm *kvm)
{
        static_call_cond(kvm_x86_guest_memory_reclaimed)(kvm);
}

static void kvm_vcpu_reload_apic_access_page(struct kvm_vcpu *vcpu)
{
        if (!lapic_in_kernel(vcpu))
                return;

        static_call_cond(kvm_x86_set_apic_access_page_addr)(vcpu);
}

void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu)
{
        smp_send_reschedule(vcpu->cpu);
}
EXPORT_SYMBOL_GPL(__kvm_request_immediate_exit);

/*
 * Called within kvm->srcu read side.
 * Returns 1 to let vcpu_run() continue the guest execution loop without
 * exiting to the userspace.  Otherwise, the value will be returned to the
 * userspace.
 */
static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
{
        int r;
        bool req_int_win =
                dm_request_for_irq_injection(vcpu) &&
                kvm_cpu_accept_dm_intr(vcpu);
        fastpath_t exit_fastpath;

        bool req_immediate_exit = false;

        if (kvm_request_pending(vcpu)) {
                if (kvm_check_request(KVM_REQ_VM_DEAD, vcpu)) {
                        r = -EIO;
                        goto out;
                }

                if (kvm_dirty_ring_check_request(vcpu)) {
                        r = 0;
                        goto out;
                }

                if (kvm_check_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu)) {
                        if (unlikely(!kvm_x86_ops.nested_ops->get_nested_state_pages(vcpu))) {
                                r = 0;
                                goto out;
                        }
                }
                if (kvm_check_request(KVM_REQ_MMU_FREE_OBSOLETE_ROOTS, vcpu))
                        kvm_mmu_free_obsolete_roots(vcpu);
                if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu))
                        __kvm_migrate_timers(vcpu);
                if (kvm_check_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu))
                        kvm_update_masterclock(vcpu->kvm);
                if (kvm_check_request(KVM_REQ_GLOBAL_CLOCK_UPDATE, vcpu))
                        kvm_gen_kvmclock_update(vcpu);
                if (kvm_check_request(KVM_REQ_CLOCK_UPDATE, vcpu)) {
                        r = kvm_guest_time_update(vcpu);
                        if (unlikely(r))
                                goto out;
                }
                if (kvm_check_request(KVM_REQ_MMU_SYNC, vcpu))
                        kvm_mmu_sync_roots(vcpu);
                if (kvm_check_request(KVM_REQ_LOAD_MMU_PGD, vcpu))
                        kvm_mmu_load_pgd(vcpu);

                /*
                 * Note, the order matters here, as flushing "all" TLB entries
                 * also flushes the "current" TLB entries, i.e. servicing the
                 * flush "all" will clear any request to flush "current".
                 */
                if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu))
                        kvm_vcpu_flush_tlb_all(vcpu);

                kvm_service_local_tlb_flush_requests(vcpu);

                /*
                 * Fall back to a "full" guest flush if Hyper-V's precise
                 * flushing fails.  Note, Hyper-V's flushing is per-vCPU, but
                 * the flushes are considered "remote" and not "local" because
                 * the requests can be initiated from other vCPUs.
                 */
                if (kvm_check_request(KVM_REQ_HV_TLB_FLUSH, vcpu) &&
                    kvm_hv_vcpu_flush_tlb(vcpu))
                        kvm_vcpu_flush_tlb_guest(vcpu);

                if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) {
                        vcpu->run->exit_reason = KVM_EXIT_TPR_ACCESS;
                        r = 0;
                        goto out;
                }
                if (kvm_test_request(KVM_REQ_TRIPLE_FAULT, vcpu)) {
                        if (is_guest_mode(vcpu))
                                kvm_x86_ops.nested_ops->triple_fault(vcpu);

                        if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) {
                                vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
                                vcpu->mmio_needed = 0;
                                r = 0;
                                goto out;
                        }
                }
                if (kvm_check_request(KVM_REQ_APF_HALT, vcpu)) {
                        /* Page is swapped out. Do synthetic halt */
                        vcpu->arch.apf.halted = true;
                        r = 1;
                        goto out;
                }
                if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu))
                        record_steal_time(vcpu);
#ifdef CONFIG_KVM_SMM
                if (kvm_check_request(KVM_REQ_SMI, vcpu))
                        process_smi(vcpu);
#endif
                if (kvm_check_request(KVM_REQ_NMI, vcpu))
                        process_nmi(vcpu);
                if (kvm_check_request(KVM_REQ_PMU, vcpu))
                        kvm_pmu_handle_event(vcpu);
                if (kvm_check_request(KVM_REQ_PMI, vcpu))
                        kvm_pmu_deliver_pmi(vcpu);
                if (kvm_check_request(KVM_REQ_IOAPIC_EOI_EXIT, vcpu)) {
                        BUG_ON(vcpu->arch.pending_ioapic_eoi > 255);
                        if (test_bit(vcpu->arch.pending_ioapic_eoi,
                                     vcpu->arch.ioapic_handled_vectors)) {
                                vcpu->run->exit_reason = KVM_EXIT_IOAPIC_EOI;
                                vcpu->run->eoi.vector =
                                                vcpu->arch.pending_ioapic_eoi;
                                r = 0;
                                goto out;
                        }
                }
                if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu))
                        vcpu_scan_ioapic(vcpu);
                if (kvm_check_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu))
                        vcpu_load_eoi_exitmap(vcpu);
                if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu))
                        kvm_vcpu_reload_apic_access_page(vcpu);
                if (kvm_check_request(KVM_REQ_HV_CRASH, vcpu)) {
                        vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
                        vcpu->run->system_event.type = KVM_SYSTEM_EVENT_CRASH;
                        vcpu->run->system_event.ndata = 0;
                        r = 0;
                        goto out;
                }
                if (kvm_check_request(KVM_REQ_HV_RESET, vcpu)) {
                        vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
                        vcpu->run->system_event.type = KVM_SYSTEM_EVENT_RESET;
                        vcpu->run->system_event.ndata = 0;
                        r = 0;
                        goto out;
                }
                if (kvm_check_request(KVM_REQ_HV_EXIT, vcpu)) {
                        struct kvm_vcpu_hv *hv_vcpu = to_hv_vcpu(vcpu);

                        vcpu->run->exit_reason = KVM_EXIT_HYPERV;
                        vcpu->run->hyperv = hv_vcpu->exit;
                        r = 0;
                        goto out;
                }

                /*
                 * KVM_REQ_HV_STIMER has to be processed after
                 * KVM_REQ_CLOCK_UPDATE, because Hyper-V SynIC timers
                 * depend on the guest clock being up-to-date
                 */
                if (kvm_check_request(KVM_REQ_HV_STIMER, vcpu))
                        kvm_hv_process_stimers(vcpu);
                if (kvm_check_request(KVM_REQ_APICV_UPDATE, vcpu))
                        kvm_vcpu_update_apicv(vcpu);
                if (kvm_check_request(KVM_REQ_APF_READY, vcpu))
                        kvm_check_async_pf_completion(vcpu);
                if (kvm_check_request(KVM_REQ_MSR_FILTER_CHANGED, vcpu))
                        static_call(kvm_x86_msr_filter_changed)(vcpu);

                if (kvm_check_request(KVM_REQ_UPDATE_CPU_DIRTY_LOGGING, vcpu))
                        static_call(kvm_x86_update_cpu_dirty_logging)(vcpu);
        }

        if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win ||
            kvm_xen_has_interrupt(vcpu)) {
                ++vcpu->stat.req_event;
                r = kvm_apic_accept_events(vcpu);
                if (r < 0) {
                        r = 0;
                        goto out;
                }
                if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
                        r = 1;
                        goto out;
                }

                r = kvm_check_and_inject_events(vcpu, &req_immediate_exit);
                if (r < 0) {
                        r = 0;
                        goto out;
                }
                if (req_int_win)
                        static_call(kvm_x86_enable_irq_window)(vcpu);

                if (kvm_lapic_enabled(vcpu)) {
                        update_cr8_intercept(vcpu);
                        kvm_lapic_sync_to_vapic(vcpu);
                }
        }

        r = kvm_mmu_reload(vcpu);
        if (unlikely(r)) {
                goto cancel_injection;
        }

        preempt_disable();

        static_call(kvm_x86_prepare_switch_to_guest)(vcpu);

        /*
         * Disable IRQs before setting IN_GUEST_MODE.  Posted interrupt
         * IPI are then delayed after guest entry, which ensures that they
         * result in virtual interrupt delivery.
         */
        local_irq_disable();

        /* Store vcpu->apicv_active before vcpu->mode.  */
        smp_store_release(&vcpu->mode, IN_GUEST_MODE);

        kvm_vcpu_srcu_read_unlock(vcpu);

        /*
         * 1) We should set ->mode before checking ->requests.  Please see
         * the comment in kvm_vcpu_exiting_guest_mode().
         *
         * 2) For APICv, we should set ->mode before checking PID.ON. This
         * pairs with the memory barrier implicit in pi_test_and_set_on
         * (see vmx_deliver_posted_interrupt).
         *
         * 3) This also orders the write to mode from any reads to the page
         * tables done while the VCPU is running.  Please see the comment
         * in kvm_flush_remote_tlbs.
         */
        smp_mb__after_srcu_read_unlock();

        /*
         * Process pending posted interrupts to handle the case where the
         * notification IRQ arrived in the host, or was never sent (because the
         * target vCPU wasn't running).  Do this regardless of the vCPU's APICv
         * status, KVM doesn't update assigned devices when APICv is inhibited,
         * i.e. they can post interrupts even if APICv is temporarily disabled.
         */
        if (kvm_lapic_enabled(vcpu))
                static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu);

        if (kvm_vcpu_exit_request(vcpu)) {
                vcpu->mode = OUTSIDE_GUEST_MODE;
                smp_wmb();
                local_irq_enable();
                preempt_enable();
                kvm_vcpu_srcu_read_lock(vcpu);
                r = 1;
                goto cancel_injection;
        }

        if (req_immediate_exit) {
                kvm_make_request(KVM_REQ_EVENT, vcpu);
                static_call(kvm_x86_request_immediate_exit)(vcpu);
        }

        fpregs_assert_state_consistent();
        if (test_thread_flag(TIF_NEED_FPU_LOAD))
                switch_fpu_return();

        if (vcpu->arch.guest_fpu.xfd_err)
                wrmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);

        if (unlikely(vcpu->arch.switch_db_regs)) {
                set_debugreg(0, 7);
                set_debugreg(vcpu->arch.eff_db[0], 0);
                set_debugreg(vcpu->arch.eff_db[1], 1);
                set_debugreg(vcpu->arch.eff_db[2], 2);
                set_debugreg(vcpu->arch.eff_db[3], 3);
        } else if (unlikely(hw_breakpoint_active())) {
                set_debugreg(0, 7);
        }

        guest_timing_enter_irqoff();

        for (;;) {
                /*
                 * Assert that vCPU vs. VM APICv state is consistent.  An APICv
                 * update must kick and wait for all vCPUs before toggling the
                 * per-VM state, and responsing vCPUs must wait for the update
                 * to complete before servicing KVM_REQ_APICV_UPDATE.
                 */
                WARN_ON_ONCE((kvm_vcpu_apicv_activated(vcpu) != kvm_vcpu_apicv_active(vcpu)) &&
                             (kvm_get_apic_mode(vcpu) != LAPIC_MODE_DISABLED));

                exit_fastpath = static_call(kvm_x86_vcpu_run)(vcpu);
                if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST))
                        break;

                if (kvm_lapic_enabled(vcpu))
                        static_call_cond(kvm_x86_sync_pir_to_irr)(vcpu);

                if (unlikely(kvm_vcpu_exit_request(vcpu))) {
                        exit_fastpath = EXIT_FASTPATH_EXIT_HANDLED;
                        break;
                }
        }

        /*
         * Do this here before restoring debug registers on the host.  And
         * since we do this before handling the vmexit, a DR access vmexit
         * can (a) read the correct value of the debug registers, (b) set
         * KVM_DEBUGREG_WONT_EXIT again.
         */
        if (unlikely(vcpu->arch.switch_db_regs & KVM_DEBUGREG_WONT_EXIT)) {
                WARN_ON(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP);
                static_call(kvm_x86_sync_dirty_debug_regs)(vcpu);
                kvm_update_dr0123(vcpu);
                kvm_update_dr7(vcpu);
        }

        /*
         * If the guest has used debug registers, at least dr7
         * will be disabled while returning to the host.
         * If we don't have active breakpoints in the host, we don't
         * care about the messed up debug address registers. But if
         * we have some of them active, restore the old state.
         */
        if (hw_breakpoint_active())
                hw_breakpoint_restore();

        vcpu->arch.last_vmentry_cpu = vcpu->cpu;
        vcpu->arch.last_guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc());

        vcpu->mode = OUTSIDE_GUEST_MODE;
        smp_wmb();

        /*
         * Sync xfd before calling handle_exit_irqoff() which may
         * rely on the fact that guest_fpu::xfd is up-to-date (e.g.
         * in #NM irqoff handler).
         */
        if (vcpu->arch.xfd_no_write_intercept)
                fpu_sync_guest_vmexit_xfd_state();

        static_call(kvm_x86_handle_exit_irqoff)(vcpu);

        if (vcpu->arch.guest_fpu.xfd_err)
                wrmsrl(MSR_IA32_XFD_ERR, 0);

        /*
         * Consume any pending interrupts, including the possible source of
         * VM-Exit on SVM and any ticks that occur between VM-Exit and now.
         * An instruction is required after local_irq_enable() to fully unblock
         * interrupts on processors that implement an interrupt shadow, the
         * stat.exits increment will do nicely.
         */
        kvm_before_interrupt(vcpu, KVM_HANDLING_IRQ);
        local_irq_enable();
        ++vcpu->stat.exits;
        local_irq_disable();
        kvm_after_interrupt(vcpu);

        /*
         * Wait until after servicing IRQs to account guest time so that any
         * ticks that occurred while running the guest are properly accounted
         * to the guest.  Waiting until IRQs are enabled degrades the accuracy
         * of accounting via context tracking, but the loss of accuracy is
         * acceptable for all known use cases.
         */
        guest_timing_exit_irqoff();

        local_irq_enable();
        preempt_enable();

        kvm_vcpu_srcu_read_lock(vcpu);

        /*
         * Profile KVM exit RIPs:
         */
        if (unlikely(prof_on == KVM_PROFILING)) {
                unsigned long rip = kvm_rip_read(vcpu);
                profile_hit(KVM_PROFILING, (void *)rip);
        }

        if (unlikely(vcpu->arch.tsc_always_catchup))
                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);

        if (vcpu->arch.apic_attention)
                kvm_lapic_sync_from_vapic(vcpu);

        r = static_call(kvm_x86_handle_exit)(vcpu, exit_fastpath);
        return r;

cancel_injection:
        if (req_immediate_exit)
                kvm_make_request(KVM_REQ_EVENT, vcpu);
        static_call(kvm_x86_cancel_injection)(vcpu);
        if (unlikely(vcpu->arch.apic_attention))
                kvm_lapic_sync_from_vapic(vcpu);
out:
        return r;
}

/* Called within kvm->srcu read side.  */
static inline int vcpu_block(struct kvm_vcpu *vcpu)
{
        bool hv_timer;

        if (!kvm_arch_vcpu_runnable(vcpu)) {
                /*
                 * Switch to the software timer before halt-polling/blocking as
                 * the guest's timer may be a break event for the vCPU, and the
                 * hypervisor timer runs only when the CPU is in guest mode.
                 * Switch before halt-polling so that KVM recognizes an expired
                 * timer before blocking.
                 */
                hv_timer = kvm_lapic_hv_timer_in_use(vcpu);
                if (hv_timer)
                        kvm_lapic_switch_to_sw_timer(vcpu);

                kvm_vcpu_srcu_read_unlock(vcpu);
                if (vcpu->arch.mp_state == KVM_MP_STATE_HALTED)
                        kvm_vcpu_halt(vcpu);
                else
                        kvm_vcpu_block(vcpu);
                kvm_vcpu_srcu_read_lock(vcpu);

                if (hv_timer)
                        kvm_lapic_switch_to_hv_timer(vcpu);

                /*
                 * If the vCPU is not runnable, a signal or another host event
                 * of some kind is pending; service it without changing the
                 * vCPU's activity state.
                 */
                if (!kvm_arch_vcpu_runnable(vcpu))
                        return 1;
        }

        /*
         * Evaluate nested events before exiting the halted state.  This allows
         * the halt state to be recorded properly in the VMCS12's activity
         * state field (AMD does not have a similar field and a VM-Exit always
         * causes a spurious wakeup from HLT).
         */
        if (is_guest_mode(vcpu)) {
                if (kvm_check_nested_events(vcpu) < 0)
                        return 0;
        }

        if (kvm_apic_accept_events(vcpu) < 0)
                return 0;
        switch(vcpu->arch.mp_state) {
        case KVM_MP_STATE_HALTED:
        case KVM_MP_STATE_AP_RESET_HOLD:
                vcpu->arch.pv.pv_unhalted = false;
                vcpu->arch.mp_state =
                        KVM_MP_STATE_RUNNABLE;
                fallthrough;
        case KVM_MP_STATE_RUNNABLE:
                vcpu->arch.apf.halted = false;
                break;
        case KVM_MP_STATE_INIT_RECEIVED:
                break;
        default:
                WARN_ON_ONCE(1);
                break;
        }
        return 1;
}

static inline bool kvm_vcpu_running(struct kvm_vcpu *vcpu)
{
        return (vcpu->arch.mp_state == KVM_MP_STATE_RUNNABLE &&
                !vcpu->arch.apf.halted);
}

/* Called within kvm->srcu read side.  */
static int vcpu_run(struct kvm_vcpu *vcpu)
{
        int r;

        vcpu->arch.l1tf_flush_l1d = true;

        for (;;) {
                /*
                 * If another guest vCPU requests a PV TLB flush in the middle
                 * of instruction emulation, the rest of the emulation could
                 * use a stale page translation. Assume that any code after
                 * this point can start executing an instruction.
                 */
                vcpu->arch.at_instruction_boundary = false;
                if (kvm_vcpu_running(vcpu)) {
                        r = vcpu_enter_guest(vcpu);
                } else {
                        r = vcpu_block(vcpu);
                }

                if (r <= 0)
                        break;

                kvm_clear_request(KVM_REQ_UNBLOCK, vcpu);
                if (kvm_xen_has_pending_events(vcpu))
                        kvm_xen_inject_pending_events(vcpu);

                if (kvm_cpu_has_pending_timer(vcpu))
                        kvm_inject_pending_timer_irqs(vcpu);

                if (dm_request_for_irq_injection(vcpu) &&
                        kvm_vcpu_ready_for_interrupt_injection(vcpu)) {
                        r = 0;
                        vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
                        ++vcpu->stat.request_irq_exits;
                        break;
                }

                if (__xfer_to_guest_mode_work_pending()) {
                        kvm_vcpu_srcu_read_unlock(vcpu);
                        r = xfer_to_guest_mode_handle_work(vcpu);
                        kvm_vcpu_srcu_read_lock(vcpu);
                        if (r)
                                return r;
                }
        }

        return r;
}

static inline int complete_emulated_io(struct kvm_vcpu *vcpu)
{
        return kvm_emulate_instruction(vcpu, EMULTYPE_NO_DECODE);
}

static int complete_emulated_pio(struct kvm_vcpu *vcpu)
{
        BUG_ON(!vcpu->arch.pio.count);

        return complete_emulated_io(vcpu);
}

/*
 * Implements the following, as a state machine:
 *
 * read:
 *   for each fragment
 *     for each mmio piece in the fragment
 *       write gpa, len
 *       exit
 *       copy data
 *   execute insn
 *
 * write:
 *   for each fragment
 *     for each mmio piece in the fragment
 *       write gpa, len
 *       copy data
 *       exit
 */
static int complete_emulated_mmio(struct kvm_vcpu *vcpu)
{
        struct kvm_run *run = vcpu->run;
        struct kvm_mmio_fragment *frag;
        unsigned len;

        BUG_ON(!vcpu->mmio_needed);

        /* Complete previous fragment */
        frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment];
        len = min(8u, frag->len);
        if (!vcpu->mmio_is_write)
                memcpy(frag->data, run->mmio.data, len);

        if (frag->len <= 8) {
                /* Switch to the next fragment. */
                frag++;
                vcpu->mmio_cur_fragment++;
        } else {
                /* Go forward to the next mmio piece. */
                frag->data += len;
                frag->gpa += len;
                frag->len -= len;
        }

        if (vcpu->mmio_cur_fragment >= vcpu->mmio_nr_fragments) {
                vcpu->mmio_needed = 0;

                /* FIXME: return into emulator if single-stepping.  */
                if (vcpu->mmio_is_write)
                        return 1;
                vcpu->mmio_read_completed = 1;
                return complete_emulated_io(vcpu);
        }

        run->exit_reason = KVM_EXIT_MMIO;
        run->mmio.phys_addr = frag->gpa;
        if (vcpu->mmio_is_write)
                memcpy(run->mmio.data, frag->data, min(8u, frag->len));
        run->mmio.len = min(8u, frag->len);
        run->mmio.is_write = vcpu->mmio_is_write;
        vcpu->arch.complete_userspace_io = complete_emulated_mmio;
        return 0;
}

/* Swap (qemu) user FPU context for the guest FPU context. */
static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
{
        /* Exclude PKRU, it's restored separately immediately after VM-Exit. */
        fpu_swap_kvm_fpstate(&vcpu->arch.guest_fpu, true);
        trace_kvm_fpu(1);
}

/* When vcpu_run ends, restore user space FPU context. */
static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
{
        fpu_swap_kvm_fpstate(&vcpu->arch.guest_fpu, false);
        ++vcpu->stat.fpu_reload;
        trace_kvm_fpu(0);
}

int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
{
        struct kvm_queued_exception *ex = &vcpu->arch.exception;
        struct kvm_run *kvm_run = vcpu->run;
        int r;

        vcpu_load(vcpu);
        kvm_sigset_activate(vcpu);
        kvm_run->flags = 0;
        kvm_load_guest_fpu(vcpu);

        kvm_vcpu_srcu_read_lock(vcpu);
        if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
                if (kvm_run->immediate_exit) {
                        r = -EINTR;
                        goto out;
                }
                /*
                 * It should be impossible for the hypervisor timer to be in
                 * use before KVM has ever run the vCPU.
                 */
                WARN_ON_ONCE(kvm_lapic_hv_timer_in_use(vcpu));

                kvm_vcpu_srcu_read_unlock(vcpu);
                kvm_vcpu_block(vcpu);
                kvm_vcpu_srcu_read_lock(vcpu);

                if (kvm_apic_accept_events(vcpu) < 0) {
                        r = 0;
                        goto out;
                }
                r = -EAGAIN;
                if (signal_pending(current)) {
                        r = -EINTR;
                        kvm_run->exit_reason = KVM_EXIT_INTR;
                        ++vcpu->stat.signal_exits;
                }
                goto out;
        }

        if ((kvm_run->kvm_valid_regs & ~KVM_SYNC_X86_VALID_FIELDS) ||
            (kvm_run->kvm_dirty_regs & ~KVM_SYNC_X86_VALID_FIELDS)) {
                r = -EINVAL;
                goto out;
        }

        if (kvm_run->kvm_dirty_regs) {
                r = sync_regs(vcpu);
                if (r != 0)
                        goto out;
        }

        /* re-sync apic's tpr */
        if (!lapic_in_kernel(vcpu)) {
                if (kvm_set_cr8(vcpu, kvm_run->cr8) != 0) {
                        r = -EINVAL;
                        goto out;
                }
        }

        /*
         * If userspace set a pending exception and L2 is active, convert it to
         * a pending VM-Exit if L1 wants to intercept the exception.
         */
        if (vcpu->arch.exception_from_userspace && is_guest_mode(vcpu) &&
            kvm_x86_ops.nested_ops->is_exception_vmexit(vcpu, ex->vector,
                                                        ex->error_code)) {
                kvm_queue_exception_vmexit(vcpu, ex->vector,
                                           ex->has_error_code, ex->error_code,
                                           ex->has_payload, ex->payload);
                ex->injected = false;
                ex->pending = false;
        }
        vcpu->arch.exception_from_userspace = false;

        if (unlikely(vcpu->arch.complete_userspace_io)) {
                int (*cui)(struct kvm_vcpu *) = vcpu->arch.complete_userspace_io;
                vcpu->arch.complete_userspace_io = NULL;
                r = cui(vcpu);
                if (r <= 0)
                        goto out;
        } else {
                WARN_ON_ONCE(vcpu->arch.pio.count);
                WARN_ON_ONCE(vcpu->mmio_needed);
        }

        if (kvm_run->immediate_exit) {
                r = -EINTR;
                goto out;
        }

        r = static_call(kvm_x86_vcpu_pre_run)(vcpu);
        if (r <= 0)
                goto out;

        r = vcpu_run(vcpu);

out:
        kvm_put_guest_fpu(vcpu);
        if (kvm_run->kvm_valid_regs)
                store_regs(vcpu);
        post_kvm_run_save(vcpu);
        kvm_vcpu_srcu_read_unlock(vcpu);

        kvm_sigset_deactivate(vcpu);
        vcpu_put(vcpu);
        return r;
}

static void __get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
        if (vcpu->arch.emulate_regs_need_sync_to_vcpu) {
                /*
                 * We are here if userspace calls get_regs() in the middle of
                 * instruction emulation. Registers state needs to be copied
                 * back from emulation context to vcpu. Userspace shouldn't do
                 * that usually, but some bad designed PV devices (vmware
                 * backdoor interface) need this to work
                 */
                emulator_writeback_register_cache(vcpu->arch.emulate_ctxt);
                vcpu->arch.emulate_regs_need_sync_to_vcpu = false;
        }
        regs->rax = kvm_rax_read(vcpu);
        regs->rbx = kvm_rbx_read(vcpu);
        regs->rcx = kvm_rcx_read(vcpu);
        regs->rdx = kvm_rdx_read(vcpu);
        regs->rsi = kvm_rsi_read(vcpu);
        regs->rdi = kvm_rdi_read(vcpu);
        regs->rsp = kvm_rsp_read(vcpu);
        regs->rbp = kvm_rbp_read(vcpu);
#ifdef CONFIG_X86_64
        regs->r8 = kvm_r8_read(vcpu);
        regs->r9 = kvm_r9_read(vcpu);
        regs->r10 = kvm_r10_read(vcpu);
        regs->r11 = kvm_r11_read(vcpu);
        regs->r12 = kvm_r12_read(vcpu);
        regs->r13 = kvm_r13_read(vcpu);
        regs->r14 = kvm_r14_read(vcpu);
        regs->r15 = kvm_r15_read(vcpu);
#endif

        regs->rip = kvm_rip_read(vcpu);
        regs->rflags = kvm_get_rflags(vcpu);
}

int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
        vcpu_load(vcpu);
        __get_regs(vcpu, regs);
        vcpu_put(vcpu);
        return 0;
}

static void __set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
        vcpu->arch.emulate_regs_need_sync_from_vcpu = true;
        vcpu->arch.emulate_regs_need_sync_to_vcpu = false;

        kvm_rax_write(vcpu, regs->rax);
        kvm_rbx_write(vcpu, regs->rbx);
        kvm_rcx_write(vcpu, regs->rcx);
        kvm_rdx_write(vcpu, regs->rdx);
        kvm_rsi_write(vcpu, regs->rsi);
        kvm_rdi_write(vcpu, regs->rdi);
        kvm_rsp_write(vcpu, regs->rsp);
        kvm_rbp_write(vcpu, regs->rbp);
#ifdef CONFIG_X86_64
        kvm_r8_write(vcpu, regs->r8);
        kvm_r9_write(vcpu, regs->r9);
        kvm_r10_write(vcpu, regs->r10);
        kvm_r11_write(vcpu, regs->r11);
        kvm_r12_write(vcpu, regs->r12);
        kvm_r13_write(vcpu, regs->r13);
        kvm_r14_write(vcpu, regs->r14);
        kvm_r15_write(vcpu, regs->r15);
#endif

        kvm_rip_write(vcpu, regs->rip);
        kvm_set_rflags(vcpu, regs->rflags | X86_EFLAGS_FIXED);

        vcpu->arch.exception.pending = false;
        vcpu->arch.exception_vmexit.pending = false;

        kvm_make_request(KVM_REQ_EVENT, vcpu);
}

int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
{
        vcpu_load(vcpu);
        __set_regs(vcpu, regs);
        vcpu_put(vcpu);
        return 0;
}

static void __get_sregs_common(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
{
        struct desc_ptr dt;

        if (vcpu->arch.guest_state_protected)
                goto skip_protected_regs;

        kvm_get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
        kvm_get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
        kvm_get_segment(vcpu, &sregs->es, VCPU_SREG_ES);
        kvm_get_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
        kvm_get_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
        kvm_get_segment(vcpu, &sregs->ss, VCPU_SREG_SS);

        kvm_get_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
        kvm_get_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);

        static_call(kvm_x86_get_idt)(vcpu, &dt);
        sregs->idt.limit = dt.size;
        sregs->idt.base = dt.address;
        static_call(kvm_x86_get_gdt)(vcpu, &dt);
        sregs->gdt.limit = dt.size;
        sregs->gdt.base = dt.address;

        sregs->cr2 = vcpu->arch.cr2;
        sregs->cr3 = kvm_read_cr3(vcpu);

skip_protected_regs:
        sregs->cr0 = kvm_read_cr0(vcpu);
        sregs->cr4 = kvm_read_cr4(vcpu);
        sregs->cr8 = kvm_get_cr8(vcpu);
        sregs->efer = vcpu->arch.efer;
        sregs->apic_base = kvm_get_apic_base(vcpu);
}

static void __get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
{
        __get_sregs_common(vcpu, sregs);

        if (vcpu->arch.guest_state_protected)
                return;

        if (vcpu->arch.interrupt.injected && !vcpu->arch.interrupt.soft)
                set_bit(vcpu->arch.interrupt.nr,
                        (unsigned long *)sregs->interrupt_bitmap);
}

static void __get_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2)
{
        int i;

        __get_sregs_common(vcpu, (struct kvm_sregs *)sregs2);

        if (vcpu->arch.guest_state_protected)
                return;

        if (is_pae_paging(vcpu)) {
                for (i = 0 ; i < 4 ; i++)
                        sregs2->pdptrs[i] = kvm_pdptr_read(vcpu, i);
                sregs2->flags |= KVM_SREGS2_FLAGS_PDPTRS_VALID;
        }
}

int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
                                  struct kvm_sregs *sregs)
{
        vcpu_load(vcpu);
        __get_sregs(vcpu, sregs);
        vcpu_put(vcpu);
        return 0;
}

int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        int r;

        vcpu_load(vcpu);
        if (kvm_mpx_supported())
                kvm_load_guest_fpu(vcpu);

        r = kvm_apic_accept_events(vcpu);
        if (r < 0)
                goto out;
        r = 0;

        if ((vcpu->arch.mp_state == KVM_MP_STATE_HALTED ||
             vcpu->arch.mp_state == KVM_MP_STATE_AP_RESET_HOLD) &&
            vcpu->arch.pv.pv_unhalted)
                mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
        else
                mp_state->mp_state = vcpu->arch.mp_state;

out:
        if (kvm_mpx_supported())
                kvm_put_guest_fpu(vcpu);
        vcpu_put(vcpu);
        return r;
}

int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        int ret = -EINVAL;

        vcpu_load(vcpu);

        switch (mp_state->mp_state) {
        case KVM_MP_STATE_UNINITIALIZED:
        case KVM_MP_STATE_HALTED:
        case KVM_MP_STATE_AP_RESET_HOLD:
        case KVM_MP_STATE_INIT_RECEIVED:
        case KVM_MP_STATE_SIPI_RECEIVED:
                if (!lapic_in_kernel(vcpu))
                        goto out;
                break;

        case KVM_MP_STATE_RUNNABLE:
                break;

        default:
                goto out;
        }

        /*
         * Pending INITs are reported using KVM_SET_VCPU_EVENTS, disallow
         * forcing the guest into INIT/SIPI if those events are supposed to be
         * blocked.  KVM prioritizes SMI over INIT, so reject INIT/SIPI state
         * if an SMI is pending as well.
         */
        if ((!kvm_apic_init_sipi_allowed(vcpu) || vcpu->arch.smi_pending) &&
            (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED ||
             mp_state->mp_state == KVM_MP_STATE_INIT_RECEIVED))
                goto out;

        if (mp_state->mp_state == KVM_MP_STATE_SIPI_RECEIVED) {
                vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
                set_bit(KVM_APIC_SIPI, &vcpu->arch.apic->pending_events);
        } else
                vcpu->arch.mp_state = mp_state->mp_state;
        kvm_make_request(KVM_REQ_EVENT, vcpu);

        ret = 0;
out:
        vcpu_put(vcpu);
        return ret;
}

int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int idt_index,
                    int reason, bool has_error_code, u32 error_code)
{
        struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt;
        int ret;

        init_emulate_ctxt(vcpu);

        ret = emulator_task_switch(ctxt, tss_selector, idt_index, reason,
                                   has_error_code, error_code);
        if (ret) {
                vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
                vcpu->run->internal.ndata = 0;
                return 0;
        }

        kvm_rip_write(vcpu, ctxt->eip);
        kvm_set_rflags(vcpu, ctxt->eflags);
        return 1;
}
EXPORT_SYMBOL_GPL(kvm_task_switch);

static bool kvm_is_valid_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
{
        if ((sregs->efer & EFER_LME) && (sregs->cr0 & X86_CR0_PG)) {
                /*
                 * When EFER.LME and CR0.PG are set, the processor is in
                 * 64-bit mode (though maybe in a 32-bit code segment).
                 * CR4.PAE and EFER.LMA must be set.
                 */
                if (!(sregs->cr4 & X86_CR4_PAE) || !(sregs->efer & EFER_LMA))
                        return false;
                if (kvm_vcpu_is_illegal_gpa(vcpu, sregs->cr3))
                        return false;
        } else {
                /*
                 * Not in 64-bit mode: EFER.LMA is clear and the code
                 * segment cannot be 64-bit.
                 */
                if (sregs->efer & EFER_LMA || sregs->cs.l)
                        return false;
        }

        return kvm_is_valid_cr4(vcpu, sregs->cr4);
}

static int __set_sregs_common(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs,
                int *mmu_reset_needed, bool update_pdptrs)
{
        struct msr_data apic_base_msr;
        int idx;
        struct desc_ptr dt;

        if (!kvm_is_valid_sregs(vcpu, sregs))
                return -EINVAL;

        apic_base_msr.data = sregs->apic_base;
        apic_base_msr.host_initiated = true;
        if (kvm_set_apic_base(vcpu, &apic_base_msr))
                return -EINVAL;

        if (vcpu->arch.guest_state_protected)
                return 0;

        dt.size = sregs->idt.limit;
        dt.address = sregs->idt.base;
        static_call(kvm_x86_set_idt)(vcpu, &dt);
        dt.size = sregs->gdt.limit;
        dt.address = sregs->gdt.base;
        static_call(kvm_x86_set_gdt)(vcpu, &dt);

        vcpu->arch.cr2 = sregs->cr2;
        *mmu_reset_needed |= kvm_read_cr3(vcpu) != sregs->cr3;
        vcpu->arch.cr3 = sregs->cr3;
        kvm_register_mark_dirty(vcpu, VCPU_EXREG_CR3);
        static_call_cond(kvm_x86_post_set_cr3)(vcpu, sregs->cr3);

        kvm_set_cr8(vcpu, sregs->cr8);

        *mmu_reset_needed |= vcpu->arch.efer != sregs->efer;
        static_call(kvm_x86_set_efer)(vcpu, sregs->efer);

        *mmu_reset_needed |= kvm_read_cr0(vcpu) != sregs->cr0;
        static_call(kvm_x86_set_cr0)(vcpu, sregs->cr0);
        vcpu->arch.cr0 = sregs->cr0;

        *mmu_reset_needed |= kvm_read_cr4(vcpu) != sregs->cr4;
        static_call(kvm_x86_set_cr4)(vcpu, sregs->cr4);

        if (update_pdptrs) {
                idx = srcu_read_lock(&vcpu->kvm->srcu);
                if (is_pae_paging(vcpu)) {
                        load_pdptrs(vcpu, kvm_read_cr3(vcpu));
                        *mmu_reset_needed = 1;
                }
                srcu_read_unlock(&vcpu->kvm->srcu, idx);
        }

        kvm_set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
        kvm_set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
        kvm_set_segment(vcpu, &sregs->es, VCPU_SREG_ES);
        kvm_set_segment(vcpu, &sregs->fs, VCPU_SREG_FS);
        kvm_set_segment(vcpu, &sregs->gs, VCPU_SREG_GS);
        kvm_set_segment(vcpu, &sregs->ss, VCPU_SREG_SS);

        kvm_set_segment(vcpu, &sregs->tr, VCPU_SREG_TR);
        kvm_set_segment(vcpu, &sregs->ldt, VCPU_SREG_LDTR);

        update_cr8_intercept(vcpu);

        /* Older userspace won't unhalt the vcpu on reset. */
        if (kvm_vcpu_is_bsp(vcpu) && kvm_rip_read(vcpu) == 0xfff0 &&
            sregs->cs.selector == 0xf000 && sregs->cs.base == 0xffff0000 &&
            !is_protmode(vcpu))
                vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;

        return 0;
}

static int __set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs)
{
        int pending_vec, max_bits;
        int mmu_reset_needed = 0;
        int ret = __set_sregs_common(vcpu, sregs, &mmu_reset_needed, true);

        if (ret)
                return ret;

        if (mmu_reset_needed)
                kvm_mmu_reset_context(vcpu);

        max_bits = KVM_NR_INTERRUPTS;
        pending_vec = find_first_bit(
                (const unsigned long *)sregs->interrupt_bitmap, max_bits);

        if (pending_vec < max_bits) {
                kvm_queue_interrupt(vcpu, pending_vec, false);
                pr_debug("Set back pending irq %d\n", pending_vec);
                kvm_make_request(KVM_REQ_EVENT, vcpu);
        }
        return 0;
}

static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2)
{
        int mmu_reset_needed = 0;
        bool valid_pdptrs = sregs2->flags & KVM_SREGS2_FLAGS_PDPTRS_VALID;
        bool pae = (sregs2->cr0 & X86_CR0_PG) && (sregs2->cr4 & X86_CR4_PAE) &&
                !(sregs2->efer & EFER_LMA);
        int i, ret;

        if (sregs2->flags & ~KVM_SREGS2_FLAGS_PDPTRS_VALID)
                return -EINVAL;

        if (valid_pdptrs && (!pae || vcpu->arch.guest_state_protected))
                return -EINVAL;

        ret = __set_sregs_common(vcpu, (struct kvm_sregs *)sregs2,
                                 &mmu_reset_needed, !valid_pdptrs);
        if (ret)
                return ret;

        if (valid_pdptrs) {
                for (i = 0; i < 4 ; i++)
                        kvm_pdptr_write(vcpu, i, sregs2->pdptrs[i]);

                kvm_register_mark_dirty(vcpu, VCPU_EXREG_PDPTR);
                mmu_reset_needed = 1;
                vcpu->arch.pdptrs_from_userspace = true;
        }
        if (mmu_reset_needed)
                kvm_mmu_reset_context(vcpu);
        return 0;
}

int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
                                  struct kvm_sregs *sregs)
{
        int ret;

        vcpu_load(vcpu);
        ret = __set_sregs(vcpu, sregs);
        vcpu_put(vcpu);
        return ret;
}

static void kvm_arch_vcpu_guestdbg_update_apicv_inhibit(struct kvm *kvm)
{
        bool set = false;
        struct kvm_vcpu *vcpu;
        unsigned long i;

        if (!enable_apicv)
                return;

        down_write(&kvm->arch.apicv_update_lock);

        kvm_for_each_vcpu(i, vcpu, kvm) {
                if (vcpu->guest_debug & KVM_GUESTDBG_BLOCKIRQ) {
                        set = true;
                        break;
                }
        }
        __kvm_set_or_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_BLOCKIRQ, set);
        up_write(&kvm->arch.apicv_update_lock);
}

int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
                                        struct kvm_guest_debug *dbg)
{
        unsigned long rflags;
        int i, r;

        if (vcpu->arch.guest_state_protected)
                return -EINVAL;

        vcpu_load(vcpu);

        if (dbg->control & (KVM_GUESTDBG_INJECT_DB | KVM_GUESTDBG_INJECT_BP)) {
                r = -EBUSY;
                if (kvm_is_exception_pending(vcpu))
                        goto out;
                if (dbg->control & KVM_GUESTDBG_INJECT_DB)
                        kvm_queue_exception(vcpu, DB_VECTOR);
                else
                        kvm_queue_exception(vcpu, BP_VECTOR);
        }

        /*
         * Read rflags as long as potentially injected trace flags are still
         * filtered out.
         */
        rflags = kvm_get_rflags(vcpu);

        vcpu->guest_debug = dbg->control;
        if (!(vcpu->guest_debug & KVM_GUESTDBG_ENABLE))
                vcpu->guest_debug = 0;

        if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) {
                for (i = 0; i < KVM_NR_DB_REGS; ++i)
                        vcpu->arch.eff_db[i] = dbg->arch.debugreg[i];
                vcpu->arch.guest_debug_dr7 = dbg->arch.debugreg[7];
        } else {
                for (i = 0; i < KVM_NR_DB_REGS; i++)
                        vcpu->arch.eff_db[i] = vcpu->arch.db[i];
        }
        kvm_update_dr7(vcpu);

        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                vcpu->arch.singlestep_rip = kvm_get_linear_rip(vcpu);

        /*
         * Trigger an rflags update that will inject or remove the trace
         * flags.
         */
        kvm_set_rflags(vcpu, rflags);

        static_call(kvm_x86_update_exception_bitmap)(vcpu);

        kvm_arch_vcpu_guestdbg_update_apicv_inhibit(vcpu->kvm);

        r = 0;

out:
        vcpu_put(vcpu);
        return r;
}

/*
 * Translate a guest virtual address to a guest physical address.
 */
int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
                                    struct kvm_translation *tr)
{
        unsigned long vaddr = tr->linear_address;
        gpa_t gpa;
        int idx;

        vcpu_load(vcpu);

        idx = srcu_read_lock(&vcpu->kvm->srcu);
        gpa = kvm_mmu_gva_to_gpa_system(vcpu, vaddr, NULL);
        srcu_read_unlock(&vcpu->kvm->srcu, idx);
        tr->physical_address = gpa;
        tr->valid = gpa != INVALID_GPA;
        tr->writeable = 1;
        tr->usermode = 0;

        vcpu_put(vcpu);
        return 0;
}

int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
        struct fxregs_state *fxsave;

        if (fpstate_is_confidential(&vcpu->arch.guest_fpu))
                return 0;

        vcpu_load(vcpu);

        fxsave = &vcpu->arch.guest_fpu.fpstate->regs.fxsave;
        memcpy(fpu->fpr, fxsave->st_space, 128);
        fpu->fcw = fxsave->cwd;
        fpu->fsw = fxsave->swd;
        fpu->ftwx = fxsave->twd;
        fpu->last_opcode = fxsave->fop;
        fpu->last_ip = fxsave->rip;
        fpu->last_dp = fxsave->rdp;
        memcpy(fpu->xmm, fxsave->xmm_space, sizeof(fxsave->xmm_space));

        vcpu_put(vcpu);
        return 0;
}

int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
{
        struct fxregs_state *fxsave;

        if (fpstate_is_confidential(&vcpu->arch.guest_fpu))
                return 0;

        vcpu_load(vcpu);

        fxsave = &vcpu->arch.guest_fpu.fpstate->regs.fxsave;

        memcpy(fxsave->st_space, fpu->fpr, 128);
        fxsave->cwd = fpu->fcw;
        fxsave->swd = fpu->fsw;
        fxsave->twd = fpu->ftwx;
        fxsave->fop = fpu->last_opcode;
        fxsave->rip = fpu->last_ip;
        fxsave->rdp = fpu->last_dp;
        memcpy(fxsave->xmm_space, fpu->xmm, sizeof(fxsave->xmm_space));

        vcpu_put(vcpu);
        return 0;
}

static void store_regs(struct kvm_vcpu *vcpu)
{
        BUILD_BUG_ON(sizeof(struct kvm_sync_regs) > SYNC_REGS_SIZE_BYTES);

        if (vcpu->run->kvm_valid_regs & KVM_SYNC_X86_REGS)
                __get_regs(vcpu, &vcpu->run->s.regs.regs);

        if (vcpu->run->kvm_valid_regs & KVM_SYNC_X86_SREGS)
                __get_sregs(vcpu, &vcpu->run->s.regs.sregs);

        if (vcpu->run->kvm_valid_regs & KVM_SYNC_X86_EVENTS)
                kvm_vcpu_ioctl_x86_get_vcpu_events(
                                vcpu, &vcpu->run->s.regs.events);
}

static int sync_regs(struct kvm_vcpu *vcpu)
{
        if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_REGS) {
                __set_regs(vcpu, &vcpu->run->s.regs.regs);
                vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_REGS;
        }
        if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_SREGS) {
                if (__set_sregs(vcpu, &vcpu->run->s.regs.sregs))
                        return -EINVAL;
                vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_SREGS;
        }
        if (vcpu->run->kvm_dirty_regs & KVM_SYNC_X86_EVENTS) {
                if (kvm_vcpu_ioctl_x86_set_vcpu_events(
                                vcpu, &vcpu->run->s.regs.events))
                        return -EINVAL;
                vcpu->run->kvm_dirty_regs &= ~KVM_SYNC_X86_EVENTS;
        }

        return 0;
}

int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
{
        if (kvm_check_tsc_unstable() && kvm->created_vcpus)
                pr_warn_once("kvm: SMP vm created on host with unstable TSC; "
                             "guest TSC will not be reliable\n");

        if (!kvm->arch.max_vcpu_ids)
                kvm->arch.max_vcpu_ids = KVM_MAX_VCPU_IDS;

        if (id >= kvm->arch.max_vcpu_ids)
                return -EINVAL;

        return static_call(kvm_x86_vcpu_precreate)(kvm);
}

int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
{
        struct page *page;
        int r;

        vcpu->arch.last_vmentry_cpu = -1;
        vcpu->arch.regs_avail = ~0;
        vcpu->arch.regs_dirty = ~0;

        kvm_gpc_init(&vcpu->arch.pv_time, vcpu->kvm, vcpu, KVM_HOST_USES_PFN);

        if (!irqchip_in_kernel(vcpu->kvm) || kvm_vcpu_is_reset_bsp(vcpu))
                vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
        else
                vcpu->arch.mp_state = KVM_MP_STATE_UNINITIALIZED;

        r = kvm_mmu_create(vcpu);
        if (r < 0)
                return r;

        if (irqchip_in_kernel(vcpu->kvm)) {
                r = kvm_create_lapic(vcpu, lapic_timer_advance_ns);
                if (r < 0)
                        goto fail_mmu_destroy;

                /*
                 * Defer evaluating inhibits until the vCPU is first run, as
                 * this vCPU will not get notified of any changes until this
                 * vCPU is visible to other vCPUs (marked online and added to
                 * the set of vCPUs).  Opportunistically mark APICv active as
                 * VMX in particularly is highly unlikely to have inhibits.
                 * Ignore the current per-VM APICv state so that vCPU creation
                 * is guaranteed to run with a deterministic value, the request
                 * will ensure the vCPU gets the correct state before VM-Entry.
                 */
                if (enable_apicv) {
                        vcpu->arch.apic->apicv_active = true;
                        kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu);
                }
        } else
                static_branch_inc(&kvm_has_noapic_vcpu);

        r = -ENOMEM;

        page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
        if (!page)
                goto fail_free_lapic;
        vcpu->arch.pio_data = page_address(page);

        vcpu->arch.mce_banks = kcalloc(KVM_MAX_MCE_BANKS * 4, sizeof(u64),
                                       GFP_KERNEL_ACCOUNT);
        vcpu->arch.mci_ctl2_banks = kcalloc(KVM_MAX_MCE_BANKS, sizeof(u64),
                                            GFP_KERNEL_ACCOUNT);
        if (!vcpu->arch.mce_banks || !vcpu->arch.mci_ctl2_banks)
                goto fail_free_mce_banks;
        vcpu->arch.mcg_cap = KVM_MAX_MCE_BANKS;

        if (!zalloc_cpumask_var(&vcpu->arch.wbinvd_dirty_mask,
                                GFP_KERNEL_ACCOUNT))
                goto fail_free_mce_banks;

        if (!alloc_emulate_ctxt(vcpu))
                goto free_wbinvd_dirty_mask;

        if (!fpu_alloc_guest_fpstate(&vcpu->arch.guest_fpu)) {
                pr_err("kvm: failed to allocate vcpu's fpu\n");
                goto free_emulate_ctxt;
        }

        vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
        vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu);

        vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT;

        kvm_async_pf_hash_reset(vcpu);

        vcpu->arch.perf_capabilities = kvm_caps.supported_perf_cap;
        kvm_pmu_init(vcpu);

        vcpu->arch.pending_external_vector = -1;
        vcpu->arch.preempted_in_kernel = false;

#if IS_ENABLED(CONFIG_HYPERV)
        vcpu->arch.hv_root_tdp = INVALID_PAGE;
#endif

        r = static_call(kvm_x86_vcpu_create)(vcpu);
        if (r)
                goto free_guest_fpu;

        vcpu->arch.arch_capabilities = kvm_get_arch_capabilities();
        vcpu->arch.msr_platform_info = MSR_PLATFORM_INFO_CPUID_FAULT;
        kvm_xen_init_vcpu(vcpu);
        kvm_vcpu_mtrr_init(vcpu);
        vcpu_load(vcpu);
        kvm_set_tsc_khz(vcpu, vcpu->kvm->arch.default_tsc_khz);
        kvm_vcpu_reset(vcpu, false);
        kvm_init_mmu(vcpu);
        vcpu_put(vcpu);
        return 0;

free_guest_fpu:
        fpu_free_guest_fpstate(&vcpu->arch.guest_fpu);
free_emulate_ctxt:
        kmem_cache_free(x86_emulator_cache, vcpu->arch.emulate_ctxt);
free_wbinvd_dirty_mask:
        free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
fail_free_mce_banks:
        kfree(vcpu->arch.mce_banks);
        kfree(vcpu->arch.mci_ctl2_banks);
        free_page((unsigned long)vcpu->arch.pio_data);
fail_free_lapic:
        kvm_free_lapic(vcpu);
fail_mmu_destroy:
        kvm_mmu_destroy(vcpu);
        return r;
}

void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
        struct kvm *kvm = vcpu->kvm;

        if (mutex_lock_killable(&vcpu->mutex))
                return;
        vcpu_load(vcpu);
        kvm_synchronize_tsc(vcpu, 0);
        vcpu_put(vcpu);

        /* poll control enabled by default */
        vcpu->arch.msr_kvm_poll_control = 1;

        mutex_unlock(&vcpu->mutex);

        if (kvmclock_periodic_sync && vcpu->vcpu_idx == 0)
                schedule_delayed_work(&kvm->arch.kvmclock_sync_work,
                                                KVMCLOCK_SYNC_PERIOD);
}

void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
        int idx;

        kvmclock_reset(vcpu);

        static_call(kvm_x86_vcpu_free)(vcpu);

        kmem_cache_free(x86_emulator_cache, vcpu->arch.emulate_ctxt);
        free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
        fpu_free_guest_fpstate(&vcpu->arch.guest_fpu);

        kvm_xen_destroy_vcpu(vcpu);
        kvm_hv_vcpu_uninit(vcpu);
        kvm_pmu_destroy(vcpu);
        kfree(vcpu->arch.mce_banks);
        kfree(vcpu->arch.mci_ctl2_banks);
        kvm_free_lapic(vcpu);
        idx = srcu_read_lock(&vcpu->kvm->srcu);
        kvm_mmu_destroy(vcpu);
        srcu_read_unlock(&vcpu->kvm->srcu, idx);
        free_page((unsigned long)vcpu->arch.pio_data);
        kvfree(vcpu->arch.cpuid_entries);
        if (!lapic_in_kernel(vcpu))
                static_branch_dec(&kvm_has_noapic_vcpu);
}

void kvm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
{
        struct kvm_cpuid_entry2 *cpuid_0x1;
        unsigned long old_cr0 = kvm_read_cr0(vcpu);
        unsigned long new_cr0;

        /*
         * Several of the "set" flows, e.g. ->set_cr0(), read other registers
         * to handle side effects.  RESET emulation hits those flows and relies
         * on emulated/virtualized registers, including those that are loaded
         * into hardware, to be zeroed at vCPU creation.  Use CRs as a sentinel
         * to detect improper or missing initialization.
         */
        WARN_ON_ONCE(!init_event &&
                     (old_cr0 || kvm_read_cr3(vcpu) || kvm_read_cr4(vcpu)));

        /*
         * SVM doesn't unconditionally VM-Exit on INIT and SHUTDOWN, thus it's
         * possible to INIT the vCPU while L2 is active.  Force the vCPU back
         * into L1 as EFER.SVME is cleared on INIT (along with all other EFER
         * bits), i.e. virtualization is disabled.
         */
        if (is_guest_mode(vcpu))
                kvm_leave_nested(vcpu);

        kvm_lapic_reset(vcpu, init_event);

        WARN_ON_ONCE(is_guest_mode(vcpu) || is_smm(vcpu));
        vcpu->arch.hflags = 0;

        vcpu->arch.smi_pending = 0;
        vcpu->arch.smi_count = 0;
        atomic_set(&vcpu->arch.nmi_queued, 0);
        vcpu->arch.nmi_pending = 0;
        vcpu->arch.nmi_injected = false;
        kvm_clear_interrupt_queue(vcpu);
        kvm_clear_exception_queue(vcpu);

        memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
        kvm_update_dr0123(vcpu);
        vcpu->arch.dr6 = DR6_ACTIVE_LOW;
        vcpu->arch.dr7 = DR7_FIXED_1;
        kvm_update_dr7(vcpu);

        vcpu->arch.cr2 = 0;

        kvm_make_request(KVM_REQ_EVENT, vcpu);
        vcpu->arch.apf.msr_en_val = 0;
        vcpu->arch.apf.msr_int_val = 0;
        vcpu->arch.st.msr_val = 0;

        kvmclock_reset(vcpu);

        kvm_clear_async_pf_completion_queue(vcpu);
        kvm_async_pf_hash_reset(vcpu);
        vcpu->arch.apf.halted = false;

        if (vcpu->arch.guest_fpu.fpstate && kvm_mpx_supported()) {
                struct fpstate *fpstate = vcpu->arch.guest_fpu.fpstate;

                /*
                 * All paths that lead to INIT are required to load the guest's
                 * FPU state (because most paths are buried in KVM_RUN).
                 */
                if (init_event)
                        kvm_put_guest_fpu(vcpu);

                fpstate_clear_xstate_component(fpstate, XFEATURE_BNDREGS);
                fpstate_clear_xstate_component(fpstate, XFEATURE_BNDCSR);

                if (init_event)
                        kvm_load_guest_fpu(vcpu);
        }

        if (!init_event) {
                kvm_pmu_reset(vcpu);
                vcpu->arch.smbase = 0x30000;

                vcpu->arch.msr_misc_features_enables = 0;
                vcpu->arch.ia32_misc_enable_msr = MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL |
                                                  MSR_IA32_MISC_ENABLE_BTS_UNAVAIL;

                __kvm_set_xcr(vcpu, 0, XFEATURE_MASK_FP);
                __kvm_set_msr(vcpu, MSR_IA32_XSS, 0, true);
        }

        /* All GPRs except RDX (handled below) are zeroed on RESET/INIT. */
        memset(vcpu->arch.regs, 0, sizeof(vcpu->arch.regs));
        kvm_register_mark_dirty(vcpu, VCPU_REGS_RSP);

        /*
         * Fall back to KVM's default Family/Model/Stepping of 0x600 (P6/Athlon)
         * if no CPUID match is found.  Note, it's impossible to get a match at
         * RESET since KVM emulates RESET before exposing the vCPU to userspace,
         * i.e. it's impossible for kvm_find_cpuid_entry() to find a valid entry
         * on RESET.  But, go through the motions in case that's ever remedied.
         */
        cpuid_0x1 = kvm_find_cpuid_entry(vcpu, 1);
        kvm_rdx_write(vcpu, cpuid_0x1 ? cpuid_0x1->eax : 0x600);

        static_call(kvm_x86_vcpu_reset)(vcpu, init_event);

        kvm_set_rflags(vcpu, X86_EFLAGS_FIXED);
        kvm_rip_write(vcpu, 0xfff0);

        vcpu->arch.cr3 = 0;
        kvm_register_mark_dirty(vcpu, VCPU_EXREG_CR3);

        /*
         * CR0.CD/NW are set on RESET, preserved on INIT.  Note, some versions
         * of Intel's SDM list CD/NW as being set on INIT, but they contradict
         * (or qualify) that with a footnote stating that CD/NW are preserved.
         */
        new_cr0 = X86_CR0_ET;
        if (init_event)
                new_cr0 |= (old_cr0 & (X86_CR0_NW | X86_CR0_CD));
        else
                new_cr0 |= X86_CR0_NW | X86_CR0_CD;

        static_call(kvm_x86_set_cr0)(vcpu, new_cr0);
        static_call(kvm_x86_set_cr4)(vcpu, 0);
        static_call(kvm_x86_set_efer)(vcpu, 0);
        static_call(kvm_x86_update_exception_bitmap)(vcpu);

        /*
         * On the standard CR0/CR4/EFER modification paths, there are several
         * complex conditions determining whether the MMU has to be reset and/or
         * which PCIDs have to be flushed.  However, CR0.WP and the paging-related
         * bits in CR4 and EFER are irrelevant if CR0.PG was '0'; and a reset+flush
         * is needed anyway if CR0.PG was '1' (which can only happen for INIT, as
         * CR0 will be '0' prior to RESET).  So we only need to check CR0.PG here.
         */
        if (old_cr0 & X86_CR0_PG) {
                kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
                kvm_mmu_reset_context(vcpu);
        }

        /*
         * Intel's SDM states that all TLB entries are flushed on INIT.  AMD's
         * APM states the TLBs are untouched by INIT, but it also states that
         * the TLBs are flushed on "External initialization of the processor."
         * Flush the guest TLB regardless of vendor, there is no meaningful
         * benefit in relying on the guest to flush the TLB immediately after
         * INIT.  A spurious TLB flush is benign and likely negligible from a
         * performance perspective.
         */
        if (init_event)
                kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_reset);

void kvm_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector)
{
        struct kvm_segment cs;

        kvm_get_segment(vcpu, &cs, VCPU_SREG_CS);
        cs.selector = vector << 8;
        cs.base = vector << 12;
        kvm_set_segment(vcpu, &cs, VCPU_SREG_CS);
        kvm_rip_write(vcpu, 0);
}
EXPORT_SYMBOL_GPL(kvm_vcpu_deliver_sipi_vector);

int kvm_arch_hardware_enable(void)
{
        struct kvm *kvm;
        struct kvm_vcpu *vcpu;
        unsigned long i;
        int ret;
        u64 local_tsc;
        u64 max_tsc = 0;
        bool stable, backwards_tsc = false;

        kvm_user_return_msr_cpu_online();
        ret = static_call(kvm_x86_hardware_enable)();
        if (ret != 0)
                return ret;

        local_tsc = rdtsc();
        stable = !kvm_check_tsc_unstable();
        list_for_each_entry(kvm, &vm_list, vm_list) {
                kvm_for_each_vcpu(i, vcpu, kvm) {
                        if (!stable && vcpu->cpu == smp_processor_id())
                                kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
                        if (stable && vcpu->arch.last_host_tsc > local_tsc) {
                                backwards_tsc = true;
                                if (vcpu->arch.last_host_tsc > max_tsc)
                                        max_tsc = vcpu->arch.last_host_tsc;
                        }
                }
        }

        /*
         * Sometimes, even reliable TSCs go backwards.  This happens on
         * platforms that reset TSC during suspend or hibernate actions, but
         * maintain synchronization.  We must compensate.  Fortunately, we can
         * detect that condition here, which happens early in CPU bringup,
         * before any KVM threads can be running.  Unfortunately, we can't
         * bring the TSCs fully up to date with real time, as we aren't yet far
         * enough into CPU bringup that we know how much real time has actually
         * elapsed; our helper function, ktime_get_boottime_ns() will be using boot
         * variables that haven't been updated yet.
         *
         * So we simply find the maximum observed TSC above, then record the
         * adjustment to TSC in each VCPU.  When the VCPU later gets loaded,
         * the adjustment will be applied.  Note that we accumulate
         * adjustments, in case multiple suspend cycles happen before some VCPU
         * gets a chance to run again.  In the event that no KVM threads get a
         * chance to run, we will miss the entire elapsed period, as we'll have
         * reset last_host_tsc, so VCPUs will not have the TSC adjusted and may
         * loose cycle time.  This isn't too big a deal, since the loss will be
         * uniform across all VCPUs (not to mention the scenario is extremely
         * unlikely). It is possible that a second hibernate recovery happens
         * much faster than a first, causing the observed TSC here to be
         * smaller; this would require additional padding adjustment, which is
         * why we set last_host_tsc to the local tsc observed here.
         *
         * N.B. - this code below runs only on platforms with reliable TSC,
         * as that is the only way backwards_tsc is set above.  Also note
         * that this runs for ALL vcpus, which is not a bug; all VCPUs should
         * have the same delta_cyc adjustment applied if backwards_tsc
         * is detected.  Note further, this adjustment is only done once,
         * as we reset last_host_tsc on all VCPUs to stop this from being
         * called multiple times (one for each physical CPU bringup).
         *
         * Platforms with unreliable TSCs don't have to deal with this, they
         * will be compensated by the logic in vcpu_load, which sets the TSC to
         * catchup mode.  This will catchup all VCPUs to real time, but cannot
         * guarantee that they stay in perfect synchronization.
         */
        if (backwards_tsc) {
                u64 delta_cyc = max_tsc - local_tsc;
                list_for_each_entry(kvm, &vm_list, vm_list) {
                        kvm->arch.backwards_tsc_observed = true;
                        kvm_for_each_vcpu(i, vcpu, kvm) {
                                vcpu->arch.tsc_offset_adjustment += delta_cyc;
                                vcpu->arch.last_host_tsc = local_tsc;
                                kvm_make_request(KVM_REQ_MASTERCLOCK_UPDATE, vcpu);
                        }

                        /*
                         * We have to disable TSC offset matching.. if you were
                         * booting a VM while issuing an S4 host suspend....
                         * you may have some problem.  Solving this issue is
                         * left as an exercise to the reader.
                         */
                        kvm->arch.last_tsc_nsec = 0;
                        kvm->arch.last_tsc_write = 0;
                }

        }
        return 0;
}

void kvm_arch_hardware_disable(void)
{
        static_call(kvm_x86_hardware_disable)();
        drop_user_return_notifiers();
}

static inline void kvm_ops_update(struct kvm_x86_init_ops *ops)
{
        memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops));

#define __KVM_X86_OP(func) \
        static_call_update(kvm_x86_##func, kvm_x86_ops.func);
#define KVM_X86_OP(func) \
        WARN_ON(!kvm_x86_ops.func); __KVM_X86_OP(func)
#define KVM_X86_OP_OPTIONAL __KVM_X86_OP
#define KVM_X86_OP_OPTIONAL_RET0(func) \
        static_call_update(kvm_x86_##func, (void *)kvm_x86_ops.func ? : \
                                           (void *)__static_call_return0);
#include <asm/kvm-x86-ops.h>
#undef __KVM_X86_OP

        kvm_pmu_ops_update(ops->pmu_ops);
}

int kvm_arch_hardware_setup(void *opaque)
{
        struct kvm_x86_init_ops *ops = opaque;
        int r;

        rdmsrl_safe(MSR_EFER, &host_efer);

        if (boot_cpu_has(X86_FEATURE_XSAVES))
                rdmsrl(MSR_IA32_XSS, host_xss);

        kvm_init_pmu_capability();

        r = ops->hardware_setup();
        if (r != 0)
                return r;

        kvm_ops_update(ops);

        kvm_register_perf_callbacks(ops->handle_intel_pt_intr);

        if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
                kvm_caps.supported_xss = 0;

#define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
        cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
#undef __kvm_cpu_cap_has

        if (kvm_caps.has_tsc_control) {
                /*
                 * Make sure the user can only configure tsc_khz values that
                 * fit into a signed integer.
                 * A min value is not calculated because it will always
                 * be 1 on all machines.
                 */
                u64 max = min(0x7fffffffULL,
                              __scale_tsc(kvm_caps.max_tsc_scaling_ratio, tsc_khz));
                kvm_caps.max_guest_tsc_khz = max;
        }
        kvm_caps.default_tsc_scaling_ratio = 1ULL << kvm_caps.tsc_scaling_ratio_frac_bits;
        kvm_init_msr_list();
        return 0;
}

void kvm_arch_hardware_unsetup(void)
{
        kvm_unregister_perf_callbacks();

        static_call(kvm_x86_hardware_unsetup)();
}

int kvm_arch_check_processor_compat(void *opaque)
{
        struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
        struct kvm_x86_init_ops *ops = opaque;

        WARN_ON(!irqs_disabled());

        if (__cr4_reserved_bits(cpu_has, c) !=
            __cr4_reserved_bits(cpu_has, &boot_cpu_data))
                return -EIO;

        return ops->check_processor_compatibility();
}

bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
{
        return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;
}

bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
{
        return (vcpu->arch.apic_base & MSR_IA32_APICBASE_BSP) != 0;
}

__read_mostly DEFINE_STATIC_KEY_FALSE(kvm_has_noapic_vcpu);
EXPORT_SYMBOL_GPL(kvm_has_noapic_vcpu);

void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
{
        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);

        vcpu->arch.l1tf_flush_l1d = true;
        if (pmu->version && unlikely(pmu->event_count)) {
                pmu->need_cleanup = true;
                kvm_make_request(KVM_REQ_PMU, vcpu);
        }
        static_call(kvm_x86_sched_in)(vcpu, cpu);
}

void kvm_arch_free_vm(struct kvm *kvm)
{
        kfree(to_kvm_hv(kvm)->hv_pa_pg);
        __kvm_arch_free_vm(kvm);
}


int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
        int ret;
        unsigned long flags;

        if (type)
                return -EINVAL;

        ret = kvm_page_track_init(kvm);
        if (ret)
                goto out;

        ret = kvm_mmu_init_vm(kvm);
        if (ret)
                goto out_page_track;

        ret = static_call(kvm_x86_vm_init)(kvm);
        if (ret)
                goto out_uninit_mmu;

        INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list);
        INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
        atomic_set(&kvm->arch.noncoherent_dma_count, 0);

        /* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
        set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap);
        /* Reserve bit 1 of irq_sources_bitmap for irqfd-resampler */
        set_bit(KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
                &kvm->arch.irq_sources_bitmap);

        raw_spin_lock_init(&kvm->arch.tsc_write_lock);
        mutex_init(&kvm->arch.apic_map_lock);
        seqcount_raw_spinlock_init(&kvm->arch.pvclock_sc, &kvm->arch.tsc_write_lock);
        kvm->arch.kvmclock_offset = -get_kvmclock_base_ns();

        raw_spin_lock_irqsave(&kvm->arch.tsc_write_lock, flags);
        pvclock_update_vm_gtod_copy(kvm);
        raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);

        kvm->arch.default_tsc_khz = max_tsc_khz ? : tsc_khz;
        kvm->arch.guest_can_read_msr_platform_info = true;
        kvm->arch.enable_pmu = enable_pmu;

#if IS_ENABLED(CONFIG_HYPERV)
        spin_lock_init(&kvm->arch.hv_root_tdp_lock);
        kvm->arch.hv_root_tdp = INVALID_PAGE;
#endif

        INIT_DELAYED_WORK(&kvm->arch.kvmclock_update_work, kvmclock_update_fn);
        INIT_DELAYED_WORK(&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);

        kvm_apicv_init(kvm);
        kvm_hv_init_vm(kvm);
        kvm_xen_init_vm(kvm);

        return 0;

out_uninit_mmu:
        kvm_mmu_uninit_vm(kvm);
out_page_track:
        kvm_page_track_cleanup(kvm);
out:
        return ret;
}

int kvm_arch_post_init_vm(struct kvm *kvm)
{
        return kvm_mmu_post_init_vm(kvm);
}

static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu)
{
        vcpu_load(vcpu);
        kvm_mmu_unload(vcpu);
        vcpu_put(vcpu);
}

static void kvm_unload_vcpu_mmus(struct kvm *kvm)
{
        unsigned long i;
        struct kvm_vcpu *vcpu;

        kvm_for_each_vcpu(i, vcpu, kvm) {
                kvm_clear_async_pf_completion_queue(vcpu);
                kvm_unload_vcpu_mmu(vcpu);
        }
}

void kvm_arch_sync_events(struct kvm *kvm)
{
        cancel_delayed_work_sync(&kvm->arch.kvmclock_sync_work);
        cancel_delayed_work_sync(&kvm->arch.kvmclock_update_work);
        kvm_free_pit(kvm);
}

/**
 * __x86_set_memory_region: Setup KVM internal memory slot
 *
 * @kvm: the kvm pointer to the VM.
 * @id: the slot ID to setup.
 * @gpa: the GPA to install the slot (unused when @size == 0).
 * @size: the size of the slot. Set to zero to uninstall a slot.
 *
 * This function helps to setup a KVM internal memory slot.  Specify
 * @size > 0 to install a new slot, while @size == 0 to uninstall a
 * slot.  The return code can be one of the following:
 *
 *   HVA:           on success (uninstall will return a bogus HVA)
 *   -errno:        on error
 *
 * The caller should always use IS_ERR() to check the return value
 * before use.  Note, the KVM internal memory slots are guaranteed to
 * remain valid and unchanged until the VM is destroyed, i.e., the
 * GPA->HVA translation will not change.  However, the HVA is a user
 * address, i.e. its accessibility is not guaranteed, and must be
 * accessed via __copy_{to,from}_user().
 */
void __user * __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa,
                                      u32 size)
{
        int i, r;
        unsigned long hva, old_npages;
        struct kvm_memslots *slots = kvm_memslots(kvm);
        struct kvm_memory_slot *slot;

        /* Called with kvm->slots_lock held.  */
        if (WARN_ON(id >= KVM_MEM_SLOTS_NUM))
                return ERR_PTR_USR(-EINVAL);

        slot = id_to_memslot(slots, id);
        if (size) {
                if (slot && slot->npages)
                        return ERR_PTR_USR(-EEXIST);

                /*
                 * MAP_SHARED to prevent internal slot pages from being moved
                 * by fork()/COW.
                 */
                hva = vm_mmap(NULL, 0, size, PROT_READ | PROT_WRITE,
                              MAP_SHARED | MAP_ANONYMOUS, 0);
                if (IS_ERR((void *)hva))
                        return (void __user *)hva;
        } else {
                if (!slot || !slot->npages)
                        return NULL;

                old_npages = slot->npages;
                hva = slot->userspace_addr;
        }

        for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
                struct kvm_userspace_memory_region m;

                m.slot = id | (i << 16);
                m.flags = 0;
                m.guest_phys_addr = gpa;
                m.userspace_addr = hva;
                m.memory_size = size;
                r = __kvm_set_memory_region(kvm, &m);
                if (r < 0)
                        return ERR_PTR_USR(r);
        }

        if (!size)
                vm_munmap(hva, old_npages * PAGE_SIZE);

        return (void __user *)hva;
}
EXPORT_SYMBOL_GPL(__x86_set_memory_region);

void kvm_arch_pre_destroy_vm(struct kvm *kvm)
{
        kvm_mmu_pre_destroy_vm(kvm);
}

void kvm_arch_destroy_vm(struct kvm *kvm)
{
        if (current->mm == kvm->mm) {
                /*
                 * Free memory regions allocated on behalf of userspace,
                 * unless the memory map has changed due to process exit
                 * or fd copying.
                 */
                mutex_lock(&kvm->slots_lock);
                __x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT,
                                        0, 0);
                __x86_set_memory_region(kvm, IDENTITY_PAGETABLE_PRIVATE_MEMSLOT,
                                        0, 0);
                __x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, 0, 0);
                mutex_unlock(&kvm->slots_lock);
        }
        kvm_unload_vcpu_mmus(kvm);
        static_call_cond(kvm_x86_vm_destroy)(kvm);
        kvm_free_msr_filter(srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1));
        kvm_pic_destroy(kvm);
        kvm_ioapic_destroy(kvm);
        kvm_destroy_vcpus(kvm);
        kvfree(rcu_dereference_check(kvm->arch.apic_map, 1));
        kfree(srcu_dereference_check(kvm->arch.pmu_event_filter, &kvm->srcu, 1));
        kvm_mmu_uninit_vm(kvm);
        kvm_page_track_cleanup(kvm);
        kvm_xen_destroy_vm(kvm);
        kvm_hv_destroy_vm(kvm);
}

static void memslot_rmap_free(struct kvm_memory_slot *slot)
{
        int i;

        for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
                kvfree(slot->arch.rmap[i]);
                slot->arch.rmap[i] = NULL;
        }
}

void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
{
        int i;

        memslot_rmap_free(slot);

        for (i = 1; i < KVM_NR_PAGE_SIZES; ++i) {
                kvfree(slot->arch.lpage_info[i - 1]);
                slot->arch.lpage_info[i - 1] = NULL;
        }

        kvm_page_track_free_memslot(slot);
}

int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages)
{
        const int sz = sizeof(*slot->arch.rmap[0]);
        int i;

        for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
                int level = i + 1;
                int lpages = __kvm_mmu_slot_lpages(slot, npages, level);

                if (slot->arch.rmap[i])
                        continue;

                slot->arch.rmap[i] = __vcalloc(lpages, sz, GFP_KERNEL_ACCOUNT);
                if (!slot->arch.rmap[i]) {
                        memslot_rmap_free(slot);
                        return -ENOMEM;
                }
        }

        return 0;
}

static int kvm_alloc_memslot_metadata(struct kvm *kvm,
                                      struct kvm_memory_slot *slot)
{
        unsigned long npages = slot->npages;
        int i, r;

        /*
         * Clear out the previous array pointers for the KVM_MR_MOVE case.  The
         * old arrays will be freed by __kvm_set_memory_region() if installing
         * the new memslot is successful.
         */
        memset(&slot->arch, 0, sizeof(slot->arch));

        if (kvm_memslots_have_rmaps(kvm)) {
                r = memslot_rmap_alloc(slot, npages);
                if (r)
                        return r;
        }

        for (i = 1; i < KVM_NR_PAGE_SIZES; ++i) {
                struct kvm_lpage_info *linfo;
                unsigned long ugfn;
                int lpages;
                int level = i + 1;

                lpages = __kvm_mmu_slot_lpages(slot, npages, level);

                linfo = __vcalloc(lpages, sizeof(*linfo), GFP_KERNEL_ACCOUNT);
                if (!linfo)
                        goto out_free;

                slot->arch.lpage_info[i - 1] = linfo;

                if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
                        linfo[0].disallow_lpage = 1;
                if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
                        linfo[lpages - 1].disallow_lpage = 1;
                ugfn = slot->userspace_addr >> PAGE_SHIFT;
                /*
                 * If the gfn and userspace address are not aligned wrt each
                 * other, disable large page support for this slot.
                 */
                if ((slot->base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1)) {
                        unsigned long j;

                        for (j = 0; j < lpages; ++j)
                                linfo[j].disallow_lpage = 1;
                }
        }

        if (kvm_page_track_create_memslot(kvm, slot, npages))
                goto out_free;

        return 0;

out_free:
        memslot_rmap_free(slot);

        for (i = 1; i < KVM_NR_PAGE_SIZES; ++i) {
                kvfree(slot->arch.lpage_info[i - 1]);
                slot->arch.lpage_info[i - 1] = NULL;
        }
        return -ENOMEM;
}

void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
{
        struct kvm_vcpu *vcpu;
        unsigned long i;

        /*
         * memslots->generation has been incremented.
         * mmio generation may have reached its maximum value.
         */
        kvm_mmu_invalidate_mmio_sptes(kvm, gen);

        /* Force re-initialization of steal_time cache */
        kvm_for_each_vcpu(i, vcpu, kvm)
                kvm_vcpu_kick(vcpu);
}

int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                   const struct kvm_memory_slot *old,
                                   struct kvm_memory_slot *new,
                                   enum kvm_mr_change change)
{
        if (change == KVM_MR_CREATE || change == KVM_MR_MOVE) {
                if ((new->base_gfn + new->npages - 1) > kvm_mmu_max_gfn())
                        return -EINVAL;

                return kvm_alloc_memslot_metadata(kvm, new);
        }

        if (change == KVM_MR_FLAGS_ONLY)
                memcpy(&new->arch, &old->arch, sizeof(old->arch));
        else if (WARN_ON_ONCE(change != KVM_MR_DELETE))
                return -EIO;

        return 0;
}


static void kvm_mmu_update_cpu_dirty_logging(struct kvm *kvm, bool enable)
{
        struct kvm_arch *ka = &kvm->arch;

        if (!kvm_x86_ops.cpu_dirty_log_size)
                return;

        if ((enable && ++ka->cpu_dirty_logging_count == 1) ||
            (!enable && --ka->cpu_dirty_logging_count == 0))
                kvm_make_all_cpus_request(kvm, KVM_REQ_UPDATE_CPU_DIRTY_LOGGING);

        WARN_ON_ONCE(ka->cpu_dirty_logging_count < 0);
}

static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
                                     struct kvm_memory_slot *old,
                                     const struct kvm_memory_slot *new,
                                     enum kvm_mr_change change)
{
        u32 old_flags = old ? old->flags : 0;
        u32 new_flags = new ? new->flags : 0;
        bool log_dirty_pages = new_flags & KVM_MEM_LOG_DIRTY_PAGES;

        /*
         * Update CPU dirty logging if dirty logging is being toggled.  This
         * applies to all operations.
         */
        if ((old_flags ^ new_flags) & KVM_MEM_LOG_DIRTY_PAGES)
                kvm_mmu_update_cpu_dirty_logging(kvm, log_dirty_pages);

        /*
         * Nothing more to do for RO slots (which can't be dirtied and can't be
         * made writable) or CREATE/MOVE/DELETE of a slot.
         *
         * For a memslot with dirty logging disabled:
         * CREATE:      No dirty mappings will already exist.
         * MOVE/DELETE: The old mappings will already have been cleaned up by
         *              kvm_arch_flush_shadow_memslot()
         *
         * For a memslot with dirty logging enabled:
         * CREATE:      No shadow pages exist, thus nothing to write-protect
         *              and no dirty bits to clear.
         * MOVE/DELETE: The old mappings will already have been cleaned up by
         *              kvm_arch_flush_shadow_memslot().
         */
        if ((change != KVM_MR_FLAGS_ONLY) || (new_flags & KVM_MEM_READONLY))
                return;

        /*
         * READONLY and non-flags changes were filtered out above, and the only
         * other flag is LOG_DIRTY_PAGES, i.e. something is wrong if dirty
         * logging isn't being toggled on or off.
         */
        if (WARN_ON_ONCE(!((old_flags ^ new_flags) & KVM_MEM_LOG_DIRTY_PAGES)))
                return;

        if (!log_dirty_pages) {
                /*
                 * Dirty logging tracks sptes in 4k granularity, meaning that
                 * large sptes have to be split.  If live migration succeeds,
                 * the guest in the source machine will be destroyed and large
                 * sptes will be created in the destination.  However, if the
                 * guest continues to run in the source machine (for example if
                 * live migration fails), small sptes will remain around and
                 * cause bad performance.
                 *
                 * Scan sptes if dirty logging has been stopped, dropping those
                 * which can be collapsed into a single large-page spte.  Later
                 * page faults will create the large-page sptes.
                 */
                kvm_mmu_zap_collapsible_sptes(kvm, new);
        } else {
                /*
                 * Initially-all-set does not require write protecting any page,
                 * because they're all assumed to be dirty.
                 */
                if (kvm_dirty_log_manual_protect_and_init_set(kvm))
                        return;

                if (READ_ONCE(eager_page_split))
                        kvm_mmu_slot_try_split_huge_pages(kvm, new, PG_LEVEL_4K);

                if (kvm_x86_ops.cpu_dirty_log_size) {
                        kvm_mmu_slot_leaf_clear_dirty(kvm, new);
                        kvm_mmu_slot_remove_write_access(kvm, new, PG_LEVEL_2M);
                } else {
                        kvm_mmu_slot_remove_write_access(kvm, new, PG_LEVEL_4K);
                }

                /*
                 * Unconditionally flush the TLBs after enabling dirty logging.
                 * A flush is almost always going to be necessary (see below),
                 * and unconditionally flushing allows the helpers to omit
                 * the subtly complex checks when removing write access.
                 *
                 * Do the flush outside of mmu_lock to reduce the amount of
                 * time mmu_lock is held.  Flushing after dropping mmu_lock is
                 * safe as KVM only needs to guarantee the slot is fully
                 * write-protected before returning to userspace, i.e. before
                 * userspace can consume the dirty status.
                 *
                 * Flushing outside of mmu_lock requires KVM to be careful when
                 * making decisions based on writable status of an SPTE, e.g. a
                 * !writable SPTE doesn't guarantee a CPU can't perform writes.
                 *
                 * Specifically, KVM also write-protects guest page tables to
                 * monitor changes when using shadow paging, and must guarantee
                 * no CPUs can write to those page before mmu_lock is dropped.
                 * Because CPUs may have stale TLB entries at this point, a
                 * !writable SPTE doesn't guarantee CPUs can't perform writes.
                 *
                 * KVM also allows making SPTES writable outside of mmu_lock,
                 * e.g. to allow dirty logging without taking mmu_lock.
                 *
                 * To handle these scenarios, KVM uses a separate software-only
                 * bit (MMU-writable) to track if a SPTE is !writable due to
                 * a guest page table being write-protected (KVM clears the
                 * MMU-writable flag when write-protecting for shadow paging).
                 *
                 * The use of MMU-writable is also the primary motivation for
                 * the unconditional flush.  Because KVM must guarantee that a
                 * CPU doesn't contain stale, writable TLB entries for a
                 * !MMU-writable SPTE, KVM must flush if it encounters any
                 * MMU-writable SPTE regardless of whether the actual hardware
                 * writable bit was set.  I.e. KVM is almost guaranteed to need
                 * to flush, while unconditionally flushing allows the "remove
                 * write access" helpers to ignore MMU-writable entirely.
                 *
                 * See is_writable_pte() for more details (the case involving
                 * access-tracked SPTEs is particularly relevant).
                 */
                kvm_arch_flush_remote_tlbs_memslot(kvm, new);
        }
}

void kvm_arch_commit_memory_region(struct kvm *kvm,
                                struct kvm_memory_slot *old,
                                const struct kvm_memory_slot *new,
                                enum kvm_mr_change change)
{
        if (!kvm->arch.n_requested_mmu_pages &&
            (change == KVM_MR_CREATE || change == KVM_MR_DELETE)) {
                unsigned long nr_mmu_pages;

                nr_mmu_pages = kvm->nr_memslot_pages / KVM_MEMSLOT_PAGES_TO_MMU_PAGES_RATIO;
                nr_mmu_pages = max(nr_mmu_pages, KVM_MIN_ALLOC_MMU_PAGES);
                kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
        }

        kvm_mmu_slot_apply_flags(kvm, old, new, change);

        /* Free the arrays associated with the old memslot. */
        if (change == KVM_MR_MOVE)
                kvm_arch_free_memslot(kvm, old);
}

void kvm_arch_flush_shadow_all(struct kvm *kvm)
{
        kvm_mmu_zap_all(kvm);
}

void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
                                   struct kvm_memory_slot *slot)
{
        kvm_page_track_flush_slot(kvm, slot);
}

static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
{
        return (is_guest_mode(vcpu) &&
                static_call(kvm_x86_guest_apic_has_interrupt)(vcpu));
}

static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
{
        if (!list_empty_careful(&vcpu->async_pf.done))
                return true;

        if (kvm_apic_has_pending_init_or_sipi(vcpu) &&
            kvm_apic_init_sipi_allowed(vcpu))
                return true;

        if (vcpu->arch.pv.pv_unhalted)
                return true;

        if (kvm_is_exception_pending(vcpu))
                return true;

        if (kvm_test_request(KVM_REQ_NMI, vcpu) ||
            (vcpu->arch.nmi_pending &&
             static_call(kvm_x86_nmi_allowed)(vcpu, false)))
                return true;

#ifdef CONFIG_KVM_SMM
        if (kvm_test_request(KVM_REQ_SMI, vcpu) ||
            (vcpu->arch.smi_pending &&
             static_call(kvm_x86_smi_allowed)(vcpu, false)))
                return true;
#endif

        if (kvm_arch_interrupt_allowed(vcpu) &&
            (kvm_cpu_has_interrupt(vcpu) ||
            kvm_guest_apic_has_interrupt(vcpu)))
                return true;

        if (kvm_hv_has_stimer_pending(vcpu))
                return true;

        if (is_guest_mode(vcpu) &&
            kvm_x86_ops.nested_ops->has_events &&
            kvm_x86_ops.nested_ops->has_events(vcpu))
                return true;

        if (kvm_xen_has_pending_events(vcpu))
                return true;

        return false;
}

int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_running(vcpu) || kvm_vcpu_has_events(vcpu);
}

bool kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu)
{
        if (kvm_vcpu_apicv_active(vcpu) &&
            static_call(kvm_x86_dy_apicv_has_pending_interrupt)(vcpu))
                return true;

        return false;
}

bool kvm_arch_dy_runnable(struct kvm_vcpu *vcpu)
{
        if (READ_ONCE(vcpu->arch.pv.pv_unhalted))
                return true;

        if (kvm_test_request(KVM_REQ_NMI, vcpu) ||
#ifdef CONFIG_KVM_SMM
                kvm_test_request(KVM_REQ_SMI, vcpu) ||
#endif
                 kvm_test_request(KVM_REQ_EVENT, vcpu))
                return true;

        return kvm_arch_dy_has_pending_interrupt(vcpu);
}

bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
{
        if (vcpu->arch.guest_state_protected)
                return true;

        return vcpu->arch.preempted_in_kernel;
}

unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
{
        return kvm_rip_read(vcpu);
}

int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
}

int kvm_arch_interrupt_allowed(struct kvm_vcpu *vcpu)
{
        return static_call(kvm_x86_interrupt_allowed)(vcpu, false);
}

unsigned long kvm_get_linear_rip(struct kvm_vcpu *vcpu)
{
        /* Can't read the RIP when guest state is protected, just return 0 */
        if (vcpu->arch.guest_state_protected)
                return 0;

        if (is_64_bit_mode(vcpu))
                return kvm_rip_read(vcpu);
        return (u32)(get_segment_base(vcpu, VCPU_SREG_CS) +
                     kvm_rip_read(vcpu));
}
EXPORT_SYMBOL_GPL(kvm_get_linear_rip);

bool kvm_is_linear_rip(struct kvm_vcpu *vcpu, unsigned long linear_rip)
{
        return kvm_get_linear_rip(vcpu) == linear_rip;
}
EXPORT_SYMBOL_GPL(kvm_is_linear_rip);

unsigned long kvm_get_rflags(struct kvm_vcpu *vcpu)
{
        unsigned long rflags;

        rflags = static_call(kvm_x86_get_rflags)(vcpu);
        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
                rflags &= ~X86_EFLAGS_TF;
        return rflags;
}
EXPORT_SYMBOL_GPL(kvm_get_rflags);

static void __kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
        if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP &&
            kvm_is_linear_rip(vcpu, vcpu->arch.singlestep_rip))
                rflags |= X86_EFLAGS_TF;
        static_call(kvm_x86_set_rflags)(vcpu, rflags);
}

void kvm_set_rflags(struct kvm_vcpu *vcpu, unsigned long rflags)
{
        __kvm_set_rflags(vcpu, rflags);
        kvm_make_request(KVM_REQ_EVENT, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_set_rflags);

static inline u32 kvm_async_pf_hash_fn(gfn_t gfn)
{
        BUILD_BUG_ON(!is_power_of_2(ASYNC_PF_PER_VCPU));

        return hash_32(gfn & 0xffffffff, order_base_2(ASYNC_PF_PER_VCPU));
}

static inline u32 kvm_async_pf_next_probe(u32 key)
{
        return (key + 1) & (ASYNC_PF_PER_VCPU - 1);
}

static void kvm_add_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
        u32 key = kvm_async_pf_hash_fn(gfn);

        while (vcpu->arch.apf.gfns[key] != ~0)
                key = kvm_async_pf_next_probe(key);

        vcpu->arch.apf.gfns[key] = gfn;
}

static u32 kvm_async_pf_gfn_slot(struct kvm_vcpu *vcpu, gfn_t gfn)
{
        int i;
        u32 key = kvm_async_pf_hash_fn(gfn);

        for (i = 0; i < ASYNC_PF_PER_VCPU &&
                     (vcpu->arch.apf.gfns[key] != gfn &&
                      vcpu->arch.apf.gfns[key] != ~0); i++)
                key = kvm_async_pf_next_probe(key);

        return key;
}

bool kvm_find_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
        return vcpu->arch.apf.gfns[kvm_async_pf_gfn_slot(vcpu, gfn)] == gfn;
}

static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn)
{
        u32 i, j, k;

        i = j = kvm_async_pf_gfn_slot(vcpu, gfn);

        if (WARN_ON_ONCE(vcpu->arch.apf.gfns[i] != gfn))
                return;

        while (true) {
                vcpu->arch.apf.gfns[i] = ~0;
                do {
                        j = kvm_async_pf_next_probe(j);
                        if (vcpu->arch.apf.gfns[j] == ~0)
                                return;
                        k = kvm_async_pf_hash_fn(vcpu->arch.apf.gfns[j]);
                        /*
                         * k lies cyclically in ]i,j]
                         * |    i.k.j |
                         * |....j i.k.| or  |.k..j i...|
                         */
                } while ((i <= j) ? (i < k && k <= j) : (i < k || k <= j));
                vcpu->arch.apf.gfns[i] = vcpu->arch.apf.gfns[j];
                i = j;
        }
}

static inline int apf_put_user_notpresent(struct kvm_vcpu *vcpu)
{
        u32 reason = KVM_PV_REASON_PAGE_NOT_PRESENT;

        return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apf.data, &reason,
                                      sizeof(reason));
}

static inline int apf_put_user_ready(struct kvm_vcpu *vcpu, u32 token)
{
        unsigned int offset = offsetof(struct kvm_vcpu_pv_apf_data, token);

        return kvm_write_guest_offset_cached(vcpu->kvm, &vcpu->arch.apf.data,
                                             &token, offset, sizeof(token));
}

static inline bool apf_pageready_slot_free(struct kvm_vcpu *vcpu)
{
        unsigned int offset = offsetof(struct kvm_vcpu_pv_apf_data, token);
        u32 val;

        if (kvm_read_guest_offset_cached(vcpu->kvm, &vcpu->arch.apf.data,
                                         &val, offset, sizeof(val)))
                return false;

        return !val;
}

static bool kvm_can_deliver_async_pf(struct kvm_vcpu *vcpu)
{

        if (!kvm_pv_async_pf_enabled(vcpu))
                return false;

        if (vcpu->arch.apf.send_user_only &&
            static_call(kvm_x86_get_cpl)(vcpu) == 0)
                return false;

        if (is_guest_mode(vcpu)) {
                /*
                 * L1 needs to opt into the special #PF vmexits that are
                 * used to deliver async page faults.
                 */
                return vcpu->arch.apf.delivery_as_pf_vmexit;
        } else {
                /*
                 * Play it safe in case the guest temporarily disables paging.
                 * The real mode IDT in particular is unlikely to have a #PF
                 * exception setup.
                 */
                return is_paging(vcpu);
        }
}

bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu)
{
        if (unlikely(!lapic_in_kernel(vcpu) ||
                     kvm_event_needs_reinjection(vcpu) ||
                     kvm_is_exception_pending(vcpu)))
                return false;

        if (kvm_hlt_in_guest(vcpu->kvm) && !kvm_can_deliver_async_pf(vcpu))
                return false;

        /*
         * If interrupts are off we cannot even use an artificial
         * halt state.
         */
        return kvm_arch_interrupt_allowed(vcpu);
}

bool kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
                                     struct kvm_async_pf *work)
{
        struct x86_exception fault;

        trace_kvm_async_pf_not_present(work->arch.token, work->cr2_or_gpa);
        kvm_add_async_pf_gfn(vcpu, work->arch.gfn);

        if (kvm_can_deliver_async_pf(vcpu) &&
            !apf_put_user_notpresent(vcpu)) {
                fault.vector = PF_VECTOR;
                fault.error_code_valid = true;
                fault.error_code = 0;
                fault.nested_page_fault = false;
                fault.address = work->arch.token;
                fault.async_page_fault = true;
                kvm_inject_page_fault(vcpu, &fault);
                return true;
        } else {
                /*
                 * It is not possible to deliver a paravirtualized asynchronous
                 * page fault, but putting the guest in an artificial halt state
                 * can be beneficial nevertheless: if an interrupt arrives, we
                 * can deliver it timely and perhaps the guest will schedule
                 * another process.  When the instruction that triggered a page
                 * fault is retried, hopefully the page will be ready in the host.
                 */
                kvm_make_request(KVM_REQ_APF_HALT, vcpu);
                return false;
        }
}

void kvm_arch_async_page_present(struct kvm_vcpu *vcpu,
                                 struct kvm_async_pf *work)
{
        struct kvm_lapic_irq irq = {
                .delivery_mode = APIC_DM_FIXED,
                .vector = vcpu->arch.apf.vec
        };

        if (work->wakeup_all)
                work->arch.token = ~0; /* broadcast wakeup */
        else
                kvm_del_async_pf_gfn(vcpu, work->arch.gfn);
        trace_kvm_async_pf_ready(work->arch.token, work->cr2_or_gpa);

        if ((work->wakeup_all || work->notpresent_injected) &&
            kvm_pv_async_pf_enabled(vcpu) &&
            !apf_put_user_ready(vcpu, work->arch.token)) {
                vcpu->arch.apf.pageready_pending = true;
                kvm_apic_set_irq(vcpu, &irq, NULL);
        }

        vcpu->arch.apf.halted = false;
        vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
}

void kvm_arch_async_page_present_queued(struct kvm_vcpu *vcpu)
{
        kvm_make_request(KVM_REQ_APF_READY, vcpu);
        if (!vcpu->arch.apf.pageready_pending)
                kvm_vcpu_kick(vcpu);
}

bool kvm_arch_can_dequeue_async_page_present(struct kvm_vcpu *vcpu)
{
        if (!kvm_pv_async_pf_enabled(vcpu))
                return true;
        else
                return kvm_lapic_enabled(vcpu) && apf_pageready_slot_free(vcpu);
}

void kvm_arch_start_assignment(struct kvm *kvm)
{
        if (atomic_inc_return(&kvm->arch.assigned_device_count) == 1)
                static_call_cond(kvm_x86_pi_start_assignment)(kvm);
}
EXPORT_SYMBOL_GPL(kvm_arch_start_assignment);

void kvm_arch_end_assignment(struct kvm *kvm)
{
        atomic_dec(&kvm->arch.assigned_device_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_end_assignment);

bool noinstr kvm_arch_has_assigned_device(struct kvm *kvm)
{
        return arch_atomic_read(&kvm->arch.assigned_device_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device);

void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
{
        atomic_inc(&kvm->arch.noncoherent_dma_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_register_noncoherent_dma);

void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
{
        atomic_dec(&kvm->arch.noncoherent_dma_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_unregister_noncoherent_dma);

bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
{
        return atomic_read(&kvm->arch.noncoherent_dma_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_has_noncoherent_dma);

bool kvm_arch_has_irq_bypass(void)
{
        return true;
}

int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
                                      struct irq_bypass_producer *prod)
{
        struct kvm_kernel_irqfd *irqfd =
                container_of(cons, struct kvm_kernel_irqfd, consumer);
        int ret;

        irqfd->producer = prod;
        kvm_arch_start_assignment(irqfd->kvm);
        ret = static_call(kvm_x86_pi_update_irte)(irqfd->kvm,
                                         prod->irq, irqfd->gsi, 1);

        if (ret)
                kvm_arch_end_assignment(irqfd->kvm);

        return ret;
}

void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
                                      struct irq_bypass_producer *prod)
{
        int ret;
        struct kvm_kernel_irqfd *irqfd =
                container_of(cons, struct kvm_kernel_irqfd, consumer);

        WARN_ON(irqfd->producer != prod);
        irqfd->producer = NULL;

        /*
         * When producer of consumer is unregistered, we change back to
         * remapped mode, so we can re-use the current implementation
         * when the irq is masked/disabled or the consumer side (KVM
         * int this case doesn't want to receive the interrupts.
        */
        ret = static_call(kvm_x86_pi_update_irte)(irqfd->kvm, prod->irq, irqfd->gsi, 0);
        if (ret)
                printk(KERN_INFO "irq bypass consumer (token %p) unregistration"
                       " fails: %d\n", irqfd->consumer.token, ret);

        kvm_arch_end_assignment(irqfd->kvm);
}

int kvm_arch_update_irqfd_routing(struct kvm *kvm, unsigned int host_irq,
                                   uint32_t guest_irq, bool set)
{
        return static_call(kvm_x86_pi_update_irte)(kvm, host_irq, guest_irq, set);
}

bool kvm_arch_irqfd_route_changed(struct kvm_kernel_irq_routing_entry *old,
                                  struct kvm_kernel_irq_routing_entry *new)
{
        if (new->type != KVM_IRQ_ROUTING_MSI)
                return true;

        return !!memcmp(&old->msi, &new->msi, sizeof(new->msi));
}

bool kvm_vector_hashing_enabled(void)
{
        return vector_hashing;
}

bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
{
        return (vcpu->arch.msr_kvm_poll_control & 1) == 0;
}
EXPORT_SYMBOL_GPL(kvm_arch_no_poll);


int kvm_spec_ctrl_test_value(u64 value)
{
        /*
         * test that setting IA32_SPEC_CTRL to given value
         * is allowed by the host processor
         */

        u64 saved_value;
        unsigned long flags;
        int ret = 0;

        local_irq_save(flags);

        if (rdmsrl_safe(MSR_IA32_SPEC_CTRL, &saved_value))
                ret = 1;
        else if (wrmsrl_safe(MSR_IA32_SPEC_CTRL, value))
                ret = 1;
        else
                wrmsrl(MSR_IA32_SPEC_CTRL, saved_value);

        local_irq_restore(flags);

        return ret;
}
EXPORT_SYMBOL_GPL(kvm_spec_ctrl_test_value);

void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_code)
{
        struct kvm_mmu *mmu = vcpu->arch.walk_mmu;
        struct x86_exception fault;
        u64 access = error_code &
                (PFERR_WRITE_MASK | PFERR_FETCH_MASK | PFERR_USER_MASK);

        if (!(error_code & PFERR_PRESENT_MASK) ||
            mmu->gva_to_gpa(vcpu, mmu, gva, access, &fault) != INVALID_GPA) {
                /*
                 * If vcpu->arch.walk_mmu->gva_to_gpa succeeded, the page
                 * tables probably do not match the TLB.  Just proceed
                 * with the error code that the processor gave.
                 */
                fault.vector = PF_VECTOR;
                fault.error_code_valid = true;
                fault.error_code = error_code;
                fault.nested_page_fault = false;
                fault.address = gva;
                fault.async_page_fault = false;
        }
        vcpu->arch.walk_mmu->inject_page_fault(vcpu, &fault);
}
EXPORT_SYMBOL_GPL(kvm_fixup_and_inject_pf_error);

/*
 * Handles kvm_read/write_guest_virt*() result and either injects #PF or returns
 * KVM_EXIT_INTERNAL_ERROR for cases not currently handled by KVM. Return value
 * indicates whether exit to userspace is needed.
 */
int kvm_handle_memory_failure(struct kvm_vcpu *vcpu, int r,
                              struct x86_exception *e)
{
        if (r == X86EMUL_PROPAGATE_FAULT) {
                if (KVM_BUG_ON(!e, vcpu->kvm))
                        return -EIO;

                kvm_inject_emulated_page_fault(vcpu, e);
                return 1;
        }

        /*
         * In case kvm_read/write_guest_virt*() failed with X86EMUL_IO_NEEDED
         * while handling a VMX instruction KVM could've handled the request
         * correctly by exiting to userspace and performing I/O but there
         * doesn't seem to be a real use-case behind such requests, just return
         * KVM_EXIT_INTERNAL_ERROR for now.
         */
        kvm_prepare_emulation_failure_exit(vcpu);

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_handle_memory_failure);

int kvm_handle_invpcid(struct kvm_vcpu *vcpu, unsigned long type, gva_t gva)
{
        bool pcid_enabled;
        struct x86_exception e;
        struct {
                u64 pcid;
                u64 gla;
        } operand;
        int r;

        r = kvm_read_guest_virt(vcpu, gva, &operand, sizeof(operand), &e);
        if (r != X86EMUL_CONTINUE)
                return kvm_handle_memory_failure(vcpu, r, &e);

        if (operand.pcid >> 12 != 0) {
                kvm_inject_gp(vcpu, 0);
                return 1;
        }

        pcid_enabled = kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE);

        switch (type) {
        case INVPCID_TYPE_INDIV_ADDR:
                if ((!pcid_enabled && (operand.pcid != 0)) ||
                    is_noncanonical_address(operand.gla, vcpu)) {
                        kvm_inject_gp(vcpu, 0);
                        return 1;
                }
                kvm_mmu_invpcid_gva(vcpu, operand.gla, operand.pcid);
                return kvm_skip_emulated_instruction(vcpu);

        case INVPCID_TYPE_SINGLE_CTXT:
                if (!pcid_enabled && (operand.pcid != 0)) {
                        kvm_inject_gp(vcpu, 0);
                        return 1;
                }

                kvm_invalidate_pcid(vcpu, operand.pcid);
                return kvm_skip_emulated_instruction(vcpu);

        case INVPCID_TYPE_ALL_NON_GLOBAL:
                /*
                 * Currently, KVM doesn't mark global entries in the shadow
                 * page tables, so a non-global flush just degenerates to a
                 * global flush. If needed, we could optimize this later by
                 * keeping track of global entries in shadow page tables.
                 */

                fallthrough;
        case INVPCID_TYPE_ALL_INCL_GLOBAL:
                kvm_make_request(KVM_REQ_TLB_FLUSH_GUEST, vcpu);
                return kvm_skip_emulated_instruction(vcpu);

        default:
                kvm_inject_gp(vcpu, 0);
                return 1;
        }
}
EXPORT_SYMBOL_GPL(kvm_handle_invpcid);

static int complete_sev_es_emulated_mmio(struct kvm_vcpu *vcpu)
{
        struct kvm_run *run = vcpu->run;
        struct kvm_mmio_fragment *frag;
        unsigned int len;

        BUG_ON(!vcpu->mmio_needed);

        /* Complete previous fragment */
        frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment];
        len = min(8u, frag->len);
        if (!vcpu->mmio_is_write)
                memcpy(frag->data, run->mmio.data, len);

        if (frag->len <= 8) {
                /* Switch to the next fragment. */
                frag++;
                vcpu->mmio_cur_fragment++;
        } else {
                /* Go forward to the next mmio piece. */
                frag->data += len;
                frag->gpa += len;
                frag->len -= len;
        }

        if (vcpu->mmio_cur_fragment >= vcpu->mmio_nr_fragments) {
                vcpu->mmio_needed = 0;

                // VMG change, at this point, we're always done
                // RIP has already been advanced
                return 1;
        }

        // More MMIO is needed
        run->mmio.phys_addr = frag->gpa;
        run->mmio.len = min(8u, frag->len);
        run->mmio.is_write = vcpu->mmio_is_write;
        if (run->mmio.is_write)
                memcpy(run->mmio.data, frag->data, min(8u, frag->len));
        run->exit_reason = KVM_EXIT_MMIO;

        vcpu->arch.complete_userspace_io = complete_sev_es_emulated_mmio;

        return 0;
}

int kvm_sev_es_mmio_write(struct kvm_vcpu *vcpu, gpa_t gpa, unsigned int bytes,
                          void *data)
{
        int handled;
        struct kvm_mmio_fragment *frag;

        if (!data)
                return -EINVAL;

        handled = write_emultor.read_write_mmio(vcpu, gpa, bytes, data);
        if (handled == bytes)
                return 1;

        bytes -= handled;
        gpa += handled;
        data += handled;

        /*TODO: Check if need to increment number of frags */
        frag = vcpu->mmio_fragments;
        vcpu->mmio_nr_fragments = 1;
        frag->len = bytes;
        frag->gpa = gpa;
        frag->data = data;

        vcpu->mmio_needed = 1;
        vcpu->mmio_cur_fragment = 0;

        vcpu->run->mmio.phys_addr = gpa;
        vcpu->run->mmio.len = min(8u, frag->len);
        vcpu->run->mmio.is_write = 1;
        memcpy(vcpu->run->mmio.data, frag->data, min(8u, frag->len));
        vcpu->run->exit_reason = KVM_EXIT_MMIO;

        vcpu->arch.complete_userspace_io = complete_sev_es_emulated_mmio;

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_sev_es_mmio_write);

int kvm_sev_es_mmio_read(struct kvm_vcpu *vcpu, gpa_t gpa, unsigned int bytes,
                         void *data)
{
        int handled;
        struct kvm_mmio_fragment *frag;

        if (!data)
                return -EINVAL;

        handled = read_emultor.read_write_mmio(vcpu, gpa, bytes, data);
        if (handled == bytes)
                return 1;

        bytes -= handled;
        gpa += handled;
        data += handled;

        /*TODO: Check if need to increment number of frags */
        frag = vcpu->mmio_fragments;
        vcpu->mmio_nr_fragments = 1;
        frag->len = bytes;
        frag->gpa = gpa;
        frag->data = data;

        vcpu->mmio_needed = 1;
        vcpu->mmio_cur_fragment = 0;

        vcpu->run->mmio.phys_addr = gpa;
        vcpu->run->mmio.len = min(8u, frag->len);
        vcpu->run->mmio.is_write = 0;
        vcpu->run->exit_reason = KVM_EXIT_MMIO;

        vcpu->arch.complete_userspace_io = complete_sev_es_emulated_mmio;

        return 0;
}
EXPORT_SYMBOL_GPL(kvm_sev_es_mmio_read);

static void advance_sev_es_emulated_pio(struct kvm_vcpu *vcpu, unsigned count, int size)
{
        vcpu->arch.sev_pio_count -= count;
        vcpu->arch.sev_pio_data += count * size;
}

static int kvm_sev_es_outs(struct kvm_vcpu *vcpu, unsigned int size,
                           unsigned int port);

static int complete_sev_es_emulated_outs(struct kvm_vcpu *vcpu)
{
        int size = vcpu->arch.pio.size;
        int port = vcpu->arch.pio.port;

        vcpu->arch.pio.count = 0;
        if (vcpu->arch.sev_pio_count)
                return kvm_sev_es_outs(vcpu, size, port);
        return 1;
}

static int kvm_sev_es_outs(struct kvm_vcpu *vcpu, unsigned int size,
                           unsigned int port)
{
        for (;;) {
                unsigned int count =
                        min_t(unsigned int, PAGE_SIZE / size, vcpu->arch.sev_pio_count);
                int ret = emulator_pio_out(vcpu, size, port, vcpu->arch.sev_pio_data, count);

                /* memcpy done already by emulator_pio_out.  */
                advance_sev_es_emulated_pio(vcpu, count, size);
                if (!ret)
                        break;

                /* Emulation done by the kernel.  */
                if (!vcpu->arch.sev_pio_count)
                        return 1;
        }

        vcpu->arch.complete_userspace_io = complete_sev_es_emulated_outs;
        return 0;
}

static int kvm_sev_es_ins(struct kvm_vcpu *vcpu, unsigned int size,
                          unsigned int port);

static int complete_sev_es_emulated_ins(struct kvm_vcpu *vcpu)
{
        unsigned count = vcpu->arch.pio.count;
        int size = vcpu->arch.pio.size;
        int port = vcpu->arch.pio.port;

        complete_emulator_pio_in(vcpu, vcpu->arch.sev_pio_data);
        advance_sev_es_emulated_pio(vcpu, count, size);
        if (vcpu->arch.sev_pio_count)
                return kvm_sev_es_ins(vcpu, size, port);
        return 1;
}

static int kvm_sev_es_ins(struct kvm_vcpu *vcpu, unsigned int size,
                          unsigned int port)
{
        for (;;) {
                unsigned int count =
                        min_t(unsigned int, PAGE_SIZE / size, vcpu->arch.sev_pio_count);
                if (!emulator_pio_in(vcpu, size, port, vcpu->arch.sev_pio_data, count))
                        break;

                /* Emulation done by the kernel.  */
                advance_sev_es_emulated_pio(vcpu, count, size);
                if (!vcpu->arch.sev_pio_count)
                        return 1;
        }

        vcpu->arch.complete_userspace_io = complete_sev_es_emulated_ins;
        return 0;
}

int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size,
                         unsigned int port, void *data,  unsigned int count,
                         int in)
{
        vcpu->arch.sev_pio_data = data;
        vcpu->arch.sev_pio_count = count;
        return in ? kvm_sev_es_ins(vcpu, size, port)
                  : kvm_sev_es_outs(vcpu, size, port);
}
EXPORT_SYMBOL_GPL(kvm_sev_es_string_io);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_entry);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_inj_virq);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_page_fault);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_msr);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_cr);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmenter);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmexit_inject);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intr_vmexit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_vmenter_failed);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_invlpga);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window_update);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pml_full);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pi_irte_update);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_unaccelerated_access);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_incomplete_ipi);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_ga_log);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_kick_vcpu_slowpath);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_doorbell);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_apicv_accept_irq);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_enter);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_msr_protocol_enter);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_msr_protocol_exit);

static int __init kvm_x86_init(void)
{
        kvm_mmu_x86_module_init();
        return 0;
}
module_init(kvm_x86_init);

static void __exit kvm_x86_exit(void)
{
        /*
         * If module_init() is implemented, module_exit() must also be
         * implemented to allow module unload.
         */
}
module_exit(kvm_x86_exit);