--- /dev/null
+/*
+ * Kernel-based Virtual Machine -- Performane Monitoring Unit support
+ *
+ * Copyright 2011 Red Hat, Inc. and/or its affiliates.
+ *
+ * Authors:
+ * Avi Kivity <avi@redhat.com>
+ * Gleb Natapov <gleb@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/kvm_host.h>
+#include <linux/perf_event.h>
+#include "x86.h"
+#include "cpuid.h"
+#include "lapic.h"
+
+static struct kvm_arch_event_perf_mapping {
+ u8 eventsel;
+ u8 unit_mask;
+ unsigned event_type;
+ bool inexact;
+} arch_events[] = {
+ /* Index must match CPUID 0x0A.EBX bit vector */
+ [0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES },
+ [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
+ [2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES },
+ [3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES },
+ [4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES },
+ [5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
+ [6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
+};
+
+/* mapping between fixed pmc index and arch_events array */
+int fixed_pmc_events[] = {1, 0, 2};
+
+static bool pmc_is_gp(struct kvm_pmc *pmc)
+{
+ return pmc->type == KVM_PMC_GP;
+}
+
+static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
+{
+ struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
+
+ return pmu->counter_bitmask[pmc->type];
+}
+
+static inline bool pmc_enabled(struct kvm_pmc *pmc)
+{
+ struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
+ return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
+}
+
+static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
+ u32 base)
+{
+ if (msr >= base && msr < base + pmu->nr_arch_gp_counters)
+ return &pmu->gp_counters[msr - base];
+ return NULL;
+}
+
+static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
+{
+ int base = MSR_CORE_PERF_FIXED_CTR0;
+ if (msr >= base && msr < base + pmu->nr_arch_fixed_counters)
+ return &pmu->fixed_counters[msr - base];
+ return NULL;
+}
+
+static inline struct kvm_pmc *get_fixed_pmc_idx(struct kvm_pmu *pmu, int idx)
+{
+ return get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + idx);
+}
+
+static struct kvm_pmc *global_idx_to_pmc(struct kvm_pmu *pmu, int idx)
+{
+ if (idx < X86_PMC_IDX_FIXED)
+ return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + idx, MSR_P6_EVNTSEL0);
+ else
+ return get_fixed_pmc_idx(pmu, idx - X86_PMC_IDX_FIXED);
+}
+
+void kvm_deliver_pmi(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.apic)
+ kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTPC);
+}
+
+static void trigger_pmi(struct irq_work *irq_work)
+{
+ struct kvm_pmu *pmu = container_of(irq_work, struct kvm_pmu,
+ irq_work);
+ struct kvm_vcpu *vcpu = container_of(pmu, struct kvm_vcpu,
+ arch.pmu);
+
+ kvm_deliver_pmi(vcpu);
+}
+
+static void kvm_perf_overflow(struct perf_event *perf_event,
+ struct perf_sample_data *data,
+ struct pt_regs *regs)
+{
+ struct kvm_pmc *pmc = perf_event->overflow_handler_context;
+ struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
+ __set_bit(pmc->idx, (unsigned long *)&pmu->global_status);
+}
+
+static void kvm_perf_overflow_intr(struct perf_event *perf_event,
+ struct perf_sample_data *data, struct pt_regs *regs)
+{
+ struct kvm_pmc *pmc = perf_event->overflow_handler_context;
+ struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu;
+ if (!test_and_set_bit(pmc->idx, (unsigned long *)&pmu->reprogram_pmi)) {
+ kvm_perf_overflow(perf_event, data, regs);
+ kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
+ /*
+ * Inject PMI. If vcpu was in a guest mode during NMI PMI
+ * can be ejected on a guest mode re-entry. Otherwise we can't
+ * be sure that vcpu wasn't executing hlt instruction at the
+ * time of vmexit and is not going to re-enter guest mode until,
+ * woken up. So we should wake it, but this is impossible from
+ * NMI context. Do it from irq work instead.
+ */
+ if (!kvm_is_in_guest())
+ irq_work_queue(&pmc->vcpu->arch.pmu.irq_work);
+ else
+ kvm_make_request(KVM_REQ_PMI, pmc->vcpu);
+ }
+}
+
+static u64 read_pmc(struct kvm_pmc *pmc)
+{
+ u64 counter, enabled, running;
+
+ counter = pmc->counter;
+
+ if (pmc->perf_event)
+ counter += perf_event_read_value(pmc->perf_event,
+ &enabled, &running);
+
+ /* FIXME: Scaling needed? */
+
+ return counter & pmc_bitmask(pmc);
+}
+
+static void stop_counter(struct kvm_pmc *pmc)
+{
+ if (pmc->perf_event) {
+ pmc->counter = read_pmc(pmc);
+ perf_event_release_kernel(pmc->perf_event);
+ pmc->perf_event = NULL;
+ }
+}
+
+static void reprogram_counter(struct kvm_pmc *pmc, u32 type,
+ unsigned config, bool exclude_user, bool exclude_kernel,
+ bool intr)
+{
+ struct perf_event *event;
+ struct perf_event_attr attr = {
+ .type = type,
+ .size = sizeof(attr),
+ .pinned = true,
+ .exclude_idle = true,
+ .exclude_host = 1,
+ .exclude_user = exclude_user,
+ .exclude_kernel = exclude_kernel,
+ .config = config,
+ };
+
+ attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc);
+
+ event = perf_event_create_kernel_counter(&attr, -1, current,
+ intr ? kvm_perf_overflow_intr :
+ kvm_perf_overflow, pmc);
+ if (IS_ERR(event)) {
+ printk_once("kvm: pmu event creation failed %ld\n",
+ PTR_ERR(event));
+ return;
+ }
+
+ pmc->perf_event = event;
+ clear_bit(pmc->idx, (unsigned long*)&pmc->vcpu->arch.pmu.reprogram_pmi);
+}
+
+static unsigned find_arch_event(struct kvm_pmu *pmu, u8 event_select,
+ u8 unit_mask)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(arch_events); i++)
+ if (arch_events[i].eventsel == event_select
+ && arch_events[i].unit_mask == unit_mask
+ && (pmu->available_event_types & (1 << i)))
+ break;
+
+ if (i == ARRAY_SIZE(arch_events))
+ return PERF_COUNT_HW_MAX;
+
+ return arch_events[i].event_type;
+}
+
+static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel)
+{
+ unsigned config, type = PERF_TYPE_RAW;
+ u8 event_select, unit_mask;
+
+ pmc->eventsel = eventsel;
+
+ stop_counter(pmc);
+
+ if (!(eventsel & ARCH_PERFMON_EVENTSEL_ENABLE) || !pmc_enabled(pmc))
+ return;
+
+ event_select = eventsel & ARCH_PERFMON_EVENTSEL_EVENT;
+ unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8;
+
+ if (!(event_select & (ARCH_PERFMON_EVENTSEL_EDGE |
+ ARCH_PERFMON_EVENTSEL_INV |
+ ARCH_PERFMON_EVENTSEL_CMASK))) {
+ config = find_arch_event(&pmc->vcpu->arch.pmu, event_select,
+ unit_mask);
+ if (config != PERF_COUNT_HW_MAX)
+ type = PERF_TYPE_HARDWARE;
+ }
+
+ if (type == PERF_TYPE_RAW)
+ config = eventsel & X86_RAW_EVENT_MASK;
+
+ reprogram_counter(pmc, type, config,
+ !(eventsel & ARCH_PERFMON_EVENTSEL_USR),
+ !(eventsel & ARCH_PERFMON_EVENTSEL_OS),
+ eventsel & ARCH_PERFMON_EVENTSEL_INT);
+}
+
+static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 en_pmi, int idx)
+{
+ unsigned en = en_pmi & 0x3;
+ bool pmi = en_pmi & 0x8;
+
+ stop_counter(pmc);
+
+ if (!en || !pmc_enabled(pmc))
+ return;
+
+ reprogram_counter(pmc, PERF_TYPE_HARDWARE,
+ arch_events[fixed_pmc_events[idx]].event_type,
+ !(en & 0x2), /* exclude user */
+ !(en & 0x1), /* exclude kernel */
+ pmi);
+}
+
+static inline u8 fixed_en_pmi(u64 ctrl, int idx)
+{
+ return (ctrl >> (idx * 4)) & 0xf;
+}
+
+static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
+{
+ int i;
+
+ for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
+ u8 en_pmi = fixed_en_pmi(data, i);
+ struct kvm_pmc *pmc = get_fixed_pmc_idx(pmu, i);
+
+ if (fixed_en_pmi(pmu->fixed_ctr_ctrl, i) == en_pmi)
+ continue;
+
+ reprogram_fixed_counter(pmc, en_pmi, i);
+ }
+
+ pmu->fixed_ctr_ctrl = data;
+}
+
+static void reprogram_idx(struct kvm_pmu *pmu, int idx)
+{
+ struct kvm_pmc *pmc = global_idx_to_pmc(pmu, idx);
+
+ if (!pmc)
+ return;
+
+ if (pmc_is_gp(pmc))
+ reprogram_gp_counter(pmc, pmc->eventsel);
+ else {
+ int fidx = idx - X86_PMC_IDX_FIXED;
+ reprogram_fixed_counter(pmc,
+ fixed_en_pmi(pmu->fixed_ctr_ctrl, fidx), fidx);
+ }
+}
+
+static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data)
+{
+ int bit;
+ u64 diff = pmu->global_ctrl ^ data;
+
+ pmu->global_ctrl = data;
+
+ for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
+ reprogram_idx(pmu, bit);
+}
+
+bool kvm_pmu_msr(struct kvm_vcpu *vcpu, u32 msr)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ int ret;
+
+ switch (msr) {
+ case MSR_CORE_PERF_FIXED_CTR_CTRL:
+ case MSR_CORE_PERF_GLOBAL_STATUS:
+ case MSR_CORE_PERF_GLOBAL_CTRL:
+ case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
+ ret = pmu->version > 1;
+ break;
+ default:
+ ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)
+ || get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0)
+ || get_fixed_pmc(pmu, msr);
+ break;
+ }
+ return ret;
+}
+
+int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc;
+
+ switch (index) {
+ case MSR_CORE_PERF_FIXED_CTR_CTRL:
+ *data = pmu->fixed_ctr_ctrl;
+ return 0;
+ case MSR_CORE_PERF_GLOBAL_STATUS:
+ *data = pmu->global_status;
+ return 0;
+ case MSR_CORE_PERF_GLOBAL_CTRL:
+ *data = pmu->global_ctrl;
+ return 0;
+ case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
+ *data = pmu->global_ovf_ctrl;
+ return 0;
+ default:
+ if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) ||
+ (pmc = get_fixed_pmc(pmu, index))) {
+ *data = read_pmc(pmc);
+ return 0;
+ } else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) {
+ *data = pmc->eventsel;
+ return 0;
+ }
+ }
+ return 1;
+}
+
+int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc;
+
+ switch (index) {
+ case MSR_CORE_PERF_FIXED_CTR_CTRL:
+ if (pmu->fixed_ctr_ctrl == data)
+ return 0;
+ if (!(data & 0xfffffffffffff444)) {
+ reprogram_fixed_counters(pmu, data);
+ return 0;
+ }
+ break;
+ case MSR_CORE_PERF_GLOBAL_STATUS:
+ break; /* RO MSR */
+ case MSR_CORE_PERF_GLOBAL_CTRL:
+ if (pmu->global_ctrl == data)
+ return 0;
+ if (!(data & pmu->global_ctrl_mask)) {
+ global_ctrl_changed(pmu, data);
+ return 0;
+ }
+ break;
+ case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
+ if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) {
+ pmu->global_status &= ~data;
+ pmu->global_ovf_ctrl = data;
+ return 0;
+ }
+ break;
+ default:
+ if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) ||
+ (pmc = get_fixed_pmc(pmu, index))) {
+ data = (s64)(s32)data;
+ pmc->counter += data - read_pmc(pmc);
+ return 0;
+ } else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) {
+ if (data == pmc->eventsel)
+ return 0;
+ if (!(data & 0xffffffff00200000ull)) {
+ reprogram_gp_counter(pmc, data);
+ return 0;
+ }
+ }
+ }
+ return 1;
+}
+
+int kvm_pmu_read_pmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ bool fast_mode = pmc & (1u << 31);
+ bool fixed = pmc & (1u << 30);
+ struct kvm_pmc *counters;
+ u64 ctr;
+
+ pmc &= (3u << 30) - 1;
+ if (!fixed && pmc >= pmu->nr_arch_gp_counters)
+ return 1;
+ if (fixed && pmc >= pmu->nr_arch_fixed_counters)
+ return 1;
+ counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
+ ctr = read_pmc(&counters[pmc]);
+ if (fast_mode)
+ ctr = (u32)ctr;
+ *data = ctr;
+
+ return 0;
+}
+
+void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_cpuid_entry2 *entry;
+ unsigned bitmap_len;
+
+ pmu->nr_arch_gp_counters = 0;
+ pmu->nr_arch_fixed_counters = 0;
+ pmu->counter_bitmask[KVM_PMC_GP] = 0;
+ pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
+ pmu->version = 0;
+
+ entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
+ if (!entry)
+ return;
+
+ pmu->version = entry->eax & 0xff;
+ if (!pmu->version)
+ return;
+
+ pmu->nr_arch_gp_counters = min((int)(entry->eax >> 8) & 0xff,
+ X86_PMC_MAX_GENERIC);
+ pmu->counter_bitmask[KVM_PMC_GP] =
+ ((u64)1 << ((entry->eax >> 16) & 0xff)) - 1;
+ bitmap_len = (entry->eax >> 24) & 0xff;
+ pmu->available_event_types = ~entry->ebx & ((1ull << bitmap_len) - 1);
+
+ if (pmu->version == 1) {
+ pmu->global_ctrl = (1 << pmu->nr_arch_gp_counters) - 1;
+ return;
+ }
+
+ pmu->nr_arch_fixed_counters = min((int)(entry->edx & 0x1f),
+ X86_PMC_MAX_FIXED);
+ pmu->counter_bitmask[KVM_PMC_FIXED] =
+ ((u64)1 << ((entry->edx >> 5) & 0xff)) - 1;
+ pmu->global_ctrl_mask = ~(((1 << pmu->nr_arch_gp_counters) - 1)
+ | (((1ull << pmu->nr_arch_fixed_counters) - 1)
+ << X86_PMC_IDX_FIXED));
+}
+
+void kvm_pmu_init(struct kvm_vcpu *vcpu)
+{
+ int i;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+
+ memset(pmu, 0, sizeof(*pmu));
+ for (i = 0; i < X86_PMC_MAX_GENERIC; i++) {
+ pmu->gp_counters[i].type = KVM_PMC_GP;
+ pmu->gp_counters[i].vcpu = vcpu;
+ pmu->gp_counters[i].idx = i;
+ }
+ for (i = 0; i < X86_PMC_MAX_FIXED; i++) {
+ pmu->fixed_counters[i].type = KVM_PMC_FIXED;
+ pmu->fixed_counters[i].vcpu = vcpu;
+ pmu->fixed_counters[i].idx = i + X86_PMC_IDX_FIXED;
+ }
+ init_irq_work(&pmu->irq_work, trigger_pmi);
+ kvm_pmu_cpuid_update(vcpu);
+}
+
+void kvm_pmu_reset(struct kvm_vcpu *vcpu)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ int i;
+
+ irq_work_sync(&pmu->irq_work);
+ for (i = 0; i < X86_PMC_MAX_GENERIC; i++) {
+ struct kvm_pmc *pmc = &pmu->gp_counters[i];
+ stop_counter(pmc);
+ pmc->counter = pmc->eventsel = 0;
+ }
+
+ for (i = 0; i < X86_PMC_MAX_FIXED; i++)
+ stop_counter(&pmu->fixed_counters[i]);
+
+ pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status =
+ pmu->global_ovf_ctrl = 0;
+}
+
+void kvm_pmu_destroy(struct kvm_vcpu *vcpu)
+{
+ kvm_pmu_reset(vcpu);
+}
+
+void kvm_handle_pmu_event(struct kvm_vcpu *vcpu)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ u64 bitmask;
+ int bit;
+
+ bitmask = pmu->reprogram_pmi;
+
+ for_each_set_bit(bit, (unsigned long *)&bitmask, X86_PMC_IDX_MAX) {
+ struct kvm_pmc *pmc = global_idx_to_pmc(pmu, bit);
+
+ if (unlikely(!pmc || !pmc->perf_event)) {
+ clear_bit(bit, (unsigned long *)&pmu->reprogram_pmi);
+ continue;
+ }
+
+ reprogram_idx(pmu, bit);
+ }
+}
projects / linux-2.6-block.git / commitdiff