arch/x86/kernel/paravirt.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*  Paravirtualization interfaces
   3     Copyright (C) 2006 Rusty Russell IBM Corporation
   4
   5
   6     2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc
   7 */
   8
   9 #include <linux/errno.h>
  10 #include <linux/init.h>
  11 #include <linux/export.h>
  12 #include <linux/efi.h>
  13 #include <linux/bcd.h>
  14 #include <linux/highmem.h>
  15 #include <linux/kprobes.h>
  16 #include <linux/pgtable.h>
  17 #include <linux/static_call.h>
  18
  19 #include <asm/bug.h>
  20 #include <asm/paravirt.h>
  21 #include <asm/debugreg.h>
  22 #include <asm/desc.h>
  23 #include <asm/setup.h>
  24 #include <asm/time.h>
  25 #include <asm/pgalloc.h>
  26 #include <asm/irq.h>
  27 #include <asm/delay.h>
  28 #include <asm/fixmap.h>
  29 #include <asm/apic.h>
  30 #include <asm/tlbflush.h>
  31 #include <asm/timer.h>
  32 #include <asm/special_insns.h>
  33 #include <asm/tlb.h>
  34 #include <asm/io_bitmap.h>
  35 #include <asm/gsseg.h>
  36 #include <asm/msr.h>
  37
  38 /* stub always returning 0. */
  39 DEFINE_ASM_FUNC(paravirt_ret0, "xor %eax,%eax", .entry.text);
  40
  41 void __init default_banner(void)
  42 {
  43         printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
  44                pv_info.name);
  45 }
  46
  47 #ifdef CONFIG_PARAVIRT_XXL
  48 DEFINE_ASM_FUNC(_paravirt_ident_64, "mov %rdi, %rax", .text);
  49 DEFINE_ASM_FUNC(pv_native_save_fl, "pushf; pop %rax", .noinstr.text);
  50 DEFINE_ASM_FUNC(pv_native_irq_disable, "cli", .noinstr.text);
  51 DEFINE_ASM_FUNC(pv_native_irq_enable, "sti", .noinstr.text);
  52 DEFINE_ASM_FUNC(pv_native_read_cr2, "mov %cr2, %rax", .noinstr.text);
  53 #endif
  54
  55 DEFINE_STATIC_KEY_FALSE(virt_spin_lock_key);
  56
  57 void __init native_pv_lock_init(void)
  58 {
  59         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
  60                 static_branch_enable(&virt_spin_lock_key);
  61 }
  62
  63 struct static_key paravirt_steal_enabled;
  64 struct static_key paravirt_steal_rq_enabled;
  65
  66 static u64 native_steal_clock(int cpu)
  67 {
  68         return 0;
  69 }
  70
  71 DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
  72 DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock);
  73
  74 void paravirt_set_sched_clock(u64 (*func)(void))
  75 {
  76         static_call_update(pv_sched_clock, func);
  77 }
  78
  79 static noinstr void pv_native_safe_halt(void)
  80 {
  81         native_safe_halt();
  82 }
  83
  84 #ifdef CONFIG_PARAVIRT_XXL
  85 static noinstr void pv_native_write_cr2(unsigned long val)
  86 {
  87         native_write_cr2(val);
  88 }
  89
  90 static noinstr unsigned long pv_native_read_cr3(void)
  91 {
  92         return __native_read_cr3();
  93 }
  94
  95 static noinstr void pv_native_write_cr3(unsigned long cr3)
  96 {
  97         native_write_cr3(cr3);
  98 }
  99
 100 static noinstr unsigned long pv_native_get_debugreg(int regno)
 101 {
 102         return native_get_debugreg(regno);
 103 }
 104
 105 static noinstr void pv_native_set_debugreg(int regno, unsigned long val)
 106 {
 107         native_set_debugreg(regno, val);
 108 }
 109 #endif
 110
 111 struct pv_info pv_info = {
 112         .name = "bare hardware",
 113 #ifdef CONFIG_PARAVIRT_XXL
 114         .extra_user_64bit_cs = __USER_CS,
 115 #endif
 116 };
 117
 118 /* 64-bit pagetable entries */
 119 #define PTE_IDENT       __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
 120
 121 struct paravirt_patch_template pv_ops = {
 122         /* Cpu ops. */
 123         .cpu.io_delay           = native_io_delay,
 124
 125 #ifdef CONFIG_PARAVIRT_XXL
 126         .cpu.cpuid              = native_cpuid,
 127         .cpu.get_debugreg       = pv_native_get_debugreg,
 128         .cpu.set_debugreg       = pv_native_set_debugreg,
 129         .cpu.read_cr0           = native_read_cr0,
 130         .cpu.write_cr0          = native_write_cr0,
 131         .cpu.write_cr4          = native_write_cr4,
 132         .cpu.read_msr           = native_read_msr,
 133         .cpu.write_msr          = native_write_msr,
 134         .cpu.read_msr_safe      = native_read_msr_safe,
 135         .cpu.write_msr_safe     = native_write_msr_safe,
 136         .cpu.read_pmc           = native_read_pmc,
 137         .cpu.load_tr_desc       = native_load_tr_desc,
 138         .cpu.set_ldt            = native_set_ldt,
 139         .cpu.load_gdt           = native_load_gdt,
 140         .cpu.load_idt           = native_load_idt,
 141         .cpu.store_tr           = native_store_tr,
 142         .cpu.load_tls           = native_load_tls,
 143         .cpu.load_gs_index      = native_load_gs_index,
 144         .cpu.write_ldt_entry    = native_write_ldt_entry,
 145         .cpu.write_gdt_entry    = native_write_gdt_entry,
 146         .cpu.write_idt_entry    = native_write_idt_entry,
 147
 148         .cpu.alloc_ldt          = paravirt_nop,
 149         .cpu.free_ldt           = paravirt_nop,
 150
 151         .cpu.load_sp0           = native_load_sp0,
 152
 153 #ifdef CONFIG_X86_IOPL_IOPERM
 154         .cpu.invalidate_io_bitmap       = native_tss_invalidate_io_bitmap,
 155         .cpu.update_io_bitmap           = native_tss_update_io_bitmap,
 156 #endif
 157
 158         .cpu.start_context_switch       = paravirt_nop,
 159         .cpu.end_context_switch         = paravirt_nop,
 160
 161         /* Irq ops. */
 162         .irq.save_fl            = __PV_IS_CALLEE_SAVE(pv_native_save_fl),
 163         .irq.irq_disable        = __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
 164         .irq.irq_enable         = __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
 165 #endif /* CONFIG_PARAVIRT_XXL */
 166
 167         /* Irq HLT ops. */
 168         .irq.safe_halt          = pv_native_safe_halt,
 169         .irq.halt               = native_halt,
 170
 171         /* Mmu ops. */
 172         .mmu.flush_tlb_user     = native_flush_tlb_local,
 173         .mmu.flush_tlb_kernel   = native_flush_tlb_global,
 174         .mmu.flush_tlb_one_user = native_flush_tlb_one_user,
 175         .mmu.flush_tlb_multi    = native_flush_tlb_multi,
 176
 177         .mmu.exit_mmap          = paravirt_nop,
 178         .mmu.notify_page_enc_status_changed     = paravirt_nop,
 179
 180 #ifdef CONFIG_PARAVIRT_XXL
 181         .mmu.read_cr2           = __PV_IS_CALLEE_SAVE(pv_native_read_cr2),
 182         .mmu.write_cr2          = pv_native_write_cr2,
 183         .mmu.read_cr3           = pv_native_read_cr3,
 184         .mmu.write_cr3          = pv_native_write_cr3,
 185
 186         .mmu.pgd_alloc          = __paravirt_pgd_alloc,
 187         .mmu.pgd_free           = paravirt_nop,
 188
 189         .mmu.alloc_pte          = paravirt_nop,
 190         .mmu.alloc_pmd          = paravirt_nop,
 191         .mmu.alloc_pud          = paravirt_nop,
 192         .mmu.alloc_p4d          = paravirt_nop,
 193         .mmu.release_pte        = paravirt_nop,
 194         .mmu.release_pmd        = paravirt_nop,
 195         .mmu.release_pud        = paravirt_nop,
 196         .mmu.release_p4d        = paravirt_nop,
 197
 198         .mmu.set_pte            = native_set_pte,
 199         .mmu.set_pmd            = native_set_pmd,
 200
 201         .mmu.ptep_modify_prot_start     = __ptep_modify_prot_start,
 202         .mmu.ptep_modify_prot_commit    = __ptep_modify_prot_commit,
 203
 204         .mmu.set_pud            = native_set_pud,
 205
 206         .mmu.pmd_val            = PTE_IDENT,
 207         .mmu.make_pmd           = PTE_IDENT,
 208
 209         .mmu.pud_val            = PTE_IDENT,
 210         .mmu.make_pud           = PTE_IDENT,
 211
 212         .mmu.set_p4d            = native_set_p4d,
 213
 214         .mmu.p4d_val            = PTE_IDENT,
 215         .mmu.make_p4d           = PTE_IDENT,
 216
 217         .mmu.set_pgd            = native_set_pgd,
 218
 219         .mmu.pte_val            = PTE_IDENT,
 220         .mmu.pgd_val            = PTE_IDENT,
 221
 222         .mmu.make_pte           = PTE_IDENT,
 223         .mmu.make_pgd           = PTE_IDENT,
 224
 225         .mmu.enter_mmap         = paravirt_nop,
 226
 227         .mmu.lazy_mode = {
 228                 .enter          = paravirt_nop,
 229                 .leave          = paravirt_nop,
 230                 .flush          = paravirt_nop,
 231         },
 232
 233         .mmu.set_fixmap         = native_set_fixmap,
 234 #endif /* CONFIG_PARAVIRT_XXL */
 235
 236 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
 237         /* Lock ops. */
 238 #ifdef CONFIG_SMP
 239         .lock.queued_spin_lock_slowpath = native_queued_spin_lock_slowpath,
 240         .lock.queued_spin_unlock        =
 241                                 PV_CALLEE_SAVE(__native_queued_spin_unlock),
 242         .lock.wait                      = paravirt_nop,
 243         .lock.kick                      = paravirt_nop,
 244         .lock.vcpu_is_preempted         =
 245                                 PV_CALLEE_SAVE(__native_vcpu_is_preempted),
 246 #endif /* SMP */
 247 #endif
 248 };
 249
 250 #ifdef CONFIG_PARAVIRT_XXL
 251 NOKPROBE_SYMBOL(native_load_idt);
 252 #endif
 253
 254 EXPORT_SYMBOL(pv_ops);
 255 EXPORT_SYMBOL_GPL(pv_info);