arch/x86/kernel/paravirt_patch_32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <asm/paravirt.h>
   3
   4 DEF_NATIVE(irq, irq_disable, "cli");
   5 DEF_NATIVE(irq, irq_enable, "sti");
   6 DEF_NATIVE(irq, restore_fl, "push %eax; popf");
   7 DEF_NATIVE(irq, save_fl, "pushf; pop %eax");
   8 #ifdef CONFIG_PARAVIRT_XXL
   9 DEF_NATIVE(cpu, iret, "iret");
  10 #endif
  11 DEF_NATIVE(mmu, read_cr2, "mov %cr2, %eax");
  12 DEF_NATIVE(mmu, write_cr3, "mov %eax, %cr3");
  13 DEF_NATIVE(mmu, read_cr3, "mov %cr3, %eax");
  14
  15 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  16 DEF_NATIVE(lock, queued_spin_unlock, "movb $0, (%eax)");
  17 DEF_NATIVE(lock, vcpu_is_preempted, "xor %eax, %eax");
  18 #endif
  19
  20 unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
  21 {
  22         /* arg in %eax, return in %eax */
  23         return 0;
  24 }
  25
  26 unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
  27 {
  28         /* arg in %edx:%eax, return in %edx:%eax */
  29         return 0;
  30 }
  31
  32 extern bool pv_is_native_spin_unlock(void);
  33 extern bool pv_is_native_vcpu_is_preempted(void);
  34
  35 unsigned native_patch(u8 type, void *ibuf, unsigned long addr, unsigned len)
  36 {
  37         const unsigned char *start, *end;
  38         unsigned ret;
  39
  40 #define PATCH_SITE(ops, x)                                      \
  41                 case PARAVIRT_PATCH(ops.x):                     \
  42                         start = start_##ops##_##x;              \
  43                         end = end_##ops##_##x;                  \
  44                         goto patch_site
  45         switch (type) {
  46                 PATCH_SITE(irq, irq_disable);
  47                 PATCH_SITE(irq, irq_enable);
  48                 PATCH_SITE(irq, restore_fl);
  49                 PATCH_SITE(irq, save_fl);
  50 #ifdef CONFIG_PARAVIRT_XXL
  51                 PATCH_SITE(cpu, iret);
  52 #endif
  53                 PATCH_SITE(mmu, read_cr2);
  54                 PATCH_SITE(mmu, read_cr3);
  55                 PATCH_SITE(mmu, write_cr3);
  56 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  57                 case PARAVIRT_PATCH(lock.queued_spin_unlock):
  58                         if (pv_is_native_spin_unlock()) {
  59                                 start = start_lock_queued_spin_unlock;
  60                                 end   = end_lock_queued_spin_unlock;
  61                                 goto patch_site;
  62                         }
  63                         goto patch_default;
  64
  65                 case PARAVIRT_PATCH(lock.vcpu_is_preempted):
  66                         if (pv_is_native_vcpu_is_preempted()) {
  67                                 start = start_lock_vcpu_is_preempted;
  68                                 end   = end_lock_vcpu_is_preempted;
  69                                 goto patch_site;
  70                         }
  71                         goto patch_default;
  72 #endif
  73
  74         default:
  75 patch_default: __maybe_unused
  76                 ret = paravirt_patch_default(type, ibuf, addr, len);
  77                 break;
  78
  79 patch_site:
  80                 ret = paravirt_patch_insns(ibuf, len, start, end);
  81                 break;
  82         }
  83 #undef PATCH_SITE
  84         return ret;
  85 }