arch/x86/kernel/paravirt_patch_32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <asm/paravirt.h>
   3
   4 #ifdef CONFIG_PARAVIRT_XXL
   5 DEF_NATIVE(irq, irq_disable, "cli");
   6 DEF_NATIVE(irq, irq_enable, "sti");
   7 DEF_NATIVE(irq, restore_fl, "push %eax; popf");
   8 DEF_NATIVE(irq, save_fl, "pushf; pop %eax");
   9 DEF_NATIVE(cpu, iret, "iret");
  10 DEF_NATIVE(mmu, read_cr2, "mov %cr2, %eax");
  11 DEF_NATIVE(mmu, write_cr3, "mov %eax, %cr3");
  12 DEF_NATIVE(mmu, read_cr3, "mov %cr3, %eax");
  13 #endif
  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 #define PATCH_SITE(ops, x)                                      \
  38         case PARAVIRT_PATCH(ops.x):                             \
  39                 return paravirt_patch_insns(ibuf, len, start_##ops##_##x, end_##ops##_##x)
  40
  41         switch (type) {
  42 #ifdef CONFIG_PARAVIRT_XXL
  43                 PATCH_SITE(irq, irq_disable);
  44                 PATCH_SITE(irq, irq_enable);
  45                 PATCH_SITE(irq, restore_fl);
  46                 PATCH_SITE(irq, save_fl);
  47                 PATCH_SITE(cpu, iret);
  48                 PATCH_SITE(mmu, read_cr2);
  49                 PATCH_SITE(mmu, read_cr3);
  50                 PATCH_SITE(mmu, write_cr3);
  51 #endif
  52 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  53         case PARAVIRT_PATCH(lock.queued_spin_unlock):
  54                 if (pv_is_native_spin_unlock())
  55                         return paravirt_patch_insns(ibuf, len,
  56                                                     start_lock_queued_spin_unlock,
  57                                                     end_lock_queued_spin_unlock);
  58                 break;
  59
  60         case PARAVIRT_PATCH(lock.vcpu_is_preempted):
  61                 if (pv_is_native_vcpu_is_preempted())
  62                         return paravirt_patch_insns(ibuf, len,
  63                                                     start_lock_vcpu_is_preempted,
  64                                                     end_lock_vcpu_is_preempted);
  65                 break;
  66 #endif
  67
  68         default:
  69                 break;
  70         }
  71 #undef PATCH_SITE
  72         return paravirt_patch_default(type, ibuf, addr, len);
  73 }