LXR linux/arch/x86/kernel/paravirt_patch

   1#include <asm/paravirt.h>
   2
   3DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
   4DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
   5DEF_NATIVE(pv_irq_ops, restore_fl, "push %eax; popf");
   6DEF_NATIVE(pv_irq_ops, save_fl, "pushf; pop %eax");
   7DEF_NATIVE(pv_cpu_ops, iret, "iret");
   8DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax");
   9DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3");
  10DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax");
  11
  12#if defined(CONFIG_PARAVIRT_SPINLOCKS)
  13DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)");
  14DEF_NATIVE(pv_lock_ops, vcpu_is_preempted, "xor %eax, %eax");
  15#endif
  16
  17unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
  18{
  19        /* arg in %eax, return in %eax */
  20        return 0;
  21}
  22
  23unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
  24{
  25        /* arg in %edx:%eax, return in %edx:%eax */
  26        return 0;
  27}
  28
  29extern bool pv_is_native_spin_unlock(void);
  30extern bool pv_is_native_vcpu_is_preempted(void);
  31
  32unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
  33                      unsigned long addr, unsigned len)
  34{
  35        const unsigned char *start, *end;
  36        unsigned ret;
  37
  38#define PATCH_SITE(ops, x)                                      \
  39                case PARAVIRT_PATCH(ops.x):                     \
  40                        start = start_##ops##_##x;              \
  41                        end = end_##ops##_##x;                  \
  42                        goto patch_site
  43        switch (type) {
  44                PATCH_SITE(pv_irq_ops, irq_disable);
  45                PATCH_SITE(pv_irq_ops, irq_enable);
  46                PATCH_SITE(pv_irq_ops, restore_fl);
  47                PATCH_SITE(pv_irq_ops, save_fl);
  48                PATCH_SITE(pv_cpu_ops, iret);
  49                PATCH_SITE(pv_mmu_ops, read_cr2);
  50                PATCH_SITE(pv_mmu_ops, read_cr3);
  51                PATCH_SITE(pv_mmu_ops, write_cr3);
  52#if defined(CONFIG_PARAVIRT_SPINLOCKS)
  53                case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock):
  54                        if (pv_is_native_spin_unlock()) {
  55                                start = start_pv_lock_ops_queued_spin_unlock;
  56                                end   = end_pv_lock_ops_queued_spin_unlock;
  57                                goto patch_site;
  58                        }
  59                        goto patch_default;
  60
  61                case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
  62                        if (pv_is_native_vcpu_is_preempted()) {
  63                                start = start_pv_lock_ops_vcpu_is_preempted;
  64                                end   = end_pv_lock_ops_vcpu_is_preempted;
  65                                goto patch_site;
  66                        }
  67                        goto patch_default;
  68#endif
  69
  70        default:
  71patch_default: __maybe_unused
  72                ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
  73                break;
  74
  75patch_site:
  76                ret = paravirt_patch_insns(ibuf, len, start, end);
  77                break;
  78        }
  79#undef PATCH_SITE
  80        return ret;
  81}
  82