arch/x86/kernel/paravirt_patch_64.c

   1 #include <asm/paravirt.h>
   2 #include <asm/asm-offsets.h>
   3 #include <linux/stringify.h>
   4
   5 DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
   6 DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
   7 DEF_NATIVE(pv_irq_ops, restore_fl, "pushq %rdi; popfq");
   8 DEF_NATIVE(pv_irq_ops, save_fl, "pushfq; popq %rax");
   9 DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax");
  10 DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax");
  11 DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3");
  12 DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd");
  13
  14 DEF_NATIVE(pv_cpu_ops, usergs_sysret64, "swapgs; sysretq");
  15 DEF_NATIVE(pv_cpu_ops, swapgs, "swapgs");
  16
  17 DEF_NATIVE(, mov32, "mov %edi, %eax");
  18 DEF_NATIVE(, mov64, "mov %rdi, %rax");
  19
  20 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  21 DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%rdi)");
  22 DEF_NATIVE(pv_lock_ops, vcpu_is_preempted, "xor %rax, %rax");
  23 #endif
  24
  25 unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
  26 {
  27         return paravirt_patch_insns(insnbuf, len,
  28                                     start__mov32, end__mov32);
  29 }
  30
  31 unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
  32 {
  33         return paravirt_patch_insns(insnbuf, len,
  34                                     start__mov64, end__mov64);
  35 }
  36
  37 extern bool pv_is_native_spin_unlock(void);
  38 extern bool pv_is_native_vcpu_is_preempted(void);
  39
  40 unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
  41                       unsigned long addr, unsigned len)
  42 {
  43         const unsigned char *start, *end;
  44         unsigned ret;
  45
  46 #define PATCH_SITE(ops, x)                                      \
  47                 case PARAVIRT_PATCH(ops.x):                     \
  48                         start = start_##ops##_##x;              \
  49                         end = end_##ops##_##x;                  \
  50                         goto patch_site
  51         switch(type) {
  52                 PATCH_SITE(pv_irq_ops, restore_fl);
  53                 PATCH_SITE(pv_irq_ops, save_fl);
  54                 PATCH_SITE(pv_irq_ops, irq_enable);
  55                 PATCH_SITE(pv_irq_ops, irq_disable);
  56                 PATCH_SITE(pv_cpu_ops, usergs_sysret64);
  57                 PATCH_SITE(pv_cpu_ops, swapgs);
  58                 PATCH_SITE(pv_mmu_ops, read_cr2);
  59                 PATCH_SITE(pv_mmu_ops, read_cr3);
  60                 PATCH_SITE(pv_mmu_ops, write_cr3);
  61                 PATCH_SITE(pv_cpu_ops, wbinvd);
  62 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  63                 case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock):
  64                         if (pv_is_native_spin_unlock()) {
  65                                 start = start_pv_lock_ops_queued_spin_unlock;
  66                                 end   = end_pv_lock_ops_queued_spin_unlock;
  67                                 goto patch_site;
  68                         }
  69                         goto patch_default;
  70
  71                 case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
  72                         if (pv_is_native_vcpu_is_preempted()) {
  73                                 start = start_pv_lock_ops_vcpu_is_preempted;
  74                                 end   = end_pv_lock_ops_vcpu_is_preempted;
  75                                 goto patch_site;
  76                         }
  77                         goto patch_default;
  78 #endif
  79
  80         default:
  81 patch_default: __maybe_unused
  82                 ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
  83                 break;
  84
  85 patch_site:
  86                 ret = paravirt_patch_insns(ibuf, len, start, end);
  87                 break;
  88         }
  89 #undef PATCH_SITE
  90         return ret;
  91 }