arch/x86/kernel/paravirt_patch_64.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <asm/paravirt.h>
   3 #include <asm/asm-offsets.h>
   4 #include <linux/stringify.h>
   5
   6 DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
   7 DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
   8 DEF_NATIVE(pv_irq_ops, restore_fl, "pushq %rdi; popfq");
   9 DEF_NATIVE(pv_irq_ops, save_fl, "pushfq; popq %rax");
  10 DEF_NATIVE(pv_mmu_ops, read_cr2, "movq %cr2, %rax");
  11 DEF_NATIVE(pv_mmu_ops, read_cr3, "movq %cr3, %rax");
  12 DEF_NATIVE(pv_mmu_ops, write_cr3, "movq %rdi, %cr3");
  13 DEF_NATIVE(pv_cpu_ops, wbinvd, "wbinvd");
  14
  15 DEF_NATIVE(pv_cpu_ops, usergs_sysret64, "swapgs; sysretq");
  16 DEF_NATIVE(pv_cpu_ops, swapgs, "swapgs");
  17
  18 DEF_NATIVE(, mov32, "mov %edi, %eax");
  19 DEF_NATIVE(, mov64, "mov %rdi, %rax");
  20
  21 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  22 DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%rdi)");
  23 DEF_NATIVE(pv_lock_ops, vcpu_is_preempted, "xor %eax, %eax");
  24 #endif
  25
  26 unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
  27 {
  28         return paravirt_patch_insns(insnbuf, len,
  29                                     start__mov32, end__mov32);
  30 }
  31
  32 unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
  33 {
  34         return paravirt_patch_insns(insnbuf, len,
  35                                     start__mov64, end__mov64);
  36 }
  37
  38 extern bool pv_is_native_spin_unlock(void);
  39 extern bool pv_is_native_vcpu_is_preempted(void);
  40
  41 unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
  42                       unsigned long addr, unsigned len)
  43 {
  44         const unsigned char *start, *end;
  45         unsigned ret;
  46
  47 #define PATCH_SITE(ops, x)                                      \
  48                 case PARAVIRT_PATCH(ops.x):                     \
  49                         start = start_##ops##_##x;              \
  50                         end = end_##ops##_##x;                  \
  51                         goto patch_site
  52         switch(type) {
  53                 PATCH_SITE(pv_irq_ops, restore_fl);
  54                 PATCH_SITE(pv_irq_ops, save_fl);
  55                 PATCH_SITE(pv_irq_ops, irq_enable);
  56                 PATCH_SITE(pv_irq_ops, irq_disable);
  57                 PATCH_SITE(pv_cpu_ops, usergs_sysret64);
  58                 PATCH_SITE(pv_cpu_ops, swapgs);
  59                 PATCH_SITE(pv_mmu_ops, read_cr2);
  60                 PATCH_SITE(pv_mmu_ops, read_cr3);
  61                 PATCH_SITE(pv_mmu_ops, write_cr3);
  62                 PATCH_SITE(pv_cpu_ops, wbinvd);
  63 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
  64                 case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock):
  65                         if (pv_is_native_spin_unlock()) {
  66                                 start = start_pv_lock_ops_queued_spin_unlock;
  67                                 end   = end_pv_lock_ops_queued_spin_unlock;
  68                                 goto patch_site;
  69                         }
  70                         goto patch_default;
  71
  72                 case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
  73                         if (pv_is_native_vcpu_is_preempted()) {
  74                                 start = start_pv_lock_ops_vcpu_is_preempted;
  75                                 end   = end_pv_lock_ops_vcpu_is_preempted;
  76                                 goto patch_site;
  77                         }
  78                         goto patch_default;
  79 #endif
  80
  81         default:
  82 patch_default: __maybe_unused
  83                 ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
  84                 break;
  85
  86 patch_site:
  87                 ret = paravirt_patch_insns(ibuf, len, start, end);
  88                 break;
  89         }
  90 #undef PATCH_SITE
  91         return ret;
  92 }