2 files changed, 13 insertions, 0 deletions

diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 9ddfa5ed2289..0f901c16cf1c 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -190,6 +190,7 @@ struct decode_cache {
         bool has_seg_override;
         u8 seg_override;
         unsigned int d;
+        int (*execute)(struct x86_emulate_ctxt *ctxt);
         unsigned long regs[NR_VCPU_REGS];
         unsigned long eip;
         /* modrm */
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 3689f34a303a..799e895fb08e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -106,6 +106,7 @@
 struct opcode {
         u32 flags;
         union {
+                int (*execute)(struct x86_emulate_ctxt *ctxt);
                 struct opcode *group;
                 struct group_dual *gdual;
         } u;
@@ -120,6 +121,7 @@ struct group_dual {
 #define N    D(0)
 #define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
 #define GD(_f, _g) { .flags = ((_f) | Group | GroupDual), .u.gdual = (_g) }
+#define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
 
 static struct opcode group1[] = {
         X7(D(Lock)), N
@@ -349,6 +351,7 @@ static struct opcode twobyte_table[256] = {
 #undef N
 #undef G
 #undef GD
+#undef I
 
 /* EFLAGS bit definitions. */
 #define EFLG_ID (1<<21)
@@ -1070,6 +1073,8 @@ done_prefixes:
                 c->d |= opcode.flags;
         }
 
+        c->execute = opcode.u.execute;
+
         /* Unrecognised? */
         if (c->d == 0 || (c->d & Undefined)) {
                 DPRINTF("Cannot emulate %02x\n", c->b);
@@ -2705,6 +2710,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 
 special_insn:
 
+        if (c->execute) {
+                rc = c->execute(ctxt);
+                if (rc != X86EMUL_CONTINUE)
+                        goto done;
+                goto writeback;
+        }
+
         if (c->twobyte)
                 goto twobyte_insn;