KVM: x86 emulator: Use opcode::execute for CMPXCHG

CMPXCHG: 0F B0, 0F B1

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 19 insertions, 18 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 906c5eb34aa7..799000d8bf8b 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1832,6 +1832,24 @@ static int em_ret_far(struct x86_emulate_ctxt *ctxt)
         return rc;
 }
 
+static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
+{
+        /* Save real source value, then compare EAX against destination. */
+        ctxt->src.orig_val = ctxt->src.val;
+        ctxt->src.val = ctxt->regs[VCPU_REGS_RAX];
+        emulate_2op_SrcV(ctxt, "cmp");
+
+        if (ctxt->eflags & EFLG_ZF) {
+                /* Success: write back to memory. */
+                ctxt->dst.val = ctxt->src.orig_val;
+        } else {
+                /* Failure: write the value we saw to EAX. */
+                ctxt->dst.type = OP_REG;
+                ctxt->dst.addr.reg = (unsigned long *)&ctxt->regs[VCPU_REGS_RAX];
+        }
+        return X86EMUL_CONTINUE;
+}
+
 static int em_lseg(struct x86_emulate_ctxt *ctxt)
 {
         int seg = ctxt->src2.val;
@@ -3400,7 +3418,7 @@ static struct opcode twobyte_table[256] = {
         D(DstMem | SrcReg | Src2CL | ModRM),
         D(ModRM), I(DstReg | SrcMem | ModRM, em_imul),
         /* 0xB0 - 0xB7 */
-        D2bv(DstMem | SrcReg | ModRM | Lock | PageTable),
+        I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
         I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
         I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
         I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
@@ -4153,23 +4171,6 @@ twobyte_insn:
                 break;
         case 0xae:              /* clflush */
                 break;
-        case 0xb0 ... 0xb1:     /* cmpxchg */
-                /*
-                 * Save real source value, then compare EAX against
-                 * destination.
-                 */
-                ctxt->src.orig_val = ctxt->src.val;
-                ctxt->src.val = ctxt->regs[VCPU_REGS_RAX];
-                emulate_2op_SrcV(ctxt, "cmp");
-                if (ctxt->eflags & EFLG_ZF) {
-                        /* Success: write back to memory. */
-                        ctxt->dst.val = ctxt->src.orig_val;
-                } else {
-                        /* Failure: write the value we saw to EAX. */
-                        ctxt->dst.type = OP_REG;
-                        ctxt->dst.addr.reg = (unsigned long *)&ctxt->regs[VCPU_REGS_RAX];
-                }
-                break;
         case 0xb6 ... 0xb7:     /* movzx */
                 ctxt->dst.bytes = ctxt->op_bytes;
                 ctxt->dst.val = (ctxt->d & ByteOp) ? (u8) ctxt->src.val