KVM: x86 emulator: convert XADD to fastop

Signed-off-by: Avi Kivity <avi.kivity@gmail.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>

1 files changed, 3 insertions, 7 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d71aac0bf32f..9ebe95c5836e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -853,6 +853,8 @@ FASTOP2W(bts);
 FASTOP2W(btr);
 FASTOP2W(btc);
 
+FASTOP2(xadd);
+
 static u8 test_cc(unsigned int condition, unsigned long flags)
 {
         u8 rc;
@@ -3861,7 +3863,7 @@ static const struct opcode twobyte_table[256] = {
         F(DstReg | SrcMem | ModRM, em_bsf), F(DstReg | SrcMem | ModRM, em_bsr),
         D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
         /* 0xC0 - 0xC7 */
-        D2bv(DstMem | SrcReg | ModRM | Lock),
+        F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd),
         N, D(DstMem | SrcReg | ModRM | Mov),
         N, N, N, GD(0, &group9),
         /* 0xC8 - 0xCF */
@@ -4698,12 +4700,6 @@ twobyte_insn:
                 ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val :
                                                         (s16) ctxt->src.val;
                 break;
-        case 0xc0 ... 0xc1:     /* xadd */
-                fastop(ctxt, em_add);
-                /* Write back the register source. */
-                ctxt->src.val = ctxt->dst.orig_val;
-                write_register_operand(&ctxt->src);
-                break;
         case 0xc3:              /* movnti */
                 ctxt->dst.bytes = ctxt->op_bytes;
                 ctxt->dst.val = (ctxt->op_bytes == 4) ? (u32) ctxt->src.val :