KVM: x86 emulator: Use opcode::execute for XCHG(86/87)
In addition, replace one "goto xchg" with an em_xchg() call.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d25cfc2..c3d071d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2613,6 +2613,20 @@
return X86EMUL_CONTINUE;
}
+static int em_xchg(struct x86_emulate_ctxt *ctxt)
+{
+ struct decode_cache *c = &ctxt->decode;
+
+ /* Write back the register source. */
+ c->src.val = c->dst.val;
+ write_register_operand(&c->src);
+
+ /* Write back the memory destination with implicit LOCK prefix. */
+ c->dst.val = c->src.orig_val;
+ c->lock_prefix = 1;
+ return X86EMUL_CONTINUE;
+}
+
static int em_imul(struct x86_emulate_ctxt *ctxt)
{
struct decode_cache *c = &ctxt->decode;
@@ -3144,7 +3158,7 @@
G(ByteOp | DstMem | SrcImm | ModRM | No64 | Group, group1),
G(DstMem | SrcImmByte | ModRM | Group, group1),
I2bv(DstMem | SrcReg | ModRM, em_test),
- D2bv(DstMem | SrcReg | ModRM | Lock),
+ I2bv(DstMem | SrcReg | ModRM | Lock, em_xchg),
/* 0x88 - 0x8F */
I2bv(DstMem | SrcReg | ModRM | Mov, em_mov),
I2bv(DstReg | SrcMem | ModRM | Mov, em_mov),
@@ -3882,18 +3896,6 @@
if (test_cc(c->b, ctxt->eflags))
jmp_rel(c, c->src.val);
break;
- case 0x86 ... 0x87: /* xchg */
- xchg:
- /* Write back the register source. */
- c->src.val = c->dst.val;
- write_register_operand(&c->src);
- /*
- * Write back the memory destination with implicit LOCK
- * prefix.
- */
- c->dst.val = c->src.orig_val;
- c->lock_prefix = 1;
- break;
case 0x8c: /* mov r/m, sreg */
if (c->modrm_reg > VCPU_SREG_GS) {
rc = emulate_ud(ctxt);
@@ -3929,7 +3931,8 @@
case 0x90 ... 0x97: /* nop / xchg reg, rax */
if (c->dst.addr.reg == &c->regs[VCPU_REGS_RAX])
break;
- goto xchg;
+ rc = em_xchg(ctxt);
+ break;
case 0x98: /* cbw/cwde/cdqe */
switch (c->op_bytes) {
case 2: c->dst.val = (s8)c->dst.val; break;