KVM: x86 emulator: add CBW/CWDE/CDQE instruction emulation
Add CBW/CWDE/CDQE instruction emulation.(opcode 0x98)
Used by FreeBSD's boot loader.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aab62d5..312dda5 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2300,7 +2300,7 @@
/* 0x90 - 0x97 */
X8(D(SrcAcc | DstReg)),
/* 0x98 - 0x9F */
- N, N, D(SrcImmFAddr | No64), N,
+ D(DstAcc | SrcNone), N, D(SrcImmFAddr | No64), N,
D(ImplicitOps | Stack), D(ImplicitOps | Stack), N, N,
/* 0xA0 - 0xA7 */
D(ByteOp | DstAcc | SrcMem | Mov | MemAbs), D(DstAcc | SrcMem | Mov | MemAbs),
@@ -3003,6 +3003,13 @@
if (c->dst.addr.reg == &c->regs[VCPU_REGS_RAX])
break;
goto xchg;
+ case 0x98: /* cbw/cwde/cdqe */
+ switch (c->op_bytes) {
+ case 2: c->dst.val = (s8)c->dst.val; break;
+ case 4: c->dst.val = (s16)c->dst.val; break;
+ case 8: c->dst.val = (s32)c->dst.val; break;
+ }
+ break;
case 0x9c: /* pushf */
c->src.val = (unsigned long) ctxt->eflags;
emulate_push(ctxt, ops);