From 2adb5ad9fe1b44d0ae8b00d2bd6568e6163215b3 Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@redhat.com>
Date: Mon, 16 Jan 2012 15:08:45 +0200
Subject: [PATCH] KVM: x86 emulator: Remove byte-sized MOVSX/MOVZX hack
Currently we treat MOVSX/MOVZX with a byte source as a byte instruction,
and change the destination operand size with a hack. Change it to be
a word instruction, so the destination receives its natural size, and
change the source to be SrcMem8.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
arch/x86/kvm/emulate.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 5da6b3619201..6eaedac7cf6a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -860,8 +860,7 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
}
static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
- struct operand *op,
- int inhibit_bytereg)
+ struct operand *op)
{
unsigned reg = ctxt->modrm_reg;
int highbyte_regs = ctxt->rex_prefix == 0;
@@ -878,7 +877,7 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
}
op->type = OP_REG;
- if ((ctxt->d & ByteOp) && !inhibit_bytereg) {
+ if (ctxt->d & ByteOp) {
op->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs);
op->bytes = 1;
} else {
@@ -3516,13 +3515,13 @@ static struct opcode twobyte_table[256] = {
I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
- D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+ D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xB8 - 0xBF */
N, N,
G(BitOp, group8),
I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
I(DstReg | SrcMem | ModRM, em_bsf), I(DstReg | SrcMem | ModRM, em_bsr),
- D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+ D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xC0 - 0xCF */
D2bv(DstMem | SrcReg | ModRM | Lock),
N, D(DstMem | SrcReg | ModRM | Mov),
@@ -3604,9 +3603,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
switch (d) {
case OpReg:
- decode_register_operand(ctxt, op,
- op == &ctxt->dst &&
- ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7));
+ decode_register_operand(ctxt, op);
break;
case OpImmUByte:
rc = decode_imm(ctxt, op, 1, false);
--
2.34.1