diff options
| author | Gleb Natapov <gleb@redhat.com> | 2013-11-04 15:52:41 +0200 |
|---|---|---|
| committer | Gleb Natapov <gleb@redhat.com> | 2013-11-05 09:11:18 +0200 |
| commit | aa9ac1a6323d21065e121902fef4f1b6c07c37c7 (patch) | |
| tree | 8d2691f0b1633519595db3b3244b3a84a1bae46a /arch/x86/kvm/emulate.c | |
| parent | 95f328d3ad1a8e4e3175a18546fb35c495e31130 (diff) | |
KVM: emulator: check rex prefix inside decode_register()
All decode_register() callers check if instruction has rex prefix
to properly decode one byte operand. It make sense to move the check
inside.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 282d28cb9931..0bd372f3c989 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -785,9 +785,10 @@ static int do_insn_fetch(struct x86_emulate_ctxt *ctxt, * @highbyte_regs specifies whether to decode AH,CH,DH,BH. */ static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, - int highbyte_regs) + int byteop) { void *p; + int highbyte_regs = (ctxt->rex_prefix == 0) && byteop; if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1; @@ -1024,7 +1025,6 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt, struct operand *op) { unsigned reg = ctxt->modrm_reg; - int highbyte_regs = ctxt->rex_prefix == 0; if (!(ctxt->d & ModRM)) reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3); @@ -1046,10 +1046,10 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt, op->type = OP_REG; if (ctxt->d & ByteOp) { - op->addr.reg = decode_register(ctxt, reg, highbyte_regs); + op->addr.reg = decode_register(ctxt, reg, true); op->bytes = 1; } else { - op->addr.reg = decode_register(ctxt, reg, 0); + op->addr.reg = decode_register(ctxt, reg, false); op->bytes = ctxt->op_bytes; } fetch_register_operand(op); @@ -1082,12 +1082,10 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, ctxt->modrm_seg = VCPU_SREG_DS; if (ctxt->modrm_mod == 3) { - int highbyte_regs = ctxt->rex_prefix == 0; - op->type = OP_REG; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, - highbyte_regs && (ctxt->d & ByteOp)); + ctxt->d & ByteOp); if (ctxt->d & Sse) { op->type = OP_XMM; op->bytes = 16; @@ -4117,10 +4115,8 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, case OpMem8: ctxt->memop.bytes = 1; if (ctxt->memop.type == OP_REG) { - int highbyte_regs = ctxt->rex_prefix == 0; - - ctxt->memop.addr.reg = decode_register(ctxt, ctxt->modrm_rm, - highbyte_regs); + ctxt->memop.addr.reg = decode_register(ctxt, + ctxt->modrm_rm, true); fetch_register_operand(&ctxt->memop); } goto mem_common; |