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Commit 2adb5ad9 authored by Avi Kivity's avatar Avi Kivity
Browse files

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: default avatarAvi Kivity <avi@redhat.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 28867cee

arch/x86/kvm/emulate.c

+5 −8
Original line number Original line Diff line number Diff line
@@ -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,

static void decode_register_operand(struct x86_emulate_ctxt *ctxt,

				    struct operand *op,

				    struct operand *op)

				    int inhibit_bytereg)

{

{

	unsigned reg = ctxt->modrm_reg;

	unsigned reg = ctxt->modrm_reg;

	int highbyte_regs = ctxt->rex_prefix == 0;

	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;

	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->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs);

		op->bytes = 1;

		op->bytes = 1;

	} else {

	} else {
@@ -3516,13 +3515,13 @@ static struct opcode twobyte_table[256] = { 
	I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),

	I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),

	I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),

	I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),

	I(DstReg | SrcMemFAddr | ModRM | Src2GS, 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 */

	/* 0xB8 - 0xBF */

	N, N,

	N, N,

	G(BitOp, group8),

	G(BitOp, group8),

	I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),

	I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),

	I(DstReg | SrcMem | ModRM, em_bsf), I(DstReg | SrcMem | ModRM, em_bsr),

	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 */

	/* 0xC0 - 0xCF */

	D2bv(DstMem | SrcReg | ModRM | Lock),

	D2bv(DstMem | SrcReg | ModRM | Lock),

	N, D(DstMem | SrcReg | ModRM | Mov),

	N, D(DstMem | SrcReg | ModRM | Mov),
@@ -3604,9 +3603,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, 




	switch (d) {

	switch (d) {

	case OpReg:

	case OpReg:

		decode_register_operand(ctxt, op,

		decode_register_operand(ctxt, op);

			 op == &ctxt->dst &&

			 ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7));

		break;

		break;

	case OpImmUByte:

	case OpImmUByte:

		rc = decode_imm(ctxt, op, 1, false);

		rc = decode_imm(ctxt, op, 1, false);