Commit 350f69dc authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: x86 emulator: Make emulate_pop() a little more generic 



Allow emulate_pop() to read into arbitrary memory rather than just the
source operand.  Needed for complicated instructions like far returns.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 10f32d84

arch/x86/kvm/x86_emulate.c

+6 −9
Original line number Diff line number Diff line
@@ -1136,18 +1136,19 @@ static inline void emulate_push(struct x86_emulate_ctxt *ctxt) 
}



static int emulate_pop(struct x86_emulate_ctxt *ctxt,

		       struct x86_emulate_ops *ops)

		       struct x86_emulate_ops *ops,

		       void *dest, int len)

{

	struct decode_cache *c = &ctxt->decode;

	int rc;



	rc = ops->read_emulated(register_address(c, ss_base(ctxt),

						 c->regs[VCPU_REGS_RSP]),

				&c->src.val, c->src.bytes, ctxt->vcpu);

				dest, len, ctxt->vcpu);

	if (rc != 0)

		return rc;



	register_address_increment(c, &c->regs[VCPU_REGS_RSP], c->src.bytes);

	register_address_increment(c, &c->regs[VCPU_REGS_RSP], len);

	return rc;

}
@@ -1157,11 +1158,9 @@ static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt, 
	struct decode_cache *c = &ctxt->decode;

	int rc;



	c->src.bytes = c->dst.bytes;

	rc = emulate_pop(ctxt, ops);

	rc = emulate_pop(ctxt, ops, &c->dst.val, c->dst.bytes);

	if (rc != 0)

		return rc;

	c->dst.val = c->src.val;

	return 0;

}
@@ -1467,11 +1466,9 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 
		break;

	case 0x58 ... 0x5f: /* pop reg */

	pop_instruction:

		c->src.bytes = c->op_bytes;

		rc = emulate_pop(ctxt, ops);

		rc = emulate_pop(ctxt, ops, &c->dst.val, c->op_bytes);

		if (rc != 0)

			goto done;

		c->dst.val = c->src.val;

		break;

	case 0x63:		/* movsxd */

		if (ctxt->mode != X86EMUL_MODE_PROT64)