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: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index 54fb098..94459f3 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -1136,18 +1136,19 @@
}
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 @@
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 @@
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)