Gleb Natapov wrote:
If LOCK prefix is used dest arg should be memory, otherwise instruction
should generate #UD.
Well, there is one exception:
There is an AMD specific "lock mov cr0 = mov cr8" equivalence, where
there is no memory involved (and we intercept this). I am not sure if
anyone actually uses this code sequence, but it is definitely legal.
Regards,
Andre.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index b89a8f2..46a7ee3 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1842,7 +1842,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
}
/* LOCK prefix is allowed only with some instructions */
- if (c->lock_prefix && !(c->d & Lock)) {
+ if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) {
kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
goto done;
}
--
Andre Przywara
AMD-OSRC (Dresden)
Tel: x29712
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
