From a41ffb7540cb37426759e688083502d6463421b2 Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Thu, 18 Mar 2010 15:20:14 +0200 Subject: [PATCH] KVM: x86 emulator: If LOCK prefix is used dest arg should be memory. If LOCK prefix is used dest arg should be memory, otherwise instruction should generate #UD. Signed-off-by: Gleb Natapov Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/emulate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index b89a8f217332..46a7ee3040a0 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; }