On Mon, Mar 15, 2010 at 04:46:20PM +0100, Andre Przywara wrote: > 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. > Even without this patch "lock mov cr0" will cause #UD to be injected by emulator since mov does not have Lock in opcode table. Also it look like Intel does not support this extension so no portable program can use it.
> Regards, > Andre. > > > > >Signed-off-by: Gleb Natapov <[email protected]> > >--- > > 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 -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
