Re: [Xen-devel] Invalid op code emulation for HVM guest and GPF

[Keir Fraser <keir@xxxxxxx>]

On 23/03/2012 19:58, "Andrew Cooper" <andrew.cooper3@xxxxxxxxxx> wrote:

> On 23/03/12 19:38, Andrew Cooper wrote:
>> Sadly, given your other email, I doubt it will work, because of the big
>> catch all regarding the lock prefix.
>> 
>> A brief scan over the Intel manuals and I cant see a case where an
>> incorrect LOCK prefix would cause #GPF rather than #UD.
>> 
>> Perhaps try changing it to EXP_UD instead of EXP_GP.  (Although I make
>> no guarantee that this wont cause a lot of things to break.)
> 
> Try this patch instead.
> 
> I have still yet to find a single example in either manual 2A or B where
> an invalid lock prefix would cause a #GPF rather than #UD

Yeah, this is a good fix. The origin of #GP is way back when I was doing a
major weekend hack on extending the emulator for vmx realmode emulation. I
expect in haste I picked the wrong exception type and that has propagated
onward.

I will apply to xen-unstable, and if it seems okay theer it can be
backported for 4.1 and 4.0.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel