Re: [Xen-devel] [PATCH] x86/HVM: correct repeat count update in linear->phys translation

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 07.09.17 at 12:50, <Paul.Durrant@xxxxxxxxxx> wrote:
>>  -----Original Message-----
>> From: Jan Beulich [mailto:JBeulich@xxxxxxxx]
>> Sent: 07 September 2017 11:42
>> To: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
>> Cc: Andrew Cooper <Andrew.Cooper3@xxxxxxxxxx>; Paul Durrant
>> <Paul.Durrant@xxxxxxxxxx>
>> Subject: [PATCH] x86/HVM: correct repeat count update in linear->phys
>> translation
>> 
>> For the insn emulator's fallback logic in REP MOVS/STOS/INS/OUTS
>> handling to work correctly, *reps must not be set to zero when
>> returning X86EMUL_UNHANDLEABLE.
> 
> Does it really need to be zero when returning X86EMUL_EXCEPTION?

Yes. Since an exception may occur on other than the first
iteration, in that case the number of successfully done one
needs to be handed back. See also the other #PF invocation
a few lines up.

Jan


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