Re: [PATCH 6/6] KVM: x86: Emulator support for TF

Jan Kiszka
2010-02-23T12:04:01Z

Avi Kivity wrote:
> On 02/23/2010 01:30 PM, Jan Kiszka wrote:
>>> How to detect that emulation is complete? emulate_instruction() should
>>> return EMULATE_DONE in this case.
>>>
>> ...*and* RIP moved forward.
>>
>
> A branch or rep instruction can successfully execute and not change rip.
>
> Btw, do we expect a #DB on every iteration of rep? In this case we need
> to modify the code, currently we'll batch rep;ins and rep;outs up to a
> page's worth.

Right, TF triggers after each rep step. So we need to break this up when
tracing is on. That's now definitely something we need a deeper emulator
change.

Jan

--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux