Re: Question about EMULATE_DO_MMIO

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Nitin A Kamble wrote:
> On Tue, 2007-10-16 at 13:12 -0700, Avi Kivity wrote:
>
>   
>> Why do you think it is better?  I would have thought that vm86 is much
>> faster.
>>
>>     
> I am seeing execution going to strange places in vm86 mode. That issue
> is not coming in the emulation.
>
>   

That means there's a bug somewhere.  We need to fix it.


>> That will also handle the few cases where VT can't handle protected
>> mode.
>>
>> It should exit to userspace, same as the non-emulating case.  However
>> it
>> shouldn't happen for normal writes.
>>
>>     
> Only thing is if it in the real mode, then returning back to user mode
> will setup the cpu state as real mode, and because of that vmenter will
> fail.
>   

It will fail, and we'll see it and go back to emulation.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.


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