Re: [ToDo] Real Mode Support

[Avi Kivity <avi@qumranet.com>]

Guillaume Thouvenin wrote:
>>>   
>>>       
>> As using the emulator is likely to be slower than VT, we can call the 
>> emulator only if we are in a "VT unfriendly" state, so the code might 
>> look like
>>
>>     if (vmx->rmode.active && big_real_mode(vmx))
>>           ...
>>
>> In addition, there are some protected-mode states that VT can't handle 
>> (cs.rpl != ss.rpl IIRC) so we can emulate those cases as well.
>>
>> To improve speed, we may want to emulate >1 instruction per iteration.
>>     
>
> So the plan is to keep the usage of vm86 mode until we detect a "VT
> unfriendly" state. I think about a VMentry failure to detect this kind
> of state?
>   

Yes, that's a good way.

> Then, when we are in big_real_mode state, we emulate the code as
> suggested by Avi with the optimisation that consists to emulate more
> than one instruction per iteration.
>
>   

Yes.  Note we sometimes need to emulate in protected mode as well.

-- 
error compiling committee.c: too many arguments to function


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