Re: Unhandled vm exit with old protected mode test

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

Jan Kiszka wrote:
> Avi Kivity wrote:
>   
>> Jan Kiszka wrote:
>>     
>>> Hi,
>>>
>>> running some oldish 286 protected mode demo in kvm, I came across this
>>> bug of kvm-52:
>>>
>>> unhandled vm exit: 0x80000021 vcpu_id 0
>>> ds 0000 (00100000/0000ffff p 1 dpl 3 db 0 s 1 type 3 l 0 g 0 avl 0)
>>>
>>>   
>>>       
>> ds.base must equal ds.sel<<4 when entering real-mode on Intel.  See
>> fix_rmode_seg() in vmx.c which clearly doesn't handle cases where
>> ds.base >= 0x100000.  You might try forcing bits 20+ of ds.base to zero
>> in there.  This may fix the problem or move it elsewhere.
>>
>>     
>
> Yeah, this actually fixed my test case:
>
> Ensure that segment.base == segment.selector << 4 when entering the real
> mode on Intel so that the CPU will not bark at us.
>
>   

Applied (after de-optimizing), thanks.

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


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