Re: [PATCH v4 5/6] KVM: MMU: combine guest pte read between walkand pte prefetch

[Avi Kivity]

On 07/03/2010 04:03 PM, Xiao Guangrong wrote:
> Avi Kivity wrote:
>
>    
> > > Well, in the description, it looked like everything was using small
> > > pages (in kvm, level=1 means PTE level, we need to change this one
> > > day).  Please describe again and say exactly when the guest or host
> > > uses large pages.
> > >
> > >
> > >        
> > Oh, I see what you mean.
> >
> > Regarding the patch, is it possible just to move the check before,
> > instead of adding the 'check' variable?
> >
> >      
> Umm, if we move the check before the judgment, it'll check every level,
> actually, only the opened mapping and the laster level need checked, so
> for the performance reason, maybe it's better to keep two check-point.
>    

What exactly are the conditions when you want to check?

Perhaps we do need to check every level.  A write to a PDE (or higher 
level) will clear the corresponding spte, but a fault immediately 
afterwards can re-establish the spte to point to the new page.

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

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