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

Xiao Guangrong
2010-07-05T09:13:12Z

Avi Kivity wrote:

>
> I'm not convinced we can bypass the checks. Consider:
>
>
> VCPU0 VCPU1
>
> #PF
> walk_addr
> -> gpml4e0,gpdpe0,gpde0,gpte0
>
> replace gpdpe0 with gpdpe1
> #PF
> walk_addr
> -> gpml4e0,gpdpe1,gpde1,gpte1
> fetch
> -> establish hpml4e0,hpdpte1,hpde0,hpte1
> fetch
> read hpdpe1
> if (present(hpdpe1))
> continue;
> ...
> write hpte0 using shadow hieratchy for hpte1
>

Ah, i missed this case, thanks for you point it out, i'll fix it in
the next version.