Re: [PATCH v2 8/10] KVM: MMU: prefetch ptes when intercepted guest #PF

Xiao Guangrong
2010-06-30T00:58:22Z

Marcelo Tosatti wrote:

>>> Also prefetch should be disabled for EPT, due to lack of accessed bit.
>>>
>> But we call mmu_set_spte() with speculative == false, it not touch the accessed bit.
>
> There is no accessed bit on EPT. So the aging code (kvm_age_rmapp)
> considers any present translation as accessed. There is no way to
> distinguish between actually accessed translations and prefetched (but
> unused) ones.
>

You are right, i'll disable the prefetch for EPT in the next version, thanks for
you point it out.