Messages in this thread | | | Date | Thu, 01 Jul 2010 09:11:36 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v3 9/11] KVM: MMU: prefetch ptes when intercepted guest #PF |
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Marcelo Tosatti wrote:
>> + >> + addr = gfn_to_hva_many(vcpu->kvm, gfn, &entry); >> + if (kvm_is_error_hva(addr)) >> + return -1; >> + >> + entry = min(entry, (int)(end - start)); >> + ret = __get_user_pages_fast(addr, entry, 1, pages); >> + if (ret <= 0) >> + return -1; > > Why can't you use gfn_to_pfn_atomic() here, one page at a time? Is > the overhead significant that this is worthwhile? > > You're bypassing the centralized interface.
I think it's worthwhile to do since we can reduce gup overhead, no reason to traverse process's page table again and again for the consecutive pages.
> >> + >> + pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte); >> + mmu_set_spte(vcpu, spte, sp->role.access, pte_access, 0, 0, >> + is_dirty_gpte(gpte), NULL, sp->role.level, gfn, >> + pfn, true, false); > > reset_host_protection should be true, see commit 1403283acca (also for > direct case to be consistent). >
Ah, i forgot it, thanks, Marcelo!
I'll post a small fix patch base on this patchset to change 'false' to 'true' if no other places no to be improved. :-)
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