Messages in this thread | | | Date | Thu, 26 May 2022 17:52:44 +0200 | Subject | Re: [PATCH] KVM: x86/MMU: Zap non-leaf SPTEs when disabling dirty logging | From | Paolo Bonzini <> |
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On 5/26/22 16:30, Peter Xu wrote: > On Thu, May 26, 2022 at 02:01:43PM +0200, Paolo Bonzini wrote: >> On 5/26/22 01:09, Ben Gardon wrote: >>> + WARN_ON(max_mapping_level < iter.level); >>> + >>> + /* >>> + * If this page is already mapped at the highest >>> + * viable level, there's nothing more to do. >>> + */ >>> + if (max_mapping_level == iter.level) >>> + continue; >>> + >>> + /* >>> + * The page can be remapped at a higher level, so step >>> + * up to zap the parent SPTE. >>> + */ >>> + while (max_mapping_level > iter.level) >>> + tdp_iter_step_up(&iter); >>> + >>> /* Note, a successful atomic zap also does a remote TLB flush. */ >>> - if (tdp_mmu_zap_spte_atomic(kvm, &iter)) >>> - goto retry; >>> + tdp_mmu_zap_spte_atomic(kvm, &iter); >>> + >> >> Can you make this a sparate function (for example >> tdp_mmu_zap_collapsible_spte_atomic)? Otherwise looks great! > > There could be a tiny downside of using a helper in that it'll hide the > step-up of the iterator, which might not be as obvious as keeping it in the > loop?
That's true, my reasoning is that zapping at a higher level can only be done by first moving the iterator up. Maybe tdp_mmu_zap_at_level_atomic() is a better Though, I can very well apply this patch as is.
Paolo
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