From: Vipin Sharma Date: Tue, 21 Mar 2023 22:00:17 +0000 (-0700) Subject: KVM: x86/mmu: Drop unnecessary dirty log checks when aging TDP MMU SPTEs X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=6141df067d04599706994b616e1a4b4c19ae5d07;p=linux.git KVM: x86/mmu: Drop unnecessary dirty log checks when aging TDP MMU SPTEs Drop the unnecessary call to handle dirty log updates when aging TDP MMU SPTEs, as neither clearing the Accessed bit nor marking a SPTE for access tracking can _set_ the Writable bit, i.e. can't trigger marking a gfn dirty in its memslot. The access tracking path can _clear_ the Writable bit, e.g. if the XCHG races with fast_page_fault() and writes the stale value without the Writable bit set, but clearing the Writable bit outside of mmu_lock is not allowed, i.e. access tracking can't spuriously set the Writable bit. Signed-off-by: Vipin Sharma [sean: split to separate patch, apply to dirty path, write changelog] Link: https://lore.kernel.org/r/20230321220021.2119033-10-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index adbdfed287ccb..29bb97ff266e2 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1277,8 +1277,6 @@ static bool age_gfn_range(struct kvm *kvm, struct tdp_iter *iter, __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte, new_spte, iter->level, false); - handle_changed_spte_dirty_log(kvm, iter->as_id, iter->gfn, - iter->old_spte, new_spte, iter->level); return true; }