From 6141df067d04599706994b616e1a4b4c19ae5d07 Mon Sep 17 00:00:00 2001 From: Vipin Sharma <vipinsh@google.com> Date: Tue, 21 Mar 2023 15:00:17 -0700 Subject: [PATCH] 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 <vipinsh@google.com> [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 <seanjc@google.com> --- arch/x86/kvm/mmu/tdp_mmu.c | 2 -- 1 file changed, 2 deletions(-) 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; } -- 2.30.2