From 85649117511ddf9971e4759fe8ac9fbb69ad5064 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 10 Oct 2024 19:10:48 -0700 Subject: [PATCH] KVM: x86/mmu: Set Dirty bit for new SPTEs, even if _hardware_ A/D bits are disabled When making a SPTE, set the Dirty bit in the SPTE as appropriate, even if hardware A/D bits are disabled. Only EPT allows A/D bits to be disabled, and for EPT, the bits are software-available (ignored by hardware) when A/D bits are disabled, i.e. it is perfectly legal for KVM to use the Dirty to track dirty pages in software. Link: https://lore.kernel.org/r/20241011021051.1557902-17-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/spte.c | 2 +- arch/x86/kvm/mmu/spte.h | 6 ------ 2 files changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 617479efd127..fd8c3c92ade0 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -237,7 +237,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, wrprot = true; else spte |= PT_WRITABLE_MASK | shadow_mmu_writable_mask | - spte_shadow_dirty_mask(spte); + shadow_dirty_mask; } if (prefetch && !synchronizing) diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index 1d83614baac5..ccfd5a091b7a 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -316,12 +316,6 @@ static inline bool spte_ad_need_write_protect(u64 spte) return (spte & SPTE_TDP_AD_MASK) != SPTE_TDP_AD_ENABLED; } -static inline u64 spte_shadow_dirty_mask(u64 spte) -{ - KVM_MMU_WARN_ON(!is_shadow_present_pte(spte)); - return spte_ad_enabled(spte) ? shadow_dirty_mask : 0; -} - static inline bool is_access_track_spte(u64 spte) { return !spte_ad_enabled(spte) && (spte & shadow_acc_track_mask) == 0;