From: Sean Christopherson Date: Fri, 11 Oct 2024 02:10:48 +0000 (-0700) Subject: KVM: x86/mmu: Set Dirty bit for new SPTEs, even if _hardware_ A/D bits are disabled X-Git-Tag: v6.13-rc1~97^2~13^2~12 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=85649117511ddf9971e4759fe8ac9fbb69ad5064;p=thirdparty%2Fkernel%2Flinux.git 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 --- diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 617479efd127a..fd8c3c92ade07 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 1d83614baac58..ccfd5a091b7a7 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;