diff options
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 14 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/spte.h | 7 |
2 files changed, 8 insertions, 13 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 067b6bb7bfca..cb4f0a8c52e0 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -521,12 +521,15 @@ static u64 mmu_spte_update_no_track(u64 *sptep, u64 new_spte) * not whether or not SPTEs were modified, i.e. only the write-tracking case * needs to flush at the time the SPTEs is modified, before dropping mmu_lock. * - * Remote TLBs also need to be flushed if the Dirty bit is cleared, as false - * negatives are not acceptable, e.g. if KVM is using D-bit based PML on VMX. - * * Don't flush if the Accessed bit is cleared, as access tracking tolerates * false negatives, and the one path that does care about TLB flushes, - * kvm_mmu_notifier_clear_flush_young(), uses mmu_spte_update_no_track(). + * kvm_mmu_notifier_clear_flush_young(), flushes if a young SPTE is found, i.e. + * doesn't rely on lower helpers to detect the need to flush. + * + * Lastly, don't flush if the Dirty bit is cleared, as KVM unconditionally + * flushes when enabling dirty logging (see kvm_mmu_slot_apply_flags()), and + * when clearing dirty logs, KVM flushes based on whether or not dirty entries + * were reaped from the bitmap/ring, not whether or not dirty SPTEs were found. * * Returns true if the TLB needs to be flushed */ @@ -537,8 +540,7 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) if (!is_shadow_present_pte(old_spte)) return false; - return (is_mmu_writable_spte(old_spte) && !is_mmu_writable_spte(new_spte)) || - (is_dirty_spte(old_spte) && !is_dirty_spte(new_spte)); + return is_mmu_writable_spte(old_spte) && !is_mmu_writable_spte(new_spte); } /* diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index c81cac9358e0..574ca9a1fcab 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -363,13 +363,6 @@ static inline bool is_accessed_spte(u64 spte) : !is_access_track_spte(spte); } -static inline bool is_dirty_spte(u64 spte) -{ - u64 dirty_mask = spte_shadow_dirty_mask(spte); - - return dirty_mask ? spte & dirty_mask : spte & PT_WRITABLE_MASK; -} - static inline u64 get_rsvd_bits(struct rsvd_bits_validate *rsvd_check, u64 pte, int level) { |