KVM: X86: MMU: no mmu_notifier_seq++ in kvm_age_hva

The MMU notifier sequence number keeps GPA->HPA mappings in sync when
GPA->HPA lookups are done outside of the MMU lock (e.g., in
tdp_page_fault). Since kvm_age_hva doesn't change GPA->HPA, it's
unnecessary to increment the sequence number.

Signed-off-by: Peter Feiner <pfeiner@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

1 files changed, 1 insertions, 9 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d9c7e986b4e4..d3a94ea9f6ac 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1660,17 +1660,9 @@ int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
          * This has some overhead, but not as much as the cost of swapping
          * out actively used pages or breaking up actively used hugepages.
          */
-        if (!shadow_accessed_mask) {
-                /*
-                 * We are holding the kvm->mmu_lock, and we are blowing up
-                 * shadow PTEs. MMU notifier consumers need to be kept at bay.
-                 * This is correct as long as we don't decouple the mmu_lock
-                 * protected regions (like invalidate_range_start|end does).
-                 */
-                kvm->mmu_notifier_seq++;
+        if (!shadow_accessed_mask)
                 return kvm_handle_hva_range(kvm, start, end, 0,
                                             kvm_unmap_rmapp);
-        }
 
         return kvm_handle_hva_range(kvm, start, end, 0, kvm_age_rmapp);
 }