From 66d73e12f2786497424cb611b359e3580978cad7 Mon Sep 17 00:00:00 2001 From: Peter Feiner Date: Mon, 26 Sep 2016 10:45:34 -0700 Subject: [PATCH] KVM: X86: MMU: no mmu_notifier_seq++ in kvm_age_hva MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Paolo Bonzini Signed-off-by: Radim Krčmář --- arch/x86/kvm/mmu.c | 10 +--------- 1 file changed, 1 insertion(+), 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); }