From 888104138cb8e88c3825efc07b0000c195346387 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Fri, 13 Aug 2021 20:35:02 +0000 Subject: [PATCH] KVM: x86/mmu: Avoid memslot lookup in page_fault_handle_page_track Now that kvm_page_fault has a pointer to the memslot it can be passed down to the page tracking code to avoid a redundant slot lookup. No functional change intended. Signed-off-by: David Matlack Message-Id: <20210813203504.2742757-5-dmatlack@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_page_track.h | 2 ++ arch/x86/kvm/mmu/mmu.c | 2 +- arch/x86/kvm/mmu/page_track.c | 28 ++++++++++++++++----------- 3 files changed, 20 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index 6a5f3acf2b33..9cd9230e5cc8 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -61,6 +61,8 @@ void kvm_slot_page_track_remove_page(struct kvm *kvm, enum kvm_page_track_mode mode); bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn, enum kvm_page_track_mode mode); +bool kvm_slot_page_track_is_active(struct kvm_memory_slot *slot, gfn_t gfn, + enum kvm_page_track_mode mode); void kvm_page_track_register_notifier(struct kvm *kvm, diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 754578458cb7..d63fe7b10bd1 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3819,7 +3819,7 @@ static bool page_fault_handle_page_track(struct kvm_vcpu *vcpu, * guest is writing the page which is write tracked which can * not be fixed by page fault handler. */ - if (kvm_page_track_is_active(vcpu, fault->gfn, KVM_PAGE_TRACK_WRITE)) + if (kvm_slot_page_track_is_active(fault->slot, fault->gfn, KVM_PAGE_TRACK_WRITE)) return true; return false; diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 21427e84a82e..859800f7bb95 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -136,24 +136,30 @@ void kvm_slot_page_track_remove_page(struct kvm *kvm, } EXPORT_SYMBOL_GPL(kvm_slot_page_track_remove_page); +bool kvm_slot_page_track_is_active(struct kvm_memory_slot *slot, gfn_t gfn, + enum kvm_page_track_mode mode) +{ + int index; + + if (WARN_ON(!page_track_mode_is_valid(mode))) + return false; + + if (!slot) + return false; + + index = gfn_to_index(gfn, slot->base_gfn, PG_LEVEL_4K); + return !!READ_ONCE(slot->arch.gfn_track[mode][index]); +} + /* * check if the corresponding access on the specified guest page is tracked. */ bool kvm_page_track_is_active(struct kvm_vcpu *vcpu, gfn_t gfn, enum kvm_page_track_mode mode) { - struct kvm_memory_slot *slot; - int index; + struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); - if (WARN_ON(!page_track_mode_is_valid(mode))) - return false; - - slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); - if (!slot) - return false; - - index = gfn_to_index(gfn, slot->base_gfn, PG_LEVEL_4K); - return !!READ_ONCE(slot->arch.gfn_track[mode][index]); + return kvm_slot_page_track_is_active(slot, gfn, mode); } void kvm_page_track_cleanup(struct kvm *kvm)