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charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Sean Christopherson Cc: kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, David Matlack , David Stevens , loongarch@lists.linux.dev, kvmarm@lists.linux.dev, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Mark pages accessed only in the slow page fault path in order to remove an unnecessary user of kvm_pfn_to_refcounted_page(). Marking pages accessed in the primary MMU during KVM page fault handling isn't harmful, but it's largely pointless and likely a waste of a cycles since the primary MMU will call into KVM via mmu_notifiers when aging pages. I.e. KVM participates in a "pull" model, so there's no need to also "push" updates. Signed-off-by: Sean Christopherson --- arch/mips/kvm/mmu.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/arch/mips/kvm/mmu.c b/arch/mips/kvm/mmu.c index 4da9ce4eb54d..f1e4b618ec6d 100644 --- a/arch/mips/kvm/mmu.c +++ b/arch/mips/kvm/mmu.c @@ -484,8 +484,6 @@ static int _kvm_mips_map_page_fast(struct kvm_vcpu *vcpu, unsigned long gpa, struct kvm *kvm = vcpu->kvm; gfn_t gfn = gpa >> PAGE_SHIFT; pte_t *ptep; - kvm_pfn_t pfn = 0; /* silence bogus GCC warning */ - bool pfn_valid = false; int ret = 0; spin_lock(&kvm->mmu_lock); @@ -498,12 +496,9 @@ static int _kvm_mips_map_page_fast(struct kvm_vcpu *vcpu, unsigned long gpa, } /* Track access to pages marked old */ - if (!pte_young(*ptep)) { + if (!pte_young(*ptep)) set_pte(ptep, pte_mkyoung(*ptep)); - pfn = pte_pfn(*ptep); - pfn_valid = true; - /* call kvm_set_pfn_accessed() after unlock */ - } + if (write_fault && !pte_dirty(*ptep)) { if (!pte_write(*ptep)) { ret = -EFAULT; @@ -512,7 +507,6 @@ static int _kvm_mips_map_page_fast(struct kvm_vcpu *vcpu, unsigned long gpa, /* Track dirtying of writeable pages */ set_pte(ptep, pte_mkdirty(*ptep)); - pfn = pte_pfn(*ptep); mark_page_dirty(kvm, gfn); } @@ -523,8 +517,6 @@ static int _kvm_mips_map_page_fast(struct kvm_vcpu *vcpu, unsigned long gpa, out: spin_unlock(&kvm->mmu_lock); - if (pfn_valid) - kvm_set_pfn_accessed(pfn); return ret; } -- 2.46.0.rc1.232.g9752f9e123-goog