From: Sean Christopherson Date: Thu, 10 Oct 2024 18:24:25 +0000 (-0700) Subject: KVM: arm64: Don't mark "struct page" accessed when making SPTE young X-Git-Tag: v6.13-rc1~13^2~20^2~2 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=2362506f7cff7cdd6b734b7d350568a545a1009b;p=linux-2.6-block.git KVM: arm64: Don't mark "struct page" accessed when making SPTE young Don't mark pages/folios as accessed in the primary MMU when making a SPTE young in KVM's secondary MMU, as doing so relies on kvm_pfn_to_refcounted_page(), and generally speaking is unnecessary and wasteful. KVM participates in page aging via mmu_notifiers, so there's no need to push "accessed" updates to the primary MMU. Dropping use of kvm_set_pfn_accessed() also paves the way for removing kvm_pfn_to_refcounted_page() and all its users. Tested-by: Alex Bennée Signed-off-by: Sean Christopherson Tested-by: Dmitry Osipenko Signed-off-by: Paolo Bonzini Message-ID: <20241010182427.1434605-84-seanjc@google.com> --- diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 03f4c3d7839c..aab04097b505 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -674,10 +674,8 @@ int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size); * * If there is a valid, leaf page-table entry used to translate @addr, then * set the access flag in that entry. - * - * Return: The old page-table entry prior to setting the flag, 0 on failure. */ -kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr); +void kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr); /** * kvm_pgtable_stage2_test_clear_young() - Test and optionally clear the access diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index b11bcebac908..40bd55966540 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -1245,19 +1245,16 @@ int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size) NULL, NULL, 0); } -kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) +void kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) { - kvm_pte_t pte = 0; int ret; ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, - &pte, NULL, + NULL, NULL, KVM_PGTABLE_WALK_HANDLE_FAULT | KVM_PGTABLE_WALK_SHARED); if (!ret) dsb(ishst); - - return pte; } struct stage2_age_data { diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 75795fb67d1d..a71fe6f6bd90 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1707,18 +1707,14 @@ out_unlock: /* Resolve the access fault by making the page young again. */ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) { - kvm_pte_t pte; struct kvm_s2_mmu *mmu; trace_kvm_access_fault(fault_ipa); read_lock(&vcpu->kvm->mmu_lock); mmu = vcpu->arch.hw_mmu; - pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa); + kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa); read_unlock(&vcpu->kvm->mmu_lock); - - if (kvm_pte_valid(pte)) - kvm_set_pfn_accessed(kvm_pte_to_pfn(pte)); } /**