[PATCH v12 82/84] KVM: arm64: Don't mark "struct page" accessed when making SPTE young
From: Sean Christopherson <seanjc@google.com>
Date: 2024-07-26 23:55:28
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-mips, linux-riscv, lkml, loongarch
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
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. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/arm64/include/asm/kvm_pgtable.h | 4 +--- arch/arm64/kvm/hyp/pgtable.c | 7 ++----- arch/arm64/kvm/mmu.c | 6 +----- 3 files changed, 4 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 19278dfe7978..676d80723c38 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h@@ -632,10 +632,8 @@ 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 9e2bbee77491..6679e02a02c4 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c@@ -1287,19 +1287,16 @@ 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 756fc856ab44..8fd8ea5b5795 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c@@ -1699,18 +1699,14 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, /* 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)); } /**
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2.46.0.rc1.232.g9752f9e123-goog