[PATCH v3 11/21] KVM: arm64: Convert page-aging and access faults to generic page-table API

Will Deacon
2020-08-25T09:44:40Z

Convert the page-aging functions and access fault handler to use the
generic page-table code instead of walking the page-table directly.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/mmu.c | 74 ++++++++++----------------------------------
1 file changed, 16 insertions(+), 58 deletions(-)

diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 751ce2462765..d3db8e00ce0a 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1698,46 +1698,23 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
return ret;
}

-/*
- * Resolve the access fault by making the page young again.
- * Note that because the faulting entry is guaranteed not to be
- * cached in the TLB, we don't need to invalidate anything.
- * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
- * so there is no need for atomic (pte|pmd)_mkyoung operations.
- */
+/* Resolve the access fault by making the page young again. */
static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
{
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
- kvm_pfn_t pfn;
- bool pfn_valid = false;
+ pte_t pte;
+ kvm_pte_t kpte;
+ struct kvm_s2_mmu *mmu;

trace_kvm_access_fault(fault_ipa);

spin_lock(&vcpu->kvm->mmu_lock);
-
- if (!stage2_get_leaf_entry(vcpu->arch.hw_mmu, fault_ipa, &pud, &pmd, &pte))
- goto out;
-
- if (pud) { /* HugeTLB */
- *pud = kvm_s2pud_mkyoung(*pud);
- pfn = kvm_pud_pfn(*pud);
- pfn_valid = true;
- } else if (pmd) { /* THP, HugeTLB */
- *pmd = pmd_mkyoung(*pmd);
- pfn = pmd_pfn(*pmd);
- pfn_valid = true;
- } else {
- *pte = pte_mkyoung(*pte); /* Just a page... */
- pfn = pte_pfn(*pte);
- pfn_valid = true;
- }
-
-out:
+ mmu = vcpu->arch.hw_mmu;
+ kpte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
spin_unlock(&vcpu->kvm->mmu_lock);
- if (pfn_valid)
- kvm_set_pfn_accessed(pfn);
+
+ pte = __pte(kpte);
+ if (pte_valid(pte))
+ kvm_set_pfn_accessed(pte_pfn(pte));
}

/**
@@ -1954,38 +1931,19 @@ int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)

static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
{
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
+ pte_t pte;
+ kvm_pte_t kpte;

WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
- if (!stage2_get_leaf_entry(&kvm->arch.mmu, gpa, &pud, &pmd, &pte))
- return 0;
-
- if (pud)
- return stage2_pudp_test_and_clear_young(pud);
- else if (pmd)
- return stage2_pmdp_test_and_clear_young(pmd);
- else
- return stage2_ptep_test_and_clear_young(pte);
+ kpte = kvm_pgtable_stage2_mkold(kvm->arch.mmu.pgt, gpa);
+ pte = __pte(kpte);
+ return pte_valid(pte) && pte_young(pte);
}

static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
{
- pud_t *pud;
- pmd_t *pmd;
- pte_t *pte;
-
WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
- if (!stage2_get_leaf_entry(&kvm->arch.mmu, gpa, &pud, &pmd, &pte))
- return 0;
-
- if (pud)
- return kvm_s2pud_young(*pud);
- else if (pmd)
- return pmd_young(*pmd);
- else
- return pte_young(*pte);
+ return kvm_pgtable_stage2_is_young(kvm->arch.mmu.pgt, gpa);
}

int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
--
2.28.0.297.g1956fa8f8d-goog