Commit ee8efad7 authored by Will Deacon's avatar Will Deacon Committed by Marc Zyngier
Browse files

KVM: arm64: Convert page-aging and access faults to generic page-table API 



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

Signed-off-by: default avatarWill Deacon <will@kernel.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarGavin Shan <gshan@redhat.com>
Reviewed-by: default avatarAlexandru Elisei <alexandru.elisei@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200911132529.19844-12-will@kernel.org
parent e0e5a07f

arch/arm64/kvm/mmu.c

+16 −58
Original line number Diff line number Diff line
@@ -1706,46 +1706,23 @@ 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));

}



/**
@@ -1962,38 +1939,19 @@ 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)