From eb3f0624ea082def887acc79e97934e27d0188b7 Mon Sep 17 00:00:00 2001 From: Punit Agrawal Date: Tue, 11 Dec 2018 17:10:39 +0000 Subject: [PATCH] KVM: arm64: Support handling access faults for PUD hugepages In preparation for creating larger hugepages at Stage 2, extend the access fault handling at Stage 2 to support PUD hugepages when encountered. Provide trivial helpers for arm32 to allow sharing of code. Signed-off-by: Punit Agrawal Reviewed-by: Christoffer Dall Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon [ Replaced BUG() => WARN_ON(1) in PUD helpers ] Signed-off-by: Suzuki K Poulose Signed-off-by: Marc Zyngier --- arch/arm/include/asm/kvm_mmu.h | 9 +++++++++ arch/arm64/include/asm/kvm_mmu.h | 7 +++++++ arch/arm64/include/asm/pgtable.h | 6 ++++++ virt/kvm/arm/mmu.c | 22 +++++++++++----------- 4 files changed, 33 insertions(+), 11 deletions(-) diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h index a49655fe7cd90f..3a407204b957cd 100644 --- a/arch/arm/include/asm/kvm_mmu.h +++ b/arch/arm/include/asm/kvm_mmu.h @@ -85,6 +85,9 @@ void kvm_clear_hyp_idmap(void); #define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) #define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) +#define kvm_pud_pfn(pud) ({ WARN_ON(1); 0; }) + + #define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) /* @@ -108,6 +111,12 @@ static inline bool kvm_s2pud_exec(pud_t *pud) return false; } +static inline pud_t kvm_s2pud_mkyoung(pud_t pud) +{ + BUG(); + return pud; +} + static inline pte_t kvm_s2pte_mkwrite(pte_t pte) { pte_val(pte) |= L_PTE_S2_RDWR; diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index c755b37b3f927e..612032bbb428fa 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -187,6 +187,8 @@ void kvm_clear_hyp_idmap(void); #define kvm_pfn_pte(pfn, prot) pfn_pte(pfn, prot) #define kvm_pfn_pmd(pfn, prot) pfn_pmd(pfn, prot) +#define kvm_pud_pfn(pud) pud_pfn(pud) + #define kvm_pmd_mkhuge(pmd) pmd_mkhuge(pmd) static inline pte_t kvm_s2pte_mkwrite(pte_t pte) @@ -266,6 +268,11 @@ static inline bool kvm_s2pud_exec(pud_t *pudp) return !(READ_ONCE(pud_val(*pudp)) & PUD_S2_XN); } +static inline pud_t kvm_s2pud_mkyoung(pud_t pud) +{ + return pud_mkyoung(pud); +} + #define hyp_pte_table_empty(ptep) kvm_page_empty(ptep) #ifdef __PAGETABLE_PMD_FOLDED diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 50b1ef8584c054..f51e2271e6a34f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -314,6 +314,11 @@ static inline pte_t pud_pte(pud_t pud) return __pte(pud_val(pud)); } +static inline pud_t pte_pud(pte_t pte) +{ + return __pud(pte_val(pte)); +} + static inline pmd_t pud_pmd(pud_t pud) { return __pmd(pud_val(pud)); @@ -381,6 +386,7 @@ static inline int pmd_protnone(pmd_t pmd) #define pfn_pmd(pfn,prot) __pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)) #define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot) +#define pud_mkyoung(pud) pte_pud(pte_mkyoung(pud_pte(pud))) #define pud_write(pud) pte_write(pud_pte(pud)) #define __pud_to_phys(pud) __pte_to_phys(pud_pte(pud)) diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 8e44dccd1b476d..bd749601195f74 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1698,6 +1698,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, */ 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; @@ -1707,24 +1708,23 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa) spin_lock(&vcpu->kvm->mmu_lock); - pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa); - if (!pmd || pmd_none(*pmd)) /* Nothing there */ + if (!stage2_get_leaf_entry(vcpu->kvm, fault_ipa, &pud, &pmd, &pte)) goto out; - if (pmd_thp_or_huge(*pmd)) { /* THP, HugeTLB */ + 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; - goto out; + } else { + *pte = pte_mkyoung(*pte); /* Just a page... */ + pfn = pte_pfn(*pte); + pfn_valid = true; } - pte = pte_offset_kernel(pmd, fault_ipa); - if (pte_none(*pte)) /* Nothing there either */ - goto out; - - *pte = pte_mkyoung(*pte); /* Just a page... */ - pfn = pte_pfn(*pte); - pfn_valid = true; out: spin_unlock(&vcpu->kvm->mmu_lock); if (pfn_valid)