diff options
| -rw-r--r-- | arch/arm/kvm/mmu.c | 97 |
1 files changed, 88 insertions, 9 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 565e903..6685c68 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -47,6 +47,18 @@ static phys_addr_t hyp_idmap_vector; #define kvm_pmd_huge(_x) (pmd_huge(_x) || pmd_trans_huge(_x)) #define kvm_pud_huge(_x) pud_huge(_x) +#define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0) +#define KVM_S2_FLAG_LOGGING_ACTIVE (1UL << 1) + +static bool memslot_is_logging(struct kvm_memory_slot *memslot) +{ +#ifdef CONFIG_ARM + return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY); +#else + return false; +#endif +} + static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { /* @@ -59,6 +71,25 @@ static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa); } +/** + * stage2_dissolve_pmd() - clear and flush huge PMD entry + * @kvm: pointer to kvm structure. + * @addr: IPA + * @pmd: pmd pointer for IPA + * + * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all + * pages in the range dirty. + */ +static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd) +{ + if (!kvm_pmd_huge(*pmd)) + return; + + pmd_clear(pmd); + kvm_tlb_flush_vmid_ipa(kvm, addr); + put_page(virt_to_page(pmd)); +} + static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, int min, int max) { @@ -768,10 +799,15 @@ static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache } static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, - phys_addr_t addr, const pte_t *new_pte, bool iomap) + phys_addr_t addr, const pte_t *new_pte, + unsigned long flags) { pmd_t *pmd; pte_t *pte, old_pte; + bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP; + bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE; + + VM_BUG_ON(logging_active && !cache); /* Create stage-2 page table mapping - Levels 0 and 1 */ pmd = stage2_get_pmd(kvm, cache, addr); @@ -783,6 +819,13 @@ static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache, return 0; } + /* + * While dirty page logging - dissolve huge PMD, then continue on to + * allocate page. + */ + if (logging_active) + stage2_dissolve_pmd(kvm, addr, pmd); + /* Create stage-2 page mappings - Level 2 */ if (pmd_none(*pmd)) { if (!cache) @@ -839,7 +882,8 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, if (ret) goto out; spin_lock(&kvm->mmu_lock); - ret = stage2_set_pte(kvm, &cache, addr, &pte, true); + ret = stage2_set_pte(kvm, &cache, addr, &pte, + KVM_S2PTE_FLAG_IS_IOMAP); spin_unlock(&kvm->mmu_lock); if (ret) goto out; @@ -1067,6 +1111,8 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, pfn_t pfn; pgprot_t mem_type = PAGE_S2; bool fault_ipa_uncached; + bool logging_active = memslot_is_logging(memslot); + unsigned long flags = 0; write_fault = kvm_is_write_fault(vcpu); if (fault_status == FSC_PERM && !write_fault) { @@ -1083,7 +1129,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, return -EFAULT; } - if (is_vm_hugetlb_page(vma)) { + if (is_vm_hugetlb_page(vma) && !logging_active) { hugetlb = true; gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT; } else { @@ -1124,12 +1170,30 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (is_error_pfn(pfn)) return -EFAULT; - if (kvm_is_device_pfn(pfn)) + if (kvm_is_device_pfn(pfn)) { mem_type = PAGE_S2_DEVICE; + flags |= KVM_S2PTE_FLAG_IS_IOMAP; + } else if (logging_active) { + /* + * Faults on pages in a memslot with logging enabled + * should not be mapped with huge pages (it introduces churn + * and performance degradation), so force a pte mapping. + */ + force_pte = true; + flags |= KVM_S2_FLAG_LOGGING_ACTIVE; + + /* + * Only actually map the page as writable if this was a write + * fault. + */ + if (!write_fault) + writable = false; + } spin_lock(&kvm->mmu_lock); if (mmu_notifier_retry(kvm, mmu_seq)) goto out_unlock; + if (!hugetlb && !force_pte) hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); @@ -1147,17 +1211,17 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd); } else { pte_t new_pte = pfn_pte(pfn, mem_type); + if (writable) { kvm_set_s2pte_writable(&new_pte); kvm_set_pfn_dirty(pfn); + mark_page_dirty(kvm, gfn); } coherent_cache_guest_page(vcpu, hva, PAGE_SIZE, fault_ipa_uncached); - ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, - pgprot_val(mem_type) == pgprot_val(PAGE_S2_DEVICE)); + ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags); } - out_unlock: spin_unlock(&kvm->mmu_lock); kvm_release_pfn_clean(pfn); @@ -1307,7 +1371,14 @@ static void kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, void *data) { pte_t *pte = (pte_t *)data; - stage2_set_pte(kvm, NULL, gpa, pte, false); + /* + * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE + * flag clear because MMU notifiers will have unmapped a huge PMD before + * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and + * therefore stage2_set_pte() never needs to clear out a huge PMD + * through this calling path. + */ + stage2_set_pte(kvm, NULL, gpa, pte, 0); } @@ -1461,7 +1532,8 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, bool writable = !(mem->flags & KVM_MEM_READONLY); int ret = 0; - if (change != KVM_MR_CREATE && change != KVM_MR_MOVE) + if (change != KVM_MR_CREATE && change != KVM_MR_MOVE && + change != KVM_MR_FLAGS_ONLY) return 0; /* @@ -1512,6 +1584,10 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, phys_addr_t pa = (vma->vm_pgoff << PAGE_SHIFT) + vm_start - vma->vm_start; + /* IO region dirty page logging not allowed */ + if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) + return -EINVAL; + ret = kvm_phys_addr_ioremap(kvm, gpa, pa, vm_end - vm_start, writable); @@ -1521,6 +1597,9 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, hva = vm_end; } while (hva < reg_end); + if (change == KVM_MR_FLAGS_ONLY) + return ret; + spin_lock(&kvm->mmu_lock); if (ret) unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size); |
