diff options
Diffstat (limited to 'arch/arm/kvm/mmu.c')
| -rw-r--r-- | arch/arm/kvm/mmu.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 1dc9778..c9e5f38 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -45,6 +45,7 @@ static phys_addr_t hyp_idmap_vector; #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t)) #define kvm_pmd_huge(_x) (pmd_huge(_x) || pmd_trans_huge(_x)) +#define kvm_pud_huge(_x) pud_huge(_x) static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa) { @@ -905,6 +906,131 @@ static bool kvm_is_device_pfn(unsigned long pfn) return !pfn_valid(pfn); } +#ifdef CONFIG_ARM +/** + * stage2_wp_ptes - write protect PMD range + * @pmd: pointer to pmd entry + * @addr: range start address + * @end: range end address + */ +static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end) +{ + pte_t *pte; + + pte = pte_offset_kernel(pmd, addr); + do { + if (!pte_none(*pte)) { + if (!kvm_s2pte_readonly(pte)) + kvm_set_s2pte_readonly(pte); + } + } while (pte++, addr += PAGE_SIZE, addr != end); +} + +/** + * stage2_wp_pmds - write protect PUD range + * @pud: pointer to pud entry + * @addr: range start address + * @end: range end address + */ +static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end) +{ + pmd_t *pmd; + phys_addr_t next; + + pmd = pmd_offset(pud, addr); + + do { + next = kvm_pmd_addr_end(addr, end); + if (!pmd_none(*pmd)) { + if (kvm_pmd_huge(*pmd)) { + if (!kvm_s2pmd_readonly(pmd)) + kvm_set_s2pmd_readonly(pmd); + } else { + stage2_wp_ptes(pmd, addr, next); + } + } + } while (pmd++, addr = next, addr != end); +} + +/** + * stage2_wp_puds - write protect PGD range + * @pgd: pointer to pgd entry + * @addr: range start address + * @end: range end address + * + * Process PUD entries, for a huge PUD we cause a panic. + */ +static void stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end) +{ + pud_t *pud; + phys_addr_t next; + + pud = pud_offset(pgd, addr); + do { + next = kvm_pud_addr_end(addr, end); + if (!pud_none(*pud)) { + /* TODO:PUD not supported, revisit later if supported */ + BUG_ON(kvm_pud_huge(*pud)); + stage2_wp_pmds(pud, addr, next); + } + } while (pud++, addr = next, addr != end); +} + +/** + * stage2_wp_range() - write protect stage2 memory region range + * @kvm: The KVM pointer + * @addr: Start address of range + * @end: End address of range + */ +static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end) +{ + pgd_t *pgd; + phys_addr_t next; + + pgd = kvm->arch.pgd + pgd_index(addr); + do { + /* + * Release kvm_mmu_lock periodically if the memory region is + * large. Otherwise, we may see kernel panics with + * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCK_DETECTOR, + * CONFIG_LOCK_DEP. Additionally, holding the lock too long + * will also starve other vCPUs. + */ + if (need_resched() || spin_needbreak(&kvm->mmu_lock)) + cond_resched_lock(&kvm->mmu_lock); + + next = kvm_pgd_addr_end(addr, end); + if (pgd_present(*pgd)) + stage2_wp_puds(pgd, addr, next); + } while (pgd++, addr = next, addr != end); +} + +/** + * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot + * @kvm: The KVM pointer + * @slot: The memory slot to write protect + * + * Called to start logging dirty pages after memory region + * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns + * all present PMD and PTEs are write protected in the memory region. + * Afterwards read of dirty page log can be called. + * + * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired, + * serializing operations for VM memory regions. + */ +void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot) +{ + struct kvm_memory_slot *memslot = id_to_memslot(kvm->memslots, slot); + phys_addr_t start = memslot->base_gfn << PAGE_SHIFT; + phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT; + + spin_lock(&kvm->mmu_lock); + stage2_wp_range(kvm, start, end); + spin_unlock(&kvm->mmu_lock); + kvm_flush_remote_tlbs(kvm); +} +#endif + static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, struct kvm_memory_slot *memslot, unsigned long hva, unsigned long fault_status) @@ -1292,6 +1418,15 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, const struct kvm_memory_slot *old, enum kvm_mr_change change) { +#ifdef CONFIG_ARM + /* + * At this point memslot has been committed and there is an + * allocated dirty_bitmap[], dirty pages will be be tracked while the + * memory slot is write protected. + */ + if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES) + kvm_mmu_wp_memory_region(kvm, mem->slot); +#endif } int kvm_arch_prepare_memory_region(struct kvm *kvm, |