For hardware management of dirty state, dirty state is stored in page table entries. We have to traverse page table entries when sync dirty log.
Signed-off-by: Keqian Zhu <[email protected]> Signed-off-by: Peng Liang <[email protected]> --- arch/arm64/include/asm/kvm_host.h | 1 + virt/kvm/arm/arm.c | 6 +- virt/kvm/arm/mmu.c | 127 ++++++++++++++++++++++++++++++ 3 files changed, 133 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 32c8a675e5a4..916617d3fed6 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -480,6 +480,7 @@ u64 __kvm_call_hyp(void *hypfn, ...); void force_vm_exit(const cpumask_t *mask); void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot); +int kvm_mmu_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot); int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run, int exception_index); diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 48d0ec44ad77..975311fa3a27 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -1191,7 +1191,11 @@ long kvm_arch_vcpu_ioctl(struct file *filp, void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) { - +#ifdef CONFIG_ARM64_HW_AFDBM + if (kvm_hw_dbm_enabled()) { + kvm_mmu_sync_dirty_log(kvm, memslot); + } +#endif } void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm, diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index dc97988eb2e0..ff8df9702e04 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -2266,6 +2266,133 @@ int kvm_mmu_init(void) return err; } +#ifdef CONFIG_ARM64_HW_AFDBM +/** + * stage2_sync_dirty_log_ptes() - synchronize dirty log from PMD range + * @kvm: The KVM pointer + * @pmd: pointer to pmd entry + * @addr: range start address + * @end: range end address + */ +static void stage2_sync_dirty_log_ptes(struct kvm *kvm, 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) && !kvm_s2pte_readonly(pte)) { + mark_page_dirty(kvm, addr >> PAGE_SHIFT); + } + } while (pte++, addr += PAGE_SIZE, addr != end); +} + +/** + * stage2_sync_dirty_log_pmds() - synchronize dirty log from PUD range + * @kvm: The KVM pointer + * @pud: pointer to pud entry + * @addr: range start address + * @end: range end address + */ +static void stage2_sync_dirty_log_pmds(struct kvm *kvm, pud_t *pud, + phys_addr_t addr, phys_addr_t end) +{ + pmd_t *pmd; + phys_addr_t next; + + pmd = stage2_pmd_offset(kvm, pud, addr); + do { + next = stage2_pmd_addr_end(kvm, addr, end); + if (!pmd_none(*pmd) && !pmd_thp_or_huge(*pmd)) { + stage2_sync_dirty_log_ptes(kvm, pmd, addr, next); + } + } while (pmd++, addr = next, addr != end); +} + +/** + * stage2_sync_dirty_log_puds() - synchronize dirty log from PGD range + * @kvm: The KVM pointer + * @pgd: pointer to pgd entry + * @addr: range start address + * @end: range end address + */ +static void stage2_sync_dirty_log_puds(struct kvm *kvm, pgd_t *pgd, + phys_addr_t addr, phys_addr_t end) +{ + pud_t *pud; + phys_addr_t next; + + pud = stage2_pud_offset(kvm, pgd, addr); + do { + next = stage2_pud_addr_end(kvm, addr, end); + if (!stage2_pud_none(kvm, *pud) && !stage2_pud_huge(kvm, *pud)) { + stage2_sync_dirty_log_pmds(kvm, pud, addr, next); + } + } while (pud++, addr = next, addr != end); +} + +/** + * stage2_sync_dirty_log_range() - synchronize dirty log from stage2 memory + * region range + * @kvm: The KVM pointer + * @addr: Start address of range + * @end: End address of range + */ +static void stage2_sync_dirty_log_range(struct kvm *kvm, phys_addr_t addr, + phys_addr_t end) +{ + pgd_t *pgd; + phys_addr_t next; + + pgd = kvm->arch.pgd + stage2_pgd_index(kvm, 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_LOCKUP_DETECTOR, + * CONFIG_LOCKDEP. Additionally, holding the lock too long + * will also starve other vCPUs. We have to also make sure + * that the page tables are not freed while we released + * the lock. + */ + cond_resched_lock(&kvm->mmu_lock); + if (!READ_ONCE(kvm->arch.pgd)) + break; + next = stage2_pgd_addr_end(kvm, addr, end); + if (stage2_pgd_present(kvm, *pgd)) + stage2_sync_dirty_log_puds(kvm, pgd, addr, next); + } while (pgd++, addr = next, addr != end); +} + +/** + * kvm_mmu_sync_dirty_log() - synchronize dirty log from stage2 entries for + * memory slot + * @kvm: The KVM pointer + * @slot: The memory slot to synchronize dirty log + * + * Called to synchronize dirty log (marked by hw) after memory region + * KVM_GET_DIRTY_LOG operation is called. After this function returns + * all dirty log information (for that hw will modify page tables during + * this routine, it is true only when guest is stopped, but it is OK + * because we won't miss dirty log finally.) are collected into memslot + * dirty_bitmap. Afterwards dirty_bitmap can be copied to userspace. + * + * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired, + * serializing operations for VM memory regions. + */ +int kvm_mmu_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot) +{ + 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_sync_dirty_log_range(kvm, start, end); + spin_unlock(&kvm->mmu_lock); + + return 0; +} +#endif /* CONFIG_ARM64_HW_AFDBM */ + void kvm_arch_commit_memory_region(struct kvm *kvm, const struct kvm_userspace_memory_region *mem, struct kvm_memory_slot *old, -- 2.19.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
