For hardware management of dirty state, dirty state is stored in
PTEs. We have to scan all PTEs to sync dirty log to memslot dirty
bitmap.
Signed-off-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
Signed-off-by: Peng Liang <liangpeng10@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 2 +
arch/arm64/kvm/arm.c | 6 +-
arch/arm64/kvm/mmu.c | 162 ++++++++++++++++++++++++++++++
virt/kvm/kvm_main.c | 4 +-
4 files changed, 172 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2bc3256759e3..910ec33afea8 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -489,6 +489,8 @@ void force_vm_exit(const cpumask_t *mask);
void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
void kvm_mmu_clear_dbm(struct kvm *kvm, struct kvm_memory_slot *memslot);
void kvm_mmu_clear_dbm_all(struct kvm *kvm);
+void kvm_mmu_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot);
+void kvm_mmu_sync_dirty_log_all(struct kvm *kvm);
int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
int exception_index);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 850cc5cbc6f0..92f0b40a30fa 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1209,7 +1209,11 @@ 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->arch.hw_dirty_log) {
+ kvm_mmu_sync_dirty_log(kvm, memslot);
+ }
+#endif
}
void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 742c7943176f..3aa0303d83f0 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -2600,6 +2600,168 @@ void kvm_mmu_clear_dbm_all(struct kvm *kvm)
kvm_mmu_clear_dbm(kvm, memslot);
}
}
+
+/**
+ * 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 P4D 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, p4d_t *p4d,
+ phys_addr_t addr, phys_addr_t end)
+{
+ pud_t *pud;
+ phys_addr_t next;
+
+ pud = stage2_pud_offset(kvm, p4d, 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_p4ds() - 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_p4ds(struct kvm *kvm, pgd_t *pgd,
+ phys_addr_t addr, phys_addr_t end)
+{
+ p4d_t *p4d;
+ phys_addr_t next;
+
+ p4d = stage2_p4d_offset(kvm, pgd, addr);
+ do {
+ next = stage2_p4d_addr_end(kvm, addr, end);
+ if (!stage2_p4d_none(kvm, *p4d))
+ stage2_sync_dirty_log_puds(kvm, p4d, addr, next);
+ } while (p4d++, 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 {
+ 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_p4ds(kvm, pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+}
+
+/**
+ * kvm_mmu_sync_dirty_log() - synchronize dirty log from stage2 PTEs 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.
+ */
+void 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;
+ int idx;
+
+ if (WARN_ON_ONCE(!memslot->dirty_bitmap))
+ return;
+
+ idx = srcu_read_lock(&kvm->srcu);
+ spin_lock(&kvm->mmu_lock);
+
+ stage2_sync_dirty_log_range(kvm, start, end);
+
+ spin_unlock(&kvm->mmu_lock);
+ srcu_read_unlock(&kvm->srcu, idx);
+}
+
+/**
+ * kvm_mmu_sync_dirty_log_all() - synchronize dirty log from PTEs for whole VM
+ * @kvm: The KVM pointer
+ *
+ * Called with kvm->slots_lock mutex acquired
+ */
+void kvm_mmu_sync_dirty_log_all(struct kvm *kvm)
+{
+ struct kvm_memslots *slots = kvm_memslots(kvm);
+ struct kvm_memory_slot *memslots = slots->memslots;
+ struct kvm_memory_slot *memslot;
+ int slot;
+
+ if (unlikely(!slots->used_slots))
+ return;
+
+ for (slot = 0; slot < slots->used_slots; slot++) {
+ memslot = &memslots[slot];
+ kvm_mmu_sync_dirty_log(kvm, memslot);
+ }
+}
#endif /* CONFIG_ARM64_HW_AFDBM */
void kvm_arch_commit_memory_region(struct kvm *kvm,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a852af5c3214..3722343fd460 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2581,7 +2581,9 @@ static void mark_page_dirty_in_slot(struct kvm_memory_slot *memslot,
if (memslot && memslot->dirty_bitmap) {
unsigned long rel_gfn = gfn - memslot->base_gfn;
- set_bit_le(rel_gfn, memslot->dirty_bitmap);
+ /* Speed up if this bit has already been set */
+ if (!test_bit_le(rel_gfn, memslot->dirty_bitmap))
+ set_bit_le(rel_gfn, memslot->dirty_bitmap);
}
}
--
2.19.1
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