This is the arm64 counterpart of commit cb00a70bd4b7 ("KVM: x86/mmu:
Split huge pages mapped by the TDP MMU during KVM_CLEAR_DIRTY_LOG"),
which has the benefit of splitting the cost of splitting a memslot
across multiple ioctls.
Split huge pages on the range specified using KVM_CLEAR_DIRTY_LOG.
And do not split when enabling dirty logging if
KVM_DIRTY_LOG_INITIALLY_SET is set.
Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
Reviewed-by: Gavin Shan <gshan@xxxxxxxxxx>
---
arch/arm64/kvm/mmu.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 835e4b8f4e5c3..7a68398517c95 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1095,8 +1095,8 @@ static void kvm_mmu_split_memory_region(struct kvm *kvm, int slot)
* @mask: The mask of pages at offset 'gfn_offset' in this memory
* slot to enable dirty logging on
*
- * Writes protect selected pages to enable dirty logging for them. Caller must
- * acquire kvm->mmu_lock.
+ * Writes protect selected pages to enable dirty logging, and then
+ * splits them to PAGE_SIZE. Caller must acquire kvm->mmu_lock.
*/
void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
struct kvm_memory_slot *slot,
@@ -1109,6 +1109,17 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
lockdep_assert_held_write(&kvm->mmu_lock);
stage2_wp_range(&kvm->arch.mmu, start, end);
+
+ /*
+ * Eager-splitting is done when manual-protect is set. We
+ * also check for initially-all-set because we can avoid
+ * eager-splitting if initially-all-set is false.
+ * Initially-all-set equal false implies that huge-pages were
+ * already split when enabling dirty logging: no need to do it
+ * again.
+ */
+ if (kvm_dirty_log_manual_protect_and_init_set(kvm))
+ kvm_mmu_split_huge_pages(kvm, start, end);
}
static void kvm_send_hwpoison_signal(unsigned long address, short lsb)
--
2.40.1.495.gc816e09b53d-goog
