[PATCH 1/3] KVM/memslot: Move the initial set of dirty bitmap to arch

[Keqian Zhu]

Currently, when KVM_DIRTY_LOG_INITIALLY_SET is enabled, the initial set
of memslot dirty bitmap is located at arch shared path. By making this
implementation be architecture depended, we can realize some architecture
depended optimizations (e.g. Only mark dirty for these pages with valid
translation entries, then userspace can use this information to only send
these pages during migration).

Signed-off-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
---
 arch/x86/kvm/x86.c  | 3 +++
 virt/kvm/kvm_main.c | 3 ---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e54c6ad628a8..ccab8b56bc7c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10031,6 +10031,9 @@ static void kvm_mmu_slot_apply_flags(struct kvm *kvm,
 	 * See the comments in fast_page_fault().
 	 */
 	if (new->flags & KVM_MEM_LOG_DIRTY_PAGES) {
+		if (kvm_dirty_log_manual_protect_and_init_set(kvm))
+			bitmap_set(new->dirty_bitmap, 0, new->npages);
+
 		if (kvm_x86_ops->slot_enable_log_dirty) {
 			kvm_x86_ops->slot_enable_log_dirty(kvm, new);
 		} else {
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 28eae681859f..531d96c6871e 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1289,9 +1289,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
 		r = kvm_alloc_dirty_bitmap(&new);
 		if (r)
 			return r;
-
-		if (kvm_dirty_log_manual_protect_and_init_set(kvm))
-			bitmap_set(new.dirty_bitmap, 0, new.npages);
 	}
 
 	r = kvm_set_memslot(kvm, mem, &old, &new, as_id, change);
-- 
2.19.1