vfio/iommu_type1: Mantain a counter for non_pinned_groups

With this counter, we never need to traverse all groups to update
pinned_scope of vfio_iommu.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/vfio_iommu_type1.c

@@ -70,10 +70,10 @@ struct vfio_iommu {
 	struct blocking_notifier_head notifier;
 	unsigned int		dma_avail;
 	uint64_t		pgsize_bitmap;
+	uint64_t		num_non_pinned_groups;
 	bool			v2;
 	bool			nesting;
 	bool			dirty_page_tracking;
-	bool			pinned_page_dirty_scope;
 };
 
 struct vfio_domain {
@@ -148,7 +148,6 @@ static int put_pfn(unsigned long pfn, int prot);
 static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
 					       struct iommu_group *iommu_group);
 
-static void update_pinned_page_dirty_scope(struct vfio_iommu *iommu);
 /*
  * This code handles mapping and unmapping of user data buffers
  * into DMA'ble space using the IOMMU
@@ -726,7 +725,7 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
 	group = vfio_iommu_find_iommu_group(iommu, iommu_group);
 	if (!group->pinned_page_dirty_scope) {
 		group->pinned_page_dirty_scope = true;
-		update_pinned_page_dirty_scope(iommu);
+		iommu->num_non_pinned_groups--;
 	}
 
 	goto pin_done;
@@ -1004,7 +1003,7 @@ static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
 	 * mark all pages dirty if any IOMMU capable device is not able
 	 * to report dirty pages and all pages are pinned and mapped.
 	 */
-	if (!iommu->pinned_page_dirty_scope && dma->iommu_mapped)
+	if (iommu->num_non_pinned_groups && dma->iommu_mapped)
 		bitmap_set(dma->bitmap, 0, nbits);
 
 	if (shift) {
@@ -1635,33 +1634,6 @@ static struct vfio_group *vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
 	return group;
 }
 
-static void update_pinned_page_dirty_scope(struct vfio_iommu *iommu)
-{
-	struct vfio_domain *domain;
-	struct vfio_group *group;
-
-	list_for_each_entry(domain, &iommu->domain_list, next) {
-		list_for_each_entry(group, &domain->group_list, next) {
-			if (!group->pinned_page_dirty_scope) {
-				iommu->pinned_page_dirty_scope = false;
-				return;
-			}
-		}
-	}
-
-	if (iommu->external_domain) {
-		domain = iommu->external_domain;
-		list_for_each_entry(group, &domain->group_list, next) {
-			if (!group->pinned_page_dirty_scope) {
-				iommu->pinned_page_dirty_scope = false;
-				return;
-			}
-		}
-	}
-
-	iommu->pinned_page_dirty_scope = true;
-}
-
 static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
 				  phys_addr_t *base)
 {
@@ -2070,8 +2042,6 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 			 * addition of a dirty tracking group.
 			 */
 			group->pinned_page_dirty_scope = true;
-			if (!iommu->pinned_page_dirty_scope)
-				update_pinned_page_dirty_scope(iommu);
 			mutex_unlock(&iommu->lock);
 
 			return 0;
@@ -2201,7 +2171,7 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	 * demotes the iommu scope until it declares itself dirty tracking
 	 * capable via the page pinning interface.
 	 */
-	iommu->pinned_page_dirty_scope = false;
+	iommu->num_non_pinned_groups++;
 	mutex_unlock(&iommu->lock);
 	vfio_iommu_resv_free(&group_resv_regions);
 
@@ -2414,7 +2384,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 	 * to be promoted.
 	 */
 	if (update_dirty_scope) {
-		update_pinned_page_dirty_scope(iommu);
+		iommu->num_non_pinned_groups--;
 		if (iommu->dirty_page_tracking)
 			vfio_iommu_populate_bitmap_full(iommu);
 	}