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From:   Nicolin Chen <nicolinc@nvidia.com>
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Subject: [PATCH v6 4/5] vfio/iommu_type1: Clean up update_dirty_scope in detach_group()
Date:   Mon, 15 Aug 2022 11:14:36 -0700
Message-ID: <20220815181437.28127-5-nicolinc@nvidia.com>
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All devices in emulated_iommu_groups have pinned_page_dirty_scope
set, so the update_dirty_scope in the first list_for_each_entry
is always false. Clean it up, and move the "if update_dirty_scope"
part from the detach_group_done routine to the domain_list part.

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/vfio/vfio_iommu_type1.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 523927d61aac..3b63a5a237c9 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2464,14 +2464,12 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 	struct vfio_iommu *iommu = iommu_data;
 	struct vfio_domain *domain;
 	struct vfio_iommu_group *group;
-	bool update_dirty_scope = false;
 	LIST_HEAD(iova_copy);
 
 	mutex_lock(&iommu->lock);
 	list_for_each_entry(group, &iommu->emulated_iommu_groups, next) {
 		if (group->iommu_group != iommu_group)
 			continue;
-		update_dirty_scope = !group->pinned_page_dirty_scope;
 		list_del(&group->next);
 		kfree(group);
 
@@ -2480,7 +2478,8 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 			WARN_ON(!list_empty(&iommu->device_list));
 			vfio_iommu_unmap_unpin_all(iommu);
 		}
-		goto detach_group_done;
+		mutex_unlock(&iommu->lock);
+		return;
 	}
 
 	/*
@@ -2496,9 +2495,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 			continue;
 
 		iommu_detach_group(domain->domain, group->iommu_group);
-		update_dirty_scope = !group->pinned_page_dirty_scope;
 		list_del(&group->next);
-		kfree(group);
 		/*
 		 * Group ownership provides privilege, if the group list is
 		 * empty, the domain goes away. If it's the last domain with
@@ -2522,6 +2519,16 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 			vfio_iommu_aper_expand(iommu, &iova_copy);
 			vfio_update_pgsize_bitmap(iommu);
 		}
+		/*
+		 * Removal of a group without dirty tracking may allow
+		 * the iommu scope to be promoted.
+		 */
+		if (!group->pinned_page_dirty_scope) {
+			iommu->num_non_pinned_groups--;
+			if (iommu->dirty_page_tracking)
+				vfio_iommu_populate_bitmap_full(iommu);
+		}
+		kfree(group);
 		break;
 	}
 
@@ -2530,16 +2537,6 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 	else
 		vfio_iommu_iova_free(&iova_copy);
 
-detach_group_done:
-	/*
-	 * Removal of a group without dirty tracking may allow the iommu scope
-	 * to be promoted.
-	 */
-	if (update_dirty_scope) {
-		iommu->num_non_pinned_groups--;
-		if (iommu->dirty_page_tracking)
-			vfio_iommu_populate_bitmap_full(iommu);
-	}
 	mutex_unlock(&iommu->lock);
 }
 
-- 
2.17.1