linux-kernel - [PATCH 4/5] vfio/iommu_type1: Clean up update_dirty_scope in detach

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Date:   Sun, 5 Jun 2022 23:19:26 -0700
From:   Nicolin Chen <nicolinc@...dia.com>
To:     <jgg@...dia.com>, <joro@...tes.org>, <will@...nel.org>,
        <marcan@...can.st>, <sven@...npeter.dev>, <robin.murphy@....com>,
        <robdclark@...il.com>, <m.szyprowski@...sung.com>,
        <krzysztof.kozlowski@...aro.org>, <baolu.lu@...ux.intel.com>,
        <agross@...nel.org>, <bjorn.andersson@...aro.org>,
        <matthias.bgg@...il.com>, <heiko@...ech.de>, <orsonzhai@...il.com>,
        <baolin.wang7@...il.com>, <zhang.lyra@...il.com>, <wens@...e.org>,
        <jernej.skrabec@...il.com>, <samuel@...lland.org>,
        <jean-philippe@...aro.org>, <alex.williamson@...hat.com>
CC:     <suravee.suthikulpanit@....com>, <alyssa@...enzweig.io>,
        <alim.akhtar@...sung.com>, <dwmw2@...radead.org>,
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        <vdumpa@...dia.com>, <jonathanh@...dia.com>, <cohuck@...hat.com>,
        <iommu@...ts.linux-foundation.org>, <linux-kernel@...r.kernel.org>,
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Subject: [PATCH 4/5] vfio/iommu_type1: Clean up update_dirty_scope in detach_group()

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.

Rename the "detach_group_done" goto label accordingly.

Suggested-by: Jason Gunthorpe <jgg@...dia.com>
Signed-off-by: Nicolin Chen <nicolinc@...dia.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 f4e3b423a453..b45b1cc118ef 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2463,14 +2463,12 @@ 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);
 
@@ -2479,7 +2477,7 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 			WARN_ON(iommu->notifier.head);
 			vfio_iommu_unmap_unpin_all(iommu);
 		}
-		goto detach_group_done;
+		goto out_unlock;
 	}
 
 	/*
@@ -2495,9 +2493,7 @@ 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
@@ -2519,7 +2515,17 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
 			kfree(domain);
 			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;
 	}
 
@@ -2528,16 +2534,7 @@ 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);
-	}
+out_unlock:
 	mutex_unlock(&iommu->lock);
 }
 
-- 
2.17.1