[PATCH v6 4/5] vfio/iommu_type1: Clean up update_dirty_scope in detach_group()

Nicolin Chen
2022-08-15T18:21:07Z

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