vfio/iommu_type1: Fix some sanity checks in detach group

vfio_sanity_check_pfn_list() is used to check whether pfn_list and
notifier are empty when remove the external domain, so it makes a
wrong assumption that only external domain will use the pinning
interface.

Now we apply the pfn_list check when a vfio_dma is removed and apply
the notifier check when all domains are removed.

Fixes: a54eb55045ae ("vfio iommu type1: Add support for mediated devices")
Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 1617253..78bd288 100644 (file)
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -957,6 +957,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
 
 static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
 {
+       WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list));
        vfio_unmap_unpin(iommu, dma, true);
        vfio_unlink_dma(iommu, dma);
        put_task_struct(dma->task);
@@ -2250,23 +2251,6 @@ static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
        }
 }
 
-static void vfio_sanity_check_pfn_list(struct vfio_iommu *iommu)
-{
-       struct rb_node *n;
-
-       n = rb_first(&iommu->dma_list);
-       for (; n; n = rb_next(n)) {
-               struct vfio_dma *dma;
-
-               dma = rb_entry(n, struct vfio_dma, node);
-
-               if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
-                       break;
-       }
-       /* mdev vendor driver must unregister notifier */
-       WARN_ON(iommu->notifier.head);
-}
-
 /*
  * Called when a domain is removed in detach. It is possible that
  * the removed domain decided the iova aperture window. Modify the
@@ -2366,10 +2350,10 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
                        kfree(group);
 
                        if (list_empty(&iommu->external_domain->group_list)) {
-                               vfio_sanity_check_pfn_list(iommu);
-
-                               if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
+                               if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) {
+                                       WARN_ON(iommu->notifier.head);
                                        vfio_iommu_unmap_unpin_all(iommu);
+                               }
 
                                kfree(iommu->external_domain);
                                iommu->external_domain = NULL;
@@ -2403,10 +2387,12 @@ static void vfio_iommu_type1_detach_group(void *iommu_data,
                 */
                if (list_empty(&domain->group_list)) {
                        if (list_is_singular(&iommu->domain_list)) {
-                               if (!iommu->external_domain)
+                               if (!iommu->external_domain) {
+                                       WARN_ON(iommu->notifier.head);
                                        vfio_iommu_unmap_unpin_all(iommu);
-                               else
+                               } else {
                                        vfio_iommu_unmap_unpin_reaccount(iommu);
+                               }
                        }
                        iommu_domain_free(domain->domain);
                        list_del(&domain->next);
@@ -2490,7 +2476,6 @@ static void vfio_iommu_type1_release(void *iommu_data)
 
        if (iommu->external_domain) {
                vfio_release_domain(iommu->external_domain, true);
-               vfio_sanity_check_pfn_list(iommu);
                kfree(iommu->external_domain);
        }