iommufd: Move ioas related HWPT destruction into iommufd_hw_pagetable_destroy()

A HWPT is permanently associated with an IOAS when it is created, remove
the strange situation where a refcount != 0 HWPT can have been
disconnected from the IOAS by putting all the IOAS related destruction in
the object destroy function.

Initializing a HWPT is two stages, we have to allocate it, attach it to a
device and then populate the domain. Once the domain is populated it is
fully linked to the IOAS.

Arrange things so that all the error unwinds flow through the
iommufd_hw_pagetable_destroy() and allow it to handle all cases.

Link: https://lore.kernel.org/r/4-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

1 files changed, 19 insertions, 8 deletions

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 43d473989a06..10db1359c067 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -13,7 +13,17 @@ void iommufd_hw_pagetable_destroy(struct iommufd_object *obj)
 
 	WARN_ON(!list_empty(&hwpt->devices));
 
-	iommu_domain_free(hwpt->domain);
+	if (!list_empty(&hwpt->hwpt_item)) {
+		mutex_lock(&hwpt->ioas->mutex);
+		list_del(&hwpt->hwpt_item);
+		mutex_unlock(&hwpt->ioas->mutex);
+
+		iopt_table_remove_domain(&hwpt->ioas->iopt, hwpt->domain);
+	}
+
+	if (hwpt->domain)
+		iommu_domain_free(hwpt->domain);
+
 	refcount_dec(&hwpt->ioas->obj.users);
 	mutex_destroy(&hwpt->devices_lock);
 }
@@ -37,21 +47,22 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 	if (IS_ERR(hwpt))
 		return hwpt;
 
-	hwpt->domain = iommu_domain_alloc(dev->bus);
-	if (!hwpt->domain) {
-		rc = -ENOMEM;
-		goto out_abort;
-	}
-
 	INIT_LIST_HEAD(&hwpt->devices);
 	INIT_LIST_HEAD(&hwpt->hwpt_item);
 	mutex_init(&hwpt->devices_lock);
 	/* Pairs with iommufd_hw_pagetable_destroy() */
 	refcount_inc(&ioas->obj.users);
 	hwpt->ioas = ioas;
+
+	hwpt->domain = iommu_domain_alloc(dev->bus);
+	if (!hwpt->domain) {
+		rc = -ENOMEM;
+		goto out_abort;
+	}
+
 	return hwpt;
 
 out_abort:
-	iommufd_object_abort(ictx, &hwpt->obj);
+	iommufd_object_abort_and_destroy(ictx, &hwpt->obj);
 	return ERR_PTR(rc);
 }