diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index cf2517a6472ff8..41cd65c758d3bc 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -22,7 +22,8 @@ void iommufd_device_destroy(struct iommufd_object *obj)
 
 	iommu_device_release_dma_owner(idev->dev);
 	iommu_group_put(idev->group);
-	iommufd_ctx_put(idev->ictx);
+	if (!iommufd_selftest_is_mock_dev(idev->dev))
+		iommufd_ctx_put(idev->ictx);
 }
 
 /**
@@ -69,7 +70,8 @@ struct iommufd_device *iommufd_device_bind(struct iommufd_ctx *ictx,
 		goto out_release_owner;
 	}
 	idev->ictx = ictx;
-	iommufd_ctx_get(ictx);
+	if (!iommufd_selftest_is_mock_dev(dev))
+		iommufd_ctx_get(ictx);
 	idev->dev = dev;
 	idev->enforce_cache_coherency =
 		device_iommu_capable(dev, IOMMU_CAP_ENFORCE_CACHE_COHERENCY);
@@ -151,7 +153,8 @@ static int iommufd_device_setup_msi(struct iommufd_device *idev,
 	 * operation from the device (eg a simple DMA) cannot trigger an
 	 * interrupt outside this iommufd context.
 	 */
-	if (!iommu_group_has_isolated_msi(idev->group)) {
+	if (!iommufd_selftest_is_mock_dev(idev->dev) &&
+	    !iommu_group_has_isolated_msi(idev->group)) {
 		if (!allow_unsafe_interrupts)
 			return -EPERM;
 
@@ -707,34 +710,3 @@ int iommufd_access_rw(struct iommufd_access *access, unsigned long iova,
 	return rc;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_rw, IOMMUFD);
-
-#ifdef CONFIG_IOMMUFD_TEST
-/*
- * Creating a real iommufd_device is too hard, bypass creating a iommufd_device
- * and go directly to attaching a domain.
- */
-struct iommufd_hw_pagetable *
-iommufd_device_selftest_attach(struct iommufd_ctx *ictx,
-			       struct iommufd_ioas *ioas,
-			       struct device *mock_dev)
-{
-	struct iommufd_device tmp_idev = { .dev = mock_dev };
-	struct iommufd_hw_pagetable *hwpt;
-
-	mutex_lock(&ioas->mutex);
-	hwpt = iommufd_hw_pagetable_alloc(ictx, ioas, &tmp_idev, false);
-	mutex_unlock(&ioas->mutex);
-	if (IS_ERR(hwpt))
-		return hwpt;
-
-	refcount_inc(&hwpt->obj.users);
-	iommufd_object_finalize(ictx, &hwpt->obj);
-	return hwpt;
-}
-
-void iommufd_device_selftest_detach(struct iommufd_ctx *ictx,
-				    struct iommufd_hw_pagetable *hwpt)
-{
-	refcount_dec(&hwpt->obj.users);
-}
-#endif
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 331664e917b771..d523ef12890e1e 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -297,12 +297,6 @@ void iopt_remove_access(struct io_pagetable *iopt,
 void iommufd_access_destroy_object(struct iommufd_object *obj);
 
 #ifdef CONFIG_IOMMUFD_TEST
-struct iommufd_hw_pagetable *
-iommufd_device_selftest_attach(struct iommufd_ctx *ictx,
-			       struct iommufd_ioas *ioas,
-			       struct device *mock_dev);
-void iommufd_device_selftest_detach(struct iommufd_ctx *ictx,
-				    struct iommufd_hw_pagetable *hwpt);
 int iommufd_test(struct iommufd_ucmd *ucmd);
 void iommufd_selftest_destroy(struct iommufd_object *obj);
 extern size_t iommufd_test_memory_limit;
@@ -311,6 +305,7 @@ void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd,
 bool iommufd_should_fail(void);
 void __init iommufd_test_init(void);
 void iommufd_test_exit(void);
+bool iommufd_selftest_is_mock_dev(struct device *dev);
 #else
 static inline void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd,
 						 unsigned int ioas_id,
@@ -327,5 +322,9 @@ static inline void __init iommufd_test_init(void)
 static inline void iommufd_test_exit(void)
 {
 }
+static inline bool iommufd_selftest_is_mock_dev(struct device *dev)
+{
+	return false;
+}
 #endif
 #endif
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index cfb5fe9a5e0ee8..8540adcb68f1f0 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -91,23 +91,50 @@ enum selftest_obj_type {
 	TYPE_IDEV,
 };
 
+struct mock_dev {
+	struct device dev;
+};
+
 struct selftest_obj {
 	struct iommufd_object obj;
 	enum selftest_obj_type type;
 
 	union {
 		struct {
-			struct iommufd_hw_pagetable *hwpt;
+			struct iommufd_device *idev;
 			struct iommufd_ctx *ictx;
-			struct device mock_dev;
+			struct mock_dev *mock_dev;
 		} idev;
 	};
 };
 
+static void mock_domain_blocking_free(struct iommu_domain *domain)
+{
+}
+
+static int mock_domain_nop_attach(struct iommu_domain *domain,
+				  struct device *dev)
+{
+	return 0;
+}
+
+static const struct iommu_domain_ops mock_blocking_ops = {
+	.free = mock_domain_blocking_free,
+	.attach_dev = mock_domain_nop_attach,
+};
+
+static struct iommu_domain mock_blocking_domain = {
+	.type = IOMMU_DOMAIN_BLOCKED,
+	.ops = &mock_blocking_ops,
+};
+
 static struct iommu_domain *mock_domain_alloc(unsigned int iommu_domain_type)
 {
 	struct mock_iommu_domain *mock;
 
+	if (iommu_domain_type == IOMMU_DOMAIN_BLOCKED)
+		return &mock_blocking_domain;
+
 	if (WARN_ON(iommu_domain_type != IOMMU_DOMAIN_UNMANAGED))
 		return NULL;
 
@@ -236,19 +263,39 @@ static phys_addr_t mock_domain_iova_to_phys(struct iommu_domain *domain,
 	return (xa_to_value(ent) & MOCK_PFN_MASK) * MOCK_IO_PAGE_SIZE;
 }
 
+static bool mock_domain_capable(struct device *dev, enum iommu_cap cap)
+{
+	return cap == IOMMU_CAP_CACHE_COHERENCY;
+}
+
+static void mock_domain_set_plaform_dma_ops(struct device *dev)
+{
+	/*
+	 * mock doesn't setup default domains because we can't hook into the
+	 * normal probe path
+	 */
+}
+
 static const struct iommu_ops mock_ops = {
 	.owner = THIS_MODULE,
 	.pgsize_bitmap = MOCK_IO_PAGE_SIZE,
 	.domain_alloc = mock_domain_alloc,
+	.capable = mock_domain_capable,
+	.set_platform_dma_ops = mock_domain_set_plaform_dma_ops,
 	.default_domain_ops =
 		&(struct iommu_domain_ops){
 			.free = mock_domain_free,
+			.attach_dev = mock_domain_nop_attach,
 			.map_pages = mock_domain_map_pages,
 			.unmap_pages = mock_domain_unmap_pages,
 			.iova_to_phys = mock_domain_iova_to_phys,
 		},
 };
 
+struct iommu_device mock_iommu_device = {
+	.ops = &mock_ops,
+};
+
 static inline struct iommufd_hw_pagetable *
 get_md_pagetable(struct iommufd_ucmd *ucmd, u32 mockpt_id,
 		 struct mock_iommu_domain **mock)
@@ -269,48 +316,142 @@ get_md_pagetable(struct iommufd_ucmd *ucmd, u32 mockpt_id,
 	return hwpt;
 }
 
+static struct bus_type iommufd_mock_bus_type = {
+	.name = "iommufd_mock",
+	.iommu_ops = &mock_ops,
+};
+
+static void mock_dev_release(struct device *dev)
+{
+	struct mock_dev *mdev = container_of(dev, struct mock_dev, dev);
+
+	kfree(mdev);
+}
+
+static struct mock_dev *mock_dev_create(void)
+{
+	struct iommu_group *iommu_group;
+	struct dev_iommu *dev_iommu;
+	struct mock_dev *mdev;
+	int rc;
+
+	mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return ERR_PTR(-ENOMEM);
+
+	device_initialize(&mdev->dev);
+	mdev->dev.release = mock_dev_release;
+	mdev->dev.bus = &iommufd_mock_bus_type;
+
+	iommu_group = iommu_group_alloc();
+	if (IS_ERR(iommu_group)) {
+		rc = PTR_ERR(iommu_group);
+		goto err_put;
+	}
+
+	rc = dev_set_name(&mdev->dev, "iommufd_mock%u",
+			  iommu_group_id(iommu_group));
+	if (rc)
+		goto err_group;
+
+	/*
+	 * The iommu core has no way to associate a single device with an iommu
+	 * driver (heck currently it can't even support two iommu_drivers
+	 * registering). Hack it together with an open coded dev_iommu_get().
+	 * Notice that the normal notifier triggered iommu release process also
+	 * does not work here because this bus is not in iommu_buses.
+	 */
+	mdev->dev.iommu = kzalloc(sizeof(*dev_iommu), GFP_KERNEL);
+	if (!mdev->dev.iommu) {
+		rc = -ENOMEM;
+		goto err_group;
+	}
+	mutex_init(&mdev->dev.iommu->lock);
+	mdev->dev.iommu->iommu_dev = &mock_iommu_device;
+
+	rc = device_add(&mdev->dev);
+	if (rc)
+		goto err_dev_iommu;
+
+	rc = iommu_group_add_device(iommu_group, &mdev->dev);
+	if (rc)
+		goto err_del;
+	iommu_group_put(iommu_group);
+	return mdev;
+
+err_del:
+	device_del(&mdev->dev);
+err_dev_iommu:
+	kfree(mdev->dev.iommu);
+	mdev->dev.iommu = NULL;
+err_group:
+	iommu_group_put(iommu_group);
+err_put:
+	put_device(&mdev->dev);
+	return ERR_PTR(rc);
+}
+
+static void mock_dev_destroy(struct mock_dev *mdev)
+{
+	iommu_group_remove_device(&mdev->dev);
+	device_del(&mdev->dev);
+	kfree(mdev->dev.iommu);
+	mdev->dev.iommu = NULL;
+	put_device(&mdev->dev);
+}
+
+bool iommufd_selftest_is_mock_dev(struct device *dev)
+{
+	return dev->release == mock_dev_release;
+}
+
 /* Create an hw_pagetable with the mock domain so we can test the domain ops */
 static int iommufd_test_mock_domain(struct iommufd_ucmd *ucmd,
 				    struct iommu_test_cmd *cmd)
 {
-	static struct bus_type mock_bus = { .iommu_ops = &mock_ops };
-	struct iommufd_hw_pagetable *hwpt;
+	struct iommufd_device *idev;
 	struct selftest_obj *sobj;
-	struct iommufd_ioas *ioas;
+	u32 pt_id = cmd->id;
+	u32 idev_id;
 	int rc;
 
-	ioas = iommufd_get_ioas(ucmd, cmd->id);
-	if (IS_ERR(ioas))
-		return PTR_ERR(ioas);
-
 	sobj = iommufd_object_alloc(ucmd->ictx, sobj, IOMMUFD_OBJ_SELFTEST);
-	if (IS_ERR(sobj)) {
-		rc = PTR_ERR(sobj);
-		goto out_ioas;
-	}
+	if (IS_ERR(sobj))
+		return PTR_ERR(sobj);
+
 	sobj->idev.ictx = ucmd->ictx;
 	sobj->type = TYPE_IDEV;
-	sobj->idev.mock_dev.bus = &mock_bus;
 
-	hwpt = iommufd_device_selftest_attach(ucmd->ictx, ioas,
-					      &sobj->idev.mock_dev);
-	if (IS_ERR(hwpt)) {
-		rc = PTR_ERR(hwpt);
+	sobj->idev.mock_dev = mock_dev_create();
+	if (IS_ERR(sobj->idev.mock_dev)) {
+		rc = PTR_ERR(sobj->idev.mock_dev);
 		goto out_sobj;
 	}
-	sobj->idev.hwpt = hwpt;
 
-	/* Userspace must destroy both of these IDs to destroy the object */
-	cmd->mock_domain.out_hwpt_id = hwpt->obj.id;
+	idev = iommufd_device_bind(ucmd->ictx, &sobj->idev.mock_dev->dev,
+				   &idev_id);
+	if (IS_ERR(idev)) {
+		rc = PTR_ERR(idev);
+		goto out_mdev;
+	}
+	sobj->idev.idev = idev;
+
+	rc = iommufd_device_attach(idev, &pt_id);
+	if (rc)
+		goto out_unbind;
+
+	/* Userspace must destroy the device_id to destroy the object */
+	cmd->mock_domain.out_hwpt_id = pt_id;
 	cmd->mock_domain.out_device_id = sobj->obj.id;
 	iommufd_object_finalize(ucmd->ictx, &sobj->obj);
-	iommufd_put_object(&ioas->obj);
 	return iommufd_ucmd_respond(ucmd, sizeof(*cmd));
 
+out_unbind:
+	iommufd_device_unbind(idev);
+out_mdev:
+	mock_dev_destroy(sobj->idev.mock_dev);
 out_sobj:
 	iommufd_object_abort(ucmd->ictx, &sobj->obj);
-out_ioas:
-	iommufd_put_object(&ioas->obj);
 	return rc;
 }
 
@@ -780,8 +921,9 @@ void iommufd_selftest_destroy(struct iommufd_object *obj)
 
 	switch (sobj->type) {
 	case TYPE_IDEV:
-		iommufd_device_selftest_detach(sobj->idev.ictx,
-					       sobj->idev.hwpt);
+		iommufd_device_detach(sobj->idev.idev);
+		iommufd_device_unbind(sobj->idev.idev);
+		mock_dev_destroy(sobj->idev.mock_dev);
 		break;
 	}
 }
@@ -845,9 +987,11 @@ void __init iommufd_test_init(void)
 {
 	dbgfs_root =
 		fault_create_debugfs_attr("fail_iommufd", NULL, &fail_iommufd);
+	WARN_ON(bus_register(&iommufd_mock_bus_type));
 }
 
 void iommufd_test_exit(void)
 {
 	debugfs_remove_recursive(dbgfs_root);
+	bus_unregister(&iommufd_mock_bus_type);
 }
diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c
index fa08209268c42f..0c4bbd4079a425 100644
--- a/tools/testing/selftests/iommu/iommufd.c
+++ b/tools/testing/selftests/iommu/iommufd.c
@@ -645,7 +645,6 @@ TEST_F(iommufd_ioas, access_pin)
 				   &check_map_cmd));
 
 		test_ioctl_destroy(mock_device_id);
-		test_ioctl_destroy(mock_hwpt_id);
 		test_cmd_destroy_access_pages(
 			access_cmd.id,
 			access_cmd.access_pages.out_access_pages_id);
@@ -1214,7 +1213,6 @@ TEST_F(iommufd_mock_domain, all_aligns_copy)
 				   1);
 
 			test_ioctl_destroy(mock_device_id);
-			test_ioctl_destroy(self->domain_ids[1]);
 			self->domain_ids[1] = old_id;
 
 			test_ioctl_ioas_unmap(iova, length);
diff --git a/tools/testing/selftests/iommu/iommufd_fail_nth.c b/tools/testing/selftests/iommu/iommufd_fail_nth.c
index 9713111b820dd7..dda8f0187cd88b 100644
--- a/tools/testing/selftests/iommu/iommufd_fail_nth.c
+++ b/tools/testing/selftests/iommu/iommufd_fail_nth.c
@@ -323,8 +323,6 @@ TEST_FAIL_NTH(basic_fail_nth, map_domain)
 
 	if (_test_ioctl_destroy(self->fd, device_id))
 		return -1;
-	if (_test_ioctl_destroy(self->fd, hwpt_id))
-		return -1;
 
 	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id, &hwpt_id))
 		return -1;
@@ -365,13 +363,9 @@ TEST_FAIL_NTH(basic_fail_nth, map_two_domains)
 
 	if (_test_ioctl_destroy(self->fd, device_id))
 		return -1;
-	if (_test_ioctl_destroy(self->fd, hwpt_id))
-		return -1;
 
 	if (_test_ioctl_destroy(self->fd, device_id2))
 		return -1;
-	if (_test_ioctl_destroy(self->fd, hwpt_id2))
-		return -1;
 
 	if (_test_cmd_mock_domain(self->fd, ioas_id, &device_id, &hwpt_id))
 		return -1;
@@ -572,8 +566,6 @@ TEST_FAIL_NTH(basic_fail_nth, access_pin_domain)
 
 	if (_test_ioctl_destroy(self->fd, device_id))
 		return -1;
-	if (_test_ioctl_destroy(self->fd, hwpt_id))
-		return -1;
 	return 0;
 }
 
