[PATCH v3 4/6] vfio-iommufd: Make vfio_iommufd_emulated_bind() return iommufd_access ID

[Yi Liu <yi.l.liu@xxxxxxxxx>]

vfio device cdev needs to return iommufd_access ID to userspace if
bind_iommufd succeeds.

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Tested-by: Terrence Xu <terrence.xu@xxxxxxxxx>
Signed-off-by: Yi Liu <yi.l.liu@xxxxxxxxx>
---
 drivers/iommu/iommufd/device.c   | 4 +++-
 drivers/iommu/iommufd/selftest.c | 3 ++-
 drivers/vfio/iommufd.c           | 2 +-
 include/linux/iommufd.h          | 2 +-
 4 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 6999a10b5496..25115d401d8f 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -426,6 +426,7 @@ void iommufd_access_destroy_object(struct iommufd_object *obj)
  * @ioas_id: ID for a IOMMUFD_OBJ_IOAS
  * @ops: Driver's ops to associate with the access
  * @data: Opaque data to pass into ops functions
+ * @id: Output ID number to return to userspace for this access
  *
  * An iommufd_access allows a driver to read/write to the IOAS without using
  * DMA. The underlying CPU memory can be accessed using the
@@ -435,7 +436,7 @@ void iommufd_access_destroy_object(struct iommufd_object *obj)
  */
 struct iommufd_access *
 iommufd_access_create(struct iommufd_ctx *ictx,
-		      const struct iommufd_access_ops *ops, void *data)
+		      const struct iommufd_access_ops *ops, void *data, u32 *id)
 {
 	struct iommufd_access *access;
 
@@ -460,6 +461,7 @@ iommufd_access_create(struct iommufd_ctx *ictx,
 	access->ictx = ictx;
 	iommufd_ctx_get(ictx);
 	iommufd_object_finalize(ictx, &access->obj);
+	*id = access->obj.id;
 	return access;
 }
 EXPORT_SYMBOL_NS_GPL(iommufd_access_create, IOMMUFD);
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 1e89e1a8c5f0..e6e04dceffe3 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -554,6 +554,7 @@ static int iommufd_test_create_access(struct iommufd_ucmd *ucmd,
 	struct iommu_test_cmd *cmd = ucmd->cmd;
 	struct selftest_access *staccess;
 	struct iommufd_access *access;
+	u32 id;
 	int fdno;
 	int rc;
 
@@ -575,7 +576,7 @@ static int iommufd_test_create_access(struct iommufd_ucmd *ucmd,
 		(flags & MOCK_FLAGS_ACCESS_CREATE_NEEDS_PIN_PAGES) ?
 			&selftest_access_ops_pin :
 			&selftest_access_ops,
-		staccess);
+		staccess, &id);
 	if (IS_ERR(access)) {
 		rc = PTR_ERR(access);
 		goto out_put_fdno;
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index 78e2486586d7..1ee558c0be25 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -142,7 +142,7 @@ int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
 
 	lockdep_assert_held(&vdev->dev_set->lock);
 
-	user = iommufd_access_create(ictx, &vfio_user_ops, vdev);
+	user = iommufd_access_create(ictx, &vfio_user_ops, vdev, out_device_id);
 	if (IS_ERR(user))
 		return PTR_ERR(user);
 	vdev->iommufd_access = user;
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h
index 155d3630aedc..1129a36a74c4 100644
--- a/include/linux/iommufd.h
+++ b/include/linux/iommufd.h
@@ -41,7 +41,7 @@ enum {
 
 struct iommufd_access *
 iommufd_access_create(struct iommufd_ctx *ictx,
-		      const struct iommufd_access_ops *ops, void *data);
+		      const struct iommufd_access_ops *ops, void *data, u32 *id);
 void iommufd_access_destroy(struct iommufd_access *access);
 int iommufd_access_attach(struct iommufd_access *access, u32 ioas_id);
 
-- 
2.34.1