[Intel-gfx] [PATCH v3 11/12] iommufd: Define IOMMUFD_INVALID_ID in uapi

[Yi Liu]

as there are IOMMUFD users that want to know check if an ID generated
by IOMMUFD is valid or not. e.g. vfio-pci optionaly returns invalid
dev_id to user in the VFIO_DEVICE_GET_PCI_HOT_RESET_INFO ioctl. User
needs to check if the ID is valid or not.

IOMMUFD_INVALID_ID is defined as 0 since the IDs generated by IOMMUFD
starts from 0.

Signed-off-by: Yi Liu <yi.l.liu at intel.com>
---
 include/uapi/linux/iommufd.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 98ebba80cfa1..aeae73a93833 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -9,6 +9,9 @@
 
 #define IOMMUFD_TYPE (';')
 
+/* IDs allocated by IOMMUFD starts from 0 */
+#define IOMMUFD_INVALID_ID 0
+
 /**
  * DOC: General ioctl format
  *
-- 
2.34.1