[Intel-gfx] [PATCH v10 03/10] iommufd: Reserve all negative IDs in the iommufd xarray

[Yi Liu]

With this reservation, IOMMUFD users can encode the negative IDs for
specific purposes. e.g. VFIO needs two reserved values to tell userspace
the ID returned is not valid but has other meaning.

Reviewed-by: Jason Gunthorpe <jgg at nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang at intel.com>
Tested-by: Terrence Xu <terrence.xu at intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan at intel.com>
Signed-off-by: Yi Liu <yi.l.liu at intel.com>
---
 drivers/iommu/iommufd/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 3fbe636c3d8a..32ce7befc8dd 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -50,7 +50,7 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
 	 * before calling iommufd_object_finalize().
 	 */
 	rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY,
-		      xa_limit_32b, GFP_KERNEL_ACCOUNT);
+		      xa_limit_31b, GFP_KERNEL_ACCOUNT);
 	if (rc)
 		goto out_free;
 	return obj;
-- 
2.34.1