From eda175dfe2484c1e79afaee0f65eeebfb9f89a53 Mon Sep 17 00:00:00 2001 From: Yi Liu Date: Tue, 18 Jul 2023 03:55:35 -0700 Subject: [PATCH] iommufd: Reserve all negative IDs in the iommufd xarray 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 Tested-by: Yanting Jiang Tested-by: Terrence Xu Tested-by: Zhenzhong Duan Signed-off-by: Yi Liu Link: https://lore.kernel.org/r/20230718105542.4138-4-yi.l.liu@intel.com Signed-off-by: Alex Williamson --- 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;