[RFC PATCHES 15/17] iommufd: Allow new hwpt_alloc flags

[Lu Baolu]

We have completed all puzzles for IO page fault delivery so far. We can
allow user space to opt-in the flags of IOMMU_HWPT_ALLOC_FLAGS_IOPF and
IOMMU_HWPT_ALLOC_FLAGS_USER_PASID_TABLE now.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 include/uapi/linux/iommufd.h         | 3 +++
 drivers/iommu/iommufd/hw_pagetable.c | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 65bb856dd8fb..908d12219727 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -491,6 +491,9 @@ struct iommu_hwpt_alloc {
 	__u32 flags;
 #define IOMMU_HWPT_ALLOC_FLAGS_IOPF_CAPABLE		(1 << 0)
 #define IOMMU_HWPT_ALLOC_FLAGS_USER_PASID_TABLE		(1 << 1)
+#define IOMMU_HWPT_ALLOC_FLAGS_ALL				\
+		(IOMMU_HWPT_ALLOC_FLAGS_IOPF_CAPABLE |		\
+		 IOMMU_HWPT_ALLOC_FLAGS_USER_PASID_TABLE)
 	__u32 dev_id;
 	__u32 pt_id;
 	__u32 out_hwpt_id;
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 7f18e6bd76ec..7be6bf26290f 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -208,7 +208,7 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
 	int klen = 0;
 	int rc = 0;
 
-	if (cmd->flags || cmd->__reserved)
+	if ((cmd->flags & ~IOMMU_HWPT_ALLOC_FLAGS_ALL) || cmd->__reserved)
 		return -EOPNOTSUPP;
 
 	idev = iommufd_get_device(ucmd, cmd->dev_id);
-- 
2.34.1