[PATCH v8 07/29] iommufd/viommu: Allow driver-specific user data for a vIOMMU object

[Nicolin Chen <nicolinc@nvidia.com>]

The new type of vIOMMU for tegra241-cmdqv driver needs a driver-specific
user data. So, add data_len/uptr to the iommu_viommu_alloc uAPI and pass
it in via the viommu_init iommu op.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Pranjal Shrivastava <praan@google.com>
Acked-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 include/uapi/linux/iommufd.h   | 6 ++++++
 drivers/iommu/iommufd/viommu.c | 8 +++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 4bc05e4621c1..04eee77335cf 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -965,6 +965,9 @@ enum iommu_viommu_type {
  * @dev_id: The device's physical IOMMU will be used to back the virtual IOMMU
  * @hwpt_id: ID of a nesting parent HWPT to associate to
  * @out_viommu_id: Output virtual IOMMU ID for the allocated object
+ * @data_len: Length of the type specific data
+ * @__reserved: Must be 0
+ * @data_uptr: User pointer to a driver-specific virtual IOMMU data
  *
  * Allocate a virtual IOMMU object, representing the underlying physical IOMMU's
  * virtualization support that is a security-isolated slice of the real IOMMU HW
@@ -985,6 +988,9 @@ struct iommu_viommu_alloc {
 	__u32 dev_id;
 	__u32 hwpt_id;
 	__u32 out_viommu_id;
+	__u32 data_len;
+	__u32 __reserved;
+	__aligned_u64 data_uptr;
 };
 #define IOMMU_VIOMMU_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VIOMMU_ALLOC)
 
diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c
index 2009a421efae..c0365849f849 100644
--- a/drivers/iommu/iommufd/viommu.c
+++ b/drivers/iommu/iommufd/viommu.c
@@ -17,6 +17,11 @@ void iommufd_viommu_destroy(struct iommufd_object *obj)
 int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd)
 {
 	struct iommu_viommu_alloc *cmd = ucmd->cmd;
+	const struct iommu_user_data user_data = {
+		.type = cmd->type,
+		.uptr = u64_to_user_ptr(cmd->data_uptr),
+		.len = cmd->data_len,
+	};
 	struct iommufd_hwpt_paging *hwpt_paging;
 	struct iommufd_viommu *viommu;
 	struct iommufd_device *idev;
@@ -84,7 +89,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd)
 	 */
 	viommu->iommu_dev = __iommu_get_iommu_dev(idev->dev);
 
-	rc = ops->viommu_init(viommu, hwpt_paging->common.domain, NULL);
+	rc = ops->viommu_init(viommu, hwpt_paging->common.domain,
+			      user_data.len ? &user_data : NULL);
 	if (rc)
 		goto out_put_hwpt;
 
-- 
2.43.0