[PATCH v10 14/18] iommufd: Allow allocating PASID-compatible domain

[Yi Liu <yi.l.liu@intel.com>]

The underlying infrastructure has supported the PASID attach and related
enforcement per the requirement of the IOMMU_HWPT_ALLOC_PASID flag. This
extends iommufd to support PASID compatible domain requested by userspace.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
v9 -> v10: Dropped r-b tag as the uapi description for ALLOC_PASID is modified
---
 drivers/iommu/iommufd/device.c       | 4 +++-
 drivers/iommu/iommufd/hw_pagetable.c | 7 ++++---
 include/uapi/linux/iommufd.h         | 3 +++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 54ffef9c17f7..f09dcddf777b 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -973,7 +973,9 @@ iommufd_device_auto_get_domain(struct iommufd_device *idev, ioasid_t pasid,
 	}
 
 	hwpt_paging = iommufd_hwpt_paging_alloc(idev->ictx, ioas, idev, pasid,
-						0, immediate_attach, NULL);
+						pasid != IOMMU_NO_PASID ?
+						    IOMMU_HWPT_ALLOC_PASID : 0,
+						immediate_attach, NULL);
 	if (IS_ERR(hwpt_paging)) {
 		destroy_hwpt = ERR_CAST(hwpt_paging);
 		goto out_unlock;
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index b8c1e5ca7be8..3fba11754dad 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -112,7 +112,8 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 {
 	const u32 valid_flags = IOMMU_HWPT_ALLOC_NEST_PARENT |
 				IOMMU_HWPT_ALLOC_DIRTY_TRACKING |
-				IOMMU_HWPT_FAULT_ID_VALID;
+				IOMMU_HWPT_FAULT_ID_VALID |
+				IOMMU_HWPT_ALLOC_PASID;
 	const struct iommu_ops *ops = dev_iommu_ops(idev->dev);
 	struct iommufd_hwpt_paging *hwpt_paging;
 	struct iommufd_hw_pagetable *hwpt;
@@ -233,7 +234,7 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
 	struct iommufd_hw_pagetable *hwpt;
 	int rc;
 
-	if ((flags & ~IOMMU_HWPT_FAULT_ID_VALID) ||
+	if ((flags & ~(IOMMU_HWPT_FAULT_ID_VALID | IOMMU_HWPT_ALLOC_PASID)) ||
 	    !user_data->len || !ops->domain_alloc_nested)
 		return ERR_PTR(-EOPNOTSUPP);
 	if (parent->auto_domain || !parent->nest_parent ||
@@ -290,7 +291,7 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
 	struct iommufd_hw_pagetable *hwpt;
 	int rc;
 
-	if (flags & ~IOMMU_HWPT_FAULT_ID_VALID)
+	if (flags & ~(IOMMU_HWPT_FAULT_ID_VALID | IOMMU_HWPT_ALLOC_PASID))
 		return ERR_PTR(-EOPNOTSUPP);
 	if (!user_data->len)
 		return ERR_PTR(-EOPNOTSUPP);
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 5fc7e27804b7..75f3b6829624 100644
--- a/include/uapi/linux/iommufd.h
+++ b/include/uapi/linux/iommufd.h
@@ -393,6 +393,9 @@ struct iommu_vfio_ioas {
  *                          Any domain attached to the non-PASID part of the
  *                          device must also be flagged, otherwise attaching a
  *                          PASID will blocked.
+ *                          For the user that wants to attach PASID, ioas is
+ *                          not recommended for the non-PASID part of the
+ *                          device.
  *                          If IOMMU does not support PASID it will return
  *                          error (-EOPNOTSUPP).
  */
-- 
2.34.1