[PATCH 4/6] iommufd/hw_pagetable: Support allocating nested parent domain

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

This extends IOMMU_HWPT_ALLOC to allocate domains used as parent (stage-2)
in nested translation.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
---
 drivers/iommu/iommufd/hw_pagetable.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 5be7a31cbd9c..26a8a818ffa3 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -83,6 +83,9 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 
 	lockdep_assert_held(&ioas->mutex);
 
+	if ((flags & IOMMU_HWPT_ALLOC_NEST_PARENT) && !ops->domain_alloc_user)
+		return ERR_PTR(-EOPNOTSUPP);
+
 	hwpt = iommufd_object_alloc(ictx, hwpt, IOMMUFD_OBJ_HW_PAGETABLE);
 	if (IS_ERR(hwpt))
 		return hwpt;
@@ -154,7 +157,7 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
 	struct iommufd_ioas *ioas;
 	int rc;
 
-	if (cmd->flags || cmd->__reserved)
+	if (cmd->flags & ~IOMMU_HWPT_ALLOC_NEST_PARENT || cmd->__reserved)
 		return -EOPNOTSUPP;
 
 	idev = iommufd_get_device(ucmd, cmd->dev_id);
-- 
2.34.1