[PATCH v2 4/6] iommufd/hw_pagetable: Support allocating nested parent domain

[Yi Liu]

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

Signed-off-by: Yi Liu <yi.l....@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..8b3d2875d642 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 && !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