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

From: Liu, Yi L yi.l.liu@intel.com Sent: Tuesday, September 19, 2023 5:25 PM

@@ -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);
  

if (flags && !ops->domain_alloc_user) return ERR_PTR(-EOPNOTSUPP);

as long as flags is non-zero we'll need the new alloc_user ops.