RE: [PATCH v2 03/11] iommufd/hw_pagetable: Use domain_alloc_user op for domain allocation

From: Nicolin Chen nicolinc@nvidia.com Sent: Saturday, May 20, 2023 2:58 AM

On Fri, May 19, 2023 at 08:56:25AM +0000, Tian, Kevin wrote:

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From: Yi Liu yi.l.liu@intel.com Sent: Thursday, May 11, 2023 10:39 PM

@@ -88,7 +90,10 @@ iommufd_hw_pagetable_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas, refcount_inc(&ioas->obj.users); hwpt->ioas = ioas;

• hwpt->domain = iommu_domain_alloc(idev->dev->bus);
  

• if (ops->domain_alloc_user)
  

•         hwpt->domain = ops->domain_alloc_user(idev->dev, NULL,
  

NULL);

• else
  

•         hwpt->domain = iommu_domain_alloc(idev->dev->bus);
  

this reminds the comment for @domain_alloc_user() should clarify that UNMANGED domain type is assumed when no user data is provided, to be compatible with iommu_domain_alloc().

Yes. Perhaps:

• @domain_alloc_user: allocate user iommu domain. A valid user_data

pointer and

•                 a parent pointer to a kernel-managed domain are required
  

•                 to allocate an IOMMU_DOMAIN_NESTED domain. Otherwise,
  

the

•                 new domain will be set to an IOMMU_DOMAIN_UNMANAGED
  

type.

yes, this is clearer.