RE: [PATCH v7 06/10] iommu/sva: Refactoring iommu_sva_bind/unbind_device()

Tian, Kevin
2022-05-24T10:22:43Z

> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Thursday, May 19, 2022 3:21 PM
>
> The existing iommu SVA interfaces are implemented by calling the SVA
> specific iommu ops provided by the IOMMU drivers. There's no need for
> any SVA specific ops in iommu_ops vector anymore as we can achieve
> this through the generic attach/detach_dev_pasid domain ops.

set/block_pasid_dev, to be consistent.

> +
> + mutex_lock(&iommu_sva_lock);
> + /* Search for an existing domain. */
> + domain = iommu_get_domain_for_dev_pasid(dev, mm->pasid);
> + if (domain) {
> + sva_domain = to_sva_domain(domain);
> + refcount_inc(&sva_domain->bond.users);
> + goto out_success;
> + }
> +

why would one device/pasid be bound to a mm more than once?