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To:     Lu Baolu <baolu.lu@linux.intel.com>,
        Joerg Roedel <joro@8bytes.org>,
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        "Raj, Ashok" <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
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CC:     Eric Auger <eric.auger@redhat.com>,
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        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v7 06/10] iommu/sva: Refactoring
 iommu_sva_bind/unbind_device()
Thread-Topic: [PATCH v7 06/10] iommu/sva: Refactoring
 iommu_sva_bind/unbind_device()
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Date:   Tue, 24 May 2022 10:22:28 +0000
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> From: Lu Baolu <baolu.lu@linux.intel.com>
> Sent: Thursday, May 19, 2022 3:21 PM
>=20
> 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 =3D iommu_get_domain_for_dev_pasid(dev, mm->pasid);
> +	if (domain) {
> +		sva_domain =3D 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?