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Date:   Thu, 31 Mar 2022 19:26:30 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Jacob Pan <jacob.jun.pan@intel.com>
Cc:     Lu Baolu <baolu.lu@linux.intel.com>,
        Joerg Roedel <joro@8bytes.org>,
        Christoph Hellwig <hch@infradead.org>,
        Kevin Tian <kevin.tian@intel.com>,
        Ashok Raj <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Eric Auger <eric.auger@redhat.com>,
        Liu Yi L <yi.l.liu@intel.com>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RFC v2 08/11] iommu/sva: Use attach/detach_pasid_dev in
 SVA interfaces
Message-ID: <20220331222630.GI2120790@nvidia.com>
References: <20220329053800.3049561-1-baolu.lu@linux.intel.com>
 <20220329053800.3049561-9-baolu.lu@linux.intel.com>
 <20220331135922.6c677117@jacob-builder>
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On Thu, Mar 31, 2022 at 01:59:22PM -0700, Jacob Pan wrote:

> > +	handle->dev = dev;
> > +	handle->domain = domain;
> > +	handle->pasid = mm->pasid;

> why do we need to store pasid here? Conceptually, pasid is per sva domain
> not per bind. You can get it from handle->domain->sva_cookie.

That is a mistake - SVA needs to follow the general PASID design - the
domain does not encode the PASID, the PASID comes from the device
attachment only.

Jason