Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <90619325-ea39-410e-2e8b-a38895f0dabf@linux.intel.com>
Date:   Mon, 16 May 2022 10:03:52 +0800
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.8.1
Cc:     baolu.lu@linux.intel.com, "Tian, Kevin" <kevin.tian@intel.com>,
        Joerg Roedel <joro@8bytes.org>,
        Christoph Hellwig <hch@infradead.org>,
        "Raj, Ashok" <ashok.raj@intel.com>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        "Jiang, Dave" <dave.jiang@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        Eric Auger <eric.auger@redhat.com>,
        "Liu, Yi L" <yi.l.liu@intel.com>,
        "Pan, Jacob jun" <jacob.jun.pan@intel.com>,
        "iommu@lists.linux-foundation.org" <iommu@lists.linux-foundation.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 03/12] iommu: Add attach/detach_dev_pasid domain ops
Content-Language: en-US
To:     Jason Gunthorpe <jgg@nvidia.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>
References: <20220510061738.2761430-1-baolu.lu@linux.intel.com>
 <20220510061738.2761430-4-baolu.lu@linux.intel.com>
 <20220510140238.GD49344@nvidia.com>
 <f56ea479-aa82-37ae-91c3-754816a4ed8b@linux.intel.com>
 <BN9PR11MB5276100AC9BBB7DE5CB800CF8CC89@BN9PR11MB5276.namprd11.prod.outlook.com>
 <Yntrv+nq2t/IeVo2@myrica> <20220511120240.GY49344@nvidia.com>
 <Ynywqxo4P+aEeS6c@myrica> <20220512115101.GU49344@nvidia.com>
From:   Baolu Lu <baolu.lu@linux.intel.com>
In-Reply-To: <20220512115101.GU49344@nvidia.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2022/5/12 19:51, Jason Gunthorpe wrote:
> On Thu, May 12, 2022 at 08:00:59AM +0100, Jean-Philippe Brucker wrote:
> 
>>> It is not "missing" it is just renamed to blocking_domain->ops->set_dev_pasid()
>>>
>>> The implementation of that function would be identical to
>>> detach_dev_pasid.
>>
>>    attach(dev, pasid, sva_domain)
>>    detach(dev, pasid, sva_domain)
>>
>> versus
>>
>>    set_dev_pasid(dev, pasid, sva_domain)
>>    set_dev_pasid(dev, pasid, blocking)
>>
>> we loose the information of the domain previously attached, and the SMMU
>> driver has to retrieve it to find the ASID corresponding to the mm.
> 
> It would be easy to have the old domain be an input as well - the core
> code knows it.

Thanks a lot for all suggestions. I have posted a follow-up series for
this:

https://lore.kernel.org/linux-iommu/20220516015759.2952771-1-baolu.lu@linux.intel.com/

Let's discuss this there.

Best regards,
baolu