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[82.27.106.168]) by smtp.gmail.com with ESMTPSA id o16-20020adf8b90000000b0020fc3e24041sm10338214wra.106.2022.05.24.03.58.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 May 2022 03:58:24 -0700 (PDT) Date: Tue, 24 May 2022 11:57:59 +0100 From: Jean-Philippe Brucker To: "Tian, Kevin" Subject: Re: [PATCH v7 06/10] iommu/sva: Refactoring iommu_sva_bind/unbind_device() Message-ID: References: <20220519072047.2996983-1-baolu.lu@linux.intel.com> <20220519072047.2996983-7-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Cc: "Jiang, Dave" , "Raj, Ashok" , Robin Murphy , "iommu@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , Christoph Hellwig , Jean-Philippe Brucker , Vinod Koul , "Pan, Jacob jun" , Jason Gunthorpe , Will Deacon X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Tue, May 24, 2022 at 10:22:28AM +0000, Tian, Kevin wrote: > > From: Lu Baolu > > 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? Device drivers can call bind() multiple times for the same device and mm, for example if one process wants to open multiple accelerator queues. Thanks, Jean _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu