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Thu, 18 May 2023 12:43:43 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ4rw6SJnwSqjfCyaFRoKbONMXxWejcCpLIQx2vrAykC+soNBYYP2BWJo0LZ1SBw5bDgbglmXQ== X-Received: by 2002:a5d:94cd:0:b0:76c:8a8f:edc2 with SMTP id y13-20020a5d94cd000000b0076c8a8fedc2mr7297117ior.12.1684439022870; Thu, 18 May 2023 12:43:42 -0700 (PDT) Received: from redhat.com ([38.15.36.239]) by smtp.gmail.com with ESMTPSA id w31-20020a056638379f00b00405f36ed05asm636935jal.55.2023.05.18.12.43.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 May 2023 12:43:41 -0700 (PDT) Date: Thu, 18 May 2023 13:43:40 -0600 From: Alex Williamson To: "Liu, Yi L" Cc: Jason Gunthorpe , "Tian, Kevin" , "joro@8bytes.org" , "robin.murphy@arm.com" , "cohuck@redhat.com" , "eric.auger@redhat.com" , "nicolinc@nvidia.com" , "kvm@vger.kernel.org" , "mjrosato@linux.ibm.com" , "chao.p.peng@linux.intel.com" , "yi.y.sun@linux.intel.com" , "peterx@redhat.com" , "jasowang@redhat.com" , "shameerali.kolothum.thodi@huawei.com" , "lulu@redhat.com" , "suravee.suthikulpanit@amd.com" , "intel-gvt-dev@lists.freedesktop.org" , "intel-gfx@lists.freedesktop.org" , "linux-s390@vger.kernel.org" , "Hao, Xudong" , "Zhao, Yan Y" , "Xu, Terrence" , "Jiang, Yanting" , "Duan, Zhenzhong" , "clegoate@redhat.com" Subject: Re: [PATCH v5 01/10] vfio-iommufd: Create iommufd_access for noiommu devices Message-ID: <20230518134340.0a39629b.alex.williamson@redhat.com> In-Reply-To: References: <20230513132136.15021-1-yi.l.liu@intel.com> <20230513132136.15021-2-yi.l.liu@intel.com> <20230517112609.78a3e916.alex.williamson@redhat.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.35; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Thu, 18 May 2023 12:23:29 +0000 "Liu, Yi L" wrote: > > From: Jason Gunthorpe > > Sent: Thursday, May 18, 2023 2:21 AM > > > > On Wed, May 17, 2023 at 11:26:09AM -0600, Alex Williamson wrote: > > > > > It's not clear to me why we need a separate iommufd_access for > > > noiommu. > > > > The point was to allocate an ID for the device so we can use that ID > > with the other interfaces in all cases. > > I guess Alex's question is why adding a new pointer named noiommu_access > while there is already the iommufd_access pointer named iommufd_access. Yes, precisely. Sorry that was confusing, we need the access for noiommu but it's not clear why that access needs to be stored in a separate pointer when we can already differentiate noiommu devices otherwise. Thanks, Alex