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Wed, 18 Dec 2024 02:44:42 -0800 (PST) Received: from phenom.ffwll.local ([2a02:168:57f4:0:5485:d4b2:c087:b497]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-388c8046c05sm13901360f8f.73.2024.12.18.02.44.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Dec 2024 02:44:41 -0800 (PST) Date: Wed, 18 Dec 2024 11:44:39 +0100 From: Simona Vetter To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: Keith Busch , Wei Lin Guay , alex.williamson@redhat.com, dri-devel@lists.freedesktop.org, kvm@vger.kernel.org, linux-rdma@vger.kernel.org, jgg@nvidia.com, vivek.kasireddy@intel.com, dagmoxnes@meta.com, nviljoen@meta.com, Wei Lin Guay , Oded Gabbay , Daniel Vetter , Leon Romanovsky , Maor Gottlieb Subject: Re: [PATCH 0/4] cover-letter: Allow MMIO regions to be exported through dmabuf Message-ID: References: <20241216095429.210792-1-wguay@fb.com> <89d9071b-0d3e-4fcd-963b-7aa234031a38@amd.com> <0f207bf8-572a-4d32-bd24-602a0bf02d90@amd.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0f207bf8-572a-4d32-bd24-602a0bf02d90@amd.com> X-Operating-System: Linux phenom 6.12.3-amd64 On Tue, Dec 17, 2024 at 10:53:32AM +0100, Christian König wrote: > Am 16.12.24 um 17:54 schrieb Keith Busch: > > On Mon, Dec 16, 2024 at 11:21:39AM +0100, Christian König wrote: > > > Am 16.12.24 um 10:54 schrieb Wei Lin Guay: > > > > From: Wei Lin Guay > > > > However, as a general mechanism, it can support many other scenarios with > > > > VFIO. I imagine this dmabuf approach to be usable by iommufd as well for > > > > generic and safe P2P mappings. > > > > > > > > This series goes after the "Break up ioctl dispatch functions to one > > > > function per ioctl" series. > > > Yeah that sounds like it should work. > > > > > > But where is the rest of the series, I only see the cover letter? > > Should be here: > > > > https://lore.kernel.org/linux-rdma/20241216095429.210792-2-wguay@fb.com/T/#u > > Please send that out once more with me on explicit CC. > > Apart from that I have to reject the adding of dma_buf_try_get(), that is > clearly not something we should do. Yeah if we do try_get it would need to be at least on a specific dma_buf type (so checking for dma_buf->ops), since in general this does not work (unless we add the general code in dma_buf.c somehow to make it work). Aside from any other design concerns. -Sima -- Simona Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch