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Mon, 19 Oct 2026 18:41:24 +0000 Received: from CHBPR12MB731189.namprd12.prod.outlook.com ([fe80::b0e5:123d:fe06:e10d]) by CHBPR12MB731189.namprd12.prod.outlook.com ([fe80::b0e5:123d:fe06:e10d%6]) with mapi id 15.21.0522.017; Mon, 19 Oct 2026 18:41:24 +0000 Date: Mon, 19 Oct 2026 15:41:23 -0300 From: Jason Gunthorpe To: Thomas =?utf-8?Q?Hellstr=C3=B6m?= Cc: Alistair Popple , Christian =?utf-8?B?S8O2bmln?= , Karl Mehltretter , Dongwon Kim , dri-devel@lists.freedesktop.org, intel-xe@lists.freedesktop.org, iommu@lists.linux.dev, Kevin Tian , Leon Romanovsky , linaro-mm-sig@lists.linaro.org, linux-media@vger.kernel.org, Matthew Brost , Simona Vetter , Sumit Semwal , Vivek Kasireddy Subject: Re: [PATCH RFC 03/26] dma-buf: Add dma_buf_mapping_attach() Message-ID: <20261019184123.GR13920@nvidia.com> References: <0-v1-b5cab63049c0+191af-dmabuf_map_type_jgg@nvidia.com> <3-v1-b5cab63049c0+191af-dmabuf_map_type_jgg@nvidia.com> <20261016202653.97339-1-kmehltretter@gmail.com> <8d4cb20b70ac4c3f36d8d631769757158af2ac8e.camel@linux.intel.com> <20261019133031.GQ13920@nvidia.com> <5f57c49d34f2812b0b68be71218ce0a9b6510c14.camel@linux.intel.com> Content-Type: text/plain; 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That's the only case I heard of > that needed the mapping type decision (or at least a strong hint) > early. No, it would work after the fact just mlx5 forms the attachment and the map approximately at the same time in most important cases. Also after LPC I've also realized that UIO shares alot of similarity with ATS, except getting UIO correct on both sides is functionally required not just a performance optimization :\ Jason