From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8164606A31A for ; Tue, 27 Oct 2026 13:16:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=bvRE8z8J Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 68B9910F4CF; Tue, 27 Oct 2026 13:16:06 +0000 (UTC) Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id AF57010E346 for ; Tue, 27 Oct 2026 02:16:09 +0000 (UTC) Received: by mail-wr1-f43.google.com with SMTP id ffacd0b85a97d-48e00eee27dso2272820f8f.0 for ; Mon, 26 Oct 2026 19:16:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1793067368; x=1793672168; darn=lists.freedesktop.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=213hVxaY8zz7NJ3gzXzSYUeeO0Hb0kJ1MH6CZUy6aio=; b=bvRE8z8JdFeO0qKr8ktC/A2Nk10bzaVEmThAY27UWQFk6MuvuajSOvVg4WgBx0OTPB HQ6VJhSc3APTyl/LGLOF+UU5z7h5GyIjPibKR5cdqxMN32xbGUgeaaZI0nOIHXJoIl/m 3/Ooec7CvyardFoU/y/9uH/5js/K1HAM81Zm5tXt36XgIlM7xdNsfn2zCHpOjScc38bI U4DrXulN6+n9R0gAhJngM3UF/tDBjDp1P/hY8OxBX/+W7frLM9fcZTyDTwiWE54E8OrV Gufxwe2BhIc3Io4FHt9dnbGGh2WKqC1VAR/JY9FOe9zKQfVFWyEiCHKLfZq0ZTXRK1bH 7dmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793067368; x=1793672168; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=213hVxaY8zz7NJ3gzXzSYUeeO0Hb0kJ1MH6CZUy6aio=; b=UWa7iAg/LqP4VSiSwLkkGInWehgvhY8RAG17zJIK1ceJa/lmg4MmsZOby8/E6I2BU6 5k28SvT1gr30lJLLMd7eKt2Mr5P2//XQ745RXqr3y3FD0kr/ixoovo4uwKtzsrLR0jNb S0YRAUIy8+zUhDvOORwc3eoAHA8Gko3ILxxVGBno210+XzPYjOKsszrGDd+FFR+JKWXi 5LlYuIed+yV/bsdfZSZOT0mR4Zr9ccROfkm64WBOOsaN8ETVP5YYh2RqY0ogjTpWTKD2 geumZkRQ4Jx3gFpn6VVKAbAr126B/t6UV5JkdYL0B6f+7Z04GefdS+lZxSfLqWm/LUps cyaA== X-Forwarded-Encrypted: i=1; AKwUvBxNHgp/8QZGdITm3zruJd+zwVUFoCBElxxoRfouzSKQZPEoys2W391ogjKBU9U9SSORiiMBgAUWpg==@lists.freedesktop.org X-Gm-Message-State: AFq9FYIgE00TcxFGngOsq1RrhH4+VmOoi/ejQYVrYX8ZAl+y9wQQpdkb rCX3ZvWiAKsDALnPvtjPsSNt9mXWu2KzH23sJfS7D4jBLZ6aSJvMO7C7 X-Gm-Gg: AYBFou3MXNpLAxkB09Sozws+U4y6h/sVKngRIWa881L9vFswcGsaNY8MHRcVDbxCCjG 92Hx+ha431qkWIsIZGQ7BUC8tLrrPiyOffi0AANckL3A1TDMBtizBi8zlqDfHT8M+NvRcyrWwVu gjypmQz/a1YReSWqs7Ngu9Lj9yoCMnfs1jcKpEJtUay3ADp2eSD5RE9jdPI4XjOk8JbFfDNrd0W 8RPt+INO87XeadKfJJMeMYtMGK4jrNKl2TJcNZ8QD9jbbm0B/nDl0K3qRN9sb+ZfcMmBbrLFWIv frCpqKOolJOp6YbZ3+zxq4o3o7fqtrOTRx56Q7lGYa2usXGyU5wdym3TbNUpVR8VIc/rwCYcPWJ y4ehD8ZHr3tdI77LyG29h2SROBq/mD6SZaSVvi0r+JYxNzqigbUC57ufW9rJUlMcUs+pgzs0bwo 2yQXNNlMTh1slrBTVSvLLmJyNaeZq5VlsBuVvUJi4tzHdEX0KJSM2XUUEY9NetJz70xnX1lBqw9 DPQUXlQdiJ/E9G2EFhiLn0WdRhP4gvGRjyJdMVKAjpr0f0utACNTd3aLsuJt2myA7Z8ED+5UZLU FtpI/qUavQg8/1M8HuDM5yjIMtIPZo3LqAaMMigVdWzOJyITpktxjpWKm33gQXRs7cUjl/urz5j 9uyg8v0mbcM+6gssQ7z/v1TTBWicO7UugWN+ONzPM X-Received: by 2002:a5d:6406:0:b0:48e:202:6718 with SMTP id ffacd0b85a97d-48e3eb8bbe9mr13317253f8f.25.1793067367758; Mon, 26 Oct 2026 19:16:07 -0700 (PDT) Received: from MacBook-Pro-von-Karl.localdomain (dynamic-095-117-118-122.95.117.pool.telefonica.de. [95.117.118.122]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48e3ebc3dcbsm19591505f8f.14.2026.10.26.19.16.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2026 19:16:07 -0700 (PDT) Date: Tue, 27 Oct 2026 03:15:34 +0100 From: Karl Mehltretter To: Alistair Popple Cc: dri-devel@lists.freedesktop.org, christian.koenig@amd.com, sumit.semwal@linaro.org, jgg@nvidia.com, Thomas =?utf-8?Q?Hellstr=C3=B6m?= , Simona Vetter , Matthew Brost , Vivek Kasireddy , Dongwon Kim , Leon Romanovsky , Kevin Tian , Xu Yilun , Baolu Lu , Felix Kuehling , Alex Deucher , intel-xe@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, Alexey Kardashevskiy , zhipingz@meta.com, treding@nvidia.com, jhubbard@nvidia.com Subject: Re: [PATCH 23/26] treewide: Rename dma_buf_attach() to dma_buf_sgt_attach() Message-ID: References: <20261026053623.202642-1-apopple@nvidia.com> <20261026053623.202642-24-apopple@nvidia.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261026053623.202642-24-apopple@nvidia.com> X-Mailman-Approved-At: Tue, 27 Oct 2026 13:15:56 +0000 X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Intel-xe" X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FORGED_GMAIL_RCVD,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon, Oct 26, 2026 at 04:36:14PM +0100, Alistair Popple wrote: Testing the series on a Jetson Nano exposed this path. A 3 MiB system-heap buffer was imported into Tegra DRM and scanned out over HDMI. With CONFIG_DMABUF_DEBUG=y the PRIME import succeeded, but scanout immediately produced display SMMU faults starting at 0x300000. Tracing the fault led here: > @@ -475,7 +475,7 @@ static struct tegra_bo *tegra_bo_import(struct drm_device *drm, > * domain, map it first to the DRM device to get an sgt. > */ > if (tegra->domain) { > - attach = dma_buf_attach(buf, drm->dev); > + attach = dma_buf_sgt_attach(buf, drm->dev); tegra_bo_import() passes the attachment SGT to iommu_map_sgtable(), which uses sg_phys() and sg->length. The SGT mapping contract only guarantees the DMA address and length fields. The debug wrapper clears the page-side fields, so iommu_map_sgtable() maps zero bytes. Tegra only treats negative returns as errors and keeps the reserved IOVA, which scanout then faults on. This page-side use predates the series, so the fault is not itself a v2 regression. Is dma_buf_sgt_attach() valid for this call site, or does Tegra need a page/physical mapping type first? Karl