From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A8452EDB7DC for ; Tue, 7 Apr 2026 09:26:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1835410E394; Tue, 7 Apr 2026 09:26:22 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=resnulli-us.20251104.gappssmtp.com header.i=@resnulli-us.20251104.gappssmtp.com header.b="nLrZWKKj"; dkim-atps=neutral Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) by gabe.freedesktop.org (Postfix) with ESMTPS id AF53710E394 for ; Tue, 7 Apr 2026 09:26:20 +0000 (UTC) Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-4889e045bc6so30810635e9.2 for ; Tue, 07 Apr 2026 02:26:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=resnulli-us.20251104.gappssmtp.com; s=20251104; t=1775553979; x=1776158779; darn=lists.freedesktop.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=4JppuW+8jHhiWrz5kQ42R8XjkKGXIqfSYDySDPjjqyw=; b=nLrZWKKjObT0O1maRBgYvLoLWsORSPxwxaK7epJ3NZv99dgUOsCN4pww4KpDqCowUw bCdtxzQeIvU3gVQ3jMUxriSBhRw0WKh9l/fOjVxd23miKvDSQj3cvwrc1oNxBxMkiKko 6WGSBMjKOAe/kIkAEeFvbrdo/lpJGXAzoynuhm0+eU23RJvTgRD3eoxC8uAlaPGxxgKG 7VMHcRcu73TirG11HRJLOJns0tc+YIYI2D/Mc5rO9IddHoLF7QElGuKo3GuTG6vd7WhY V2BKJaIKGeHFh01zMKqeCr9cb02QL7PD4ZXvq8JUBsO5qL9EYSl0NtZhdHFvR8Ot5kg8 l2Gw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775553979; x=1776158779; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=4JppuW+8jHhiWrz5kQ42R8XjkKGXIqfSYDySDPjjqyw=; b=YglteWwBU3QGj3fC2/gZ/O/8/1VpAulJpOxH1BZPSCh2zxwUktKpb9OyZjU3Izu/YV hLcJuXErfZOVQwKyqcBJV3LrsuihDmk6ZxfsBmflK3R1ov8RTbHZBstss3bjTDBrvXgE v97+WNpDhbo6BfdvbQTdx4U+wu8lFUmdScl0yFADoZzPrJs8xCzDwHVlWQQwJEI3LjOS B0TFnmrGXrZP7ianJ1xy+GoXt38horEM5OuslwnbkNkAFEEsea+7+rrGk/npuiYWek5L NT9kQ1OZPMDziTwQijzrVIAJdM0jGMql30KCt6uepUj6DgSx6lEofXhR/wtSEPuVwiIp sGUA== X-Gm-Message-State: AOJu0YyunHupUQn5cCLur5mapH3PlIox6vfry0iBePhW6x4EPkTsvz6+ NOoYFAveyGEkcLP1AFH1z7Y6f/oSKGFnJY/FNJFafZ7J5OQi3shdwZB0Tj/VarXUP80PbKuWY8K nOKuN X-Gm-Gg: AeBDievGz6GIsfrfT2B2/uinNVQV10sFcyENIiprWGQuInvDKCFqSidVW+pKHy1cIAF FVB8cKagFTEYdePUw/1PnkAzvOBsylc/FH+8QczG8XKlFykioF+Tbsi3KLuxyX+RVqK25vNf0ZJ hzffAcss2Olkaq4BHbYaVKw0o8AaroojWuX4UJgQgy+PUSUGJ1f6FAeE1BdZ34dmW1PIbc1qU+V vpV11yLg5vKZrXNbptfo3/fd5vsybuFa0vCEbIJjssKzFUUmUmTQn9lw0wShSnQGc6gkWt/Kcb/ HeLLuheY76drDHDGUAJD3/FaDNF7KltOhRVvMbMsUtJ1k1h4a971Izl7Qtk7DOCy/dHQwhoqOZO ix4Z4IgwIed0kg2F0BGbnRtyGFDxQBTwvstJff//YxT4FurrpcepD8A7j6Mx9c/Nl6bYOvtdctm hOTgj/9z2WF90fjw== X-Received: by 2002:a05:600c:6098:b0:488:9fb7:376d with SMTP id 5b1f17b1804b1-4889fb73b1amr196429615e9.28.1775553978818; Tue, 07 Apr 2026 02:26:18 -0700 (PDT) Received: from localhost ([85.163.81.98]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488a91686f9sm268832955e9.10.2026.04.07.02.26.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Apr 2026 02:26:18 -0700 (PDT) From: Jiri Pirko To: dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, iommu@lists.linux.dev, linux-media@vger.kernel.org Cc: sumit.semwal@linaro.org, benjamin.gaignard@collabora.com, Brian.Starkey@arm.com, jstultz@google.com, tjmercier@google.com, christian.koenig@amd.com, m.szyprowski@samsung.com, robin.murphy@arm.com, jgg@ziepe.ca, leon@kernel.org, ptesarik@suse.com, catalin.marinas@arm.com, aneesh.kumar@kernel.org, suzuki.poulose@arm.com, steven.price@arm.com, thomas.lendacky@amd.com, john.allen@amd.com, ashish.kalra@amd.com, suravee.suthikulpanit@amd.com, linux-coco@lists.linux.dev Subject: [PATCH v2] dma-buf: heaps: system: document system_cc_shared heap Date: Tue, 7 Apr 2026 11:26:17 +0200 Message-ID: <20260407092617.635223-1-jiri@resnulli.us> X-Mailer: git-send-email 2.51.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Jiri Pirko Document the system_cc_shared dma-buf heap that was introduced recently. Describe its purpose, availability conditions and relation to confidential computing VMs. Signed-off-by: Jiri Pirko Reviewed-by: T.J.Mercier --- Documentation/userspace-api/dma-buf-heaps.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/userspace-api/dma-buf-heaps.rst b/Documentation/userspace-api/dma-buf-heaps.rst index 05445c83b79a..f56b743cdb36 100644 --- a/Documentation/userspace-api/dma-buf-heaps.rst +++ b/Documentation/userspace-api/dma-buf-heaps.rst @@ -16,6 +16,13 @@ following heaps: - The ``system`` heap allocates virtually contiguous, cacheable, buffers. + - The ``system_cc_shared`` heap allocates virtually contiguous, cacheable, + buffers using shared (decrypted) memory. It is only present on + confidential computing (CoCo) VMs where memory encryption is active + (e.g., AMD SEV, Intel TDX). The allocated pages have the encryption + bit cleared, making them accessible for device DMA without TDISP + support. On non-CoCo VM configurations, this heap is not registered. + - The ``default_cma_region`` heap allocates physically contiguous, cacheable, buffers. Only present if a CMA region is present. Such a region is usually created either through the kernel commandline -- 2.51.1