From patchwork Tue Aug 1 01:17:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gurchetan Singh X-Patchwork-Id: 13335649 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 75B15C04A94 for ; Tue, 1 Aug 2023 01:18:40 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qQe1F-0001cm-Fy; Mon, 31 Jul 2023 21:17:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qQe1E-0001cd-Lw for qemu-devel@nongnu.org; Mon, 31 Jul 2023 21:17:48 -0400 Received: from mail-ot1-x329.google.com ([2607:f8b0:4864:20::329]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qQe1C-0003K5-QR for qemu-devel@nongnu.org; Mon, 31 Jul 2023 21:17:48 -0400 Received: by mail-ot1-x329.google.com with SMTP id 46e09a7af769-6b9d68a7abaso3922132a34.3 for ; Mon, 31 Jul 2023 18:17:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1690852665; x=1691457465; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=yWoWjO74TGFbJFWuRN7PtgQZicNmirMY+BnV95/WW3M=; b=mN81Gr15F67YHPY7+VbotpoeqhbB67Ihwow7T4Rd0A0UDOLcTyEl8Ufx6zH8NZbUbA qWho7WHpVzo2Il/dIjAZqddvFT3NM/oqnKJamhvW0Rk9clljoCz1F0D1cMqx0YNHJQjY VGxyOctxXBTEPEYuS1tY89BvfwSoYd0uNMgO8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690852665; x=1691457465; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=yWoWjO74TGFbJFWuRN7PtgQZicNmirMY+BnV95/WW3M=; b=CH7pnc9UQq+peeTmuU3rzPJ92FVtASwohFZKOfBKrGvTUHKbqbGV53LVElA8VaDqUg 6Ci2g5g3hclJvLAQHEtAHmX4ek1OPIQOegqm2+DDMdc71UGabD1hSpXpWpW20d6D/jAK pF3pcpqpLTWO8EtXPn4ZASd09bk6uRrogI6oPzlSszHKP+IXMRQcB6tpGtZUNf5g/eX+ y5106OUaW6DLErEwvKQB1vlABEat5ZAHI6hzq38xLbvvC2e1G34T3rtMqAvdptjMkF1A 4dWbiB6WECLpQT0g/e3q/xbGWIk1ZdHyqDiAR+95C91x/01gjbAvdOApl5j+k+A9hdWN pjFg== X-Gm-Message-State: ABy/qLbDHtlY14Jl2mBiwDOf/ex+Hmh6/DdMnDCskBzQjbnh/aLdRSHp g8g5Oec2WgimWeP4oE0O6/5Mlkbxe0cvwJBIA+s= X-Google-Smtp-Source: APBJJlHYd8OQhr9yqOZJYLh4BH/NZpt4gf7vSSuieXpLcR9IhfeW1ztdQZ+8EBQnvylw60aMmM5F9g== X-Received: by 2002:a05:6808:4044:b0:3a4:35bb:edae with SMTP id cz4-20020a056808404400b003a435bbedaemr10196811oib.29.1690852664925; Mon, 31 Jul 2023 18:17:44 -0700 (PDT) Received: from gurchetansingh0.mtv.corp.google.com ([2620:15c:a7:2:cb47:8a0d:6476:3e7b]) by smtp.gmail.com with ESMTPSA id v20-20020a17090a899400b00260a5ecd273sm6657722pjn.1.2023.07.31.18.17.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jul 2023 18:17:43 -0700 (PDT) From: Gurchetan Singh To: qemu-devel@nongnu.org Cc: kraxel@redhat.com, marcandre.lureau@redhat.com, akihiko.odaki@gmail.com, dmitry.osipenko@collabora.com, ray.huang@amd.com, alex.bennee@linaro.org, shentey@gmail.com, hi@alyssa.is Subject: [PATCH v2 9/9] docs/system: add basic virtio-gpu documentation Date: Mon, 31 Jul 2023 18:17:23 -0700 Message-Id: <20230801011723.627-10-gurchetansingh@chromium.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20230801011723.627-1-gurchetansingh@chromium.org> References: <20230801011723.627-1-gurchetansingh@chromium.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::329; envelope-from=gurchetansingh@chromium.org; helo=mail-ot1-x329.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org This adds basic documentation for virtio-gpu. Suggested-by: Akihiko Odaki Signed-off-by: Gurchetan Singh --- v2: - Incorporated suggestions by Akihiko Odaki - Listed the currently supported capset_names (Bernard) docs/system/device-emulation.rst | 1 + docs/system/devices/virtio-gpu.rst | 98 ++++++++++++++++++++++++++++++ 2 files changed, 99 insertions(+) create mode 100644 docs/system/devices/virtio-gpu.rst diff --git a/docs/system/device-emulation.rst b/docs/system/device-emulation.rst index 4491c4cbf7..1167f3a9f2 100644 --- a/docs/system/device-emulation.rst +++ b/docs/system/device-emulation.rst @@ -91,6 +91,7 @@ Emulated Devices devices/nvme.rst devices/usb.rst devices/vhost-user.rst + devices/virtio-gpu.rst devices/virtio-pmem.rst devices/vhost-user-rng.rst devices/canokey.rst diff --git a/docs/system/devices/virtio-gpu.rst b/docs/system/devices/virtio-gpu.rst new file mode 100644 index 0000000000..f359584033 --- /dev/null +++ b/docs/system/devices/virtio-gpu.rst @@ -0,0 +1,98 @@ +.. + SPDX-License-Identifier: GPL-2.0 + +virtio-gpu +========== + +This document explains the setup and usage of the virtio-gpu device. +The virtio-gpu device paravirtualizes the GPU and display controller. + +Linux kernel support +-------------------- + +virtio-gpu requires a guest Linux kernel built with the +``CONFIG_DRM_VIRTIO_GPU`` option. + +QEMU virtio-gpu variants +------------------------ + +QEMU provides a 2D virtio-gpu backend, and two accelerated backends: +virglrenderer ('gl' device label) and rutabaga_gfx ('rutabaga' device +label). There is a vhost-user backend that runs the graphics stack in +a separate process for improved isolation. + +Theses backends can be further classified into VGA and non-VGA variants. +The VGA ones are prefixed with virtio-vga or vhost-user-vga while the +non-VGA ones are prefixed with virtio-gpu or vhost-user-gpu. + +The VGA ones always use PCI interface, but for the non-VGA ones, you can +further pick simple MMIO or PCI. For MMIO, you can suffix the device +name with -device though vhost-user-gpu apparently does not support +MMIO. For PCI, you can suffix it with -pci. Without these suffixes, the +platform default will be chosen. The syntax of available combinations +is listed below. + + * ``virtio-vga[-BACKEND]`` + * ``virtio-gpu[-BACKEND][-INTERFACE]`` + * ``vhost-user-vga`` + * ``vhost-user-pci`` + +This document uses the PCI variant in examples. + +virtio-gpu 2d +------------- + +The default 2D backend only performs 2D operations. The guest needs to +employ a software renderer for 3D graphics. + +Typically, the software renderer is provided by `Mesa`_ or `SwiftShader`_. +Mesa's implementations (LLVMpipe, Lavapipe and virgl below) work out of box +on typical modern Linux distributions. + +.. parsed-literal:: + -device virtio-gpu-pci + +.. _Mesa: https://www.mesa3d.org/ +.. _SwiftShader: https://github.com/google/swiftshader + +virtio-gpu virglrenderer +------------------------ + +When using virgl accelerated graphics mode, OpenGL API calls are translated +into an intermediate representation (see `Gallium3D`_). The intermediate +representation is communicated to the host and the `virglrenderer`_ library +on the host translates the intermediate representation back to OpenGL API +calls. + +.. parsed-literal:: + -device virtio-gpu-gl-pci + +.. _Gallium3D: https://www.freedesktop.org/wiki/Software/gallium/ +.. _virglrenderer: https://gitlab.freedesktop.org/virgl/virglrenderer/ + +virtio-gpu rutabaga +------------------- + +virtio-gpu can also leverage `rutabaga_gfx`_ to provide `gfxstream`_ rendering +and `Wayland display passthrough`_. With the gfxstream rendering mode, GLES +and Vulkan calls are forwarded directly to the host with minimal modification. + +The crosvm book provides directions on how to build a `gfxstream-enabled +rutabaga`_ and launch a `guest Wayland compositor`_. + +This device does require host blob support (``hostmem`` field below), but not +all capsets (``capset_names`` below) have to enabled when starting the device. + +The currently supported ``capset_names`` are ``gfxstream-vulkan`` and +``cross-domain`` on Linux guests. For Android guests, ``gfxstream-gles`` is +also supported. + +.. parsed-literal:: + -device virtio-gpu-rutabaga-pci,capset_names=gfxstream-vulkan:cross-domain,\\ + hostmem=8G,wayland_socket_path="$XDG_RUNTIME_DIR/$WAYLAND_DISPLAY" + +.. _rutabaga_gfx: https://github.com/google/crosvm/blob/main/rutabaga_gfx/ffi/src/include/rutabaga_gfx_ffi.h +.. _gfxstream: https://android.googlesource.com/platform/hardware/google/gfxstream/ +.. _Wayland display passthrough: https://www.youtube.com/watch?v=OZJiHMtIQ2M +.. _gfxstream-enabled rutabaga: https://crosvm.dev/book/appendix/rutabaga_gfx.html +.. _guest Wayland compositor: https://crosvm.dev/book/devices/wayland.html