From patchwork Thu Aug 17 23:43:26 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gurchetan Singh X-Patchwork-Id: 13357076 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 B318FC678DD for ; Thu, 17 Aug 2023 23:44:18 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qWmeP-00082v-4r; Thu, 17 Aug 2023 19:43:37 -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 1qWmeM-00082X-WB for qemu-devel@nongnu.org; Thu, 17 Aug 2023 19:43:35 -0400 Received: from mail-pf1-x42e.google.com ([2607:f8b0:4864:20::42e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1qWmeK-0002ER-5d for qemu-devel@nongnu.org; Thu, 17 Aug 2023 19:43:34 -0400 Received: by mail-pf1-x42e.google.com with SMTP id d2e1a72fcca58-6889656eb58so307640b3a.1 for ; Thu, 17 Aug 2023 16:43:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1692315810; x=1692920610; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:from:to:cc:subject:date:message-id :reply-to; bh=wgoJ3F7Hr4z03GmXJaxJvEOZ1Wzt60NuVtaAQrIl/4o=; b=LqrETCw+1sATHfSwOIHblPJnYKA3+uPtDLoE4pu7GRE6Hf+kqYkukoVnDEWLD/vq+K 87jZmrZb4ib1ww1YDuuldbwDPaifY17WhFsd+vI1A35+RdtAdxwucRMVbOfyHrMClYH1 9ud22LuC1Dj6wA2wk036wgBJo7Uq8qR1Bd+ak= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692315810; x=1692920610; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=wgoJ3F7Hr4z03GmXJaxJvEOZ1Wzt60NuVtaAQrIl/4o=; b=VcbDVvJQkDbDM377z6gXvM3XZ81C671KEz6mnOIUL2KQu0VY5xKtC1tR6HGerdNFPn omWDFojvRxqqxtBoMLHsy9B/gMv3hyQHOatw5SeVw2i/k/nYVZCm4uTgrqpXPMmvbHOb Te6hdWqRe9yGFP790NXwP5ApK2hJHotkRZvJWqnQKn2iw4TBZHF/lM7mQKc4T+gLvyzc U9Y+FKnoGuEhJm5ZCAcKS9MXwGN16Xp8iTuyAc6xuWthpq85KRxXkp1+f9bPmC9mK0ZK AxVY2W7FEY+mMBiGvTMDooWtmLxj+vvrEVgGmulY465gl+V9zBpJYZZCK4lW1ZtZM06k yHvA== X-Gm-Message-State: AOJu0YyzRPFPL9wTv+GlV6syR5q/aSf+wMj+BVjXPKzYqUpZJ/zqm+cY ntiaW1ZNWXa5gduG6yVdlJz3XD6XbfG99xKcOS8= X-Google-Smtp-Source: AGHT+IGIlHP5p0L8SgtjjaabzZACrUIdjrIeLUPaAX8wftnxknudW0mubYno/mDbPqbciPOuEGoPTw== X-Received: by 2002:a05:6a20:ceaf:b0:139:8517:10b6 with SMTP id if47-20020a056a20ceaf00b00139851710b6mr1234522pzb.30.1692315809463; Thu, 17 Aug 2023 16:43:29 -0700 (PDT) Received: from gurchetansingh0.mtv.corp.google.com ([2620:15c:a7:2:735c:93e7:9690:c9bf]) by smtp.gmail.com with ESMTPSA id i1-20020a17090332c100b001bbf7fd354csm315934plr.213.2023.08.17.16.43.28 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Aug 2023 16:43:29 -0700 (PDT) From: Gurchetan Singh To: qemu-devel@nongnu.org Subject: [PATCH v8 9/9] docs/system: add basic virtio-gpu documentation Date: Thu, 17 Aug 2023 16:43:26 -0700 Message-Id: <20230817234326.640-1-gurchetansingh@chromium.org> X-Mailer: git-send-email 2.31.0 In-Reply-To: <1281e8f6-f91a-4ced-b5d1-773370db3eef@gmail.com> References: <1281e8f6-f91a-4ced-b5d1-773370db3eef@gmail.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::42e; envelope-from=gurchetansingh@chromium.org; helo=mail-pf1-x42e.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=-0.021, 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 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 Tested-by: Alyssa Ross Tested-by: Emmanouil Pitsidianakis Reviewed-by: Emmanouil Pitsidianakis v2: - Incorporated suggestions by Akihiko Odaki - Listed the currently supported capset_names (Bernard) v3: - Incorporated suggestions by Akihiko Odaki and Alyssa Ross v4: - Incorporated suggestions by Akihiko Odaki v5: - Removed pci suffix from examples - Verified that -device virtio-gpu-rutabaga works. Strangely enough, I don't remember changing anything, and I remember it not working. I did rebase to top of tree though. - Fixed meson examples in crosvm docs v8: - Remove different links for "rutabaga_gfx" and "gfxstream-enabled rutabaga" (Akihiko) --- docs/system/device-emulation.rst | 1 + docs/system/devices/virtio-gpu.rst | 112 +++++++++++++++++++++++++++++ 2 files changed, 113 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..2b3eb536f9 --- /dev/null +++ b/docs/system/devices/virtio-gpu.rst @@ -0,0 +1,112 @@ +.. + 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 virtio-gpu device variants come in the following form: + + * ``virtio-vga[-BACKEND]`` + * ``virtio-gpu[-BACKEND][-INTERFACE]`` + * ``vhost-user-vga`` + * ``vhost-user-pci`` + +**Backends:** 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. + +**Interfaces:** QEMU further categorizes virtio-gpu device variants based +on the interface exposed to the guest. The interfaces can be 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 the PCI interface, but for the non-VGA ones, the +user can further pick between MMIO or PCI. For MMIO, the user can suffix +the device name with -device, though vhost-user-gpu does not support MMIO. +For PCI, the user can suffix it with -pci. Without these suffixes, the +platform default will be chosen. + +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 + +.. _Mesa: https://www.mesa3d.org/ +.. _SwiftShader: https://github.com/google/swiftshader + +virtio-gpu virglrenderer +------------------------ + +When using virgl accelerated graphics mode in the guest, 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 + +.. _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 to the host with minimal +modification. + +The crosvm book provides directions on how to build a `gfxstream-enabled +rutabaga`_ and launch a `guest Wayland proxy`_. + +This device does require host blob support (``hostmem`` field below). The +``hostmem`` field specifies the size of virtio-gpu host memory window. +This is typically between 256M and 8G. + +At least one capset (see colon separated ``capset_names`` below) must be +specified 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. + +The device will try to auto-detect the wayland socket path if the +``cross-domain`` capset name is set. The user may optionally specify +``wayland_socket_path`` for non-standard paths. + +The ``wsi`` option can be set to ``surfaceless`` or ``headless``. +Surfaceless doesn't create a native window surface, but does copy from the +render target to the Pixman buffer if a virtio-gpu 2D hypercall is issued. +Headless is like surfaceless, but doesn't copy to the Pixman buffer. +Surfaceless is the default if ``wsi`` is not specified. + +.. parsed-literal:: + -device virtio-gpu-rutabaga,capset_names=gfxstream-vulkan:cross-domain, + hostmem=8G,wayland_socket_path=/tmp/nonstandard/mock_wayland.sock, + wsi=headless + +.. _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 proxy: https://crosvm.dev/book/devices/wayland.html