Rutabaga Virtual Graphics Interface

The Rutabaga Virtual Graphics Interface (VGI) is a cross-platform abstraction for GPU and display virtualization. The virtio-gpu context type feature is used to dispatch commands between various Rust, C++, and C implementations. The diagram below does not exhaustively depict all available context types.

Rust API

Although hosted in the crosvm repository, the Rutabaga VGI is designed to be portable across VMM implementations. The Rust API is available on crates.io.

Rutabaga C API

The following documentation shows how to build Rutabaga's C API with gfxstream enabled, which is the common use case.

Build dependencies

sudo apt install libdrm libglm-dev libstb-dev

Install libaemu

git clone https://android.googlesource.com/platform/hardware/google/aemu
cd aemu/
git checkout v0.1.2-aemu-release
cmake -DAEMU_COMMON_GEN_PKGCONFIG=ON \
       -DAEMU_COMMON_BUILD_CONFIG=gfxstream \
       -DENABLE_VKCEREAL_TESTS=OFF -B build
cmake --build build -j
sudo cmake --install build

Install gfxstream host

git clone https://android.googlesource.com/platform/hardware/google/gfxstream
cd gfxstream/
meson setup host-build/
meson install -C host-build/

Install FFI bindings to Rutabaga

cd $(crosvm_dir)/rutabaga_gfx/ffi/
meson setup rutabaga-ffi-build/
meson install -C rutabaga-ffi-build/

Latest releases for potential packaging

• Rutabaga FFI v0.1.2
• gfxstream v0.1.2
• AEMU v0.1.2

Kumquat Media Server

The Kumquat Media server provides a way to test virtio multi-media protocols without a virtual machine. The following example shows how to run GL and Vulkan apps with virtio-gpu + gfxstream-vulkan. Full windowing will only work on platforms that support dma_buf and dma_fence.

Only headless apps are likely to work on Nvidia, and requires this change.

Build GPU-enabled server

First install libaemu and the gfxstream-host, then:

cd $(crosvm_dir)/rutabaga_gfx/kumquat/server/
cargo build --features=gfxstream

Build and install client library

cd $(crosvm_dir)/rutabaga_gfx/kumquat/gpu_client/
meson setup client-build
ninja -C client-build/ install

Build gfxstream guest

The same repo as gfxstream host is used, but with a different build configuration.

cd $(gfxstream_dir)
meson setup guest-build/ -Dgfxstream-build=guest-test
ninja -C guest-build/

Run apps

In one terminal:

cd $(crosvm_dir)/rutabaga_gfx/kumquat/server/
./target/debug/kumquat

In another terminal, run:

export MESA_LOADER_DRIVER_OVERRIDE=zink
export VK_ICD_FILENAMES=$(gfxstream_dir)/guest-build/guest/vulkan/gfxstream_vk_devenv_icd.x86_64.json
vkcube

Linux guests

To test gfxstream with Debian guests, make sure your display environment is headless.

systemctl set-default multi-user.target

Build gfxstream-vk:

cd $(gfxstream_dir)
meson setup guest-build/ -Dgfxstream-build=guest
ninja -C guest-build/

Start the compositor:

export MESA_LOADER_DRIVER_OVERRIDE=zink
export VK_ICD_FILENAMES=$(gfxstream_dir)/guest-build/guest/vulkan/gfxstream_vk_devenv_icd.x86_64.json
weston --backend=drm

Contributing to gfxstream

To contribute to gfxstream without an Android tree:

git clone https://android.googlesource.com/platform/hardware/google/gfxstream
git commit -a -m blah
git push origin HEAD:refs/for/main

The AOSP Gerrit instance will ask for an identity. Follow the instructions, a Google account is needed.