This is a GUI agent for Qubes OS that supports the [Wayland] display server protocol. Compared to X11, Wayland is vastly simpler and aims to ensure every frame is perfect. Due to Qubes OS limitations, this agent does not achieve this, but it does its best. Compatibility with legacy X11 programs is provided via Xwayland.
The Wayland agent uses Meson to build, so you must have Meson installed.
Additionally, pkg-config must be able to find xkb, libdrm, wayland-server, xkbcommon, pixman-1, and vchan-xen.
If it can find libsystemd, the compositor will integrate nicely with systemd.
Parts of the agent are written in Rust, so you also need to have Cargo installed.
In a Fedora 37 qube, you can install these with
sudo dnf install libxcb-devel libdrm-devel wayland-devel libxkbcommon-devel pixman-devel systemd-devel qubes-libvchan-xen-devel cargo
Build the Wayland agent like any other program that uses Meson:
cd /path/to/source && meson setup build && cd build && meson compileThe Rust components are built using Cargo, but this is handled internally by the build system and you do not need to worry about it. If any of Cargo’s inputs have changed, Cargo should be rerun automatically; if it is not, this is a bug in Cargo.
If you use systemd, I recommand using a systemd user unit to start the compositor.
A sample unit file is provided.
Otherwise, it should be sufficient to run the compositor with no arguments.
Running qubes-compositor --help will provide detailed usage information; please report a bug if it is not sufficient.
The compositor and the standard agent cannot be run concurrently.
Whichever starts later will hang until the other has been stopped.
To prevent this problem, stop the standard agent first with systemctl stop qubes-gui-agent.service.
This will kill any graphical programs running in the VM, so it should be run from a console window opened with qvm-console-dispvm or the Console button in qubes-manager.
The compositor uses wlroots for all Wayland-related functionality and for rendering. Currently, all rendering is done via Pixman in software. This means that even if the VM has a GPU attached to it (via e.g. GPU pass-through) it will not be used. The code that processes messages from the GUI daemon is written in Rust, but the rest of the code is written in C due to the lack of good wlroots Rust bindings.
Demi Marie Obenour (the author of the compositor) does all development using Vim and gnome-terminal running under the compositor itself, so it is capable of running non-toy applications. Nevertheless, it is still experimental and will have bugs.
Known bugs:
- Damage tracking for Xwayland surfaces doesn’t work right and has been disabled.
- If a window is resized quickly, there may be a bar on the right with stale contents until the application redraws.