Valve funded open-source RADV Vulkan driver port for Windows already runs Counter-Strike 2
Valve is funding Collabora’s work to bring the open-source RADV Vulkan driver to Windows. The experimental port has already reached the point where it can run Counter-Strike 2 using the game’s Vulkan renderer.
RADV is part of Mesa and serves as the main Vulkan driver for AMD graphics cards on Linux. It is also part of the graphics stack used by AMD-powered devices such as the Steam Deck. Windows users currently rely on AMD’s proprietary Vulkan implementation.
We improved command stream handling and synchronization and added support for, among others, sparse bindings, tessellation and task shaders, and dynamic querying of GPU properties. It is still not conformant (even though the success rate has dramatically increased), but the real highlight is being able to run our first game with RADV: Counter-Strike 2. Anyone can try it by switching the renderer with the -vulkan argument.
— Louis-Francis Ratté-Boulianne
The Windows port does not replace AMD’s complete graphics driver. RADV operates as the user-mode Vulkan driver while continuing to communicate with AMD’s proprietary Windows kernel-mode driver through WDDM2.
Collabora expanded earlier work by Faith Ekstrand, adding native Windows support and reducing hardware-specific values. The developers also improved synchronization, command stream handling, sparse bindings, tessellation, task shaders and GPU property detection. Testing has primarily involved a Radeon RX 7900 XT.
Production support requires more work
The largest issue is the undocumented interface between AMD’s Windows kernel driver and user-mode drivers. Driver updates can change private data structures without maintaining compatibility. Collabora says a stable documented interface from AMD, or an intermediate compatibility library, would be required before RADV could become a reliable Windows driver.
So AMD has a lot of room to demonstrate how open source-friendly they truly are.
