Valve is funding a RADV Windows port through contractors at Collabora, and the open-source Radeon Vulkan driver is already far enough along to run some games, including Counter-Strike 2, Collabora developers said.
RADV is the Radeon Vulkan driver developed in Mesa, the open-source graphics stack widely used on Linux. Vulkan is a low-level graphics API used by games and rendering software to talk to the GPU with less overhead than older interfaces. On Linux, RADV has become a major path for AMD graphics support, with work coming from both AMD and community developers. On Windows, AMD’s proprietary driver remains the normal route.
Valve’s interest is not hard to read from the plumbing. The company has spent years pushing Linux gaming through SteamOS, the Steam Deck and newer Steam Machine efforts. A working RADV build on Windows would give game developers and compatibility-layer developers a more consistent driver target across Linux and Windows, at least for Radeon hardware.
How does the RADV Windows port work?
Collabora said the project became more plausible because of changes Microsoft made with Windows 10 and WDDM 2.0, the Windows Display Driver Model. That driver model separates most graphics driver logic in user space from the kernel component that talks directly to the graphics card.
That split gives Collabora a place to connect RADV’s user-space Vulkan driver to AMD’s existing Windows kernel driver. The ugly part is the private conversation between those two halves. Collabora said that data is not fully standardized, so the RADV developers need to observe and understand what AMD’s Windows driver sends to the kernel driver.
A 2024 effort by developer Faith Ekstrand produced an early tool for recording WDDM 2.0 calls and reverse-engineering enough of them to start a basic RADV implementation. Collabora said it expanded that work into a more capable logger that can examine Vulkan applications running through AMD’s official driver and dump the data passed down to the kernel.
From there, the work becomes a patient exercise in decoding structures that were not written for outsiders. Collabora said its team had to reverse-engineer obscure data formats and work through how AMD’s user-space driver interacts with the kernel piece. That work has now produced enough of a driver to launch some games.
What still blocks RADV on Windows?
The risky dependency is the interface between AMD’s user-space and kernel-space drivers. Collabora said those pieces are designed as a matched pair, which means updates are not guaranteed to preserve compatibility with an independent RADV user-space driver.
In plain English: even if the Windows version of RADV becomes useful, AMD or Microsoft could change the kernel-facing interface and break it. Collabora is asking AMD, Microsoft, or both to provide either a documented interface to the kernel driver or a compatibility layer that RADV can target without guessing.
The payoff, if the work becomes stable enough for broader use, would be practical rather than decorative. Developers could debug graphics problems in an open driver instead of treating the Windows driver as a sealed box. Studios building for both Windows and Linux could face fewer platform-specific surprises. Valve could also carry driver fixes and optimizations across its Windows compatibility work and Linux gaming stack.
Collabora’s post does not make RADV on Windows a finished replacement for AMD’s driver. It shows a real port running real games, with the hardest political and maintenance problem still sitting at the kernel boundary.
This story draws on original reporting from Tom's Hardware.
