The Mesa Radeon Vulkan driver “RADV” has merged support for the VK_NV_cooperative_matrix2 NVIDIA Vulkan extension but it’s hidden by default and only partially supported with a focus on helping FidelityFX Super Resolution 4 and VKD3D-Proton.
VK_NV_cooperative_matrix2 is a NVIDIA vendor extension for building on the cooperative matrix types introduced by VK_KHR_cooperative_matrix for expanding beyond just the scope of GEMM kernels. The extension was introduced last October with the Vulkan 1.3.300 spec update.
The RADV driver in Mesa 25.2 now has limited support for the VK_NV_cooperative_matrix2 extension but it’s disabled by default. This extension is only exposed when the “radv_cooperative_matrix2_nv” DriConf option is set.
Georg Lehmann who authored the support explained in the merge request for RADV as well as touching common SPIR-V and NIR code within Mesa:
“VK_NV_cooperative_matrix2 has multiple different capabilities/features. This only implements CooperativeMatrixConversionsNV, as it’s the most simple and vkd3d-proton wants to use it.
Note that if anyone wants to use this feature, the only operation that reasonably fast (free on gfx12) is ACC -> B conversion. ACC/B -> A conversion and ACC -> B transpose are pretty slow, and sadly the NV extension doesn’t allow ACC -> A transpose, which would be fast for us.”
After being under review the past month, the code is now merged for Mesa 25.2 with a focus on helping FSR4 and VKD3D-Proton for Steam Play (Proton) Linux gaming.
