Mesa developer Konstantin Seurer has been adding more features to the Lavapipe Vulkan driver for functionality needed by VKD3D-Proton for mapping Direct3D 12 APIs atop Vulkan.
Lavapipe as a reminder is the CPU/software-based implementation of Vulkan within Mesa. This Mesa software Vulkan driver can be useful for having a non-GPU codepath when debugging Vulkan issues, another code path for vetting Mesa changes independent of any hardware vendor, and similar purposes along the same lines as LLVMpipe is to OpenGL. Merged yesterday for Mesa 25.2 were a number of additional Vulkan features added to Lavapipe for what is needed by VKD3D-Proton.
Some of the new functionality includes VK_EXT_fragment_shader_interlock, KHR_shader_quad_control, shaderResourceMinLod, VK_EXT_shader_image_atomic_int64, 64-bit image clears and 64-bit image operations, and other bits.
The new functionality can also be useful for Lavapipe outside of strictly VKD3D-Proton but that was just the focus with the merge request that is now part of Mesa 25.2-devel.
