Beyond Linux 6.19 switching old AMD GCN 1.0 and 1.1 GPUs to the AMDGPU kernel driver by default for better performance, RADV out-of-the-box, and more, there are still more improvements planned for these aging AMD graphics cards. Timur Kristóf of Valve’s Linux graphics team has been leading the effort to enhance the old graphics card support and on Friday night merged a big improvement for the RADV Vulkan driver in Mesa 26.0.
For these original Graphics Core Next (GCN) GPUs, Timur landed a set of patches to mitigate VM faults for GFX6 and GFX7 class hardware. GFX6 is the original GCN 1.0 GPUs including the likes of the Cafe Verde, Pitcairn, Tahiti, Oland, and Hainan hardware. GFX7 covers Boinaire, Kabini, Mullins, Kaveri, and Hawaii GPUs.
A long-standing problem when using the RADV driver with these aging GPUs has been encountering VM faults when running the Vulkan Conformance Test Suite (CTS) or more prominently for Linux gamers when playing titles like Cyberpunk 2077. There could be “thousands of VM faults per second”.
This merge mitigates all those VM faults happening on AMD GFX6 / GFX7 GPUs. The fundamental issue is those GPUs having a hardware bug with SMEM instructions accessing memory even when its out of bounds and in turn causing VM faults due to unmapped pages. This fix for all those VM faults is merged for the Mesa 26.0 release due out later this quarter.
