AMD Adds New Option To Help Improve Debugging With RADV & RadeonSI Drivers

Merged to Mesa 23.1-devel yesterday was UMD metadata v2 support for the RADV and RadeonSI drivers to provide extra metadata that can be optionally enabled to help with Radeon GPU debugging.

AMD Linux graphics driver developer Pierre-Eric Pelloux-Prayer contributed a set of patches for Mesa 23.1 that provide UMD Metadata V2 as an updated metadata format for use with GFX9/Vega graphics and newer atop the latest open-source code.

"The goal here is to be able to create textures from dmabuf from umr - without these changes this is impossible because these values can't be guessed.

The new layout is compatible with version=1 so old/new UMD can be used together without issues and isn't used by default.
For radeonsi, it will be possible to use it with a AMD_DEBUG=... option."

This updated metadata format is enabled when running Mesa 23.1 with AMD_DEBUG=extra_md for the RadeonSI Gallium3D (OpenGL) driver and RADV_DEBUG=extra_md for the RADV Vulkan driver. When enabled the driver sets the UMD buffer object metadata for all color textures and enables extended metadata. That extended metadata in turn can allow debugging tools to import textures and setting these on all color textures and to import non-exported textures.

The tooling focus at this time is on AMD's UMR, the AMDGPU User-Mode Register debugger. AMD open-sourced UMR back in 2017.

More details on this metadata update for the AMD Radeon Mesa drivers to enhance the debugging support via this merge request.