radv: query and report the last GPUVM fault with RADV_DEBUG=hang

Samuel Pitoiset requested to merge hakzsam/mesa:radv_vmfault_ioctl into main

Based on drm!298 (merged).

This is how it looks when a GPUVM fault is detected. Tested with a small use-after-free Vulkan test. Next step is to hook up VK_EXT_address_binding_report to auto-detect use-after-free.

radv: GPU hang detected...
radv: GPUVM fault detected at address 0x800100041000.
radv: GPU hang report will be saved to '/home/hakzsam/radv_dumps_8103_2023.05.25_15.20.11'!

Merge request reports