RADV Driver Lands "Highly Experimental" Transfer Queue Support

Thanks to Valve's open-source developers, the Mesa Radeon Vulkan driver "RADV" has landed experimental support for transfer queues for facilitating SDMA image copies.

The past few months Valve driver developer Timur Kristóf has been working on this experimental transfer queues support for RADV, which can be enabled now on Mesa 24.0-devel via the RADV_PERFTEST=transfer_queue environment variable. He notes it's currently "highly experimental" and for complying with the specs will need to handle gang submissions that will be implemented later.

Timur explained in the patch implementing image copies atop transfer queues:

"When either of the images is linear then the implementation can use the same packets as used by the buffer/image copies. However, tiled to tiled image copies use a separate packet.

Several variations of tiled to tiled copies are not supported by the built-in packet and need a scanline copy as a workaround, this will be implemented by an upcoming commit."

This RADV transfer queue support works with AMD Vega/GFX9 hardware and newer.

More details for those interested via this merge.