Peer-To-Peer DMA-BUF Support Being Ironed Out, Patches Pending For AMDGPU

One of the latest patch series being worked on by long-time open-source AMD Linux graphics driver developer Christian König is P2P DMA-BUF support.

The support is the culmination of extensive work on allowing peer-to-peer sharing of DMA-BUF buffers between devices without being backed by system memory pages. In particular -- and the focus of AMD's work in this area -- is for allowing DMA-BUF buffers to be shared between multiple graphics cards in a more efficient/performant manner.

This builds upon earlier AMD Linux work like P2P DMA between devices on AMD Zen systems. Now the last of the series is supporting the peer-to-peer import/export at the DMA-BUF level with this buffer sharing and synchronization framework being common among the Linux GPU drivers.

On Wednesday Christian sent out the P2P DMA-BUF patches for DMA-BUF itself followed by the AMDGPU DRM driver as a reference wiring up of the support with the new "peer2peer" flag.

The window for landing new feature code into DRM-Next is quickly drawing to a close ahead of the Linux 5.7 merge window, so we'll see if this work gets picked up quickly enough or ends up being diverted to a later kernel.