Experimental Linux Patches Allow User-Space Peer-To-Peer DMA Between NVMe Drives

A set of Linux kernel patches posted on friday allow peer-to-peer DMA (P2PDMA) transfers between NVMe drives using existing O_DIRECT operations or the NVMe pass-through interface from user-space.

These patches allow for user-space transfers between NVMe solid-state drives in a more efficient manner via P2PDMA. The patches though at the moment are marked "request for comments" and there are some technical issues to overcome around scatter-gather lists (SGLs) and one of the DMA interfaces.

The P2PDMA code works with AMD hardware while Intel support is coming soon and DMA-direct implementations. Other IOMMU implementations like ARM and POWER are forthcoming.

More details on this P2PDMA support between NVMe drives via this patch series.