XDP-challenges and future work

XDP continues to see significant development, and is far from a finished system. However, XDP already offers rich facilities for high performance packet processing, and has seen deployment in several production systems. In this work, we provide an overview over some of the ongoing work around XDP, and seek to start a discussion on some of the future challenges that need to be addressed to make sure the XDP ecosystem can continue to flourish. The overview of ongoing work focuses on the XDP-related topics being discussed at the LPC networking track in Vancouver, where we provide a short overview of each topic, and refer to the talk for more details. These topics include production deployment reports, using XDP as a backend for the P4 language, zero-copy to userspace with AF_XDP, and the use of kernel helpers to evolve the XDP feature set. We also include some performance numbers from the academic paper on XDP that we have co-authored with many of the other XDP developers. In the forward-looking section, we discuss some future developments that we believe would be beneficial to work on going forward. These topics include NIC memory models and DMA mapping; moving SKB allocation out of drivers; the resource allocation around ndo_xdp_xmit; whether it is still realistic to aim for full support of all XDP features in all drivers; and the possibility for adding an XDP egress hook. We are hoping to solicit feedback on these from the wider community during and after LPC.