Hello netdev, XDP (eXpress Data Path) is a high performance, programmable network data path that is being developed as a community effort (initially within IO-visor). XDP will be useful for packet processing in forwarding, load balancing, DOS mitigation, firewalls, etc. See https://github.com/iovisor/bpf-docs/blob/master/Express_Data_Path.pdf for a description.
To achieve high performance, XDP runs as a thin layer at this lowest levels of the stack with minimal infrastructure. For instance, in Linux, XDP runs directly of the device drivers and operates directly on receive buffers and an abstracted receive descriptor instead of skbufs. XDP does not require specialized hardware, but does allow leveraging various advanced HW features. Programmability in XDP is provided by BPF, a small set of helper functions, and a well defined input-output API. XDP is intended to be platform agnostic following the principle of "write once, run anywhere", so we are expecting that XDP programs can run in the OS (Linux and others), HW (via offload), or in userspace (over DPDK for instance). We have made some good progress in the Linux implementation and are able to demonstrate single CPU packet drop performance in excess of 14M pps, and packet forwarding in excess of 10M pps. Work on real world use cases is commencing-- L4 load balancer, DOS mitigation, and an ILA router. We hope to have patches posted and a more detailed introduction of XDP for netdev 1.2. If you are interested in XDP development and discussion please join the iovisor-dev mailing list. Also, we will be holding an XDP summit on June 23-- if you are actively working on XDP right now, or believe that work on XDP is imminent, please contact me about an invitation. Thanks, Tom
