Hello everyone, We had our first official meeting of the BPF working group at IETF 117 on Monday in San Francisco. The meeting was very productive, so thank you to all those who attended and participated. We're excited to continue making progress on standardizing BPF with the IETF, and hopefully we can carry forward the momentum of the conference as we iterate on the many topics that were discussed. The meeting can be viewed in its entirety on YouTube at [0], and the meeting minutes can be accessed at [1]. A special thank you to those who collected notes, and to the presenters. [0]: https://www.youtube.com/watch?v=jTtPbJqfYwI [1]: https://notes.ietf.org/notes-ietf-117-bpf Meeting Recap ------------- Let's go over some of the highlights from the meeting: 1. Issue Tracker The WG expressed interest in using an issue tracker to ensure that any points that have been raised for discussion are properly tracked. A few different options were proposed, with the final rough consensus being that the chairs would pick an issue tracker and workflow for the WG. We'll get to work on this once the conference has concluded, and will notify you when we have everything setup. 2. eBPF Instruction Set Verification I-D called for adoption A call for adoption took place for Dave Thaler's eBPF Instruction Set Verification I-D [2]. [2]: https://datatracker.ietf.org/doc/draft-thaler-bpf-isa/ Rough consensus was obtained at the meeting, and we'll follow up with a formal call for adoption on the email list in the near future. There are already some reviews and discussions following the meeting, which is great to see. Please keep the reviews coming! 3. ISA Extension Policy Dave Thaler led a discussion on what the policy should be for extending the BPF Instruction Set Architecture (ISA) for future instructions which are added after the initial ISA standard document is ratified. The slides for this discussion can be found in [3]. [3]: https://datatracker.ietf.org/meeting/117/materials/slides-117-bpf-isa-extension-policy-03.pdf We covered a lot of ground in this discussion, but we need to close the loop on a few things such as whether the registry should be in the IANA or the Linux kernel tree, what type of ISA registration policy to use, etc. 4. All things ABI We discussed ABI and BPF program interoperability in a number of different contexts. Will Hawkins presented the slides in [4], and indicated that he had begun work on an ABI document that he would send to the bpf@xxxxxxxx and bpf@xxxxxxxxxxxxxxx lists sometime in the near future. [4]: https://datatracker.ietf.org/meeting/117/materials/slides-117-bpf-abi-00.pdf Dave Thaler also presented on a topic related to ABI: the eBPF ELF Profile Specification. The slides can be found in [5]. In Dave's presentation, he pointed out that the btf.rst document [6] currently has an "ELF File Format Interface" section that should likely be moved into a separate document such as elf.rst. This is also the case for instruction-set.rst, as mentioned in the thread in [7]. [5]: https://datatracker.ietf.org/meeting/117/materials/slides-117-bpf-elf-profile-specification-00.pdf [6]: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/tree/Documentation/bpf/btf.rst [7]: https://mailarchive.ietf.org/arch/msg/bpf/-NrwjA_6EHQ8y83cMZZGzbT8-wc/ We agreed that the next step would be to move these ABI sections out of any document that we're expecting to be a Proposed Standard, and into one or more separate .rst files. While our immediate focus is on the ISA document, getting a head-start on the ABI document(s) seems prudent if folks have the bandwidth. Closing Thoughts ---------------- Overall, the meeting seemed to go very well. We're still in the process of learning how to effectively collaborate between the IETF and Linux kernel communities, but it's encouraging to see the progress being made on the ABI doc(s), and especially the ISA doc. Thank you everyone for being patient as we navigate everything, and for setting a respectful and collaborative tone for our WG. That said, if anyone is finding the arrangement difficult or has feedback of any kind, please feel free to reach out to us at bpf-chairs@xxxxxxxx so we can help. Lastly, we're excited to mention that the first ACM SIGCOMM workshop on eBPF and Kernel Extensions will be taking place on September 10, 2023 at Columbia University in New York, NY. The list of accepted papers [8] looks very interesting, so consider attending if you'd like to learn more about BPF, and see what kind of BPF-related research is taking place. [8]: https://conferences.sigcomm.org/sigcomm/2023/workshop-ebpf.html Regards, David and Suresh
