18–20 Sept 2024
Europe/Vienna timezone

Session

RISC-V MC

19 Sept 2024, 15:00

Description

We are excited to propose the next edition of the RISC-V micro conference to be held during the Plumbers Conference in 2024. This event has consistently served as a pivotal gathering for developers, enthusiasts, and stakeholders in the RISC-V ecosystem, especially those focused on its integration and evolution within the Linux environment. Broadly speaking anything related to both Linux and RISC-V is on topic, but discussion tend to involve the following categories:

  • How to support new RISC-V ISA features in Linux mainly vendor-specific extensions.
  • Discussions related to RISC-V based SOCs, which frequently include interactions with other Linux subsystems as well as core arch/riscv code.
  • Coordination with distributions and toolchains on userspace-visible behavior.

Possible Topics

The actual list of topics tends to be hard to pin down this early, but here's a few topics that have been floating around the mailing lists and may be easier to resolve real-time:

  • Unified discovery - What to do with this ? RVI spec which has little use in kernel land
  • Control-flow integrity on RISC-V kernel.
  • Hardware breakpoints / watchpoints
  • OPTEE preemption model (interrupt delivery)
  • riscv64 text patching w/o stop_machine()
  • RISCV kernel control flow integrity
  • non-PCI MSI capable devices in ACPI
  • Napot
  • BULTIN_DTB

Key Stakeholders

Apologies if I've missed anyone, but I've tried to list a handful of the people who frequently show up and help drive discussions at the RISC-V microconferences we've held at past Plumbers:

Regular RISC-V contributors/maintainers (I probably forgot few more)

  • Palmer Atish Anup Conor Sunil Bjorn Alex Clement Andrew
  • Soc stakeholders (Arnd, Conor, Heiko, Emil: There are many new SOC families showing up with RISC-V ports, and much of the new)
  • We usually have attendance from a handful of the arm/arm64/ppc/mips/loongarch contributors/maintainers, as we share a lot of code and thus find many cross-arch issues. There's probably going to be even more now that we've got many shared SOC families.
  • Carlos/Nick: Due to the nature of RISC-V we end up with many complicated toolchain interactions, so it's always good to have some time to discuss toolchain topics.

Accomplishments post 2023 Microconference

  • All the talks at the 2023 Plumbers microconference have made at least some progress, with many of them resulting in big chunks of merged code. Specifically:
  • Futile attempt to deprecate nommu after agreement in RISC-V MC :) [1]
  • In fact, More support for nommu landed as a result of that discussion :[2]
  • Perf feature improvement patches under discussion in lore [3]
  • Good progress on supervisor software events [4] and more use cases (CFI, double trap)
  • Kernel mode vector support merged[5]

[1] https://lore.kernel.org/lkml/a49546e8-6749-4458-98da-67fd37b7df18@rivosinc.com/
[2] https://lore.kernel.org/lkml/20240325164021.3229-1-jszhang@kernel.org/
[3] https://lore.kernel.org/lkml/20240217005738.3744121-1-atishp@rivosinc.com/
[4] https://lore.kernel.org/lkml/20240112111720.2975069-1-cleger@rivosinc.com/
[5] https://lore.kernel.org/all/20240115055929.4736-3-andy.chiu@sifive.com/t/#m1d48afa31c6040e4433cbf3bae2de998ae2ca112

Presentation materials

ATISH PATRA (Rivos), Palmer Dabbelt (Google)
19/09/2024, 15:00
Building timetable...