Re: [TECH TOPIC] UALink driver upstreaming

[Mimi Zohar <zohar@linux.ibm.com>]

On Wed, 2025-09-10 at 22:37 +0300, Sinyuk, Konstantin wrote:
> Hi All,
> 
> The UALink Consortium is defining an open, vendor‑neutral interconnect aimed
> at scaling AI workloads with low‑latency, memory‑semantic communication
> beyond PCIe. Unlike proprietary solutions such as NVLink (NVIDIA) or
> Infinity Fabric (AMD), UALink is a cross‑vendor standard and was recently
> recognized at FMS 2025.
> 
> I would like to present a proposal on what UALink support could look like in
> the upstream Linux kernel.
> 
> Key areas for discussion:
> - Core driver design: proposed start under drivers/misc/ual/ for discovery,
>   topology, and resource management.
> - Memory semantics: same‑OS and multi‑OS rack scenarios, leveraging dma_buf,
>   HMM, and NUMA.
> - Control path: AUX bus for vendor extensions, offloading real‑time sequences
>   to device microcontrollers, generic UALink interface.
> - Security: confidential compute support and a userspace daemon for topology
>   and authentication.
> - Upstreaming strategy: begin with a minimal core driver, then incrementally
>   extend toward MM integration, dma_buf support, security, and
>   cross‑subsystem work.
> 
> The goal is to decide how UALink should be represented as a first‑class
> interconnect in Linux, complementing CXL while remaining vendor‑neutral,
> ABI‑stable, and maintainable.

Hi Konstantin,

It would be nice to have all the Linux Security Module (LSM) hooks in all the
right places from the beginning for integrity (e.g. signature verification).

thanks,

Mimi