Support for v1model architecture (or PSA)

[smolkaj]

I am considering adding support for the V1model architecture (whose BMv2 implementation documented here) to x4c. (And/or maybe PSA, if that makes a difference.)

Would upstream be open to accept support for v1model/PSA, or would I need to maintain a separate fork of x4c?

A bit more context: At Google, we currently use BMv2 + v1model as a reference model that we test our hardware switches against (see eg https://www.youtube.com/watch?v=qVohRRgRuvo for more details). I am exploring using x4c as a soft switch/reference model as an alternative to BMv2. I suspect that x4c may be easier to extend and maintain and may offer better performance.

[rcgoodfellow]

Hey @smolkaj. Yeah support for PSA would be welcome. I think it will be a fairly significant chunk of work to get there. Things that jump out immediately are

• Adding support for annotations
• Implementation of the externs in v1model.p4
• Generating pipelines for architecture packages beyond SoftNPU.

We've also been kicking around the idea of adding support for TNA so we can more closely emulate Tofino 2 switches. Seems likely there will be an XNA for the Xsight X2 at some point as well.