Subject: fbnic qemu is open source

From: Jakub Kicinski <[email-masked]>
Date: Mon, 9 Mar 2026 11:38:52 -0700

Hi!

The fbnic QEMU repo is now open source and available at:

https://github.com/facebook/fbnic_qemu

It contains the emulated datapath for the fbnic device, the FW
components are not included (PHY programming, NC-SI, init, sensors 
and such). 

The main practical use I imagine is being able to test TCP Rx zero
copy (kernel and/or user space) without any HW dependency.
There's work on adding relevant features to virtio but it's going 
a little slowly. Also being able to test code and selftests with 
a more "real" device than netdevsim with vng is super convenient :)

Big thanks to Zinc Lim for the open source heavy lifting (isolating 
and mocking out the FW parts, cleaning up the code base and getting 
it thru corporate reviews).

No plans at this stage to upstream it to QEMU because TBH I don't
expect that QEMU would care to carry random HW emulation drivers.

Sorry if the announcement is a bit self-serving but folks expressed
interest off list in being able to test the queue API and zero-copy 
Rx without real HW so I thought it's relevant.