#1106713 sbuild: How bind a charactere device in unshare

Package:
sbuild
Source:
sbuild
Submitter:
Picca Frédéric-Emmanuel
Date:
2025-05-29 17:59:02 UTC
Severity:
normal
#1106713#5
Date:
2025-05-28 11:03:10 UTC
From:
To:
Dear Maintainer,

Hello, we are trying to run autopkgtest with a computer with and AMD GPU card.

so the idea is to implement OpenCL test on real hardware.

In order to run these test the hardware should be available in the unshare backend.

for this the /dev/dri and /dev/kfd must be available.

I discuss about this here[1] with the guyes in charge of the rocm stack.

I would like to know if you could help and make sbuild work out of the box in our case

for now I do not know if there is an sbuild configuration that could help fixing this...

thanks for considering.

Frederic

[1] https://lists.debian.org/debian-science/2025/05/msg00029.html
#1106713#10
Date:
2025-05-29 03:47:50 UTC
From:
To:
Hi Frederic,

* Picca Frédéric-Emmanuel <picca@debian.org> [2025-05-28 13:03]:

sbuild only calls autopkgtest, so reassigning to autopkgtest
accordingly.

Why in the unshare backend?

Unlikely it is meant to provide some form of isolation and not expose
hardware. I guess one of the other autopkgtest backends would be a
better fit.

Once it is working with autopkgtest, coming up with an sbuild config
should be easy.

Cheers Jochen
#1106713#19
Date:
2025-05-29 07:30:37 UTC
From:
To:
Jochen Sprickerhof <jspricke@debian.org> writes:

Hello Joshen

because it is the sbuild prefered backend now. I try to stick to the
sbuild default so when I run sbuild it use unshare with autopkgtest.

the rocm peoples are already proposing specific backend with podman or
docker, but nothing for unshare.

Do we have someone in Debian which know unsahre enought in order to
explain what is possible and what is not with this backend ?

yes :)


Cheers

Fred
#1106713#24
Date:
2025-05-29 11:24:01 UTC
From:
To:
Am 29. Mai 2025 10:30:37 OESZ schrieb picca <picca@debian.org>:

That is only because it needs no setup. We will likely switch to this once it is there:

<https://salsa.debian.org/ci-team/autopkgtest/-/merge_requests/515>

Note that the unshare backend is rather minimal on purpose. It fits for a lot of tests but for others podman may be a better fit.

Cheers Jochen
#1106713#29
Date:
2025-05-29 17:12:42 UTC
From:
To:
  (1) sbuild's unshare backend for build-time stuff, distinct from
      the autopkgtest backend (right?)
  (2) sbuild calling autopkgtest after a completed build.

This seems to be about (2).

Regarding that, I was independently working on this a while ago and
pushed my draft implementation here [1]. This is definitely not
complete. Apart from not handling any device not directly below /dev
and missing much other validation, this will almost certainly not work
with autopkgtests for the reason listed at the very end of [2].

I don't think I can work on this before DebConf. The rootless podman
backend is just as easy to use and provides a simple workaround.

Best,
Christian

[1]: https://salsa.debian.org/ckk/autopkgtest/-/tree/unshare-bind-dev
[2]: https://lists.debian.org/debian-science/2025/05/msg00029.html