Re: [PATCH 00/33] vfio: Introduce selftests for VFIO

[Jason Gunthorpe <jgg@nvidia.com>]

On Mon, Jul 28, 2025 at 10:27:37AM -0600, Alex Williamson wrote:
> On Fri, 25 Jul 2025 09:47:48 -0700
> David Matlack <dmatlack@google.com> wrote:
> 
> > On Fri, Jun 20, 2025 at 4:21 PM David Matlack <dmatlack@google.com> wrote:
> > >
> > > This series introduces VFIO selftests, located in
> > > tools/testing/selftests/vfio/.  
> > 
> > Hi Alex,
> > 
> > I wanted to discuss how you would like to proceed with this series.
> > 
> > The series is quite large, so one thing I was wondering is if you
> > think it should be split up into separate series to make it easier to
> > review and merge. Something like this:
> > 
> >  - Patches 01-08 + 30 (VFIO selftests library, some basic tests, and run script)
> >  - Patches 09-22 (driver framework)
> >  - Patches 23-28 (iommufd support)
> >  - Patches 31-33 (integration with KVM selftests)
> > 
> > I also was curious about your thoughts on maintenance of VFIO
> > selftests, since I don't think we discussed that in the RFC. I am
> > happy to help maintain VFIO selftests in whatever way makes the most
> > sense. For now I added tools/testing/selftests/vfio under the
> > top-level VFIO section in MAINTAINERS (so you would be the maintainer)
> > and then also added a separate section for VFIO selftests with myself
> > as a Reviewer (see PATCH 01). Reviewer felt like a better choice than
> > Maintainer for myself since I am new to VFIO upstream (I've primarily
> > worked on KVM in the past).
> 
> Hi David,
> 
> There's a lot of potential here and I'd like to see it proceed.  

+1 too, I really lack time at the moment to do much with this but I'm
half inclined to suggest Alex should say it should be merged in 6
weeks (to motivate any reviewing) and we can continue to work on it
in-tree.

As they are self tests I think there is alot more value in having the
tests than having perfect tests.

> Something that we should continue to try to improve is the automation.
> These tests are often targeting a specific feature, so matching a
> device to a unit test becomes a barrier to automated runs.  I wonder if
> we might be able to reach a point where the test runner can select
> appropriate devices from a pool of devices specified via environment
> variables.

Makes a lot of sense to me!

I'd just put Dave as the VFIO selftest co-maintainer though - a
pennance for doing so much work :)

Jason