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

[Shuah Khan <skhan@linuxfoundation.org>]

On 8/18/25 13:37, Alex Williamson wrote:
> On Mon, 18 Aug 2025 11:59:39 -0700
> David Matlack <dmatlack@google.com> wrote:
> 
>> On Thu, Jul 31, 2025 at 1:55 PM David Matlack <dmatlack@google.com> wrote:
>>>
>>> On Tue, Jul 29, 2025 at 3:26 PM Jason Gunthorpe <jgg@nvidia.com> wrote:
>>>>
>>>> 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:
>>>>>> 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.
>>>
>>> They have been quite useful already within Google. Internally we have
>>> something almost identical to the RFC and have been using that for
>>> testing our 6.6-based kernel continuously since March. Already they
>>> have caught one (self-inflicted) regression where 1GiB HugeTLB pages
>>> started getting mapped with 2MiB mappings in the IOMMU, and have been
>>> very helpful with new development (e.g. Aaron's work, and Live Update
>>> support).
>>>
>>> So I agree, it's probably net positive to merge early and then iterate
>>> in-tree. Especially since these are only tests and not e.g.
>>> load-bearing kernel code (although I still want to hold a high bar for
>>> the selftests code).
>>>
>>> The only patches to hold off merging would be 31-33, since those
>>> should probably go through the KVM tree? And of course we need Acks
>>> for the drivers/dma/{ioat,idxd} changes, but the changes there are
>>> pretty minor.
>>
>> Alex, how would you like to proceed?
> 
> I think we need an ack from Shuah for the overall inclusion in
> tools/testing/selftests/

Acked-by: Shuah Khan <skhan@linuxfoundation.org>

Glad to see these test in the kselftest suite.

> 
> AFAICT the tools include files don't seem to have any central
> authority, so maybe we just need to chase those ioat/idxd acks, along
> with Shuah's and we can get this rolling and follow-up with the latter
> KVM patches once the base is merged.  Thanks,
> 

thanks,
-- Shuah