Re: [PATCH] KVM: selftests: Enable USERFAULTFD

[Oliver Upton <oliver.upton@linux.dev>]

On Mon, Feb 06, 2023 at 06:15:16PM +0000, Sean Christopherson wrote:
> On Mon, Feb 06, 2023, Oliver Upton wrote:
> > +cc x86, riscv as they're also affected.
> > 
> > On Thu, Feb 02, 2023 at 09:01:36PM +0000, Mark Brown wrote:
> > > The page_fault_test KVM selftest requires userfaultfd but the config
> > > fragment for the KVM selftests does not enable it, meaning that those tests
> > > are skipped in CI systems that rely on appropriate settings in the config
> > > fragments except on S/390 which happens to have it in defconfig. Enable
> > > the option in the config fragment so that the tests get run.
> 
> What do CI systems do for HugeTLB and THP?  Those are the other config options I
> can think of where there are very interesting interactions from a KVM perspective,
> but where KVM doesn't have a strict dependency on the feature.
> 
> E.g. x86_64_defconfig selects CONFIG_HUGETLBFS=y, but I don't see anything for THP,
> and AFAICT TRANSPARENT_HUGEPAGE is default=n.

Looks like arm64 defconfig enables THP and hugetlb. Regardless, I think
it would be valuable if our Kconfig fragment expressed the options that
buy us additional code coverage.

--
Thanks,
Oliver