Re: [PATCH 2/3] kvm: x86/mmu: Ensure TDP MMU roots are freed after yield

[Maciej S. Szmigiero]

On 06.01.2021 18:28, Ben Gardon wrote:
> On Wed, Jan 6, 2021 at 1:26 AM Maciej S. Szmigiero
> <maciej.szmigiero@xxxxxxxxxx> wrote:
> > Thanks for looking at it Ben.
> >
> > On 06.01.2021 00:38, Ben Gardon wrote:
> > (..)
> > > +Sean Christopherson, for whom I used a stale email address.
> > > .
> > > I tested this series by running kvm-unit-tests on an Intel Skylake
> > > machine. It did not introduce any new failures. I also ran the
> > > set_memory_region_test
> >
> > It's "memslot_move_test" that is crashing the kernel - a memslot
> > move test based on "set_memory_region_test".
>
> I apologize if I'm being very dense, but I can't find this test
> anywhere.

No problem, the reproducer is available here:
https://gist.github.com/maciejsszmigiero/890218151c242d99f63ea0825334c6c0
as I stated in my original report.

> Is this something you have in-house but haven't upstreamed
> or just the test_move_memory_region(); testcase from
> set_memory_region_test? I have a similar memslot-moving-stress-test in
> the pipeline I need to send out, but I didn't think such a test
> existed yet and my test hadn't caught this issue.

The reproducer at that GitHub link is taken from my KVM memslot
test mini-set, itself based on set_memory_region_test.c from
KVM selftests.
The full mini-set will be posted as soon as I finish it :)

Thanks,
Maciej