Re: [GIT PULL] KVM (mostly s390) fixes for Linux 7.2-rc7

[Tycho Andersen <tycho@kernel.org>]

On Mon, Aug 10, 2026 at 02:30:12PM -0700, Yosry Ahmed wrote:
> On Fri, Aug 7, 2026 at 10:43 PM Paolo Bonzini <pbonzini@redhat.com> wrote:
> >
> > Il sab 8 ago 2026, 00:39 Sean Christopherson <seanjc@google.com> ha scritto:
> > > On Fri, Aug 07, 2026, Paolo Bonzini wrote:
> > > > I consider two weeks of wait, on a review that so far had been
> > > > exclusively about taste, to *be* an honest attempt to gather the next
> > > > round of feedback (which never came).
> > >
> > > Heh, and I was waiting for a response to Yosry's thread:
> > > https://lore.kernel.org/all/CAO9r8zODKgCcjTBK=P6BuXBBZRoOAFMeRJU8BmkWL-BCX2LoBw@mail.gmail.com
> >
> > Heh^2, "Pick your poison, I guess" was not really inviting a response.
> > Overall the sense of my reply to you (that is: there are two callers
> > so let's not overthink wrappers) applied just as much to his message;
> > and checking AMD vs. Intel in common code is a total no-no so I kept
> > the reply in one place.
> 
> Aside from the code itself, I was really hoping for a better
> understanding of the problem, and answers from AMD/Hyper-V folks if
> possible.
> 
> Basically:
> 
> (a) Is INVLPGA intended to be used with NPT enabled to flush GVA
> translations on behalf of the guest?
> 
> I assume the answer is yes, and something is broken. But if the answer
> is no, then we shouldn't be looking any further and the fix proposed
> by you/Sean is correct regardless.

I think the answer here is "no", but we would like to introduce a
slightly different fix.

In terms of my reproducing, I may have been doing it this whole time:
Alexander's ssh script for liveness checking was working, but the
uptimes of some of the VMs are different, suggesting that BSODs were
happening along with automatic reboots. I'll see if I can get windows
to stop doing that.

I'm also about to go out of office for a while (kid++), so adding
Boris and Tom to the thread.

Thanks,

Tycho