Date:   Thu, 9 Dec 2021 01:37:04 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Maxim Levitsky <mlevitsk@redhat.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Joerg Roedel <joro@8bytes.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
        kvm@vger.kernel.org, iommu@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 00/26] KVM: x86: Halt and APICv overhaul
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References: <20211208015236.1616697-1-seanjc@google.com>
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 <8c6c38f3cc201e42629c3b8e5cf8cdb251c9ea8d.camel@redhat.com>
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On Thu, Dec 09, 2021, Maxim Levitsky wrote:
> On Thu, 2021-12-09 at 01:00 +0200, Maxim Levitsky wrote:
> > Probably just luck (can't reproduce this anymore) but
> > while running some kvm unit tests with this patch series (and few my patches
> > for AVIC co-existance which shouldn't affect this) I got this
> > 
> > (warning about is_running already set)

...
 
> Also got this while trying a VM with passed through device:

A tangentially related question: have you seen any mysterious crashes on your AMD
system?  I've been bisecting (well, attempting to bisect) bizarre crashes that
AFAICT showed up between v5.15 and v5.16-rc2.  Things like runqueues being NULL
deep in the scheduler when a CPU is coming out of idle.  I _think_ the issues have
been fixed as of v5.16-rc4, but I don't have a good reproducer so bisecting in
either direction has been a complete mess.  I've reproduced on multiple AMD hosts,
but never on an Intel system.  I have a sinking feeling that the issue is
relatively unique to our systems :-/

And a request: any testing and bug fixes you can throw at the AVIC changes would be
greatly appreciated.  I've been partially blocked on testing the AVIC stuff for the
better part of the week.  If the crashes I'm seeing have been resolved, then I should
be able to help hunt down the issues, but if not...