Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 28 Apr 2022 17:43:16 +0000
From:   Sean Christopherson <seanjc@google.com>
To:     Maxim Levitsky <mlevitsk@redhat.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        syzbot <syzbot+a8ad3ee1525a0c4b40ec@syzkaller.appspotmail.com>,
        bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com,
        jmattson@google.com, joro@8bytes.org, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, mingo@redhat.com,
        syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
        vkuznets@redhat.com, wanpengli@tencent.com, x86@kernel.org
Subject: Re: [syzbot] WARNING in kvm_mmu_uninit_tdp_mmu (2)
Message-ID: <YmrSNB83b5sKLocw@google.com>
References: <00000000000082452505dd503126@google.com>
 <13b3235ef66f22475fd4059df95ad0144548ccd1.camel@redhat.com>
 <YmqzoFqdmH1WuPv0@google.com>
 <d1e4eaba-2dcd-ec08-4e23-98ab8ea6c37b@redhat.com>
 <47eb853424ef6c7dd6439ac33dfeb64a29f49c44.camel@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <47eb853424ef6c7dd6439ac33dfeb64a29f49c44.camel@redhat.com>
Precedence: bulk

On Thu, Apr 28, 2022, Maxim Levitsky wrote:
> On Thu, 2022-04-28 at 19:22 +0200, Paolo Bonzini wrote:
> > On 4/28/22 17:32, Sean Christopherson wrote:
> > > On Tue, Apr 26, 2022, Maxim Levitsky wrote:
> > > > I can reproduce this in a VM, by running and CTRL+C'in my ipi_stress test,
> > > 
> > > Can you post your ipi_stress test?  I'm curious to see if I can repro, and also
> > > very curious as to what might be unique about your test.  I haven't been able to
> > > repro the syzbot test, nor have I been able to repro by killing VMs/tests.
> > 
> > Did you test with CONFIG_PREEMPT=y?
> 
> yes, I test with CONFIG_PREEMPT but I only enabled it a day ago,
> I think I had seen this warning before, but could bit, I'll check
> if that fails without CONFIG_PREEMPT as well.

I have not tested with CONFIG_PREEMPT.  For some unknown reason the syzbot configs
don't play nice with my VM setup and so I never use them verbatim.  I didn't think
to pull over CONFIG_PREEMPTY.  I'll give that a shot.