From: Qian Cai <cai@lca.pw>
To: Marco Elver <elver@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
"paul E. McKenney" <paulmck@kernel.org>,
kasan-dev <kasan-dev@googlegroups.com>,
LKML <linux-kernel@vger.kernel.org>,
kvm@vger.kernel.org
Subject: Re: KCSAN + KVM = host reset
Date: Thu, 9 Apr 2020 11:10:28 -0400 [thread overview]
Message-ID: <B7F7F73E-EE27-48F4-A5D0-EBB29292913E@lca.pw> (raw)
In-Reply-To: <CANpmjNMiHNVh3BVxZUqNo4jW3DPjoQPrn-KEmAJRtSYORuryEA@mail.gmail.com>
> On Apr 9, 2020, at 3:03 AM, Marco Elver <elver@google.com> wrote:
>
> On Wed, 8 Apr 2020 at 23:29, Qian Cai <cai@lca.pw> wrote:
>>
>>
>>
>>> On Apr 8, 2020, at 5:25 PM, Paolo Bonzini <pbonzini@redhat.com> wrote:
>>>
>>> On 08/04/20 22:59, Qian Cai wrote:
>>>> Running a simple thing on this AMD host would trigger a reset right away.
>>>> Unselect KCSAN kconfig makes everything work fine (the host would also
>>>> reset If only "echo off > /sys/kernel/debug/kcsan” before running qemu-kvm).
>>>
>>> Is this a regression or something you've just started to play with? (If
>>> anything, the assembly language conversion of the AMD world switch that
>>> is in linux-next could have reduced the likelihood of such a failure,
>>> not increased it).
>>
>> I don’t remember I had tried this combination before, so don’t know if it is a
>> regression or not.
>
> What happens with KASAN? My guess is that, since it also happens with
> "off", something that should not be instrumented is being
> instrumented.
No, KASAN + KVM works fine.
>
> What happens if you put a 'KCSAN_SANITIZE := n' into
> arch/x86/kvm/Makefile? Since it's hard for me to reproduce on this
Yes, that works, but this below alone does not work,
KCSAN_SANITIZE_kvm-amd.o := n
I have been able to reproduce this on a few AMD hosts.
> exact system, I'd ask you to narrow it down by placing 'KCSAN_SANITIZE
> := n' into suspect subsystems' Makefiles. Once you get it to work with
> that, we can refine the solution.
>
> Thanks,
> -- Marco
next prev parent reply other threads:[~2020-04-09 15:10 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-08 20:59 KCSAN + KVM = host reset Qian Cai
2020-04-08 21:25 ` Paolo Bonzini
2020-04-08 21:29 ` Qian Cai
2020-04-09 7:03 ` Marco Elver
2020-04-09 15:10 ` Qian Cai [this message]
2020-04-09 15:22 ` Marco Elver
2020-04-09 15:30 ` Qian Cai
2020-04-09 16:03 ` Marco Elver
2020-04-09 21:28 ` Qian Cai
2020-04-09 23:00 ` Qian Cai
2020-04-10 9:47 ` Marco Elver
2020-04-10 11:25 ` Qian Cai
2020-04-10 11:35 ` Marco Elver
2020-04-10 15:50 ` Qian Cai
2020-04-10 16:04 ` Paolo Bonzini
2020-04-10 16:06 ` Sean Christopherson
2020-04-10 19:57 ` Qian Cai
2020-04-13 8:35 ` Marco Elver
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