From: Michael Ellerman <mpe@ellerman.id.au>
To: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: "debian-powerpc@lists.debian.org"
<debian-powerpc@lists.debian.org>,
linuxppc-dev@lists.ozlabs.org
Subject: Re: Linux kernel: powerpc: KVM guest can trigger host crash on Power8
Date: Thu, 06 Jan 2022 21:58:05 +1100 [thread overview]
Message-ID: <87ilux2ksi.fsf@mpe.ellerman.id.au> (raw)
In-Reply-To: <fca7cf14-b598-d25a-8f71-8d1c16a84e5f@physik.fu-berlin.de>
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> writes:
> Hi Michael!
>
> Sorry for the long time without any responses. Shall we continue debugging this?
Yes!
Sorry also that I haven't been able to fix it yet, I had to stop chasing
this bug and work on other things before the end of the year.
> We're currently running 5.15.x on the host system and the guests and the testsuite
> for gcc-9 still reproducibly kills the KVM host.
Have you been able to try the different -smp options I suggested?
Can you separately test with (on the host):
# echo 0 > /sys/module/kvm_hv/parameters/dynamic_mt_modes
cheers
> On 11/1/21 07:53, Michael Ellerman wrote:
>> Sure, will give that a try.
>>
>> I was able to crash my machine over the weekend, building openjdk, but I
>> haven't been able to reproduce it for ~24 hours now (I didn't change
>> anything).
>>
>>
>> Can you try running your guests with no SMT threads?
>>
>> I think one of your guests was using:
>>
>> -smp 32,sockets=1,dies=1,cores=8,threads=4
>>
>> Can you change that to:
>>
>> -smp 8,sockets=1,dies=1,cores=8,threads=1
>>
>>
>> And something similar for the other guest(s).
>>
>> If the system is stable with those settings that would be useful
>> information, and would also mean you could use the system without it
>> crashing semi regularly.
>>
>> cheers
> --
> .''`. John Paul Adrian Glaubitz
> : :' : Debian Developer - glaubitz@debian.org
> `. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
> `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
next prev parent reply other threads:[~2022-01-06 10:58 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-25 11:18 Linux kernel: powerpc: KVM guest can trigger host crash on Power8 Michael Ellerman
2021-10-26 8:48 ` John Paul Adrian Glaubitz
2021-10-27 5:29 ` Nicholas Piggin
2021-10-27 5:30 ` Michael Ellerman
2021-10-27 10:03 ` John Paul Adrian Glaubitz
2021-10-27 11:06 ` Michael Ellerman
2021-10-27 11:09 ` John Paul Adrian Glaubitz
2021-10-28 6:39 ` Michael Ellerman
2021-10-28 11:20 ` John Paul Adrian Glaubitz
2021-10-28 14:05 ` John Paul Adrian Glaubitz
2021-10-28 14:15 ` John Paul Adrian Glaubitz
2021-11-01 17:36 ` Michal Suchánek
2021-10-29 0:41 ` Nicholas Piggin
2021-10-29 12:33 ` John Paul Adrian Glaubitz
2021-11-01 17:43 ` Michal Suchánek
2021-10-30 7:19 ` John Paul Adrian Glaubitz
2021-11-01 6:53 ` Michael Ellerman
2021-11-01 7:37 ` John Paul Adrian Glaubitz
2021-11-01 17:20 ` John Paul Adrian Glaubitz
2022-01-04 13:00 ` John Paul Adrian Glaubitz
2022-01-06 10:58 ` Michael Ellerman [this message]
2022-01-07 11:20 ` John Paul Adrian Glaubitz
2022-01-09 22:17 ` John Paul Adrian Glaubitz
2022-01-13 0:17 ` John Paul Adrian Glaubitz
2022-01-26 20:21 ` John Paul Adrian Glaubitz
2022-01-27 15:50 ` Mike
2021-10-28 13:52 ` John Paul Adrian Glaubitz
2021-10-28 14:00 ` John Paul Adrian Glaubitz
2021-10-28 3:58 ` [oss-security] " Salvatore Bonaccorso
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