All of lore.kernel.org
 help / color / mirror / Atom feed
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

  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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87ilux2ksi.fsf@mpe.ellerman.id.au \
    --to=mpe@ellerman.id.au \
    --cc=debian-powerpc@lists.debian.org \
    --cc=glaubitz@physik.fu-berlin.de \
    --cc=linuxppc-dev@lists.ozlabs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.