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Date: Mon, 1 Nov 2021 18:43:22 +0100
From: Michal =?iso-8859-1?Q?Such=E1nek?= <msuchanek@suse.de>
To: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Subject: Re: Linux kernel: powerpc: KVM guest can trigger host crash on Power8
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Cc: "debian-powerpc@lists.debian.org" <debian-powerpc@lists.debian.org>,
 linuxppc-dev@lists.ozlabs.org, Nicholas Piggin <npiggin@gmail.com>
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On Fri, Oct 29, 2021 at 02:33:12PM +0200, John Paul Adrian Glaubitz wrote:
> Hi Nicholas!
> 
> On 10/29/21 02:41, Nicholas Piggin wrote:
> > Soft lockup should mean it's taking timer interrupts still, just not 
> > scheduling. Do you have the hard lockup detector enabled as well? Is
> > there anything stuck spinning on another CPU?
> 

> 
> > Could you try a sysrq+w to get a trace of blocked tasks?
> 
> Not sure how to send a magic sysrequest over the IPMI serial console. Any idea?

As on any serial console sending break should be equivalent to the magic
sysrq key combo.

https://tldp.org/HOWTO/Remote-Serial-Console-HOWTO/security-sysrq.html

With ipmitool break is sent by typing ~B

https://linux.die.net/man/1/ipmitool

Thanks

Michal