[Qemu-discuss] "Uhhuh. NMI received for unknown reason" about 10 minutes after reboot

[Thomas]

Hi!

I'm trying to run a Debian testing guest on a Debian testing host.
Se uname -a below for kernel version. Se below for qemu command line.

Everything is working so long. There seems no problem if I cold start
the guest. But the guest has a problem if I reboot it via the 'reboot'
command as root in the guest.
At first the guest reboots just fine and everything is working as
before but after about 10 minutes idleing (at the moment there is not
much installed only ssh) I get the following error messages in the
syslog:

> Message from address@hidden at Dec 31 15:47:23 ...
>  kernel:[  596.984839] Uhhuh. NMI received for unknown reason 20 on CPU 0.
> Message from address@hidden at Dec 31 15:47:23 ...
>  kernel:[  596.985073] Do you have a strange power saving mode enabled?
> Message from address@hidden at Dec 31 15:47:23 ...
>  kernel:[  596.985211] Dazed and confused, but trying to continue

This repeats every thirty seconds and changes only between reason 20
and 30.

> Message from address@hidden at Dec 31 15:47:53 ...
>  kernel:[  626.985591] Uhhuh. NMI received for unknown reason 30 on CPU 0.
> Message from address@hidden at Dec 31 15:47:53 ... 
>  kernel:[  626.985827] Do you have a strange power saving mode enabled?
> Message from address@hidden at Dec 31 15:47:53 ...
>  kernel:[  626.985972] Dazed and confused, but trying to continue

At the moment I do see this only if I use reboot.
My workaround therfore: If I need to reboot, I do a poweroff and cold
start.

I checked with google if someone else has the same problem but found
only questions, no answers. It seems I'm not the only one.
<http://unix.stackexchange.com/questions/327192/unknown-nmi-reason-20-and-30-on-a-vm>
<https://bbs.archlinux.org/viewtopic.php?id=217169>

Do someone know the problem or has ideas for further debuging?

I use the qemu version which is now in testing (se below) and know
there is 2.8 available. I will test it as soon it comes to testing
which will be hopefully in about a week.

Thanks for the help.
Thomas


OUTPUT:
----------------------------------------------------------------
qemu-system-x86_64 --version
============================
QEMU emulator version 2.7.0(Debian 1:2.7+dfsg-3+b1)

----------------------------------------------------------------
uname -a
========
Linux maggi 4.8.0-2-amd64 #1 SMP Debian 4.8.11-1 (2016-12-02) x86_64 GNU/Linux

----------------------------------------------------------------
Command line:
=============
/usr/bin/qemu-system-x86_64 \
    -enable-kvm \
    -machine type=q35 \
    -cpu kvm64 \
    -m 1024 \
    -balloon none \
    -drive file=./anddav_root.img,if=scsi,media=disk \
    -boot order=c \
    -name anddav \
    -vga qxl \
    -spice tls-port=5907,addr=localhost,disable-ticketing,tls-channel=main,tls-channel=display,tls-channel=cursor,tls-channel=inputs,tls-channel=record,tls-channel=playback,x509-dir=./cert \
    -net nic,macaddr=52:54:00:00:02:67 \
    -net tap,ifname=tap3,script=no,downscript=no \
    -monitor unix:./sockets/anddav,server,nowait \
    -usbdevice tablet