Assertion failure in qemu-char.c

Assertion failure in qemu-char.c

[Wesley Holevinski]

Hi all,

I'm running into an issue that's causing my guests to crash while using vm-channels.  There is an assertion that's failing in qemu-char.c, that, when it happens causes my guest to go down.  The error can be seen in the host-side logs.

Rather than being too wordy on-list, here's a link to a bug I opened against qemu-kvm: https://bugs.launchpad.net/qemu/+bug/1268671

I apologize if this isn't the right list for this, but I'm trying to get more eyes on this since guests crashing seems like a critical issue IMO.

Also take note of the comment in the source; there is a comment about how the snippet of code that's failing exists because of a bug in glib.  Can anyone provide more info on that glib bug?

Thanks,
Wes H

Re: Assertion failure in qemu-char.c

[Paolo Bonzini]

Il 20/01/2014 13:37, Wesley Holevinski ha scritto:
> 
> Hi all,
> 
> I'm running into an issue that's causing my guests to crash while
> using vm-channels. There is an assertion that's failing in qemu-char.c,
> that, when it happens causes my guest to go down. The error can be seen
> in the host-side logs.
> 
> Rather than being too wordy on-list, here's a link to a bug I opened
> against qemu-kvm: https://bugs.launchpad.net/qemu/+bug/1268671

Unfortunately, RHEL/CentOS support is not provided by these mailing
lists.  RHEL/CentOS backport features on top of old versions of QEMU,
and thus it is quite hard to provide support here.

You also aren't describing if doing anything specifically will cause the
crash.

As an initial step, you could download QEMU 1.7 and try to reproduce the
bug there.  That would help.

> I apologize if this isn't the right list for this, but I'm trying to
> get more eyes on this since guests crashing seems like a critical issue IMO.
> 
> Also take note of the comment in the source; there is a comment about
> how the snippet of code that's failing exists because of a bug in
> glib.  Can anyone provide more info on that glib bug?

You can find some information at
https://bugzilla.gnome.org/show_bug.cgi?id=626702#c6.

Paolo

Re: [Qemu-devel] Assertion failure in qemu-char.c

[Paolo Bonzini]

Il 20/01/2014 13:37, Wesley Holevinski ha scritto:
> 
> Hi all,
> 
> I'm running into an issue that's causing my guests to crash while
> using vm-channels. There is an assertion that's failing in qemu-char.c,
> that, when it happens causes my guest to go down. The error can be seen
> in the host-side logs.
> 
> Rather than being too wordy on-list, here's a link to a bug I opened
> against qemu-kvm: https://bugs.launchpad.net/qemu/+bug/1268671

Unfortunately, RHEL/CentOS support is not provided by these mailing
lists.  RHEL/CentOS backport features on top of old versions of QEMU,
and thus it is quite hard to provide support here.

You also aren't describing if doing anything specifically will cause the
crash.

As an initial step, you could download QEMU 1.7 and try to reproduce the
bug there.  That would help.

> I apologize if this isn't the right list for this, but I'm trying to
> get more eyes on this since guests crashing seems like a critical issue IMO.
> 
> Also take note of the comment in the source; there is a comment about
> how the snippet of code that's failing exists because of a bug in
> glib.  Can anyone provide more info on that glib bug?

You can find some information at
https://bugzilla.gnome.org/show_bug.cgi?id=626702#c6.

Paolo

RE: Assertion failure in qemu-char.c

[Wesley Holevinski]

> You also aren't describing if doing anything specifically will cause the
> crash.

Sorry, I've yet to narrow down the exact case that's causing it.  Basically, it's constant use of the vm-channel; I have a binary that will write to the character device at an interval.  If I leave it running with my custom component, it will eventually die with the same backtrace.  I figured providing a core dump would be a good start.

> As an initial step, you could download QEMU 1.7 and try to reproduce the
> bug there.  That would help.

I'll see what I can do with this...I'm assuming getting 1.7 to build against CentOS/RHEL 6.5 will be non-trivial though.  I'll give it a go.

Wes

Re: [Qemu-devel] Assertion failure in qemu-char.c

[Wesley Holevinski]

> You also aren't describing if doing anything specifically will cause the
> crash.

Sorry, I've yet to narrow down the exact case that's causing it.  Basically, it's constant use of the vm-channel; I have a binary that will write to the character device at an interval.  If I leave it running with my custom component, it will eventually die with the same backtrace.  I figured providing a core dump would be a good start.

> As an initial step, you could download QEMU 1.7 and try to reproduce the
> bug there.  That would help.

I'll see what I can do with this...I'm assuming getting 1.7 to build against CentOS/RHEL 6.5 will be non-trivial though.  I'll give it a go.

Wes