[libvirt] [PATCH] [DRAFT] handle qemu event GUEST_PANICKED

[Daniel P. Berrange]

On Thu, Oct 25, 2012 at 04:04:23PM +0800, Hu Tao wrote:
> This is for early review, comments are welcome!
> 
> qemu is adding a method to detect guest panic, and a new event
> GUEST_PANICKED[1]. This patch adds support for GUEST_PANICKED.
> 
> But I have two questions:
> 
>   -  to react to GUEST_PANICKED, can xml element <on_crash> be
>      used as the action to take, or do I have to invent another
>      xml element to configure the action?

Using <on_crash> is the right thing todo, since that matches what
we do with Xen.

> 
>   -  Currently libvirt relies on watchdog to detect guest panic,
>      but this way is not that reliable(there has to be a watchdog
>      device, the watchdog itself has to be working when panic occurs),
>      so it seems to be appropriate to remove this method from libvirt
>      as there is a better one. But, will the removal cause any problems,
>      such as backward compatibility, user confusion, etc.?

I don't think we need to touch the watchdog code at all. Not all
guest OS will support this new GUEST_PANICKED event, while they
probably do have drivers for the watchdog devices. So it is
perfectly ok to have both the panick event and the watchdog events
available. Mgmt apps can decide which to use as they see fit.

Regards,
Daniel
-- 
|: http://berrange.com      -o-    http://www.flickr.com/photos/dberrange/ :|
|: http://libvirt.org              -o-             http://virt-manager.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: http://entangle-photo.org       -o-       http://live.gnome.org/gtk-vnc :|