I will give brief idea about the topic and will guide you to the Urls which include more details about this:
With this new feature, a virtual hardware watchdog device can be added to the guest via the the “devices” configuration. And only one watchdog device is supported for each VM.
When a watchdog device is active and take action, the vdsm will log this event.
The watchdog device requires an additional driver and management daemon in the guest. Just enabling the watchdog in the vdsm “devices” configuration does not do anything useful on its own.
This device can be configured in different modes like ,
The watchdog device can be used to detect guest crash or hang, and if ‘dump’ is chosen for the action of watchdog timeout, libvirt will dump guest’s memory on timeout automatically. And the directory to save dump files can be configured by auto_dump_path in file /etc/libvirt/qemu.conf.
Now, please go through the demo of this feature here:
More details are available at:
Libvirt support of watchdog device : libvirt