libvirt users - Mar 2022 - "default" watchdog device - ?

Hi guys.

Without explicitly, manually using watchdog device for a VM, 
the VM (centOS 8 Stream 4.18.0-365.el8.x86_64) shows 
'/dev/watchdog' exists.
To double check - 'dumpxml' does not show any such device - 
what kind of a 'watchdog' that is?
watchdog-5.15-2.el8.x86_64 on such a VM does not seem to do 
anything with it.

Host is centOS 9 with: qemu-img-6.2.0-11.el9.x86_64 
libvirt-daemon-8.0.0-5.el9.x86_64

many thanks, L.

On Tue, Mar 15, 2022 at 10:39:50AM +0000, lejeczek
wrote:
> Hi guys.
> 
> Without explicitly, manually using watchdog device for a VM, the VM (centOS
> 8 Stream 4.18.0-365.el8.x86_64) shows '/dev/watchdog' exists.
> To double check - 'dumpxml' does not show any such device - what
kind of a
> 'watchdog' that is?
The kernel can always provide a pure software watchdog IIRC. It can be
useful if a userspace app wants a watchdog. The limitation is that it
relies on the kernel remaining functional, as there's no hardware
backing it up.

Regards,
Daniel
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