On Thu, Aug 22, 2013 at 03:09:06PM -0500, Anthony Liguori wrote: > Paolo Bonzini <pbonzini@xxxxxxxxxx> writes: > > Also, a virtio watchdog device makes little sense, IMHO. PV makes sense > > if emulation has insufficient performance, excessive CPU usage, or > > excessive complexity. We already have both an ISA and a PCI watchdog, > > and they serve their purpose wonderfully. > > Neither of which actually work with modern versions of Windows FWIW. Correct, although someone could write a driver! > Plus emulated watchdogs do not take into account steal time or > overcommit in general. I've seen multiple cases where a naive watchdog > has a problem in the field when the system is under heavy load. The watchdog devices in qemu run on guest time. However the watchdog *daemon* inside the guest probably does behave badly as you describe. Changing the device model isn't going to help this, but it would definitely make sense to fix the daemon (although I don't know how -- is steal time exposed to guests?) I don't necessarily think a virtio-watchdog is a bad idea. For one thing it'd mean we would have a watchdog device that works on ARM. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list