Sebastian, On Tue, Apr 05, 2022 at 02:19:55PM +0000, Sebastian Ene wrote: > This patch adds support for a virtual watchdog which relies on the > per-cpu hrtimers to pet at regular intervals. > The watchdog subsystem is not intended to detect soft and hard lockups. It is intended to detect userspace issues. A watchdog driver requires a userspace compinent which needs to ping the watchdog on a regular basis to prevent timeouts (and watchdog drivers are supposed to use the watchdog kernel API). What you have here is a CPU stall detection mechanism, similar to the existing soft/hard lockup detection mechanism. This code does not belong into the watchdog subsystem; it is similar to the existing hard/softlockup detection code (kernel/watchdog.c) and should reside at the same location. Having said that, I could imagine a watchdog driver to be used in VMs, but that would be similar to existing watchdog drivers. The easiest way to get there would probably be to just instantiate one of the watchdog devices already supported by qemu. Guenter
