On Fri, Apr 29, 2022 at 08:30:29AM +0000, Sebastian Ene wrote: > This adds a mechanism to detect stalls on the guest vCPUS by creating a > per CPU hrtimer which periodically 'pets' the host backend driver. > On a conventional watchdog-core driver, the userspace is responsible for > delivering the 'pet' events by writing to the particular /dev/watchdogN node. > In this case we require a strong thread affinity to be able to > account for lost time on a per vCPU basis. > > This device driver acts as a soft lockup detector by relying on the host > backend driver to measure the elapesed time between subsequent 'pet' events. > If the elapsed time doesn't match an expected value, the backend driver > decides that the guest vCPU is locked and resets the guest. The host > backend driver takes into account the time that the guest is not > running. The communication with the backend driver is done through MMIO > and the register layout of the virtual watchdog is described as part of > the backend driver changes. > > The host backend driver is implemented as part of: > https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3548817 > > Changelog v4: > - rename the source from vm-wdt.c -> vm-watchdog.c > - convert all the error logging calls from pr_* to dev_* calls > - rename the DTS node "clock" to "clock-frequency" Why do I have a v4 now when the discussion on v3 is not concluded. Give folks some time to respond. We're busy drinking from the firehose. Rob
