On Fri, Apr 29, 2022 at 03:25:45PM -0500, Rob Herring wrote: > 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" Hi, > > 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. > I am trying to address the issues incrementlly keeping a week cadence. Any feedback on this is welcomed. Thanks, Seb > Rob
