On Mon, Oct 31, 2022 at 01:19:30PM +0000, Daniel P. Berrangé wrote: > The TCO watchdog is unconditionally integrated into the Q35 machine > type by default, but at the same time is unconditionally disabled > from firing by a host config option that overrides guest OS attempts > to enable it. People have to know to set a magic -global to make > it non-broken
Incidentally I found that originally the TCO watchdog was not unconditionally enabled. Its exposure to the guest could be turned on/off using -global ICH9-LPC.enable_tco=bool This was implemented for machine type compat, but it also gave apps a way to disable the watchdog functionality. Unfortunately that ability was discarded in this series: https://lore.kernel.org/all/1453564933-29638-1-git-send-email-ehabk...@redhat.com/ but the 'enable_tco' property still exists in QOM, but silently ignored. Seems we should either fix the impl of 'enable_tco', or remove the QOM property entirely, so we don't pretend it can be toggled anymore. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
