Comment 1 for bug 1843643

I assume you're using resume_guests_state_on_host_boot to automatically restart these instances?

If you are it looks like _resume_guests_state just needs to elevate the current context before passing it down to the driver for use by _hard_reboot as is done already when rebooting an instance:

https://github.com/openstack/nova/blob/7a18209a81539217a95ab7daad6bc67002768950/nova/compute/manager.py#L3455