On Thu, May 21, 2026 at 12:43:13 +0200, Marek Marczykowski-Górecki wrote:
Hi,
What should be the events fired when VM requests reboot? Currently the libxl driver fires VIR_DOMAIN_EVENT_STOPPED, and if on_reboot is set to restart, it fires VIR_DOMAIN_EVENT_STARTED next to it (in fact, _STARTED
So that is VIR_DOMAIN_EVENT_ID_LIFECYCLE. That one should be emitted only when the state of the VM changes, so usually not only on guest OS reboot. The question though is if that is the case e.g. in the xen paravirt cases where I'm not sure if it's considered to still be the same instance. (e.g. if the domain ID changed). If it did change there isn't much we can do. We could have a better 'reason' value for it. Currently the supported reasons are: VIR_DOMAIN_EVENT_SHUTDOWN_FINISHED < on action (e.g. via virsh) VIR_DOMAIN_EVENT_SHUTDOWN_GUEST < when the guest OS initiated it VIR_DOMAIN_EVENT_SHUTDOWN_HOST < when it was e.g. killed
gets fired before _STOPPED here, but it's another issue). What I'd like to do, is to set on_reboot to destroy, but still receive information whether VM requested just shutdown or reboot, so my application (qubesd daemon) can act on it.
I see VIR_DOMAIN_EVENT_ID_REBOOT, but it's not used in libxl. What's the intended semantic of it? Should it be fired next to the lifecycle event (VIR_DOMAIN_EVENT_STOPPED/VIR_DOMAIN_EVENT_STARTED)? Or instead? Is it okay to fire it even if on_reboot=destroy?
So in the 'qemu' driver when the VM reboots and is configured to run VIR_DOMAIN_EVENT_ID_REBOOT is emitted: event 'reboot' for domain 'cd' On the other hand if onReboot is set to destroy the VM only the LIFECYCLE events will be emitted: event 'lifecycle' for domain 'cd': Shutdown Finished after guest request event 'lifecycle' for domain 'cd': Stopped Shutdown If onReboot is set to 'destroy' though the events are the same if the guest OS invokes a shutdown. Thus it's not possible currently to differentiate the situations. In case of the qemu driver we don't even get the 'RESET' event if the action is to terminate the VM so I don't think it's technically feasible to do what you want at least in the qemu driver.