At 2020-04-14 18:00:49, "Daniel P. Berrang¨¦" <berrange@redhat.com> wrote: >On Mon, Apr 13, 2020 at 05:32:38PM +0800, thomas.kuang wrote: >> HI, everyone: >> >> >> My target deal with network hotplug use virDomainDetachDeviceFlags. Because when the API return ,the network maybe doesn¡¯t remove from my vm guest os. >> >> So I use virConnectDomainEventRegisterAny to register an event ID: VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED , >> >> my process as follow: >> >> cb_para->call_id=virConnectDomainEventRegisterAny(cb_para->conn,cb_para->dom,VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED, VIR_DOMAIN_EVENT_CALLBACK(vnf_control_del_network_cb), cb_para, vnf_control_del_network_cb_free); >> >> >> >> flags |= VIR_DOMAIN_AFFECT_CONFIG; >> if (virDomainIsActive(dom) == 1) { >> flags |= VIR_DOMAIN_AFFECT_LIVE; >> } >> >> ret = virDomainDetachDeviceFlags(dom, xml, flags); >> >> >> >> >> above code write in thread loop ,then in the same loop : >> >> >> >> while (1) { >> >> mission = vnf_mission_queue_get(task); >> >> if (mission == NULL) { >> >> sleep(1); >> >> continue; >> >> } >> >> vnf_op_process(&mission->info); // this will deal with network hotplug,will call virConnectDomainEventRegisterAny then call virDomainDetachDeviceFlags >> >> if (mission) { >> >> vnf_mission_free(mission); >> >> } >> >> if(virEventRunDefaultImpl() < 0) { // at here process the registered callback for event-registered >> >> printf();.... >> >> >> } >> >> } >> >> My problem is: some time , the virEventRunDefaultImpl can trigger the >> vnf_control_del_network_cb callback ,but some time there is nothing, >> as if the VIR_DOMAIN_EVENT_ID_DEVICE_REMOVED has lost. >> what cause the Unpredictable behavior ? what is a correct use for >> virConnectDomainEventRegisterAny ? > >The virDomainDetachDeviceFlags API is asynchronous and requires a cooperative >guest to complete. It merely injects an ACPI PCI unplug request to the guest >OS. If the guest OS doesn't honour this request (because it is in early >bootup, or is in BIOS, or is crashed, or is configured to disable hotplug, >or is maliciously not responding), then the device will never be unplugged, >and so you'll never get an event. > >So the first thing for you todo is to validate that the device really is >being unplugged in the guest OS, and in QEMU. > >To check QEMU run: > > virsh qemu-monitor-command --hmp $GUEST "info pci" > >and look to see if the PCI device is still listed in the output. > >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 :|