static int setup_cpu_watcher(struct notifier_block *notifier, unsigned long event, void *data) { int cpu; static struct xenbus_watch cpu_watch = { .node = "cpu", .callback = handle_vcpu_hotplug_event}; (void)register_xenbus_watch(&cpu_watch); for_each_possible_cpu(cpu) { if (vcpu_online(cpu) == 0) { (void)cpu_down(cpu); set_cpu_present(cpu, false); } } return NOTIFY_DONE; } static int __init setup_vcpu_hotplug_event(void) { static struct notifier_block xsn_cpu = { .notifier_call = setup_cpu_watcher }; if (!xen_pv_domain()) return -ENODEV; register_xenstore_notifier(&xsn_cpu); return 0; } arch_initcall(setup_vcpu_hotplug_event);
static void vcpu_hotplug(unsigned int cpu) { if (cpu >= nr_cpu_ids || !cpu_possible(cpu)) return; switch (vcpu_online(cpu)) { case 1: enable_hotplug_cpu(cpu); break; case 0: disable_hotplug_cpu(cpu); break; default: break; } }
static void vcpu_hotplug(unsigned int cpu) { if (!cpu_possible(cpu)) return; switch (vcpu_online(cpu)) { case 1: enable_hotplug_cpu(cpu); break; case 0: (void)cpu_down(cpu); disable_hotplug_cpu(cpu); break; default: break; } }