--- zzzz-none-000/linux-3.10.107/drivers/xen/cpu_hotplug.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/xen/cpu_hotplug.c	2021-02-04 17:41:59.000000000 +0000
@@ -1,3 +1,5 @@
+#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
+
 #include <linux/notifier.h>
 
 #include <xen/xen.h>
@@ -9,15 +11,20 @@
 static void enable_hotplug_cpu(int cpu)
 {
 	if (!cpu_present(cpu))
-		arch_register_cpu(cpu);
+		xen_arch_register_cpu(cpu);
 
 	set_cpu_present(cpu, true);
 }
 
 static void disable_hotplug_cpu(int cpu)
 {
+	if (cpu_online(cpu)) {
+		lock_device_hotplug();
+		device_offline(get_cpu_device(cpu));
+		unlock_device_hotplug();
+	}
 	if (cpu_present(cpu))
-		arch_unregister_cpu(cpu);
+		xen_arch_unregister_cpu(cpu);
 
 	set_cpu_present(cpu, false);
 }
@@ -31,7 +38,7 @@
 	err = xenbus_scanf(XBT_NIL, dir, "availability", "%15s", state);
 	if (err != 1) {
 		if (!xen_initial_domain())
-			printk(KERN_ERR "XENBUS: Unable to read cpu state\n");
+			pr_err("Unable to read cpu state\n");
 		return err;
 	}
 
@@ -40,7 +47,7 @@
 	else if (strcmp(state, "offline") == 0)
 		return 0;
 
-	printk(KERN_ERR "XENBUS: unknown state(%s) on CPU%d\n", state, cpu);
+	pr_err("unknown state(%s) on CPU%d\n", state, cpu);
 	return -EINVAL;
 }
 static void vcpu_hotplug(unsigned int cpu)
@@ -53,7 +60,6 @@
 		enable_hotplug_cpu(cpu);
 		break;
 	case 0:
-		(void)cpu_down(cpu);
 		disable_hotplug_cpu(cpu);
 		break;
 	default:
@@ -100,7 +106,11 @@
 	static struct notifier_block xsn_cpu = {
 		.notifier_call = setup_cpu_watcher };
 
+#ifdef CONFIG_X86
 	if (!xen_pv_domain())
+#else
+	if (!xen_domain())
+#endif
 		return -ENODEV;
 
 	register_xenstore_notifier(&xsn_cpu);