Merge tag 'for-linus-5.10b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fix from Juergen Gross:
 "A single fix for avoiding WARN splats when booting a Xen guest with
  nosmt"

* tag 'for-linus-5.10b-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/xen: don't unbind uninitialized lock_kicker_irq

Author: torvalds

arch/x86/xen/spinlock.c

@@ -93,10 +93,20 @@ void xen_init_lock_cpu(int cpu)
 
 void xen_uninit_lock_cpu(int cpu)
 {
+	int irq;
+
 	if (!xen_pvspin)
 		return;
 
-	unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL);
+	/*
+	 * When booting the kernel with 'mitigations=auto,nosmt', the secondary
+	 * CPUs are not activated, and lock_kicker_irq is not initialized.
+	 */
+	irq = per_cpu(lock_kicker_irq, cpu);
+	if (irq == -1)
+		return;
+
+	unbind_from_irqhandler(irq, NULL);
 	per_cpu(lock_kicker_irq, cpu) = -1;
 	kfree(per_cpu(irq_name, cpu));
 	per_cpu(irq_name, cpu) = NULL;