On Tue, 09 Sep 2025 10:45:36 +0100,
Thomas Gleixner [off-list ref] wrote:

On Mon, Sep 08 2025 at 17:31, Marc Zyngier wrote:

quoted

@@ -2564,13 +2566,14 @@ int request_percpu_nmi(unsigned int irq, irq_handler_t handler,
 	    !irq_supports_nmi(desc))
 		return -EINVAL;
 
-	/* The line cannot already be NMI */
-	if (irq_is_nmi(desc))
+	/* The line cannot be NMI already if the new request covers all CPUs */
+	if (irq_is_nmi(desc) &&
+	    (!affinity || cpumask_equal(affinity, cpu_possible_mask)))
 		return -EINVAL;

This check looks odd. What makes sure that the affinities do not
overlap?

The following patch in the series does, at the point of adding the new
irqaction to the list. This is modelled after the current handling of
shared interrupts.

	M.

-- 
Without deviation from the norm, progress is not possible.