On 09/20/2016 11:21 AM, Marc Zyngier wrote:

On 19/09/16 18:39, Alexander Graf wrote:

quoted

On 19.09.16 16:48, Marc Zyngier wrote:

quoted

quoted

+
+		/*
+		 * So we can just explicitly mask or unmask the IRQ, gaining
+		 * more compatibility with oddball irq controllers.
+		 */
+		if (phys_active)
+			disable_percpu_irq(host_vtimer_irq);
+		else
+			enable_percpu_irq(host_vtimer_irq, 0);

Since you are now targeting random irqchips (as opposed to a GIC
specifically), what guarantees that the timer is a per-cpu IRQ?

This is the host interrupt controller - and we're already using percpu
irqs on it :). Also as it happens the RPi has them percpu (anything else
wouldn't make sense...).

Not really. The RPi is faking percpu interrupts just to have some level
of compatibility with the host arch timer driver. But nonetheless, if
you're opening the code to something else than a GIC, then you should
check that the interrupt you're getting is percpu.

This should already be covered by request_percpu_irq() in 
kvm_timer_hyp_init(), no?


Alex