Hello!

What if we use KVM_MSI_VALID_DEVID flag instead of new KVM_IRQ_ROUTING_EXTENDED_MSI
definition? I
believe this would make an API more consistent and introduce less new definitions.

 I have just found one more flaw in your implementation. If you take a look at irqfd_wakeup()...

--- cut ---

		/* An event has been signaled, inject an interrupt */
		if (irq.type == KVM_IRQ_ROUTING_MSI)
			kvm_set_msi(&irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1,
					false);
		else
			schedule_work(&irqfd->inject);

--- cut ---
 You apparently missed KVM_IRQ_ROUTING_EXTENDED_MSI here, as well as in irqfd_update(). But, if you

accept my API proposal, this becomes irrelevant.

Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia