kvm/irqchip: allow only multiple irqchip routes per GSI

Any other irq routing types (MSI, S390_ADAPTER, upcoming Hyper-V
SynIC) map one-to-one to GSI.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

virt/kvm/irqchip.c

@@ -144,11 +144,11 @@ static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 
 	/*
 	 * Do not allow GSI to be mapped to the same irqchip more than once.
-	 * Allow only one to one mapping between GSI and MSI.
+	 * Allow only one to one mapping between GSI and non-irqchip routing.
 	 */
 	hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
-		if (ei->type == KVM_IRQ_ROUTING_MSI ||
-		    ue->type == KVM_IRQ_ROUTING_MSI ||
+		if (ei->type != KVM_IRQ_ROUTING_IRQCHIP ||
+		    ue->type != KVM_IRQ_ROUTING_IRQCHIP ||
 		    ue->u.irqchip.irqchip == ei->irqchip.irqchip)
 			return r;