KVM: use KVM_CAP_IRQ_ROUTING to protect the routing related code

The KVM code sometimes uses CONFIG_HAVE_KVM_IRQCHIP to protect
code that is related to IRQ routing, which not all in-kernel
irqchips may support.

Use KVM_CAP_IRQ_ROUTING instead.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

include/linux/kvm_host.h

@@ -802,7 +802,7 @@ static inline int mmu_notifier_retry(struct kvm_vcpu *vcpu, unsigned long mmu_se
 }
 #endif
 
-#ifdef CONFIG_HAVE_KVM_IRQCHIP
+#ifdef KVM_CAP_IRQ_ROUTING
 
 #define KVM_MAX_IRQ_ROUTES 1024
 

virt/kvm/kvm_main.c

@@ -2225,7 +2225,7 @@ static long kvm_dev_ioctl_check_extension_generic(long arg)
 	case KVM_CAP_SIGNAL_MSI:
 #endif
 		return 1;
-#ifdef CONFIG_HAVE_KVM_IRQCHIP
+#ifdef KVM_CAP_IRQ_ROUTING
 	case KVM_CAP_IRQ_ROUTING:
 		return KVM_MAX_IRQ_ROUTES;
 #endif