kvm: Introduce kvm_irqchip_add_msi_route

Add a service that establishes a static route from a virtual IRQ line to
an MSI message. Will be used for IRQFD and device assignment. As we will
use this service outside of CONFIG_KVM protected code, stub it properly.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/kvm-stub.c b/kvm-stub.c
index 47c573d..db3a7dc 100644
--- a/kvm-stub.c
+++ b/kvm-stub.c
@@ -12,10 +12,13 @@
 
 #include "qemu-common.h"
 #include "hw/hw.h"
+#include "hw/msi.h"
 #include "cpu.h"
 #include "gdbstub.h"
 #include "kvm.h"
 
+KVMState *kvm_state;
+
 int kvm_init_vcpu(CPUArchState *env)
 {
     return -ENOSYS;
@@ -128,3 +131,8 @@
 {
     return 1;
 }
+
+int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
+{
+    return -ENOSYS;
+}