kvm-irqchip: simplify kvm_irqchip_add_msi_route

Changing the original MSIMessage parameter in kvm_irqchip_add_msi_route
into the vector number. Vector index provides more information than the
MSIMessage, we can retrieve the MSIMessage using the vector easily. This
will avoid fetching MSIMessage every time before adding MSI routes.

Meanwhile, the vector info will be used in the coming patches to further
enable gsi route update notifications.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/kvm-all.c b/kvm-all.c
index a88f917..d94c0e4 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -25,6 +25,7 @@
 #include "qemu/error-report.h"
 #include "hw/hw.h"
 #include "hw/pci/msi.h"
+#include "hw/pci/msix.h"
 #include "hw/s390x/adapter.h"
 #include "exec/gdbstub.h"
 #include "sysemu/kvm_int.h"
@@ -1237,10 +1238,23 @@
     return kvm_set_irq(s, route->kroute.gsi, 1);
 }
 
-int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg, PCIDevice *dev)
+int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {
     struct kvm_irq_routing_entry kroute = {};
     int virq;
+    MSIMessage msg = {0, 0};
+
+    if (dev) {
+        if (msix_enabled(dev)) {
+            msg = msix_get_message(dev, vector);
+        } else if (msi_enabled(dev)) {
+            msg = msi_get_message(dev, vector);
+        } else {
+            /* Should never happen */
+            error_report("%s: unknown interrupt type", __func__);
+            abort();
+        }
+    }
 
     if (kvm_gsi_direct_mapping()) {
         return kvm_arch_msi_data_to_gsi(msg.data);
@@ -1390,7 +1404,7 @@
     abort();
 }
 
-int kvm_irqchip_add_msi_route(KVMState *s, MSIMessage msg)
+int kvm_irqchip_add_msi_route(KVMState *s, int vector, PCIDevice *dev)
 {
     return -ENOSYS;
 }