virtio-net: use aliases instead of duplicate qdev properties

virtio-net-pci, virtio-net-s390, and virtio-net-ccw all duplicate the
qdev properties of their VirtIONet child. This approach does not work
well with string or pointer properties since we must be careful about
leaking or double-freeing them.

Use the QOM alias property to forward property accesses to the
VirtIONet child.  This way no duplication is necessary.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/s390x/s390-virtio-bus.c

@@ -161,6 +161,7 @@ static void s390_virtio_net_instance_init(Object *obj)
     VirtIONetS390 *dev = VIRTIO_NET_S390(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
 }
 
 static int s390_virtio_blk_init(VirtIOS390Device *s390_dev)
@@ -493,10 +494,8 @@ static unsigned virtio_s390_get_features(DeviceState *d)
 /**************** S390 Virtio Bus Device Descriptions *******************/
 
 static Property s390_virtio_net_properties[] = {
-    DEFINE_NIC_PROPERTIES(VirtIONetS390, vdev.nic_conf),
     DEFINE_VIRTIO_COMMON_FEATURES(VirtIOS390Device, host_features),
     DEFINE_VIRTIO_NET_FEATURES(VirtIOS390Device, host_features),
-    DEFINE_VIRTIO_NET_PROPERTIES(VirtIONetS390, vdev.net_conf),
     DEFINE_PROP_END_OF_LIST(),
 };
 

hw/s390x/virtio-ccw.c

@@ -794,6 +794,7 @@ static void virtio_ccw_net_instance_init(Object *obj)
     VirtIONetCcw *dev = VIRTIO_NET_CCW(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
 }
 
 static int virtio_ccw_blk_init(VirtioCcwDevice *ccw_dev)
@@ -1374,8 +1375,6 @@ static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
 static Property virtio_ccw_net_properties[] = {
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
     DEFINE_VIRTIO_NET_FEATURES(VirtioCcwDevice, host_features[0]),
-    DEFINE_VIRTIO_NET_PROPERTIES(VirtIONetCcw, vdev.net_conf),
-    DEFINE_NIC_PROPERTIES(VirtIONetCcw, vdev.nic_conf),
     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_END_OF_LIST(),

hw/virtio/virtio-pci.c

@@ -1425,8 +1425,6 @@ static Property virtio_net_properties[] = {
                     VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, false),
     DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3),
     DEFINE_VIRTIO_NET_FEATURES(VirtIOPCIProxy, host_features),
-    DEFINE_NIC_PROPERTIES(VirtIONetPCI, vdev.nic_conf),
-    DEFINE_VIRTIO_NET_PROPERTIES(VirtIONetPCI, vdev.net_conf),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -1467,6 +1465,7 @@ static void virtio_net_pci_instance_init(Object *obj)
     VirtIONetPCI *dev = VIRTIO_NET_PCI(obj);
     object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_NET);
     object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
+    qdev_alias_all_properties(DEVICE(&dev->vdev), obj);
 }
 
 static const TypeInfo virtio_net_pci_info = {