[Qemu-devel] [PATCH] virtio-net: require that config size is initialized

["Michael S. Tsirkin" <mst@redhat.com>]

All buses do this, and if they don't they get subtle
bugs related to cross version migration.
Let's add an assert to catch these bugs early.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---

Just a cleanup so not 1.5 material.
Seems to work fine here - any opinions?

 hw/net/virtio-net.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 908e7b8..f0a9272 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1282,6 +1282,8 @@ static int virtio_net_device_init(VirtIODevice *vdev)
     DeviceState *qdev = DEVICE(vdev);
     VirtIONet *n = VIRTIO_NET(vdev);
 
+    /* Verify that config size has been initialized */
+    assert(n->config_size != (size_t)-1);
     virtio_init(VIRTIO_DEVICE(n), "virtio-net", VIRTIO_ID_NET,
                                   n->config_size);
 
@@ -1386,10 +1388,9 @@ static void virtio_net_instance_init(Object *obj)
     VirtIONet *n = VIRTIO_NET(obj);
 
     /*
-     * The default config_size is sizeof(struct virtio_net_config).
-     * Can be overriden with virtio_net_set_config_size.
+     * The config_size must be set later with virtio_net_set_config_size.
      */
-    n->config_size = sizeof(struct virtio_net_config);
+    n->config_size = (size_t)-1;
 }
 
 static Property virtio_net_properties[] = {
-- 
MST