vhost_net: Add NetClientInfo start callback

This is used by the backend to perform actions before the device is
started.

In particular, vdpa net use it to map CVQ buffers to the device, so it
can send control commands using them.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index ccac5b7a64..2e0baeba26 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -244,6 +244,13 @@ static int vhost_net_start_one(struct vhost_net *net,
     struct vhost_vring_file file = { };
     int r;
 
+    if (net->nc->info->start) {
+        r = net->nc->info->start(net->nc);
+        if (r < 0) {
+            return r;
+        }
+    }
+
     r = vhost_dev_enable_notifiers(&net->dev, dev);
     if (r < 0) {
         goto fail_notifiers;