virtio: net: Add freeze, restore handlers to support S4

Remove all the vqs, disable napi and detach from the netdev on
hibernation.

Re-create vqs after restoring from a hibernated image, re-enable napi
and re-attach the netdev.  This keeps networking working across
hibernation.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 59109c1b6b8748e4516425865568264a3b6dc22d..4880aa8b4c28b4662446e8e56b2acc98958645e4 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1178,6 +1178,48 @@ static void __devexit virtnet_remove(struct virtio_device *vdev)
        free_netdev(vi->dev);
 }
 
+#ifdef CONFIG_PM
+static int virtnet_freeze(struct virtio_device *vdev)
+{
+       struct virtnet_info *vi = vdev->priv;
+
+       virtqueue_disable_cb(vi->rvq);
+       virtqueue_disable_cb(vi->svq);
+       if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ))
+               virtqueue_disable_cb(vi->cvq);
+
+       netif_device_detach(vi->dev);
+       cancel_delayed_work_sync(&vi->refill);
+
+       if (netif_running(vi->dev))
+               napi_disable(&vi->napi);
+
+       remove_vq_common(vi);
+
+       return 0;
+}
+
+static int virtnet_restore(struct virtio_device *vdev)
+{
+       struct virtnet_info *vi = vdev->priv;
+       int err;
+
+       err = init_vqs(vi);
+       if (err)
+               return err;
+
+       if (netif_running(vi->dev))
+               virtnet_napi_enable(vi);
+
+       netif_device_attach(vi->dev);
+
+       if (!try_fill_recv(vi, GFP_KERNEL))
+               queue_delayed_work(system_nrt_wq, &vi->refill, 0);
+
+       return 0;
+}
+#endif
+
 static struct virtio_device_id id_table[] = {
        { VIRTIO_ID_NET, VIRTIO_DEV_ANY_ID },
        { 0 },
@@ -1202,6 +1244,10 @@ static struct virtio_driver virtio_net_driver = {
        .probe =        virtnet_probe,
        .remove =       __devexit_p(virtnet_remove),
        .config_changed = virtnet_config_changed,
+#ifdef CONFIG_PM
+       .freeze =       virtnet_freeze,
+       .restore =      virtnet_restore,
+#endif
 };
 
 static int __init init(void)