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>

1 files changed, 46 insertions, 0 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 59109c1b6b87..4880aa8b4c28 100644
--- 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)