Linux Virtualization - Jan 2012 - [PATCH 1/2] virtio: net: Move vq initialization into separate function

From: Amit Shah <amit.shah at redhat.com>

The probe and PM restore functions will share this code.

Signed-off-by: Amit Shah <amit.shah at redhat.com>
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
---
 drivers/net/virtio_net.c |   47 ++++++++++++++++++++++++++++-------------------
 1 file changed, 28 insertions(+), 19 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1b67e8a..ec8c400 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -966,15 +966,38 @@ static void virtnet_config_changed(struct virtio_device
*vdev)
 	virtnet_update_status(vi);
 }
 
+static int init_vqs(struct virtnet_info *vi)
+{
+	struct virtqueue *vqs[3];
+	vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
+	const char *names[] = { "input", "output",
"control" };
+	int nvqs, err;
+
+	/* We expect two virtqueues, receive then send,
+	 * and optionally control. */
+	nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
+
+	err = vi->vdev->config->find_vqs(vi->vdev, nvqs, vqs, callbacks,
names);
+	if (err)
+		return err;
+
+	vi->rvq = vqs[0];
+	vi->svq = vqs[1];
+
+	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
+		vi->cvq = vqs[2];
+
+		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
+			vi->dev->features |= NETIF_F_HW_VLAN_FILTER;
+	}
+	return 0;
+}
+
 static int virtnet_probe(struct virtio_device *vdev)
 {
 	int err;
 	struct net_device *dev;
 	struct virtnet_info *vi;
-	struct virtqueue *vqs[3];
-	vq_callback_t *callbacks[] = { skb_recv_done, skb_xmit_done, NULL};
-	const char *names[] = { "input", "output",
"control" };
-	int nvqs;
 
 	/* Allocate ourselves a network device with room for our info */
 	dev = alloc_etherdev(sizeof(struct virtnet_info));
@@ -1046,24 +1069,10 @@ static int virtnet_probe(struct virtio_device *vdev)
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
 		vi->mergeable_rx_bufs = true;
 
-	/* We expect two virtqueues, receive then send,
-	 * and optionally control. */
-	nvqs = virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ) ? 3 : 2;
-
-	err = vdev->config->find_vqs(vdev, nvqs, vqs, callbacks, names);
+	err = init_vqs(vi);
 	if (err)
 		goto free_stats;
 
-	vi->rvq = vqs[0];
-	vi->svq = vqs[1];
-
-	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VQ)) {
-		vi->cvq = vqs[2];
-
-		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_CTRL_VLAN))
-			dev->features |= NETIF_F_HW_VLAN_FILTER;
-	}
-
 	err = register_netdev(dev);
 	if (err) {
 		pr_debug("virtio_net: registering device failed\n");

From: Amit Shah <amit.shah at redhat.com>

The remove and PM freeze functions will share this code.

Signed-off-by: Amit Shah <amit.shah at redhat.com>
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
---
 drivers/net/virtio_net.c |   20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ec8c400..7a2a5bf 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1134,22 +1134,26 @@ static void free_unused_bufs(struct virtnet_info *vi)
 	BUG_ON(vi->num != 0);
 }
 
-static void __devexit virtnet_remove(struct virtio_device *vdev)
+static void remove_vq_common(struct virtnet_info *vi)
 {
-	struct virtnet_info *vi = vdev->priv;
-
-	/* Stop all the virtqueues. */
-	vdev->config->reset(vdev);
-
-	unregister_netdev(vi->dev);
+	vi->vdev->config->reset(vi->vdev);
 
 	/* Free unused buffers in both send and recv, if any. */
 	free_unused_bufs(vi);
 
-	vdev->config->del_vqs(vi->vdev);
+	vi->vdev->config->del_vqs(vi->vdev);
 
 	while (vi->pages)
 		__free_pages(get_a_page(vi, GFP_KERNEL), 0);
+}
+
+static void __devexit virtnet_remove(struct virtio_device *vdev)
+{
+	struct virtnet_info *vi = vdev->priv;
+
+	unregister_netdev(vi->dev);
+
+	remove_vq_common(vi);
 
 	free_percpu(vi->stats);
 	free_netdev(vi->dev);

(This needs PM changes to virtio_pci which are in my tree, so best done
 via that rather than net-next.  Thanks!)
 
From: Amit Shah <amit.shah at redhat.com>

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 at redhat.com>
Signed-off-by: Rusty Russell <rusty at rustcorp.com.au>
---
 drivers/net/virtio_net.c |   46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1159,6 +1159,48 @@ static void __devexit virtnet_remove(str
 	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 },
@@ -1183,6 +1225,10 @@ static struct virtio_driver virtio_net_d
 	.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)