1 files changed, 29 insertions, 6 deletions

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 64b0a74c1523..9869e390875e 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -748,6 +748,13 @@ void netvsc_linkstatus_callback(struct net_device *net,
 	struct netvsc_reconfig *event;
 	unsigned long flags;
 
+	/* Ensure the packet is big enough to access its fields */
+	if (resp->msg_len - RNDIS_HEADER_SIZE < sizeof(struct rndis_indicate_status)) {
+		netdev_err(net, "invalid rndis_indicate_status packet, len: %u\n",
+			   resp->msg_len);
+		return;
+	}
+
 	/* Update the physical link speed when changing to another vSwitch */
 	if (indicate->status == RNDIS_STATUS_LINK_SPEED_CHANGE) {
 		u32 speed;
@@ -2366,7 +2373,16 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
 	return NOTIFY_OK;
 }
 
-/* VF up/down change detected, schedule to change data path */
+/* Change the data path when VF UP/DOWN/CHANGE are detected.
+ *
+ * Typically a UP or DOWN event is followed by a CHANGE event, so
+ * net_device_ctx->data_path_is_vf is used to cache the current data path
+ * to avoid the duplicate call of netvsc_switch_datapath() and the duplicate
+ * message.
+ *
+ * During hibernation, if a VF NIC driver (e.g. mlx5) preserves the network
+ * interface, there is only the CHANGE event and no UP or DOWN event.
+ */
 static int netvsc_vf_changed(struct net_device *vf_netdev)
 {
 	struct net_device_context *net_device_ctx;
@@ -2383,6 +2399,10 @@ static int netvsc_vf_changed(struct net_device *vf_netdev)
 	if (!netvsc_dev)
 		return NOTIFY_DONE;
 
+	if (net_device_ctx->data_path_is_vf == vf_is_up)
+		return NOTIFY_OK;
+	net_device_ctx->data_path_is_vf = vf_is_up;
+
 	netvsc_switch_datapath(ndev, vf_is_up);
 	netdev_info(ndev, "Data path switched %s VF: %s\n",
 		    vf_is_up ? "to" : "from", vf_netdev->name);
@@ -2587,8 +2607,8 @@ static int netvsc_remove(struct hv_device *dev)
 static int netvsc_suspend(struct hv_device *dev)
 {
 	struct net_device_context *ndev_ctx;
-	struct net_device *vf_netdev, *net;
 	struct netvsc_device *nvdev;
+	struct net_device *net;
 	int ret;
 
 	net = hv_get_drvdata(dev);
@@ -2604,10 +2624,6 @@ static int netvsc_suspend(struct hv_device *dev)
 		goto out;
 	}
 
-	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
-	if (vf_netdev)
-		netvsc_unregister_vf(vf_netdev);
-
 	/* Save the current config info */
 	ndev_ctx->saved_netvsc_dev_info = netvsc_devinfo_get(nvdev);
 
@@ -2628,6 +2644,12 @@ static int netvsc_resume(struct hv_device *dev)
 	rtnl_lock();
 
 	net_device_ctx = netdev_priv(net);
+
+	/* Reset the data path to the netvsc NIC before re-opening the vmbus
+	 * channel. Later netvsc_netdev_event() will switch the data path to
+	 * the VF upon the UP or CHANGE event.
+	 */
+	net_device_ctx->data_path_is_vf = false;
 	device_info = net_device_ctx->saved_netvsc_dev_info;
 
 	ret = netvsc_attach(net, device_info);
@@ -2695,6 +2717,7 @@ static int netvsc_netdev_event(struct notifier_block *this,
 		return netvsc_unregister_vf(event_dev);
 	case NETDEV_UP:
 	case NETDEV_DOWN:
+	case NETDEV_CHANGE:
 		return netvsc_vf_changed(event_dev);
 	default:
 		return NOTIFY_DONE;