hv_netvsc: don't lose VF information

BugLink: http://bugs.launchpad.net/bugs/1616677

struct netvsc_device is not suitable for storing VF information as this
structure is being destroyed on MTU change / set channel operation (see
rndis_filter_device_remove()). Move all VF related stuff to struct
net_device_context which is persistent.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit f9a7da91)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Kamal Mostafa <kamal@canonical.com>

drivers/net/hyperv/hyperv_net.h

@@ -647,7 +647,7 @@ struct netvsc_reconfig {
 struct garp_wrk {
 	struct work_struct dwrk;
 	struct net_device *netdev;
-	struct netvsc_device *netvsc_dev;
+	struct net_device_context *net_device_ctx;
 };
 
 /* The context of the netvsc device  */
@@ -678,6 +678,15 @@ struct net_device_context {
 
 	/* the device is going away */
 	bool start_remove;
+
+	/* State to manage the associated VF interface. */
+	struct net_device *vf_netdev;
+	bool vf_inject;
+	atomic_t vf_use_cnt;
+	/* 1: allocated, serial number is valid. 0: not allocated */
+	u32 vf_alloc;
+	/* Serial number of the VF to team with */
+	u32 vf_serial;
 };
 
 /* Per netvsc device */
@@ -733,15 +742,7 @@ struct netvsc_device {
 	u32 max_pkt; /* max number of pkt in one send, e.g. 8 */
 	u32 pkt_align; /* alignment bytes, e.g. 8 */
 
-	/* 1: allocated, serial number is valid. 0: not allocated */
-	u32 vf_alloc;
-	/* Serial number of the VF to team with */
-	u32 vf_serial;
 	atomic_t open_cnt;
-	/* State to manage the associated VF interface. */
-	bool vf_inject;
-	struct net_device *vf_netdev;
-	atomic_t vf_use_cnt;
 };
 
 static inline struct netvsc_device *

drivers/net/hyperv/netvsc.c

@@ -77,13 +77,9 @@ static struct netvsc_device *alloc_net_device(void)
 	init_waitqueue_head(&net_device->wait_drain);
 	net_device->destroy = false;
 	atomic_set(&net_device->open_cnt, 0);
-	atomic_set(&net_device->vf_use_cnt, 0);
 	net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
 	net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
 
-	net_device->vf_netdev = NULL;
-	net_device->vf_inject = false;
-
 	return net_device;
 }
 
@@ -1106,16 +1102,16 @@ static void netvsc_send_table(struct hv_device *hdev,
 		nvscdev->send_table[i] = tab[i];
 }
 
-static void netvsc_send_vf(struct netvsc_device *nvdev,
+static void netvsc_send_vf(struct net_device_context *net_device_ctx,
 			   struct nvsp_message *nvmsg)
 {
-	nvdev->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
-	nvdev->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
+	net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
+	net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
 }
 
 static inline void netvsc_receive_inband(struct hv_device *hdev,
-					 struct netvsc_device *nvdev,
-					 struct nvsp_message *nvmsg)
+				 struct net_device_context *net_device_ctx,
+				 struct nvsp_message *nvmsg)
 {
 	switch (nvmsg->hdr.msg_type) {
 	case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
@@ -1123,7 +1119,7 @@ static inline void netvsc_receive_inband(struct hv_device *hdev,
 		break;
 
 	case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
-		netvsc_send_vf(nvdev, nvmsg);
+		netvsc_send_vf(net_device_ctx, nvmsg);
 		break;
 	}
 }
@@ -1136,6 +1132,7 @@ static void netvsc_process_raw_pkt(struct hv_device *device,
 				   struct vmpacket_descriptor *desc)
 {
 	struct nvsp_message *nvmsg;
+	struct net_device_context *net_device_ctx = netdev_priv(ndev);
 
 	nvmsg = (struct nvsp_message *)((unsigned long)
 		desc + (desc->offset8 << 3));
@@ -1150,7 +1147,7 @@ static void netvsc_process_raw_pkt(struct hv_device *device,
 		break;
 
 	case VM_PKT_DATA_INBAND:
-		netvsc_receive_inband(device, net_device, nvmsg);
+		netvsc_receive_inband(device, net_device_ctx, nvmsg);
 		break;
 
 	default:

drivers/net/hyperv/netvsc_drv.c

@@ -658,20 +658,19 @@ int netvsc_recv_callback(struct hv_device *device_obj,
 	struct sk_buff *skb;
 	struct sk_buff *vf_skb;
 	struct netvsc_stats *rx_stats;
-	struct netvsc_device *netvsc_dev = net_device_ctx->nvdev;
 	u32 bytes_recvd = packet->total_data_buflen;
 	int ret = 0;
 
 	if (!net || net->reg_state != NETREG_REGISTERED)
 		return NVSP_STAT_FAIL;
 
-	if (READ_ONCE(netvsc_dev->vf_inject)) {
-		atomic_inc(&netvsc_dev->vf_use_cnt);
-		if (!READ_ONCE(netvsc_dev->vf_inject)) {
+	if (READ_ONCE(net_device_ctx->vf_inject)) {
+		atomic_inc(&net_device_ctx->vf_use_cnt);
+		if (!READ_ONCE(net_device_ctx->vf_inject)) {
 			/*
 			 * We raced; just move on.
 			 */
-			atomic_dec(&netvsc_dev->vf_use_cnt);
+			atomic_dec(&net_device_ctx->vf_use_cnt);
 			goto vf_injection_done;
 		}
 
@@ -683,17 +682,19 @@ int netvsc_recv_callback(struct hv_device *device_obj,
 		 * the host). Deliver these via the VF interface
 		 * in the guest.
 		 */
-		vf_skb = netvsc_alloc_recv_skb(netvsc_dev->vf_netdev, packet,
-					       csum_info, *data, vlan_tci);
+		vf_skb = netvsc_alloc_recv_skb(net_device_ctx->vf_netdev,
+					       packet, csum_info, *data,
+					       vlan_tci);
 		if (vf_skb != NULL) {
-			++netvsc_dev->vf_netdev->stats.rx_packets;
-			netvsc_dev->vf_netdev->stats.rx_bytes += bytes_recvd;
+			++net_device_ctx->vf_netdev->stats.rx_packets;
+			net_device_ctx->vf_netdev->stats.rx_bytes +=
+				bytes_recvd;
 			netif_receive_skb(vf_skb);
 		} else {
 			++net->stats.rx_dropped;
 			ret = NVSP_STAT_FAIL;
 		}
-		atomic_dec(&netvsc_dev->vf_use_cnt);
+		atomic_dec(&net_device_ctx->vf_use_cnt);
 		return ret;
 	}
 
@@ -1158,7 +1159,7 @@ static void netvsc_notify_peers(struct work_struct *wrk)
 
 	netdev_notify_peers(gwrk->netdev);
 
-	atomic_dec(&gwrk->netvsc_dev->vf_use_cnt);
+	atomic_dec(&gwrk->net_device_ctx->vf_use_cnt);
 }
 
 static struct net_device *get_netvsc_net_device(char *mac)
@@ -1211,7 +1212,7 @@ static int netvsc_register_vf(struct net_device *vf_netdev)
 	 * Take a reference on the module.
 	 */
 	try_module_get(THIS_MODULE);
-	netvsc_dev->vf_netdev = vf_netdev;
+	net_device_ctx->vf_netdev = vf_netdev;
 	return NOTIFY_OK;
 }
 
@@ -1233,11 +1234,11 @@ static int netvsc_vf_up(struct net_device *vf_netdev)
 	net_device_ctx = netdev_priv(ndev);
 	netvsc_dev = net_device_ctx->nvdev;
 
-	if ((netvsc_dev == NULL) || (netvsc_dev->vf_netdev == NULL))
+	if (!netvsc_dev || !net_device_ctx->vf_netdev)
 		return NOTIFY_DONE;
 
 	netdev_info(ndev, "VF up: %s\n", vf_netdev->name);
-	netvsc_dev->vf_inject = true;
+	net_device_ctx->vf_inject = true;
 
 	/*
 	 * Open the device before switching data path.
@@ -1257,9 +1258,9 @@ static int netvsc_vf_up(struct net_device *vf_netdev)
 	 * notify peers; take a reference to prevent
 	 * the VF interface from vanishing.
 	 */
-	atomic_inc(&netvsc_dev->vf_use_cnt);
+	atomic_inc(&net_device_ctx->vf_use_cnt);
 	net_device_ctx->gwrk.netdev = vf_netdev;
-	net_device_ctx->gwrk.netvsc_dev = netvsc_dev;
+	net_device_ctx->gwrk.net_device_ctx = net_device_ctx;
 	schedule_work(&net_device_ctx->gwrk.dwrk);
 
 	return NOTIFY_OK;
@@ -1283,17 +1284,17 @@ static int netvsc_vf_down(struct net_device *vf_netdev)
 	net_device_ctx = netdev_priv(ndev);
 	netvsc_dev = net_device_ctx->nvdev;
 
-	if ((netvsc_dev == NULL) || (netvsc_dev->vf_netdev == NULL))
+	if (!netvsc_dev || !net_device_ctx->vf_netdev)
 		return NOTIFY_DONE;
 
 	netdev_info(ndev, "VF down: %s\n", vf_netdev->name);
-	netvsc_dev->vf_inject = false;
+	net_device_ctx->vf_inject = false;
 	/*
 	 * Wait for currently active users to
 	 * drain out.
 	 */
 
-	while (atomic_read(&netvsc_dev->vf_use_cnt) != 0)
+	while (atomic_read(&net_device_ctx->vf_use_cnt) != 0)
 		udelay(50);
 	netvsc_switch_datapath(ndev, false);
 	netdev_info(ndev, "Data path switched from VF: %s\n", vf_netdev->name);
@@ -1302,9 +1303,9 @@ static int netvsc_vf_down(struct net_device *vf_netdev)
 	/*
 	 * Notify peers.
 	 */
-	atomic_inc(&netvsc_dev->vf_use_cnt);
+	atomic_inc(&net_device_ctx->vf_use_cnt);
 	net_device_ctx->gwrk.netdev = ndev;
-	net_device_ctx->gwrk.netvsc_dev = netvsc_dev;
+	net_device_ctx->gwrk.net_device_ctx = net_device_ctx;
 	schedule_work(&net_device_ctx->gwrk.dwrk);
 
 	return NOTIFY_OK;
@@ -1331,7 +1332,7 @@ static int netvsc_unregister_vf(struct net_device *vf_netdev)
 		return NOTIFY_DONE;
 	netdev_info(ndev, "VF unregistering: %s\n", vf_netdev->name);
 
-	netvsc_dev->vf_netdev = NULL;
+	net_device_ctx->vf_netdev = NULL;
 	module_put(THIS_MODULE);
 	return NOTIFY_OK;
 }
@@ -1382,6 +1383,10 @@ static int netvsc_probe(struct hv_device *dev,
 	spin_lock_init(&net_device_ctx->lock);
 	INIT_LIST_HEAD(&net_device_ctx->reconfig_events);
 
+	atomic_set(&net_device_ctx->vf_use_cnt, 0);
+	net_device_ctx->vf_netdev = NULL;
+	net_device_ctx->vf_inject = false;
+
 	net->netdev_ops = &device_ops;
 
 	net->hw_features = NETVSC_HW_FEATURES;