netdev_features: convert NETIF_F_NETNS_LOCAL to dev->netns_local

"Interface can't change network namespaces" is rather an attribute,
not a feature, and it can't be changed via Ethtool.
Make it a "cold" private flag instead of a netdev_feature and free
one more bit.

Signed-off-by: Alexander Lobakin <[e-mail]>
Signed-off-by: Paolo Abeni <[e-mail]>

Documentation/networking/net_cachelines/net_device.rst

···
 unsigned:1                          threaded                -                   -                   napi_poll(napi_enable,dev_set_threaded)
 unsigned_long:1                     see_all_hwtstamp_requests                                       
 unsigned_long:1                     change_proto_down                                               
+unsigned_long:1                     netns_local                                                     
 struct_list_head                    net_notifier_list                                               
 struct_macsec_ops*                  macsec_ops                                                      
 struct_udp_tunnel_nic_info*         udp_tunnel_nic_info                                             

Documentation/networking/netdev-features.rst

···
 Features contained in NETIF_F_SOFT_FEATURES are features of networking
 stack. Driver should not change behaviour based on them.
 
- * netns-local device
-
-NETIF_F_NETNS_LOCAL is set for devices that are not allowed to move between
-network namespaces (e.g. loopback).
-
-Don't use it in drivers.
-
  * VLAN challenged
 
 NETIF_F_VLAN_CHALLENGED should be set for devices which can't cope with VLAN

Documentation/networking/switchdev.rst

···
 Port Features
 ^^^^^^^^^^^^^
 
-NETIF_F_NETNS_LOCAL
+dev->netns_local
 
 If the switchdev driver (and device) only supports offloading of the default
-network namespace (netns), the driver should set this feature flag to prevent
+network namespace (netns), the driver should set this private flag to prevent
 the port netdev from being moved out of the default netns.  A netns-aware
 driver/device would not set this flag and be responsible for partitioning
 hardware to preserve netns containment.  This means hardware cannot forward

drivers/net/amt.c

···
 	dev->addr_len		= 0;
 	dev->priv_flags		|= IFF_NO_QUEUE;
 	dev->lltx		= true;
+	dev->netns_local	= true;
 	dev->features		|= NETIF_F_GSO_SOFTWARE;
-	dev->features		|= NETIF_F_NETNS_LOCAL;
 	dev->hw_features	|= NETIF_F_SG | NETIF_F_HW_CSUM;
 	dev->hw_features	|= NETIF_F_FRAGLIST | NETIF_F_RXCSUM;
 	dev->hw_features	|= NETIF_F_GSO_SOFTWARE;

drivers/net/bonding/bond_main.c

···
 	/* don't acquire bond device's netif_tx_lock when transmitting */
 	bond_dev->lltx = true;
 
+	/* Don't allow bond devices to change network namespaces. */
+	bond_dev->netns_local = true;
+
 	/* By default, we declare the bond to be fully
 	 * VLAN hardware accelerated capable. Special
 	 * care is taken in the various xmit functions
 	 * when there are slaves that are not hw accel
 	 * capable
 	 */
-
-	/* Don't allow bond devices to change network namespaces. */
-	bond_dev->features |= NETIF_F_NETNS_LOCAL;
 
 	bond_dev->hw_features = BOND_VLAN_FEATURES |
 				NETIF_F_HW_VLAN_CTAG_RX |

drivers/net/ethernet/adi/adin1110.c

···
 		netdev->netdev_ops = &adin1110_netdev_ops;
 		netdev->ethtool_ops = &adin1110_ethtool_ops;
 		netdev->priv_flags |= IFF_UNICAST_FLT;
-		netdev->features |= NETIF_F_NETNS_LOCAL;
+		netdev->netns_local = true;
 
 		port_priv->phydev = get_phy_device(priv->mii_bus, i + 1, false);
 		if (IS_ERR(port_priv->phydev)) {

drivers/net/ethernet/marvell/prestera/prestera_main.c

···
 	if (err)
 		goto err_dl_port_register;
 
-	dev->features |= NETIF_F_NETNS_LOCAL | NETIF_F_HW_TC;
+	dev->features |= NETIF_F_HW_TC;
+	dev->netns_local = true;
 	dev->netdev_ops = &prestera_netdev_ops;
 	dev->ethtool_ops = &prestera_ethtool_ops;
 	SET_NETDEV_DEV(dev, sw->dev->dev);

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

···
 
 	if (mlx5e_is_uplink_rep(priv)) {
 		features = mlx5e_fix_uplink_rep_features(netdev, features);
-		features |= NETIF_F_NETNS_LOCAL;
+		netdev->netns_local = true;
 	} else {
-		features &= ~NETIF_F_NETNS_LOCAL;
+		netdev->netns_local = false;
 	}
 
 	mutex_unlock(&priv->state_lock);

drivers/net/ethernet/mellanox/mlx5/core/en_rep.c

···
 	netdev->hw_features    |= NETIF_F_RXCSUM;
 
 	netdev->features |= netdev->hw_features;
-	netdev->features |= NETIF_F_NETNS_LOCAL;
+
+	netdev->netns_local = true;
 }
 
 static int mlx5e_init_rep(struct mlx5_core_dev *mdev,

drivers/net/ethernet/mellanox/mlxsw/spectrum.c

···
 
 	netif_carrier_off(dev);
 
-	dev->features |= NETIF_F_NETNS_LOCAL | NETIF_F_SG |
-			 NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_HW_TC;
+	dev->features |= NETIF_F_SG | NETIF_F_HW_VLAN_CTAG_FILTER |
+			 NETIF_F_HW_TC;
 	dev->hw_features |= NETIF_F_HW_TC | NETIF_F_LOOPBACK;
 	dev->lltx = true;
+	dev->netns_local = true;
 
 	dev->min_mtu = ETH_MIN_MTU;
 	dev->max_mtu = MLXSW_PORT_MAX_MTU - MLXSW_PORT_ETH_FRAME_HDR;

drivers/net/ethernet/rocker/rocker_main.c

···
 	netif_napi_add(dev, &rocker_port->napi_rx, rocker_port_poll_rx);
 	rocker_carrier_init(rocker_port);
 
-	dev->features |= NETIF_F_NETNS_LOCAL | NETIF_F_SG;
+	dev->features |= NETIF_F_SG;
+	dev->netns_local = true;
 
 	/* MTU range: 68 - 9000 */
 	dev->min_mtu = ROCKER_PORT_MIN_MTU;

drivers/net/ethernet/ti/cpsw_new.c

···
 		cpsw->slaves[i].ndev = ndev;
 
 		ndev->features |= NETIF_F_HW_VLAN_CTAG_FILTER |
-				  NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_NETNS_LOCAL | NETIF_F_HW_TC;
+				  NETIF_F_HW_VLAN_CTAG_RX | NETIF_F_HW_TC;
+		ndev->netns_local = true;
 
 		ndev->xdp_features = NETDEV_XDP_ACT_BASIC |
 				     NETDEV_XDP_ACT_REDIRECT |

drivers/net/loopback.c

···
 	dev->flags		= IFF_LOOPBACK;
 	dev->priv_flags		|= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
 	dev->lltx		= true;
+	dev->netns_local	= true;
 	netif_keep_dst(dev);
 	dev->hw_features	= NETIF_F_GSO_SOFTWARE;
 	dev->features		= NETIF_F_SG | NETIF_F_FRAGLIST
···
 		| NETIF_F_RXCSUM
 		| NETIF_F_SCTP_CRC
 		| NETIF_F_HIGHDMA
-		| NETIF_F_NETNS_LOCAL
 		| NETIF_F_VLAN_CHALLENGED
 		| NETIF_F_LOOPBACK;
 	dev->ethtool_ops	= eth_ops;

drivers/net/net_failover.c

···
 	failover_dev->lltx = true;
 
 	/* Don't allow failover devices to change network namespaces. */
-	failover_dev->features |= NETIF_F_NETNS_LOCAL;
+	failover_dev->netns_local = true;
 
 	failover_dev->hw_features = FAILOVER_VLAN_FEATURES |
 				    NETIF_F_HW_VLAN_CTAG_TX |

drivers/net/team/team_core.c

···
 	dev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
 	dev->lltx = true;
 
-	dev->features |= NETIF_F_GRO;
-
 	/* Don't allow team devices to change network namespaces. */
-	dev->features |= NETIF_F_NETNS_LOCAL;
+	dev->netns_local = true;
+
+	dev->features |= NETIF_F_GRO;
 
 	dev->hw_features = TEAM_VLAN_FEATURES |
 			   NETIF_F_HW_VLAN_CTAG_RX |

drivers/net/vrf.c

···
 	dev->lltx = true;
 
 	/* don't allow vrf devices to change network namespaces. */
-	dev->features |= NETIF_F_NETNS_LOCAL;
+	dev->netns_local = true;
 
 	/* does not make sense for a VLAN to be added to a vrf device */
 	dev->features   |= NETIF_F_VLAN_CHALLENGED;

include/linux/netdev_features.h

···
 	NETIF_F_VLAN_CHALLENGED_BIT,	/* Device cannot handle VLAN packets */
 	NETIF_F_GSO_BIT,		/* Enable software GSO. */
 	__UNUSED_NETIF_F_12,
-	NETIF_F_NETNS_LOCAL_BIT,	/* Does not change network namespaces */
+	__UNUSED_NETIF_F_13,
 	NETIF_F_GRO_BIT,		/* Generic receive offload */
 	NETIF_F_LRO_BIT,		/* large receive offload */
 
···
 #define NETIF_F_IPV6_CSUM	__NETIF_F(IPV6_CSUM)
 #define NETIF_F_LOOPBACK	__NETIF_F(LOOPBACK)
 #define NETIF_F_LRO		__NETIF_F(LRO)
-#define NETIF_F_NETNS_LOCAL	__NETIF_F(NETNS_LOCAL)
 #define NETIF_F_NOCACHE_COPY	__NETIF_F(NOCACHE_COPY)
 #define NETIF_F_NTUPLE		__NETIF_F(NTUPLE)
 #define NETIF_F_RXCSUM		__NETIF_F(RXCSUM)
···
 
 /* Features valid for ethtool to change */
 /* = all defined minus driver/device-class-related */
-#define NETIF_F_NEVER_CHANGE	(NETIF_F_VLAN_CHALLENGED | \
-				 NETIF_F_NETNS_LOCAL)
+#define NETIF_F_NEVER_CHANGE	NETIF_F_VLAN_CHALLENGED
 
 /* remember that ((t)1 << t_BITS) is undefined in C99 */
 #define NETIF_F_ETHTOOL_BITS	((__NETIF_F_BIT(NETDEV_FEATURE_COUNT - 1) | \

include/linux/netdevice.h

···
  *			regardless of source, even if those aren't
  *			HWTSTAMP_SOURCE_NETDEV
  *	@change_proto_down: device supports setting carrier via IFLA_PROTO_DOWN
+ *	@netns_local: interface can't change network namespaces
  *
  *	@net_notifier_list:	List of per-net netdev notifier block
  *				that follow this device when it is moved
···
 	/* priv_flags_slow, ungrouped to save space */
 	unsigned long		see_all_hwtstamp_requests:1;
 	unsigned long		change_proto_down:1;
+	unsigned long		netns_local:1;
 
 	struct list_head	net_notifier_list;
 

net/batman-adv/soft-interface.c

···
 	dev->netdev_ops = &batadv_netdev_ops;
 	dev->needs_free_netdev = true;
 	dev->priv_destructor = batadv_softif_free;
-	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_NETNS_LOCAL;
+	dev->features |= NETIF_F_HW_VLAN_CTAG_FILTER;
 	dev->priv_flags |= IFF_NO_QUEUE;
 	dev->lltx = true;
+	dev->netns_local = true;
 
 	/* can't call min_mtu, because the needed variables
 	 * have not been initialized yet

net/bridge/br_device.c

···
 	SET_NETDEV_DEVTYPE(dev, &br_type);
 	dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 	dev->lltx = true;
+	dev->netns_local = true;
 
-	dev->features = COMMON_FEATURES | NETIF_F_NETNS_LOCAL |
-			NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
+	dev->features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
+			NETIF_F_HW_VLAN_STAG_TX;
 	dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 			   NETIF_F_HW_VLAN_STAG_TX;
 	dev->vlan_features = COMMON_FEATURES;

net/core/dev.c

···
 
 	/* Don't allow namespace local devices to be moved. */
 	err = -EINVAL;
-	if (dev->features & NETIF_F_NETNS_LOCAL)
+	if (dev->netns_local)
 		goto out;
 
 	/* Ensure the device has been registered */
···
 		char fb_name[IFNAMSIZ];
 
 		/* Ignore unmoveable devices (i.e. loopback) */
-		if (dev->features & NETIF_F_NETNS_LOCAL)
+		if (dev->netns_local)
 			continue;
 
 		/* Leave virtual devices for the generic cleanup */

net/ethtool/common.c

···
 	[NETIF_F_HW_VLAN_STAG_FILTER_BIT] = "rx-vlan-stag-filter",
 	[NETIF_F_VLAN_CHALLENGED_BIT] =  "vlan-challenged",
 	[NETIF_F_GSO_BIT] =              "tx-generic-segmentation",
-	[NETIF_F_NETNS_LOCAL_BIT] =      "netns-local",
 	[NETIF_F_GRO_BIT] =              "rx-gro",
 	[NETIF_F_GRO_HW_BIT] =           "rx-gro-hw",
 	[NETIF_F_LRO_BIT] =              "rx-lro",

net/hsr/hsr_device.c

···
 	dev->priv_flags |= IFF_NO_QUEUE | IFF_DISABLE_NETPOLL;
 	/* Prevent recursive tx locking */
 	dev->lltx = true;
+	/* Not sure about this. Taken from bridge code. netdevice.h says
+	 * it means "Does not change network namespaces".
+	 */
+	dev->netns_local = true;
 
 	dev->needs_free_netdev = true;
 
···
 	 * hsr_header_create() etc.
 	 */
 	dev->features |= NETIF_F_VLAN_CHALLENGED;
-	/* Not sure about this. Taken from bridge code. netdev_features.h says
-	 * it means "Does not change network namespaces".
-	 */
-	dev->features |= NETIF_F_NETNS_LOCAL;
 }
 
 /* Return true if dev is a HSR master; return false otherwise.

net/ieee802154/6lowpan/core.c

···
 	ldev->netdev_ops	= &lowpan_netdev_ops;
 	ldev->header_ops	= &lowpan_header_ops;
 	ldev->needs_free_netdev	= true;
-	ldev->features		|= NETIF_F_NETNS_LOCAL;
+	ldev->netns_local	= true;
 }
 
 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[],

net/ieee802154/core.c

···
 	list_for_each_entry(wpan_dev, &rdev->wpan_dev_list, list) {
 		if (!wpan_dev->netdev)
 			continue;
-		wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
+		wpan_dev->netdev->netns_local = false;
 		err = dev_change_net_namespace(wpan_dev->netdev, net, "wpan%d");
 		if (err)
 			break;
-		wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
+		wpan_dev->netdev->netns_local = true;
 	}
 
 	if (err) {
···
 						     list) {
 			if (!wpan_dev->netdev)
 				continue;
-			wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
+			wpan_dev->netdev->netns_local = false;
 			err = dev_change_net_namespace(wpan_dev->netdev, net,
 						       "wpan%d");
 			WARN_ON(err);
-			wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
+			wpan_dev->netdev->netns_local = true;
 		}
 
 		return err;
···
 	switch (state) {
 		/* TODO NETDEV_DEVTYPE */
 	case NETDEV_REGISTER:
-		dev->features |= NETIF_F_NETNS_LOCAL;
+		dev->netns_local = true;
 		wpan_dev->identifier = ++rdev->wpan_dev_id;
 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
 		rdev->devlist_generation++;

net/ipv4/ip_tunnel.c

···
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
 	if (!IS_ERR(itn->fb_tunnel_dev)) {
-		itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
+		itn->fb_tunnel_dev->netns_local = true;
 		itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev);
 		ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev));
 		itn->type = itn->fb_tunnel_dev->type;

net/ipv4/ipmr.c

···
 	dev->flags		= IFF_NOARP;
 	dev->netdev_ops		= &reg_vif_netdev_ops;
 	dev->needs_free_netdev	= true;
-	dev->features		|= NETIF_F_NETNS_LOCAL;
+	dev->netns_local	= true;
 }
 
 static struct net_device *ipmr_reg_vif(struct net *net, struct mr_table *mrt)

net/ipv6/ip6_gre.c

···
 	/* FB netdevice is special: we have one, and only one per netns.
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
-	ign->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
-
+	ign->fb_tunnel_dev->netns_local = true;
 
 	ip6gre_fb_tunnel_init(ign->fb_tunnel_dev);
 	ign->fb_tunnel_dev->rtnl_link_ops = &ip6gre_link_ops;

net/ipv6/ip6_tunnel.c

···
 	/* FB netdevice is special: we have one, and only one per netns.
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
-	ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
+	ip6n->fb_tnl_dev->netns_local = true;
 
 	err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
 	if (err < 0)

net/ipv6/ip6mr.c

···
 	dev->flags		= IFF_NOARP;
 	dev->netdev_ops		= &reg_vif_netdev_ops;
 	dev->needs_free_netdev	= true;
-	dev->features		|= NETIF_F_NETNS_LOCAL;
+	dev->netns_local	= true;
 }
 
 static struct net_device *ip6mr_reg_vif(struct net *net, struct mr_table *mrt)

net/ipv6/sit.c

···
 	/* FB netdevice is special: we have one, and only one per netns.
 	 * Allowing to move it to another netns is clearly unsafe.
 	 */
-	sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
+	sitn->fb_tunnel_dev->netns_local = true;
 
 	err = register_netdev(sitn->fb_tunnel_dev);
 	if (err)

net/openvswitch/vport-internal_dev.c

···
 
 	/* Restrict bridge port to current netns. */
 	if (vport->port_no == OVSP_LOCAL)
-		vport->dev->features |= NETIF_F_NETNS_LOCAL;
+		vport->dev->netns_local = true;
 
 	rtnl_lock();
 	err = register_netdevice(vport->dev);

net/wireless/core.c

···
 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		if (!wdev->netdev)
 			continue;
-		wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
+		wdev->netdev->netns_local = false;
 		err = dev_change_net_namespace(wdev->netdev, net, "wlan%d");
 		if (err)
 			break;
-		wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
+		wdev->netdev->netns_local = true;
 	}
 
 	if (err) {
···
 						     list) {
 			if (!wdev->netdev)
 				continue;
-			wdev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
+			wdev->netdev->netns_local = false;
 			err = dev_change_net_namespace(wdev->netdev, net,
 							"wlan%d");
 			WARN_ON(err);
-			wdev->netdev->features |= NETIF_F_NETNS_LOCAL;
+			wdev->netdev->netns_local = true;
 		}
 
 		return err;
···
 		SET_NETDEV_DEVTYPE(dev, &wiphy_type);
 		wdev->netdev = dev;
 		/* can only change netns with wiphy */
-		dev->features |= NETIF_F_NETNS_LOCAL;
+		dev->netns_local = true;
 
 		cfg80211_init_wdev(wdev);
 		break;

tools/testing/selftests/net/forwarding/README

···
 
 Unfortunately, these namespaces can not be used with actual switching
 ASICs, as their ports can not be migrated to other network namespaces
-(NETIF_F_NETNS_LOCAL) and most of them probably do not support the
+(dev->netns_local) and most of them probably do not support the
 L1-separation provided by namespaces.
 
 However, a similar kind of flexibility can be achieved by using VRFs and