Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:

 1) BPF debugger and asm tool by Daniel Borkmann.

 2) Speed up create/bind in AF_PACKET, also from Daniel Borkmann.

 3) Correct reciprocal_divide and update users, from Hannes Frederic
    Sowa and Daniel Borkmann.

 4) Currently we only have a "set" operation for the hw timestamp socket
    ioctl, add a "get" operation to match.  From Ben Hutchings.

 5) Add better trace events for debugging driver datapath problems, also
    from Ben Hutchings.

 6) Implement auto corking in TCP, from Eric Dumazet.  Basically, if we
    have a small send and a previous packet is already in the qdisc or
    device queue, defer until TX completion or we get more data.

 7) Allow userspace to manage ipv6 temporary addresses, from Jiri Pirko.

 8) Add a qdisc bypass option for AF_PACKET sockets, from Daniel
    Borkmann.

 9) Share IP header compression code between Bluetooth and IEEE802154
    layers, from Jukka Rissanen.

10) Fix ipv6 router reachability probing, from Jiri Benc.

11) Allow packets to be captured on macvtap devices, from Vlad Yasevich.

12) Support tunneling in GRO layer, from Jerry Chu.

13) Allow bonding to be configured fully using netlink, from Scott
    Feldman.

14) Allow AF_PACKET users to obtain the VLAN TPID, just like they can
    already get the TCI.  From Atzm Watanabe.

15) New "Heavy Hitter" qdisc, from Terry Lam.

16) Significantly improve the IPSEC support in pktgen, from Fan Du.

17) Allow ipv4 tunnels to cache routes, just like sockets.  From Tom
    Herbert.

18) Add Proportional Integral Enhanced packet scheduler, from Vijay
    Subramanian.

19) Allow openvswitch to mmap'd netlink, from Thomas Graf.

20) Key TCP metrics blobs also by source address, not just destination
    address.  From Christoph Paasch.

21) Support 10G in generic phylib.  From Andy Fleming.

22) Try to short-circuit GRO flow compares using device provided RX
    hash, if provided.  From Tom Herbert.

The wireless and netfilter folks have been busy little bees too.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2064 commits)
  net/cxgb4: Fix referencing freed adapter
  ipv6: reallocate addrconf router for ipv6 address when lo device up
  fib_frontend: fix possible NULL pointer dereference
  rtnetlink: remove IFLA_BOND_SLAVE definition
  rtnetlink: remove check for fill_slave_info in rtnl_have_link_slave_info
  qlcnic: update version to 5.3.55
  qlcnic: Enhance logic to calculate msix vectors.
  qlcnic: Refactor interrupt coalescing code for all adapters.
  qlcnic: Update poll controller code path
  qlcnic: Interrupt code cleanup
  qlcnic: Enhance Tx timeout debugging.
  qlcnic: Use bool for rx_mac_learn.
  bonding: fix u64 division
  rtnetlink: add missing IFLA_BOND_AD_INFO_UNSPEC
  sfc: Use the correct maximum TX DMA ring size for SFC9100
  Add Shradha Shah as the sfc driver maintainer.
  net/vxlan: Share RX skb de-marking and checksum checks with ovs
  tulip: cleanup by using ARRAY_SIZE()
  ip_tunnel: clear IPCB in ip_tunnel_xmit() in case dst_link_failure() is called
  net/cxgb4: Don't retrieve stats during recovery
  ...

1 files changed, 128 insertions, 103 deletions

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 6f5e1dd3be2d..df4692826ead 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -108,10 +108,9 @@ int lockdep_ovsl_is_held(void)
 #endif
 
 static struct vport *new_vport(const struct vport_parms *);
-static int queue_gso_packets(struct net *, int dp_ifindex, struct sk_buff *,
+static int queue_gso_packets(struct datapath *dp, struct sk_buff *,
 			     const struct dp_upcall_info *);
-static int queue_userspace_packet(struct net *, int dp_ifindex,
-				  struct sk_buff *,
+static int queue_userspace_packet(struct datapath *dp, struct sk_buff *,
 				  const struct dp_upcall_info *);
 
 /* Must be called with rcu_read_lock or ovs_mutex. */
@@ -133,7 +132,7 @@ static struct datapath *get_dp(struct net *net, int dp_ifindex)
 }
 
 /* Must be called with rcu_read_lock or ovs_mutex. */
-const char *ovs_dp_name(const struct datapath *dp)
+static const char *ovs_dp_name(const struct datapath *dp)
 {
 	struct vport *vport = ovs_vport_ovsl_rcu(dp, OVSP_LOCAL);
 	return vport->ops->get_name(vport);
@@ -234,7 +233,7 @@ void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
 	}
 
 	/* Look up flow. */
-	flow = ovs_flow_tbl_lookup(&dp->table, &key, &n_mask_hit);
+	flow = ovs_flow_tbl_lookup_stats(&dp->table, &key, &n_mask_hit);
 	if (unlikely(!flow)) {
 		struct dp_upcall_info upcall;
 
@@ -251,9 +250,9 @@ void ovs_dp_process_received_packet(struct vport *p, struct sk_buff *skb)
 	OVS_CB(skb)->flow = flow;
 	OVS_CB(skb)->pkt_key = &key;
 
-	stats_counter = &stats->n_hit;
-	ovs_flow_used(OVS_CB(skb)->flow, skb);
+	ovs_flow_stats_update(OVS_CB(skb)->flow, skb);
 	ovs_execute_actions(dp, skb);
+	stats_counter = &stats->n_hit;
 
 out:
 	/* Update datapath statistics. */
@@ -277,7 +276,6 @@ int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
 		  const struct dp_upcall_info *upcall_info)
 {
 	struct dp_stats_percpu *stats;
-	int dp_ifindex;
 	int err;
 
 	if (upcall_info->portid == 0) {
@@ -285,16 +283,10 @@ int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
 		goto err;
 	}
 
-	dp_ifindex = get_dpifindex(dp);
-	if (!dp_ifindex) {
-		err = -ENODEV;
-		goto err;
-	}
-
 	if (!skb_is_gso(skb))
-		err = queue_userspace_packet(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
+		err = queue_userspace_packet(dp, skb, upcall_info);
 	else
-		err = queue_gso_packets(ovs_dp_get_net(dp), dp_ifindex, skb, upcall_info);
+		err = queue_gso_packets(dp, skb, upcall_info);
 	if (err)
 		goto err;
 
@@ -310,8 +302,7 @@ err:
 	return err;
 }
 
-static int queue_gso_packets(struct net *net, int dp_ifindex,
-			     struct sk_buff *skb,
+static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
 			     const struct dp_upcall_info *upcall_info)
 {
 	unsigned short gso_type = skb_shinfo(skb)->gso_type;
@@ -320,14 +311,14 @@ static int queue_gso_packets(struct net *net, int dp_ifindex,
 	struct sk_buff *segs, *nskb;
 	int err;
 
-	segs = __skb_gso_segment(skb, NETIF_F_SG | NETIF_F_HW_CSUM, false);
+	segs = __skb_gso_segment(skb, NETIF_F_SG, false);
 	if (IS_ERR(segs))
 		return PTR_ERR(segs);
 
 	/* Queue all of the segments. */
 	skb = segs;
 	do {
-		err = queue_userspace_packet(net, dp_ifindex, skb, upcall_info);
+		err = queue_userspace_packet(dp, skb, upcall_info);
 		if (err)
 			break;
 
@@ -380,11 +371,11 @@ static size_t key_attr_size(void)
 		+ nla_total_size(28); /* OVS_KEY_ATTR_ND */
 }
 
-static size_t upcall_msg_size(const struct sk_buff *skb,
-			      const struct nlattr *userdata)
+static size_t upcall_msg_size(const struct nlattr *userdata,
+			      unsigned int hdrlen)
 {
 	size_t size = NLMSG_ALIGN(sizeof(struct ovs_header))
-		+ nla_total_size(skb->len) /* OVS_PACKET_ATTR_PACKET */
+		+ nla_total_size(hdrlen) /* OVS_PACKET_ATTR_PACKET */
 		+ nla_total_size(key_attr_size()); /* OVS_PACKET_ATTR_KEY */
 
 	/* OVS_PACKET_ATTR_USERDATA */
@@ -394,15 +385,24 @@ static size_t upcall_msg_size(const struct sk_buff *skb,
 	return size;
 }
 
-static int queue_userspace_packet(struct net *net, int dp_ifindex,
-				  struct sk_buff *skb,
+static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 				  const struct dp_upcall_info *upcall_info)
 {
 	struct ovs_header *upcall;
 	struct sk_buff *nskb = NULL;
 	struct sk_buff *user_skb; /* to be queued to userspace */
 	struct nlattr *nla;
-	int err;
+	struct genl_info info = {
+		.dst_sk = ovs_dp_get_net(dp)->genl_sock,
+		.snd_portid = upcall_info->portid,
+	};
+	size_t len;
+	unsigned int hlen;
+	int err, dp_ifindex;
+
+	dp_ifindex = get_dpifindex(dp);
+	if (!dp_ifindex)
+		return -ENODEV;
 
 	if (vlan_tx_tag_present(skb)) {
 		nskb = skb_clone(skb, GFP_ATOMIC);
@@ -422,7 +422,22 @@ static int queue_userspace_packet(struct net *net, int dp_ifindex,
 		goto out;
 	}
 
-	user_skb = genlmsg_new(upcall_msg_size(skb, upcall_info->userdata), GFP_ATOMIC);
+	/* Complete checksum if needed */
+	if (skb->ip_summed == CHECKSUM_PARTIAL &&
+	    (err = skb_checksum_help(skb)))
+		goto out;
+
+	/* Older versions of OVS user space enforce alignment of the last
+	 * Netlink attribute to NLA_ALIGNTO which would require extensive
+	 * padding logic. Only perform zerocopy if padding is not required.
+	 */
+	if (dp->user_features & OVS_DP_F_UNALIGNED)
+		hlen = skb_zerocopy_headlen(skb);
+	else
+		hlen = skb->len;
+
+	len = upcall_msg_size(upcall_info->userdata, hlen);
+	user_skb = genlmsg_new_unicast(len, &info, GFP_ATOMIC);
 	if (!user_skb) {
 		err = -ENOMEM;
 		goto out;
@@ -441,26 +456,24 @@ static int queue_userspace_packet(struct net *net, int dp_ifindex,
 			  nla_len(upcall_info->userdata),
 			  nla_data(upcall_info->userdata));
 
-	nla = __nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, skb->len);
+	/* Only reserve room for attribute header, packet data is added
+	 * in skb_zerocopy() */
+	if (!(nla = nla_reserve(user_skb, OVS_PACKET_ATTR_PACKET, 0))) {
+		err = -ENOBUFS;
+		goto out;
+	}
+	nla->nla_len = nla_attr_size(skb->len);
 
-	skb_copy_and_csum_dev(skb, nla_data(nla));
+	skb_zerocopy(user_skb, skb, skb->len, hlen);
 
-	genlmsg_end(user_skb, upcall);
-	err = genlmsg_unicast(net, user_skb, upcall_info->portid);
+	((struct nlmsghdr *) user_skb->data)->nlmsg_len = user_skb->len;
 
+	err = genlmsg_unicast(ovs_dp_get_net(dp), user_skb, upcall_info->portid);
 out:
 	kfree_skb(nskb);
 	return err;
 }
 
-static void clear_stats(struct sw_flow *flow)
-{
-	flow->used = 0;
-	flow->tcp_flags = 0;
-	flow->packet_count = 0;
-	flow->byte_count = 0;
-}
-
 static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 {
 	struct ovs_header *ovs_header = info->userhdr;
@@ -499,7 +512,7 @@ static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 		packet->protocol = htons(ETH_P_802_2);
 
 	/* Build an sw_flow for sending this packet. */
-	flow = ovs_flow_alloc();
+	flow = ovs_flow_alloc(false);
 	err = PTR_ERR(flow);
 	if (IS_ERR(flow))
 		goto err_kfree_skb;
@@ -635,10 +648,10 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
 	const int skb_orig_len = skb->len;
 	struct nlattr *start;
 	struct ovs_flow_stats stats;
+	__be16 tcp_flags;
+	unsigned long used;
 	struct ovs_header *ovs_header;
 	struct nlattr *nla;
-	unsigned long used;
-	u8 tcp_flags;
 	int err;
 
 	ovs_header = genlmsg_put(skb, portid, seq, &dp_flow_genl_family, flags, cmd);
@@ -667,24 +680,17 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
 
 	nla_nest_end(skb, nla);
 
-	spin_lock_bh(&flow->lock);
-	used = flow->used;
-	stats.n_packets = flow->packet_count;
-	stats.n_bytes = flow->byte_count;
-	tcp_flags = (u8)ntohs(flow->tcp_flags);
-	spin_unlock_bh(&flow->lock);
-
+	ovs_flow_stats_get(flow, &stats, &used, &tcp_flags);
 	if (used &&
 	    nla_put_u64(skb, OVS_FLOW_ATTR_USED, ovs_flow_used_time(used)))
 		goto nla_put_failure;
 
 	if (stats.n_packets &&
-	    nla_put(skb, OVS_FLOW_ATTR_STATS,
-		    sizeof(struct ovs_flow_stats), &stats))
+	    nla_put(skb, OVS_FLOW_ATTR_STATS, sizeof(struct ovs_flow_stats), &stats))
 		goto nla_put_failure;
 
-	if (tcp_flags &&
-	    nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, tcp_flags))
+	if ((u8)ntohs(tcp_flags) &&
+	     nla_put_u8(skb, OVS_FLOW_ATTR_TCP_FLAGS, (u8)ntohs(tcp_flags)))
 		goto nla_put_failure;
 
 	/* If OVS_FLOW_ATTR_ACTIONS doesn't fit, skip dumping the actions if
@@ -701,8 +707,7 @@ static int ovs_flow_cmd_fill_info(struct sw_flow *flow, struct datapath *dp,
 	if (start) {
 		const struct sw_flow_actions *sf_acts;
 
-		sf_acts = rcu_dereference_check(flow->sf_acts,
-						lockdep_ovsl_is_held());
+		sf_acts = rcu_dereference_ovsl(flow->sf_acts);
 
 		err = ovs_nla_put_actions(sf_acts->actions,
 					  sf_acts->actions_len, skb);
@@ -726,39 +731,34 @@ error:
 	return err;
 }
 
-static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow)
+static struct sk_buff *ovs_flow_cmd_alloc_info(struct sw_flow *flow,
+					       struct genl_info *info)
 {
-	const struct sw_flow_actions *sf_acts;
+	size_t len;
 
-	sf_acts = ovsl_dereference(flow->sf_acts);
+	len = ovs_flow_cmd_msg_size(ovsl_dereference(flow->sf_acts));
 
-	return genlmsg_new(ovs_flow_cmd_msg_size(sf_acts), GFP_KERNEL);
+	return genlmsg_new_unicast(len, info, GFP_KERNEL);
 }
 
 static struct sk_buff *ovs_flow_cmd_build_info(struct sw_flow *flow,
 					       struct datapath *dp,
-					       u32 portid, u32 seq, u8 cmd)
+					       struct genl_info *info,
+					       u8 cmd)
 {
 	struct sk_buff *skb;
 	int retval;
 
-	skb = ovs_flow_cmd_alloc_info(flow);
+	skb = ovs_flow_cmd_alloc_info(flow, info);
 	if (!skb)
 		return ERR_PTR(-ENOMEM);
 
-	retval = ovs_flow_cmd_fill_info(flow, dp, skb, portid, seq, 0, cmd);
+	retval = ovs_flow_cmd_fill_info(flow, dp, skb, info->snd_portid,
+					info->snd_seq, 0, cmd);
 	BUG_ON(retval < 0);
 	return skb;
 }
 
-static struct sw_flow *__ovs_flow_tbl_lookup(struct flow_table *tbl,
-					      const struct sw_flow_key *key)
-{
-	u32 __always_unused n_mask_hit;
-
-	return ovs_flow_tbl_lookup(tbl, key, &n_mask_hit);
-}
-
 static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr **a = info->attrs;
@@ -770,6 +770,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 	struct datapath *dp;
 	struct sw_flow_actions *acts = NULL;
 	struct sw_flow_match match;
+	bool exact_5tuple;
 	int error;
 
 	/* Extract key. */
@@ -778,7 +779,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 		goto error;
 
 	ovs_match_init(&match, &key, &mask);
-	error = ovs_nla_get_match(&match,
+	error = ovs_nla_get_match(&match, &exact_5tuple,
 				  a[OVS_FLOW_ATTR_KEY], a[OVS_FLOW_ATTR_MASK]);
 	if (error)
 		goto error;
@@ -809,7 +810,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 		goto err_unlock_ovs;
 
 	/* Check if this is a duplicate flow */
-	flow = __ovs_flow_tbl_lookup(&dp->table, &key);
+	flow = ovs_flow_tbl_lookup(&dp->table, &key);
 	if (!flow) {
 		/* Bail out if we're not allowed to create a new flow. */
 		error = -ENOENT;
@@ -817,12 +818,11 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 			goto err_unlock_ovs;
 
 		/* Allocate flow. */
-		flow = ovs_flow_alloc();
+		flow = ovs_flow_alloc(!exact_5tuple);
 		if (IS_ERR(flow)) {
 			error = PTR_ERR(flow);
 			goto err_unlock_ovs;
 		}
-		clear_stats(flow);
 
 		flow->key = masked_key;
 		flow->unmasked_key = key;
@@ -835,8 +835,7 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 			goto err_flow_free;
 		}
 
-		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
-						info->snd_seq, OVS_FLOW_CMD_NEW);
+		reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
 	} else {
 		/* We found a matching flow. */
 		struct sw_flow_actions *old_acts;
@@ -864,15 +863,11 @@ static int ovs_flow_cmd_new_or_set(struct sk_buff *skb, struct genl_info *info)
 		rcu_assign_pointer(flow->sf_acts, acts);
 		ovs_nla_free_flow_actions(old_acts);
 
-		reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
-					       info->snd_seq, OVS_FLOW_CMD_NEW);
+		reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
 
 		/* Clear stats. */
-		if (a[OVS_FLOW_ATTR_CLEAR]) {
-			spin_lock_bh(&flow->lock);
-			clear_stats(flow);
-			spin_unlock_bh(&flow->lock);
-		}
+		if (a[OVS_FLOW_ATTR_CLEAR])
+			ovs_flow_stats_clear(flow);
 	}
 	ovs_unlock();
 
@@ -910,7 +905,7 @@ static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	ovs_match_init(&match, &key, NULL);
-	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
+	err = ovs_nla_get_match(&match, NULL, a[OVS_FLOW_ATTR_KEY], NULL);
 	if (err)
 		return err;
 
@@ -921,14 +916,13 @@ static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
 		goto unlock;
 	}
 
-	flow = __ovs_flow_tbl_lookup(&dp->table, &key);
+	flow = ovs_flow_tbl_lookup(&dp->table, &key);
 	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
 		err = -ENOENT;
 		goto unlock;
 	}
 
-	reply = ovs_flow_cmd_build_info(flow, dp, info->snd_portid,
-					info->snd_seq, OVS_FLOW_CMD_NEW);
+	reply = ovs_flow_cmd_build_info(flow, dp, info, OVS_FLOW_CMD_NEW);
 	if (IS_ERR(reply)) {
 		err = PTR_ERR(reply);
 		goto unlock;
@@ -965,17 +959,17 @@ static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	ovs_match_init(&match, &key, NULL);
-	err = ovs_nla_get_match(&match, a[OVS_FLOW_ATTR_KEY], NULL);
+	err = ovs_nla_get_match(&match, NULL, a[OVS_FLOW_ATTR_KEY], NULL);
 	if (err)
 		goto unlock;
 
-	flow = __ovs_flow_tbl_lookup(&dp->table, &key);
+	flow = ovs_flow_tbl_lookup(&dp->table, &key);
 	if (!flow || !ovs_flow_cmp_unmasked_key(flow, &match)) {
 		err = -ENOENT;
 		goto unlock;
 	}
 
-	reply = ovs_flow_cmd_alloc_info(flow);
+	reply = ovs_flow_cmd_alloc_info(flow, info);
 	if (!reply) {
 		err = -ENOMEM;
 		goto unlock;
@@ -1061,6 +1055,7 @@ static const struct genl_ops dp_flow_genl_ops[] = {
 static const struct nla_policy datapath_policy[OVS_DP_ATTR_MAX + 1] = {
 	[OVS_DP_ATTR_NAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
 	[OVS_DP_ATTR_UPCALL_PID] = { .type = NLA_U32 },
+	[OVS_DP_ATTR_USER_FEATURES] = { .type = NLA_U32 },
 };
 
 static struct genl_family dp_datapath_genl_family = {
@@ -1119,6 +1114,9 @@ static int ovs_dp_cmd_fill_info(struct datapath *dp, struct sk_buff *skb,
 			&dp_megaflow_stats))
 		goto nla_put_failure;
 
+	if (nla_put_u32(skb, OVS_DP_ATTR_USER_FEATURES, dp->user_features))
+		goto nla_put_failure;
+
 	return genlmsg_end(skb, ovs_header);
 
 nla_put_failure:
@@ -1127,17 +1125,17 @@ error:
 	return -EMSGSIZE;
 }
 
-static struct sk_buff *ovs_dp_cmd_build_info(struct datapath *dp, u32 portid,
-					     u32 seq, u8 cmd)
+static struct sk_buff *ovs_dp_cmd_build_info(struct datapath *dp,
+					     struct genl_info *info, u8 cmd)
 {
 	struct sk_buff *skb;
 	int retval;
 
-	skb = genlmsg_new(ovs_dp_cmd_msg_size(), GFP_KERNEL);
+	skb = genlmsg_new_unicast(ovs_dp_cmd_msg_size(), info, GFP_KERNEL);
 	if (!skb)
 		return ERR_PTR(-ENOMEM);
 
-	retval = ovs_dp_cmd_fill_info(dp, skb, portid, seq, 0, cmd);
+	retval = ovs_dp_cmd_fill_info(dp, skb, info->snd_portid, info->snd_seq, 0, cmd);
 	if (retval < 0) {
 		kfree_skb(skb);
 		return ERR_PTR(retval);
@@ -1165,6 +1163,24 @@ static struct datapath *lookup_datapath(struct net *net,
 	return dp ? dp : ERR_PTR(-ENODEV);
 }
 
+static void ovs_dp_reset_user_features(struct sk_buff *skb, struct genl_info *info)
+{
+	struct datapath *dp;
+
+	dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
+	if (!dp)
+		return;
+
+	WARN(dp->user_features, "Dropping previously announced user features\n");
+	dp->user_features = 0;
+}
+
+static void ovs_dp_change(struct datapath *dp, struct nlattr **a)
+{
+	if (a[OVS_DP_ATTR_USER_FEATURES])
+		dp->user_features = nla_get_u32(a[OVS_DP_ATTR_USER_FEATURES]);
+}
+
 static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr **a = info->attrs;
@@ -1223,17 +1239,27 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	parms.port_no = OVSP_LOCAL;
 	parms.upcall_portid = nla_get_u32(a[OVS_DP_ATTR_UPCALL_PID]);
 
+	ovs_dp_change(dp, a);
+
 	vport = new_vport(&parms);
 	if (IS_ERR(vport)) {
 		err = PTR_ERR(vport);
 		if (err == -EBUSY)
 			err = -EEXIST;
 
+		if (err == -EEXIST) {
+			/* An outdated user space instance that does not understand
+			 * the concept of user_features has attempted to create a new
+			 * datapath and is likely to reuse it. Drop all user features.
+			 */
+			if (info->genlhdr->version < OVS_DP_VER_FEATURES)
+				ovs_dp_reset_user_features(skb, info);
+		}
+
 		goto err_destroy_ports_array;
 	}
 
-	reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
-				      info->snd_seq, OVS_DP_CMD_NEW);
+	reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_NEW);
 	err = PTR_ERR(reply);
 	if (IS_ERR(reply))
 		goto err_destroy_local_port;
@@ -1299,8 +1325,7 @@ static int ovs_dp_cmd_del(struct sk_buff *skb, struct genl_info *info)
 	if (IS_ERR(dp))
 		goto unlock;
 
-	reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
-				      info->snd_seq, OVS_DP_CMD_DEL);
+	reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_DEL);
 	err = PTR_ERR(reply);
 	if (IS_ERR(reply))
 		goto unlock;
@@ -1328,8 +1353,9 @@ static int ovs_dp_cmd_set(struct sk_buff *skb, struct genl_info *info)
 	if (IS_ERR(dp))
 		goto unlock;
 
-	reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
-				      info->snd_seq, OVS_DP_CMD_NEW);
+	ovs_dp_change(dp, info->attrs);
+
+	reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_NEW);
 	if (IS_ERR(reply)) {
 		err = PTR_ERR(reply);
 		genl_set_err(&dp_datapath_genl_family, sock_net(skb->sk), 0,
@@ -1360,8 +1386,7 @@ static int ovs_dp_cmd_get(struct sk_buff *skb, struct genl_info *info)
 		goto unlock;
 	}
 
-	reply = ovs_dp_cmd_build_info(dp, info->snd_portid,
-				      info->snd_seq, OVS_DP_CMD_NEW);
+	reply = ovs_dp_cmd_build_info(dp, info, OVS_DP_CMD_NEW);
 	if (IS_ERR(reply)) {
 		err = PTR_ERR(reply);
 		goto unlock;
@@ -1441,7 +1466,7 @@ struct genl_family dp_vport_genl_family = {
 	.parallel_ops = true,
 };
 
-struct genl_multicast_group ovs_dp_vport_multicast_group = {
+static struct genl_multicast_group ovs_dp_vport_multicast_group = {
 	.name = OVS_VPORT_MCGROUP
 };