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* [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps
@ 2026-09-11  6:21 Eric Dumazet
  2026-09-11  6:21 ` [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev() Eric Dumazet
                   ` (5 more replies)
  0 siblings, 6 replies; 12+ messages in thread
From: Eric Dumazet @ 2026-09-11  6:21 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Kuniyuki Iwashima, Ido Schimmel, Andrew Lunn,
	netdev, eric.dumazet, Eric Dumazet

This patch series converts struct vxlan_config to RCU protection, eliminates
redundant destination fields, and enables lockless RTNL-free link dumping
in vxlan_fill_info().

Changes in v3:
- Folded configuration conversion patches into a single patch to maintain
  clean bisectability and avoid intermediate mutable state.
- In vxlan_changelink(), pass lowerdev to vxlan_config_apply() to prevent
  truncating dev->needed_headroom and dev->needed_tailroom when lowerdev
  does not change.
- In vxlan_changelink(), ensure default FDB updates for VNI filters trigger
  when remote_ifindex changes, even if remote_ip is unchanged.
- Pass old and new ifindex to vxlan_vnilist_update_group() and
  vxlan_update_default_fdb_entry() so newly added FDB entries point to
  the new interface and deletions target the old interface.
- Cleaned up redundant NULL checks and unreachable error paths.

Eric Dumazet (6):
  vxlan: vnifilter: use list_for_each_entry_rcu() in
    vxlan_vnifilter_dump_dev()
  vxlan: pass vxlan_config pointer to helper functions
  vxlan: move VXLAN_F_MDB to struct vxlan_dev flags
  vxlan: convert configuration to RCU protection
  vxlan: remove default_dst and use vxlan_config and lowerdev
  vxlan: no longer rely on RTNL in vxlan_fill_info()

 .../mellanox/mlx5/core/en/tc_tun_vxlan.c      |  11 +-
 .../mellanox/mlxsw/spectrum_nve_vxlan.c       |  14 +-
 .../mellanox/mlxsw/spectrum_switchdev.c       |  57 +-
 drivers/net/vxlan/vxlan_core.c                | 717 +++++++++++-------
 drivers/net/vxlan/vxlan_mdb.c                 |  45 +-
 drivers/net/vxlan/vxlan_multicast.c           |  76 +-
 drivers/net/vxlan/vxlan_private.h             |  19 +-
 drivers/net/vxlan/vxlan_vnifilter.c           |  96 ++-
 include/net/vxlan.h                           |  12 +-
 9 files changed, 638 insertions(+), 409 deletions(-)

-- 
2.55.0.1007.g17ff1f9808-goog


^ permalink raw reply	[flat|nested] 12+ messages in thread

* [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()
  2026-09-11  6:21 [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps Eric Dumazet
@ 2026-09-11  6:21 ` Eric Dumazet
  2026-09-15  2:00   ` Jakub Kicinski
  2026-09-11  6:21 ` [PATCH v3 net-next 2/6] vxlan: pass vxlan_config pointer to helper functions Eric Dumazet
                   ` (4 subsequent siblings)
  5 siblings, 1 reply; 12+ messages in thread
From: Eric Dumazet @ 2026-09-11  6:21 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Kuniyuki Iwashima, Ido Schimmel, Andrew Lunn,
	netdev, eric.dumazet, Eric Dumazet

RTM_GETTUNNEL dumps currently run under RTNL lock, but
vxlan_vnifilter_dump() also acquires rcu_read_lock().

1) Currently vxlan_vnifilter_dump_dev() traverses vg->vni_list using
   list_for_each_entry_safe(). Even though RTNL is held today, writers
   modify vg->vni_list with list_add_rcu() and list_del_rcu().
   Switch to list_for_each_entry_rcu() for proper RCU traversal and
   as preparation for future lockless dump support.

2) During a paginated dump, RTNL is released between dump skbs.
   If vxlan_vnifilter_dump_dev() returns early because VXLAN_F_VNIFILTER
   is not set or vg has no VNIs, cb->args[1] was not cleared. This leaked
   a non-zero VNI offset to subsequent devices, silently skipping their
   first N VNIs.
   Furthermore, if devices are added or removed between dump calls,
   ordinal device indexes can shift. Track the current device ifindex
   in cb->args[2] and reset cb->args[1] if the device changes.

Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 drivers/net/vxlan/vxlan_vnifilter.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
index dd94085e088656d27b62420a5c8c95c609510a4c..0a18c32902da08dc2732e2aea10d58b8753fe57f 100644
--- a/drivers/net/vxlan/vxlan_vnifilter.c
+++ b/drivers/net/vxlan/vxlan_vnifilter.c
@@ -333,22 +333,34 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
 				    struct sk_buff *skb,
 				    struct netlink_callback *cb)
 {
-	struct vxlan_vni_node *tmp, *v, *vbegin = NULL, *vend = NULL;
+	struct vxlan_vni_node *v, *vbegin = NULL, *vend = NULL;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct tunnel_msg *new_tmsg, *tmsg;
-	int idx = 0, s_idx = cb->args[1];
 	struct vxlan_vni_group *vg;
 	struct nlmsghdr *nlh;
+	int idx = 0, s_idx;
 	bool dump_stats;
 	int err = 0;
 
-	if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER))
+	if (cb->args[2] != dev->ifindex) {
+		cb->args[1] = 0;
+		cb->args[2] = dev->ifindex;
+	}
+	s_idx = cb->args[1];
+
+	if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER)) {
+		cb->args[1] = 0;
+		cb->args[2] = 0;
 		return -EINVAL;
+	}
 
 	/* RCU needed because of the vni locking rules (rcu || rtnl) */
 	vg = rcu_dereference(vxlan->vnigrp);
-	if (!vg || !vg->num_vnis)
+	if (!vg || !vg->num_vnis) {
+		cb->args[1] = 0;
+		cb->args[2] = 0;
 		return 0;
+	}
 
 	tmsg = nlmsg_data(cb->nlh);
 	dump_stats = !!(tmsg->flags & TUNNEL_MSG_FLAG_STATS);
@@ -362,7 +374,7 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
 	new_tmsg->family = PF_BRIDGE;
 	new_tmsg->ifindex = dev->ifindex;
 
-	list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
+	list_for_each_entry_rcu(v, &vg->vni_list, vlist) {
 		if (idx < s_idx) {
 			idx++;
 			continue;
@@ -394,6 +406,7 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
 	}
 
 	cb->args[1] = err ? idx : 0;
+	cb->args[2] = err ? dev->ifindex : 0;
 
 	nlmsg_end(skb, nlh);
 
-- 
2.55.0.1007.g17ff1f9808-goog


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v3 net-next 2/6] vxlan: pass vxlan_config pointer to helper functions
  2026-09-11  6:21 [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps Eric Dumazet
  2026-09-11  6:21 ` [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev() Eric Dumazet
@ 2026-09-11  6:21 ` Eric Dumazet
  2026-09-11  6:21 ` [PATCH v3 net-next 3/6] vxlan: move VXLAN_F_MDB to struct vxlan_dev flags Eric Dumazet
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 12+ messages in thread
From: Eric Dumazet @ 2026-09-11  6:21 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Kuniyuki Iwashima, Ido Schimmel, Andrew Lunn,
	netdev, eric.dumazet, Eric Dumazet

In preparation for converting vxlan->cfg to an RCU-protected pointer,
refactor internal helper functions in the RX, TX, MDB, and VNIFILTER
paths to accept a pointer to struct vxlan_config (or pass flags/
saddr_family where appropriate) rather than directly accessing
vxlan->cfg.

No functional changes.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 drivers/net/vxlan/vxlan_core.c      | 343 +++++++++++++++-------------
 drivers/net/vxlan/vxlan_mdb.c       |  21 +-
 drivers/net/vxlan/vxlan_private.h   |   8 +-
 drivers/net/vxlan/vxlan_vnifilter.c |   5 +-
 4 files changed, 206 insertions(+), 171 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 347245cc1de4ea44f723176312b0b53869a1641c..3115b056a68ddae35720bf6e25558b77f51beba0 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -377,14 +377,15 @@ static void vxlan_fdb_miss(struct vxlan_dev *vxlan, const u8 eth_addr[ETH_ALEN])
 
 /* Look up Ethernet address in forwarding table */
 static struct vxlan_fdb *vxlan_find_mac_rcu(struct vxlan_dev *vxlan,
+					    const struct vxlan_config *cfg,
 					    const u8 *mac, __be32 vni)
 {
 	struct vxlan_fdb_key key;
 
 	memset(&key, 0, sizeof(key));
 	memcpy(key.eth_addr, mac, sizeof(key.eth_addr));
-	if (!(vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA))
-		key.vni = vxlan->default_dst.remote_vni;
+	if (!(cfg->flags & VXLAN_F_COLLECT_METADATA))
+		key.vni = cfg->vni;
 	else
 		key.vni = vni;
 
@@ -393,11 +394,12 @@ static struct vxlan_fdb *vxlan_find_mac_rcu(struct vxlan_dev *vxlan,
 }
 
 static struct vxlan_fdb *vxlan_find_mac_tx(struct vxlan_dev *vxlan,
+					   const struct vxlan_config *cfg,
 					   const u8 *mac, __be32 vni)
 {
 	struct vxlan_fdb *f;
 
-	f = vxlan_find_mac_rcu(vxlan, mac, vni);
+	f = vxlan_find_mac_rcu(vxlan, cfg, mac, vni);
 	if (f) {
 		unsigned long now = jiffies;
 
@@ -416,7 +418,7 @@ static struct vxlan_fdb *vxlan_find_mac(struct vxlan_dev *vxlan,
 	lockdep_assert_held_once(&vxlan->hash_lock);
 
 	rcu_read_lock();
-	f = vxlan_find_mac_rcu(vxlan, mac, vni);
+	f = vxlan_find_mac_rcu(vxlan, &vxlan->cfg, mac, vni);
 	rcu_read_unlock();
 
 	return f;
@@ -457,7 +459,7 @@ int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 
 	rcu_read_lock();
 
-	f = vxlan_find_mac_rcu(vxlan, eth_addr, vni);
+	f = vxlan_find_mac_rcu(vxlan, &vxlan->cfg, eth_addr, vni);
 	if (f)
 		rdst = first_remote_rcu(f);
 	if (!rdst) {
@@ -1416,7 +1418,7 @@ static int vxlan_fdb_get(struct sk_buff *skb,
 
 	rcu_read_lock();
 
-	f = vxlan_find_mac_rcu(vxlan, addr, vni);
+	f = vxlan_find_mac_rcu(vxlan, &vxlan->cfg, addr, vni);
 	if (!f) {
 		NL_SET_ERR_MSG(extack, "Fdb entry not found");
 		err = -ENOENT;
@@ -1434,6 +1436,7 @@ static int vxlan_fdb_get(struct sk_buff *skb,
  * and Tunnel endpoint.
  */
 static enum skb_drop_reason vxlan_snoop(struct net_device *dev,
+					const struct vxlan_config *cfg,
 					union vxlan_addr *src_ip,
 					const u8 *src_mac, u32 src_ifindex,
 					__be32 vni)
@@ -1452,7 +1455,7 @@ static enum skb_drop_reason vxlan_snoop(struct net_device *dev,
 		ifindex = src_ifindex;
 #endif
 
-	f = vxlan_find_mac_rcu(vxlan, src_mac, vni);
+	f = vxlan_find_mac_rcu(vxlan, cfg, src_mac, vni);
 	if (likely(f)) {
 		struct vxlan_rdst *rdst = first_remote_rcu(f);
 		unsigned long now = jiffies;
@@ -1488,9 +1491,9 @@ static enum skb_drop_reason vxlan_snoop(struct net_device *dev,
 			vxlan_fdb_update(vxlan, src_mac, src_ip,
 					 NUD_REACHABLE,
 					 NLM_F_EXCL|NLM_F_CREATE,
-					 vxlan->cfg.dst_port,
+					 cfg->dst_port,
 					 vni,
-					 vxlan->default_dst.remote_vni,
+					 cfg->vni,
 					 ifindex, NTF_SELF, 0, true, NULL);
 		spin_unlock(&vxlan->hash_lock);
 	}
@@ -1598,6 +1601,7 @@ static void vxlan_parse_gbp_hdr(struct sk_buff *skb, u32 vxflags,
 }
 
 static enum skb_drop_reason vxlan_set_mac(struct vxlan_dev *vxlan,
+					  const struct vxlan_config *cfg,
 					  struct vxlan_sock *vs,
 					  struct sk_buff *skb, __be32 vni)
 {
@@ -1623,10 +1627,10 @@ static enum skb_drop_reason vxlan_set_mac(struct vxlan_dev *vxlan,
 #endif
 	}
 
-	if (!(vxlan->cfg.flags & VXLAN_F_LEARN))
+	if (!(cfg->flags & VXLAN_F_LEARN))
 		return SKB_NOT_DROPPED_YET;
 
-	return vxlan_snoop(skb->dev, &saddr, eth_hdr(skb)->h_source,
+	return vxlan_snoop(skb->dev, cfg, &saddr, eth_hdr(skb)->h_source,
 			   ifindex, vni);
 }
 
@@ -1657,18 +1661,21 @@ static bool vxlan_ecn_decapsulate(struct vxlan_sock *vs, void *oiph,
 static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 {
 	struct vxlan_vni_node *vninode = NULL;
-	const struct vxlanhdr *vh;
-	struct vxlan_dev *vxlan;
-	struct vxlan_sock *vs;
-	struct vxlan_metadata _md;
-	struct vxlan_metadata *md = &_md;
 	__be16 protocol = htons(ETH_P_TEB);
+	const struct vxlan_config *cfg;
 	enum skb_drop_reason reason;
+	const struct vxlanhdr *vh;
+	struct vxlan_metadata *md;
+	struct vxlan_metadata _md;
+	struct vxlan_dev *vxlan;
 	bool raw_proto = false;
-	void *oiph;
+	struct vxlan_sock *vs;
 	__be32 vni = 0;
+	void *oiph;
 	int nh;
 
+	md = &_md;
+
 	/* Need UDP and VXLAN header to be present */
 	reason = pskb_may_pull_reason(skb, VXLAN_HLEN);
 	if (reason)
@@ -1696,8 +1703,9 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 	}
 
-	if (vh->vx_flags & vxlan->cfg.reserved_bits.vx_flags ||
-	    vh->vx_vni & vxlan->cfg.reserved_bits.vx_vni) {
+	cfg = &vxlan->cfg;
+	if (vh->vx_flags & cfg->reserved_bits.vx_flags ||
+	    vh->vx_vni & cfg->reserved_bits.vx_vni) {
 		/* If the header uses bits besides those enabled by the
 		 * netdevice configuration, treat this as a malformed packet.
 		 * This behavior diverges from VXLAN RFC (RFC7348) which
@@ -1709,12 +1717,12 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		reason = SKB_DROP_REASON_VXLAN_INVALID_HDR;
 		DEV_STATS_INC(vxlan->dev, rx_frame_errors);
 		DEV_STATS_INC(vxlan->dev, rx_errors);
-		vxlan_vnifilter_count(vxlan, vni, vninode,
+		vxlan_vnifilter_count(vxlan, cfg, vni, vninode,
 				      VXLAN_VNI_STATS_RX_ERRORS, 0);
 		goto drop;
 	}
 
-	if (vxlan->cfg.flags & VXLAN_F_GPE) {
+	if (cfg->flags & VXLAN_F_GPE) {
 		if (!vxlan_parse_gpe_proto(vh, &protocol))
 			goto drop;
 		raw_proto = true;
@@ -1726,8 +1734,8 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 	}
 
-	if (vxlan->cfg.flags & VXLAN_F_REMCSUM_RX) {
-		reason = vxlan_remcsum(skb, vxlan->cfg.flags);
+	if (cfg->flags & VXLAN_F_REMCSUM_RX) {
+		reason = vxlan_remcsum(skb, cfg->flags);
 		if (unlikely(reason))
 			goto drop;
 	}
@@ -1752,14 +1760,14 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		memset(md, 0, sizeof(*md));
 	}
 
-	if (vxlan->cfg.flags & VXLAN_F_GBP)
-		vxlan_parse_gbp_hdr(skb, vxlan->cfg.flags, md);
+	if (cfg->flags & VXLAN_F_GBP)
+		vxlan_parse_gbp_hdr(skb, cfg->flags, md);
 	/* Note that GBP and GPE can never be active together. This is
 	 * ensured in vxlan_dev_configure.
 	 */
 
 	if (!raw_proto) {
-		reason = vxlan_set_mac(vxlan, vs, skb, vni);
+		reason = vxlan_set_mac(vxlan, cfg, vs, skb, vni);
 		if (reason)
 			goto drop;
 	} else {
@@ -1780,7 +1788,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	if (reason) {
 		DEV_STATS_INC(vxlan->dev, rx_length_errors);
 		DEV_STATS_INC(vxlan->dev, rx_errors);
-		vxlan_vnifilter_count(vxlan, vni, vninode,
+		vxlan_vnifilter_count(vxlan, cfg, vni, vninode,
 				      VXLAN_VNI_STATS_RX_ERRORS, 0);
 		goto drop;
 	}
@@ -1792,7 +1800,7 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		reason = SKB_DROP_REASON_IP_TUNNEL_ECN;
 		DEV_STATS_INC(vxlan->dev, rx_frame_errors);
 		DEV_STATS_INC(vxlan->dev, rx_errors);
-		vxlan_vnifilter_count(vxlan, vni, vninode,
+		vxlan_vnifilter_count(vxlan, cfg, vni, vninode,
 				      VXLAN_VNI_STATS_RX_ERRORS, 0);
 		goto drop;
 	}
@@ -1802,14 +1810,15 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 	if (unlikely(!(vxlan->dev->flags & IFF_UP))) {
 		rcu_read_unlock();
 		dev_dstats_rx_dropped(vxlan->dev);
-		vxlan_vnifilter_count(vxlan, vni, vninode,
+		vxlan_vnifilter_count(vxlan, cfg, vni, vninode,
 				      VXLAN_VNI_STATS_RX_DROPS, 0);
 		reason = SKB_DROP_REASON_DEV_READY;
 		goto drop;
 	}
 
 	dev_dstats_rx_add(vxlan->dev, skb->len);
-	vxlan_vnifilter_count(vxlan, vni, vninode, VXLAN_VNI_STATS_RX, skb->len);
+	vxlan_vnifilter_count(vxlan, cfg, vni, vninode, VXLAN_VNI_STATS_RX,
+			      skb->len);
 	gro_cells_receive(&vxlan->gro_cells, skb);
 
 	rcu_read_unlock();
@@ -1850,7 +1859,7 @@ static int vxlan_err_lookup(struct sock *sk, struct sk_buff *skb)
 	return 0;
 }
 
-static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
+static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni, u32 flags)
 {
 	struct neigh_table *tbl = arp_table(dev_net(dev));
 	struct vxlan_dev *vxlan = netdev_priv(dev);
@@ -1864,7 +1873,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 
 	if (!pskb_network_may_pull(skb, arp_hdr_len(dev))) {
 		dev_dstats_tx_dropped(dev);
-		vxlan_vnifilter_count(vxlan, vni, NULL,
+		vxlan_vnifilter_count(vxlan, &vxlan->cfg, vni, NULL,
 				      VXLAN_VNI_STATS_TX_DROPS, 0);
 		goto out;
 	}
@@ -1905,7 +1914,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 		neigh_ha_snapshot(ha, n, n->dev);
 
 		rcu_read_lock();
-		f = vxlan_find_mac_tx(vxlan, ha, vni);
+		f = vxlan_find_mac_tx(vxlan, &vxlan->cfg, ha, vni);
 		if (f)
 			rdst = first_remote_rcu(f);
 		if (rdst && vxlan_addr_any(&rdst->remote_ip)) {
@@ -1931,11 +1940,11 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 
 		if (netif_rx(reply) == NET_RX_DROP) {
 			dev_dstats_rx_dropped(dev);
-			vxlan_vnifilter_count(vxlan, vni, NULL,
+			vxlan_vnifilter_count(vxlan, &vxlan->cfg, vni, NULL,
 					      VXLAN_VNI_STATS_RX_DROPS, 0);
 		}
 
-	} else if (vxlan->cfg.flags & VXLAN_F_L3MISS) {
+	} else if (flags & VXLAN_F_L3MISS) {
 		union vxlan_addr ipa = {
 			.sin.sin_addr.s_addr = tip,
 			.sin.sin_family = AF_INET,
@@ -2043,7 +2052,7 @@ static struct sk_buff *vxlan_na_create(struct sk_buff *request,
 	return reply;
 }
 
-static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
+static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni, u32 flags)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	const struct in6_addr *daddr;
@@ -2077,7 +2086,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 		}
 
 		neigh_ha_snapshot(ha, n, n->dev);
-		f = vxlan_find_mac_tx(vxlan, ha, vni);
+		f = vxlan_find_mac_tx(vxlan, &vxlan->cfg, ha, vni);
 		if (f)
 			rdst = first_remote_rcu(f);
 		if (rdst && vxlan_addr_any(&rdst->remote_ip)) {
@@ -2096,10 +2105,10 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 
 		if (netif_rx(reply) == NET_RX_DROP) {
 			dev_dstats_rx_dropped(dev);
-			vxlan_vnifilter_count(vxlan, vni, NULL,
+			vxlan_vnifilter_count(vxlan, &vxlan->cfg, vni, NULL,
 					      VXLAN_VNI_STATS_RX_DROPS, 0);
 		}
-	} else if (vxlan->cfg.flags & VXLAN_F_L3MISS) {
+	} else if (flags & VXLAN_F_L3MISS) {
 		union vxlan_addr ipa = {
 			.sin6.sin6_addr = msg->target,
 			.sin6.sin6_family = AF_INET6,
@@ -2115,9 +2124,9 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni)
 }
 #endif
 
-static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
+static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb,
+			       const struct vxlan_config *cfg)
 {
-	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct neigh_table *tbl;
 	struct neighbour *n;
 
@@ -2136,7 +2145,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
 		tbl = arp_table(dev_net(dev));
 		pip = ip_hdr(skb);
 		n = neigh_lookup(tbl, &pip->daddr, dev);
-		if (!n && (vxlan->cfg.flags & VXLAN_F_L3MISS)) {
+		if (!n && (cfg->flags & VXLAN_F_L3MISS)) {
 			union vxlan_addr ipa = {
 				.sin.sin_addr.s_addr = pip->daddr,
 				.sin.sin_family = AF_INET,
@@ -2164,7 +2173,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb)
 		tbl = nd_table(dev_net(dev));
 		pip6 = ipv6_hdr(skb);
 		n = neigh_lookup(tbl, &pip6->daddr, dev);
-		if (!n && (vxlan->cfg.flags & VXLAN_F_L3MISS)) {
+		if (!n && (cfg->flags & VXLAN_F_L3MISS)) {
 			union vxlan_addr ipa = {
 				.sin6.sin6_addr = pip6->daddr,
 				.sin6.sin6_family = AF_INET6,
@@ -2282,20 +2291,21 @@ static int vxlan_build_skb(struct sk_buff *skb, struct dst_entry *dst,
 
 /* Bypass encapsulation if the destination is local */
 static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
-			       struct vxlan_dev *dst_vxlan, __be32 vni,
-			       bool snoop)
+			       struct vxlan_dev *dst_vxlan,
+			       const struct vxlan_config *src_cfg,
+			       __be32 vni, bool snoop)
 {
+	const struct vxlan_config *dst_cfg = &dst_vxlan->cfg;
 	union vxlan_addr loopback;
-	union vxlan_addr *remote_ip = &dst_vxlan->default_dst.remote_ip;
 	unsigned int len = skb->len;
-	struct net_device *dev;
+	struct net_device *dev = dst_vxlan->dev;
 
 	skb->pkt_type = PACKET_HOST;
 	skb->encapsulation = 0;
-	skb->dev = dst_vxlan->dev;
+	skb->dev = dev;
 	__skb_pull(skb, skb_network_offset(skb));
 
-	if (remote_ip->sa.sa_family == AF_INET) {
+	if (dst_vxlan->default_dst.remote_ip.sa.sa_family == AF_INET) {
 		loopback.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 		loopback.sa.sa_family =  AF_INET;
 #if IS_ENABLED(CONFIG_IPV6)
@@ -2306,26 +2316,25 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
 	}
 
 	rcu_read_lock();
-	dev = skb->dev;
 	if (unlikely(!(dev->flags & IFF_UP))) {
 		kfree_skb_reason(skb, SKB_DROP_REASON_DEV_READY);
 		goto drop;
 	}
 
-	if ((dst_vxlan->cfg.flags & VXLAN_F_LEARN) && snoop)
-		vxlan_snoop(dev, &loopback, eth_hdr(skb)->h_source, 0, vni);
+	if ((dst_cfg->flags & VXLAN_F_LEARN) && snoop)
+		vxlan_snoop(dev, dst_cfg, &loopback, eth_hdr(skb)->h_source, 0, vni);
 
 	dev_dstats_tx_add(src_vxlan->dev, len);
-	vxlan_vnifilter_count(src_vxlan, vni, NULL, VXLAN_VNI_STATS_TX, len);
+	vxlan_vnifilter_count(src_vxlan, src_cfg, vni, NULL, VXLAN_VNI_STATS_TX, len);
 
 	if (__netif_rx(skb) == NET_RX_SUCCESS) {
 		dev_dstats_rx_add(dst_vxlan->dev, len);
-		vxlan_vnifilter_count(dst_vxlan, vni, NULL, VXLAN_VNI_STATS_RX,
+		vxlan_vnifilter_count(dst_vxlan, dst_cfg, vni, NULL, VXLAN_VNI_STATS_RX,
 				      len);
 	} else {
 drop:
 		dev_dstats_rx_dropped(dev);
-		vxlan_vnifilter_count(dst_vxlan, vni, NULL,
+		vxlan_vnifilter_count(dst_vxlan, dst_cfg, vni, NULL,
 				      VXLAN_VNI_STATS_RX_DROPS, 0);
 	}
 	rcu_read_unlock();
@@ -2333,6 +2342,7 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
 
 static int encap_bypass_if_local(struct sk_buff *skb, struct net_device *dev,
 				 struct vxlan_dev *vxlan,
+				 const struct vxlan_config *cfg,
 				 int addr_family,
 				 __be16 dst_port, int dst_ifindex, __be32 vni,
 				 struct dst_entry *dst,
@@ -2348,22 +2358,22 @@ static int encap_bypass_if_local(struct sk_buff *skb, struct net_device *dev,
 	/* Bypass encapsulation if the destination is local */
 	if (rt_flags & RTCF_LOCAL &&
 	    !(rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST)) &&
-	    vxlan->cfg.flags & VXLAN_F_LOCALBYPASS) {
+	    cfg->flags & VXLAN_F_LOCALBYPASS) {
 		struct vxlan_dev *dst_vxlan;
 
 		dst_release(dst);
 		dst_vxlan = vxlan_find_vni(vxlan->net, dst_ifindex, vni,
 					   addr_family, dst_port,
-					   vxlan->cfg.flags);
+					   cfg->flags);
 		if (!dst_vxlan) {
 			DEV_STATS_INC(dev, tx_errors);
-			vxlan_vnifilter_count(vxlan, vni, NULL,
+			vxlan_vnifilter_count(vxlan, cfg, vni, NULL,
 					      VXLAN_VNI_STATS_TX_ERRORS, 0);
 			kfree_skb_reason(skb, SKB_DROP_REASON_VXLAN_VNI_NOT_FOUND);
 
 			return -ENOENT;
 		}
-		vxlan_encap_bypass(skb, vxlan, dst_vxlan, vni, true);
+		vxlan_encap_bypass(skb, vxlan, dst_vxlan, cfg, vni, true);
 		return 1;
 	}
 
@@ -2371,30 +2381,35 @@ static int encap_bypass_if_local(struct sk_buff *skb, struct net_device *dev,
 }
 
 void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
+		    const struct vxlan_config *cfg,
 		    __be32 default_vni, struct vxlan_rdst *rdst, bool did_rsc)
 {
+	unsigned int pkt_len = skb->len;
+	struct vxlan_metadata _md = {};
+	__be16 src_port = 0, dst_port;
+	struct dst_entry *ndst = NULL;
+	enum skb_drop_reason reason;
 	struct dst_cache *dst_cache;
+	const struct iphdr *old_iph;
 	struct ip_tunnel_info *info;
 	struct ip_tunnel_key *pkey;
+	struct vxlan_metadata *md;
 	struct ip_tunnel_key key;
-	struct vxlan_dev *vxlan = netdev_priv(dev);
-	const struct iphdr *old_iph;
-	struct vxlan_metadata _md = {};
-	struct vxlan_metadata *md = &_md;
-	unsigned int pkt_len = skb->len;
-	__be16 src_port = 0, dst_port;
-	struct dst_entry *ndst = NULL;
+	struct vxlan_dev *vxlan;
+	u32 flags = cfg->flags;
+	bool udp_sum = false;
+	bool no_eth_encap;
 	int addr_family;
+	bool use_cache;
+	__be32 vni = 0;
 	__u8 tos, ttl;
 	int ifindex;
 	int err = 0;
-	u32 flags = vxlan->cfg.flags;
-	bool use_cache;
-	bool udp_sum = false;
-	bool xnet = !net_eq(vxlan->net, dev_net(vxlan->dev));
-	enum skb_drop_reason reason;
-	bool no_eth_encap;
-	__be32 vni = 0;
+	bool xnet;
+
+	vxlan = netdev_priv(dev);
+	xnet = !net_eq(vxlan->net, dev_net(vxlan->dev));
+	md = &_md;
 
 	no_eth_encap = flags & VXLAN_F_GPE && skb->protocol != htons(ETH_P_TEB);
 	reason = skb_vlan_inet_prepare(skb, no_eth_encap);
@@ -2414,23 +2429,23 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		if (vxlan_addr_any(&rdst->remote_ip)) {
 			if (did_rsc) {
 				/* short-circuited back to local bridge */
-				vxlan_encap_bypass(skb, vxlan, vxlan,
+				vxlan_encap_bypass(skb, vxlan, vxlan, cfg,
 						   default_vni, true);
 				return;
 			}
 			goto drop;
 		}
 
-		addr_family = vxlan->cfg.saddr.sa.sa_family;
-		dst_port = rdst->remote_port ? rdst->remote_port : vxlan->cfg.dst_port;
+		addr_family = cfg->saddr.sa.sa_family;
+		dst_port = rdst->remote_port ? rdst->remote_port : cfg->dst_port;
 		vni = (rdst->remote_vni) ? : default_vni;
 		ifindex = rdst->remote_ifindex;
 
 		if (addr_family == AF_INET) {
-			key.u.ipv4.src = vxlan->cfg.saddr.sin.sin_addr.s_addr;
+			key.u.ipv4.src = cfg->saddr.sin.sin_addr.s_addr;
 			key.u.ipv4.dst = rdst->remote_ip.sin.sin_addr.s_addr;
 		} else {
-			key.u.ipv6.src = vxlan->cfg.saddr.sin6.sin6_addr;
+			key.u.ipv6.src = cfg->saddr.sin6.sin6_addr;
 			key.u.ipv6.dst = rdst->remote_ip.sin6.sin6_addr;
 		}
 
@@ -2439,11 +2454,11 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		if (flags & VXLAN_F_TTL_INHERIT) {
 			ttl = ip_tunnel_get_ttl(old_iph, skb);
 		} else {
-			ttl = vxlan->cfg.ttl;
+			ttl = cfg->ttl;
 			if (!ttl && vxlan_addr_multicast(&rdst->remote_ip))
 				ttl = 1;
 		}
-		tos = vxlan->cfg.tos;
+		tos = cfg->tos;
 		if (tos == 1)
 			tos = ip_tunnel_get_dsfield(old_iph, skb);
 		if (tos && !info)
@@ -2454,9 +2469,9 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		else
 			udp_sum = !(flags & VXLAN_F_UDP_ZERO_CSUM6_TX);
 #if IS_ENABLED(CONFIG_IPV6)
-		switch (vxlan->cfg.label_policy) {
+		switch (cfg->label_policy) {
 		case VXLAN_LABEL_FIXED:
-			key.label = vxlan->cfg.label;
+			key.label = cfg->label;
 			break;
 		case VXLAN_LABEL_INHERIT:
 			key.label = ip_tunnel_get_flowlabel(old_iph, skb);
@@ -2474,7 +2489,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		}
 		pkey = &info->key;
 		addr_family = ip_tunnel_info_af(info);
-		dst_port = info->key.tp_dst ? : vxlan->cfg.dst_port;
+		dst_port = info->key.tp_dst ? : cfg->dst_port;
 		vni = tunnel_id_to_key32(info->key.tun_id);
 		ifindex = 0;
 		dst_cache = &info->dst_cache;
@@ -2487,8 +2502,8 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		tos = info->key.tos;
 		udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
 	}
-	src_port = udp_flow_src_port(dev_net(dev), skb, vxlan->cfg.port_min,
-				     vxlan->cfg.port_max, true);
+	src_port = udp_flow_src_port(dev_net(dev), skb, cfg->port_min,
+				     cfg->port_max, true);
 
 	rcu_read_lock();
 	if (addr_family == AF_INET) {
@@ -2521,15 +2536,15 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 
 		if (!info) {
 			/* Bypass encapsulation if the destination is local */
-			err = encap_bypass_if_local(skb, dev, vxlan, AF_INET,
+			err = encap_bypass_if_local(skb, dev, vxlan, cfg, AF_INET,
 						    dst_port, ifindex, vni,
 						    &rt->dst, rt->rt_flags);
 			if (err)
 				goto out_unlock;
 
-			if (vxlan->cfg.df == VXLAN_DF_SET) {
+			if (cfg->df == VXLAN_DF_SET) {
 				df = htons(IP_DF);
-			} else if (vxlan->cfg.df == VXLAN_DF_INHERIT) {
+			} else if (cfg->df == VXLAN_DF_INHERIT) {
 				struct ethhdr *eth = eth_hdr(skb);
 
 				if (ntohs(eth->h_proto) == ETH_P_IPV6 ||
@@ -2558,7 +2573,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 				unclone->key.u.ipv4.src = pkey->u.ipv4.dst;
 				unclone->key.u.ipv4.dst = saddr;
 			}
-			vxlan_encap_bypass(skb, vxlan, vxlan, vni, false);
+			vxlan_encap_bypass(skb, vxlan, vxlan, cfg, vni, false);
 			dst_release(ndst);
 			goto out_unlock;
 		}
@@ -2608,7 +2623,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		if (!info) {
 			u32 rt6i_flags = dst_rt6_info(ndst)->rt6i_flags;
 
-			err = encap_bypass_if_local(skb, dev, vxlan, AF_INET6,
+			err = encap_bypass_if_local(skb, dev, vxlan, cfg, AF_INET6,
 						    dst_port, ifindex, vni,
 						    ndst, rt6i_flags);
 			if (err)
@@ -2632,7 +2647,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 				unclone->key.u.ipv6.dst = saddr;
 			}
 
-			vxlan_encap_bypass(skb, vxlan, vxlan, vni, false);
+			vxlan_encap_bypass(skb, vxlan, vxlan, cfg, vni, false);
 			dst_release(ndst);
 			goto out_unlock;
 		}
@@ -2653,14 +2668,14 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 				     ip6cb_flags);
 #endif
 	}
-	vxlan_vnifilter_count(vxlan, vni, NULL, VXLAN_VNI_STATS_TX, pkt_len);
+	vxlan_vnifilter_count(vxlan, cfg, vni, NULL, VXLAN_VNI_STATS_TX, pkt_len);
 out_unlock:
 	rcu_read_unlock();
 	return;
 
 drop:
 	dev_dstats_tx_dropped(dev);
-	vxlan_vnifilter_count(vxlan, vni, NULL, VXLAN_VNI_STATS_TX_DROPS, 0);
+	vxlan_vnifilter_count(vxlan, cfg, vni, NULL, VXLAN_VNI_STATS_TX_DROPS, 0);
 	kfree_skb_reason(skb, reason);
 	return;
 
@@ -2672,11 +2687,12 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		DEV_STATS_INC(dev, tx_carrier_errors);
 	dst_release(ndst);
 	DEV_STATS_INC(dev, tx_errors);
-	vxlan_vnifilter_count(vxlan, vni, NULL, VXLAN_VNI_STATS_TX_ERRORS, 0);
+	vxlan_vnifilter_count(vxlan, cfg, vni, NULL, VXLAN_VNI_STATS_TX_ERRORS, 0);
 	kfree_skb_reason(skb, reason);
 }
 
 static void vxlan_xmit_nh(struct sk_buff *skb, struct net_device *dev,
+			  const struct vxlan_config *cfg,
 			  struct vxlan_fdb *f, __be32 vni, bool did_rsc)
 {
 	struct vxlan_rdst nh_rdst;
@@ -2693,7 +2709,7 @@ static void vxlan_xmit_nh(struct sk_buff *skb, struct net_device *dev,
 	do_xmit = vxlan_fdb_nh_path_select(nh, hash, &nh_rdst);
 
 	if (likely(do_xmit))
-		vxlan_xmit_one(skb, dev, vni, &nh_rdst, did_rsc);
+		vxlan_xmit_one(skb, dev, cfg, vni, &nh_rdst, did_rsc);
 	else
 		goto drop;
 
@@ -2701,15 +2717,15 @@ static void vxlan_xmit_nh(struct sk_buff *skb, struct net_device *dev,
 
 drop:
 	dev_dstats_tx_dropped(dev);
-	vxlan_vnifilter_count(netdev_priv(dev), vni, NULL,
+	vxlan_vnifilter_count(netdev_priv(dev), cfg, vni, NULL,
 			      VXLAN_VNI_STATS_TX_DROPS, 0);
 	dev_kfree_skb(skb);
 }
 
 static netdev_tx_t vxlan_xmit_nhid(struct sk_buff *skb, struct net_device *dev,
-				   u32 nhid, __be32 vni)
+				   u32 nhid, __be32 vni,
+				   const struct vxlan_config *cfg)
 {
-	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_rdst nh_rdst;
 	struct nexthop *nh;
 	bool do_xmit;
@@ -2727,11 +2743,11 @@ static netdev_tx_t vxlan_xmit_nhid(struct sk_buff *skb, struct net_device *dev,
 	do_xmit = vxlan_fdb_nh_path_select(nh, hash, &nh_rdst);
 	rcu_read_unlock();
 
-	if (vxlan->cfg.saddr.sa.sa_family != nh_rdst.remote_ip.sa.sa_family)
+	if (cfg->saddr.sa.sa_family != nh_rdst.remote_ip.sa.sa_family)
 		goto drop;
 
 	if (likely(do_xmit))
-		vxlan_xmit_one(skb, dev, vni, &nh_rdst, false);
+		vxlan_xmit_one(skb, dev, cfg, vni, &nh_rdst, false);
 	else
 		goto drop;
 
@@ -2739,7 +2755,7 @@ static netdev_tx_t vxlan_xmit_nhid(struct sk_buff *skb, struct net_device *dev,
 
 drop:
 	dev_dstats_tx_dropped(dev);
-	vxlan_vnifilter_count(netdev_priv(dev), vni, NULL,
+	vxlan_vnifilter_count(netdev_priv(dev), cfg, vni, NULL,
 			      VXLAN_VNI_STATS_TX_DROPS, 0);
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK;
@@ -2756,34 +2772,41 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_rdst *rdst, *fdst = NULL;
 	const struct ip_tunnel_info *info;
+	const struct vxlan_config *cfg;
+	__be32 default_vni;
 	struct vxlan_fdb *f;
 	struct ethhdr *eth;
 	__be32 vni = 0;
-	u32 nhid = 0;
 	bool did_rsc;
+	u32 nhid = 0;
+	u32 flags;
+
+	cfg = &vxlan->cfg;
+	flags = cfg->flags;
+	default_vni = cfg->vni;
 
 	info = skb_tunnel_info(skb);
 
 	skb_reset_mac_header(skb);
 
-	if (vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA) {
+	if (flags & VXLAN_F_COLLECT_METADATA) {
 		if (info && info->mode & IP_TUNNEL_INFO_BRIDGE &&
 		    info->mode & IP_TUNNEL_INFO_TX) {
 			vni = tunnel_id_to_key32(info->key.tun_id);
 			nhid = info->key.nhid;
 		} else {
 			if (info && info->mode & IP_TUNNEL_INFO_TX)
-				vxlan_xmit_one(skb, dev, vni, NULL, false);
+				vxlan_xmit_one(skb, dev, cfg, vni, NULL, false);
 			else
 				kfree_skb_reason(skb, SKB_DROP_REASON_TUNNEL_TXINFO);
 			return NETDEV_TX_OK;
 		}
 	}
 
-	if (vxlan->cfg.flags & VXLAN_F_PROXY) {
+	if (flags & VXLAN_F_PROXY) {
 		eth = eth_hdr(skb);
 		if (ntohs(eth->h_proto) == ETH_P_ARP)
-			return arp_reduce(dev, skb, vni);
+			return arp_reduce(dev, skb, vni, flags);
 #if IS_ENABLED(CONFIG_IPV6)
 		else if (ntohs(eth->h_proto) == ETH_P_IPV6 &&
 			 pskb_network_may_pull(skb, sizeof(struct ipv6hdr) +
@@ -2793,23 +2816,23 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 
 			if (m->icmph.icmp6_code == 0 &&
 			    m->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION)
-				return neigh_reduce(dev, skb, vni);
+				return neigh_reduce(dev, skb, vni, flags);
 		}
 #endif
 	}
 
 	if (nhid)
-		return vxlan_xmit_nhid(skb, dev, nhid, vni);
+		return vxlan_xmit_nhid(skb, dev, nhid, vni, cfg);
 
-	if (vxlan->cfg.flags & VXLAN_F_MDB) {
+	if (flags & VXLAN_F_MDB) {
 		struct vxlan_mdb_entry *mdb_entry;
 
 		rcu_read_lock();
-		mdb_entry = vxlan_mdb_entry_skb_get(vxlan, skb, vni);
+		mdb_entry = vxlan_mdb_entry_skb_get(vxlan, cfg, skb, vni);
 		if (mdb_entry) {
 			netdev_tx_t ret;
 
-			ret = vxlan_mdb_xmit(vxlan, mdb_entry, skb);
+			ret = vxlan_mdb_xmit(vxlan, cfg, mdb_entry, skb);
 			rcu_read_unlock();
 			return ret;
 		}
@@ -2818,27 +2841,27 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	eth = eth_hdr(skb);
 	rcu_read_lock();
-	f = vxlan_find_mac_tx(vxlan, eth->h_dest, vni);
+	f = vxlan_find_mac_tx(vxlan, cfg, eth->h_dest, vni);
 	did_rsc = false;
 
-	if (f && (f->flags & NTF_ROUTER) && (vxlan->cfg.flags & VXLAN_F_RSC) &&
+	if (f && (f->flags & NTF_ROUTER) && (flags & VXLAN_F_RSC) &&
 	    (ntohs(eth->h_proto) == ETH_P_IP ||
 	     ntohs(eth->h_proto) == ETH_P_IPV6)) {
-		did_rsc = route_shortcircuit(dev, skb);
+		did_rsc = route_shortcircuit(dev, skb, cfg);
 		eth = eth_hdr(skb);
 		if (did_rsc)
-			f = vxlan_find_mac_tx(vxlan, eth->h_dest, vni);
+			f = vxlan_find_mac_tx(vxlan, cfg, eth->h_dest, vni);
 	}
 
 	if (f == NULL) {
-		f = vxlan_find_mac_tx(vxlan, all_zeros_mac, vni);
+		f = vxlan_find_mac_tx(vxlan, cfg, all_zeros_mac, vni);
 		if (f == NULL) {
-			if ((vxlan->cfg.flags & VXLAN_F_L2MISS) &&
+			if ((flags & VXLAN_F_L2MISS) &&
 			    !is_multicast_ether_addr(eth->h_dest))
 				vxlan_fdb_miss(vxlan, eth->h_dest);
 
 			dev_dstats_tx_dropped(dev);
-			vxlan_vnifilter_count(vxlan, vni, NULL,
+			vxlan_vnifilter_count(vxlan, cfg, vni, NULL,
 					      VXLAN_VNI_STATS_TX_DROPS, 0);
 			kfree_skb_reason(skb, SKB_DROP_REASON_NO_TX_TARGET);
 			goto out;
@@ -2846,8 +2869,8 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	if (rcu_access_pointer(f->nh)) {
-		vxlan_xmit_nh(skb, dev, f,
-			      (vni ? : vxlan->default_dst.remote_vni), did_rsc);
+		vxlan_xmit_nh(skb, dev, cfg, f,
+			      (vni ? : default_vni), did_rsc);
 	} else {
 		list_for_each_entry_rcu(rdst, &f->remotes, list) {
 			struct sk_buff *skb1;
@@ -2858,10 +2881,10 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 			}
 			skb1 = skb_clone(skb, GFP_ATOMIC);
 			if (skb1)
-				vxlan_xmit_one(skb1, dev, vni, rdst, did_rsc);
+				vxlan_xmit_one(skb1, dev, cfg, vni, rdst, did_rsc);
 		}
 		if (fdst)
-			vxlan_xmit_one(skb, dev, vni, fdst, did_rsc);
+			vxlan_xmit_one(skb, dev, cfg, vni, fdst, did_rsc);
 		else
 			kfree_skb_reason(skb, SKB_DROP_REASON_NO_TX_TARGET);
 	}
@@ -3734,7 +3757,7 @@ static int vxlan_sock_add(struct vxlan_dev *vxlan)
 }
 
 int vxlan_vni_in_use(struct net *src_net, struct vxlan_dev *vxlan,
-		     struct vxlan_config *conf, __be32 vni)
+		     const struct vxlan_config *conf, __be32 vni)
 {
 	struct vxlan_net *vn = net_generic(src_net, vxlan_net_id);
 	struct vxlan_dev *tmp;
@@ -4596,10 +4619,10 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	const struct vxlan_dev *vxlan = netdev_priv(dev);
 	const struct vxlan_rdst *dst = &vxlan->default_dst;
-	struct ifla_vxlan_port_range ports = {
-		.low =  htons(vxlan->cfg.port_min),
-		.high = htons(vxlan->cfg.port_max),
-	};
+	struct ifla_vxlan_port_range ports;
+	const struct vxlan_config *cfg;
+
+	cfg = &vxlan->cfg;
 
 	if (nla_put_u32(skb, IFLA_VXLAN_ID, be32_to_cpu(dst->remote_vni)))
 		goto nla_put_failure;
@@ -4621,79 +4644,81 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	if (dst->remote_ifindex && nla_put_u32(skb, IFLA_VXLAN_LINK, dst->remote_ifindex))
 		goto nla_put_failure;
 
-	if (!vxlan_addr_any(&vxlan->cfg.saddr)) {
-		if (vxlan->cfg.saddr.sa.sa_family == AF_INET) {
+	if (!vxlan_addr_any(&cfg->saddr)) {
+		if (cfg->saddr.sa.sa_family == AF_INET) {
 			if (nla_put_in_addr(skb, IFLA_VXLAN_LOCAL,
-					    vxlan->cfg.saddr.sin.sin_addr.s_addr))
+					    cfg->saddr.sin.sin_addr.s_addr))
 				goto nla_put_failure;
 #if IS_ENABLED(CONFIG_IPV6)
 		} else {
 			if (nla_put_in6_addr(skb, IFLA_VXLAN_LOCAL6,
-					     &vxlan->cfg.saddr.sin6.sin6_addr))
+					     &cfg->saddr.sin6.sin6_addr))
 				goto nla_put_failure;
 #endif
 		}
 	}
 
-	if (nla_put_u8(skb, IFLA_VXLAN_TTL, vxlan->cfg.ttl) ||
+	if (nla_put_u8(skb, IFLA_VXLAN_TTL, cfg->ttl) ||
 	    nla_put_u8(skb, IFLA_VXLAN_TTL_INHERIT,
-		       !!(vxlan->cfg.flags & VXLAN_F_TTL_INHERIT)) ||
-	    nla_put_u8(skb, IFLA_VXLAN_TOS, vxlan->cfg.tos) ||
-	    nla_put_u8(skb, IFLA_VXLAN_DF, vxlan->cfg.df) ||
-	    nla_put_be32(skb, IFLA_VXLAN_LABEL, vxlan->cfg.label) ||
-	    nla_put_u32(skb, IFLA_VXLAN_LABEL_POLICY, vxlan->cfg.label_policy) ||
+		       !!(cfg->flags & VXLAN_F_TTL_INHERIT)) ||
+	    nla_put_u8(skb, IFLA_VXLAN_TOS, cfg->tos) ||
+	    nla_put_u8(skb, IFLA_VXLAN_DF, cfg->df) ||
+	    nla_put_be32(skb, IFLA_VXLAN_LABEL, cfg->label) ||
+	    nla_put_u32(skb, IFLA_VXLAN_LABEL_POLICY, cfg->label_policy) ||
 	    nla_put_u8(skb, IFLA_VXLAN_LEARNING,
-		       !!(vxlan->cfg.flags & VXLAN_F_LEARN)) ||
+		       !!(cfg->flags & VXLAN_F_LEARN)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_PROXY,
-		       !!(vxlan->cfg.flags & VXLAN_F_PROXY)) ||
+		       !!(cfg->flags & VXLAN_F_PROXY)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_RSC,
-		       !!(vxlan->cfg.flags & VXLAN_F_RSC)) ||
+		       !!(cfg->flags & VXLAN_F_RSC)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_L2MISS,
-		       !!(vxlan->cfg.flags & VXLAN_F_L2MISS)) ||
+		       !!(cfg->flags & VXLAN_F_L2MISS)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_L3MISS,
-		       !!(vxlan->cfg.flags & VXLAN_F_L3MISS)) ||
+		       !!(cfg->flags & VXLAN_F_L3MISS)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_COLLECT_METADATA,
-		       !!(vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA)) ||
-	    nla_put_u32(skb, IFLA_VXLAN_AGEING, vxlan->cfg.age_interval) ||
-	    nla_put_u32(skb, IFLA_VXLAN_LIMIT, vxlan->cfg.addrmax) ||
-	    nla_put_be16(skb, IFLA_VXLAN_PORT, vxlan->cfg.dst_port) ||
+		       !!(cfg->flags & VXLAN_F_COLLECT_METADATA)) ||
+	    nla_put_u32(skb, IFLA_VXLAN_AGEING, cfg->age_interval) ||
+	    nla_put_u32(skb, IFLA_VXLAN_LIMIT, cfg->addrmax) ||
+	    nla_put_be16(skb, IFLA_VXLAN_PORT, cfg->dst_port) ||
 	    nla_put_u8(skb, IFLA_VXLAN_UDP_CSUM,
-		       !(vxlan->cfg.flags & VXLAN_F_UDP_ZERO_CSUM_TX)) ||
+		       !(cfg->flags & VXLAN_F_UDP_ZERO_CSUM_TX)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_UDP_ZERO_CSUM6_TX,
-		       !!(vxlan->cfg.flags & VXLAN_F_UDP_ZERO_CSUM6_TX)) ||
+		       !!(cfg->flags & VXLAN_F_UDP_ZERO_CSUM6_TX)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_UDP_ZERO_CSUM6_RX,
-		       !!(vxlan->cfg.flags & VXLAN_F_UDP_ZERO_CSUM6_RX)) ||
+		       !!(cfg->flags & VXLAN_F_UDP_ZERO_CSUM6_RX)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_REMCSUM_TX,
-		       !!(vxlan->cfg.flags & VXLAN_F_REMCSUM_TX)) ||
+		       !!(cfg->flags & VXLAN_F_REMCSUM_TX)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_REMCSUM_RX,
-		       !!(vxlan->cfg.flags & VXLAN_F_REMCSUM_RX)) ||
+		       !!(cfg->flags & VXLAN_F_REMCSUM_RX)) ||
 	    nla_put_u8(skb, IFLA_VXLAN_LOCALBYPASS,
-		       !!(vxlan->cfg.flags & VXLAN_F_LOCALBYPASS)))
+		       !!(cfg->flags & VXLAN_F_LOCALBYPASS)))
 		goto nla_put_failure;
 
+	ports.low = htons(cfg->port_min);
+	ports.high = htons(cfg->port_max);
 	if (nla_put(skb, IFLA_VXLAN_PORT_RANGE, sizeof(ports), &ports))
 		goto nla_put_failure;
 
-	if (vxlan->cfg.flags & VXLAN_F_GBP &&
+	if (cfg->flags & VXLAN_F_GBP &&
 	    nla_put_flag(skb, IFLA_VXLAN_GBP))
 		goto nla_put_failure;
 
-	if (vxlan->cfg.flags & VXLAN_F_GPE &&
+	if (cfg->flags & VXLAN_F_GPE &&
 	    nla_put_flag(skb, IFLA_VXLAN_GPE))
 		goto nla_put_failure;
 
-	if (vxlan->cfg.flags & VXLAN_F_REMCSUM_NOPARTIAL &&
+	if (cfg->flags & VXLAN_F_REMCSUM_NOPARTIAL &&
 	    nla_put_flag(skb, IFLA_VXLAN_REMCSUM_NOPARTIAL))
 		goto nla_put_failure;
 
-	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER &&
+	if (cfg->flags & VXLAN_F_VNIFILTER &&
 	    nla_put_u8(skb, IFLA_VXLAN_VNIFILTER,
-		       !!(vxlan->cfg.flags & VXLAN_F_VNIFILTER)))
+		       !!(cfg->flags & VXLAN_F_VNIFILTER)))
 		goto nla_put_failure;
 
 	if (nla_put(skb, IFLA_VXLAN_RESERVED_BITS,
-		    sizeof(vxlan->cfg.reserved_bits),
-		    &vxlan->cfg.reserved_bits))
+		    sizeof(cfg->reserved_bits),
+		    &cfg->reserved_bits))
 		goto nla_put_failure;
 
 	return 0;
diff --git a/drivers/net/vxlan/vxlan_mdb.c b/drivers/net/vxlan/vxlan_mdb.c
index 841f42ffecb9aa351b10cfadf3d423f7e0f9f290..56ca9283283307d8b1231c3b26724474e6c838d6 100644
--- a/drivers/net/vxlan/vxlan_mdb.c
+++ b/drivers/net/vxlan/vxlan_mdb.c
@@ -165,6 +165,7 @@ static int vxlan_mdb_entry_info_fill(const struct vxlan_dev *vxlan,
 				     const struct vxlan_mdb_entry *mdb_entry,
 				     const struct vxlan_mdb_remote *remote)
 {
+	const struct vxlan_config *cfg = &vxlan->cfg;
 	struct vxlan_rdst *rd = rtnl_dereference(remote->rd);
 	struct br_mdb_entry e;
 	struct nlattr *nest;
@@ -189,7 +190,7 @@ static int vxlan_mdb_entry_info_fill(const struct vxlan_dev *vxlan,
 	    vxlan_nla_put_addr(skb, MDBA_MDB_EATTR_DST, &rd->remote_ip))
 		goto nest_err;
 
-	if (rd->remote_port && rd->remote_port != vxlan->cfg.dst_port &&
+	if (rd->remote_port && rd->remote_port != cfg->dst_port &&
 	    nla_put_u16(skb, MDBA_MDB_EATTR_DST_PORT,
 			be16_to_cpu(rd->remote_port)))
 		goto nest_err;
@@ -202,7 +203,7 @@ static int vxlan_mdb_entry_info_fill(const struct vxlan_dev *vxlan,
 	    nla_put_u32(skb, MDBA_MDB_EATTR_IFINDEX, rd->remote_ifindex))
 		goto nest_err;
 
-	if ((vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA) &&
+	if ((cfg->flags & VXLAN_F_COLLECT_METADATA) &&
 	    mdb_entry->key.vni && nla_put_u32(skb, MDBA_MDB_EATTR_SRC_VNI,
 					      be32_to_cpu(mdb_entry->key.vni)))
 		goto nest_err;
@@ -613,6 +614,7 @@ static int vxlan_mdb_config_init(struct vxlan_mdb_config *cfg,
 {
 	struct br_mdb_entry *entry = nla_data(tb[MDBA_SET_ENTRY]);
 	struct vxlan_dev *vxlan = netdev_priv(dev);
+	const struct vxlan_config *vcfg = &vxlan->cfg;
 
 	memset(cfg, 0, sizeof(*cfg));
 	cfg->vxlan = vxlan;
@@ -622,7 +624,7 @@ static int vxlan_mdb_config_init(struct vxlan_mdb_config *cfg,
 	cfg->filter_mode = MCAST_EXCLUDE;
 	cfg->rt_protocol = RTPROT_STATIC;
 	cfg->remote_vni = vxlan->default_dst.remote_vni;
-	cfg->remote_port = vxlan->cfg.dst_port;
+	cfg->remote_port = vcfg->dst_port;
 
 	if (entry->ifindex != dev->ifindex) {
 		NL_SET_ERR_MSG_MOD(extack, "Port net device must be the VXLAN net device");
@@ -957,6 +959,7 @@ vxlan_mdb_nlmsg_remote_size(const struct vxlan_dev *vxlan,
 			    const struct vxlan_mdb_entry *mdb_entry,
 			    const struct vxlan_mdb_remote *remote)
 {
+	const struct vxlan_config *cfg = &vxlan->cfg;
 	const struct vxlan_mdb_entry_key *group = &mdb_entry->key;
 	struct vxlan_rdst *rd = rtnl_dereference(remote->rd);
 	size_t nlmsg_size;
@@ -978,7 +981,7 @@ vxlan_mdb_nlmsg_remote_size(const struct vxlan_dev *vxlan,
 	/* MDBA_MDB_EATTR_DST */
 	nlmsg_size += nla_total_size(vxlan_addr_size(&rd->remote_ip));
 	/* MDBA_MDB_EATTR_DST_PORT */
-	if (rd->remote_port && rd->remote_port != vxlan->cfg.dst_port)
+	if (rd->remote_port && rd->remote_port != cfg->dst_port)
 		nlmsg_size += nla_total_size(sizeof(u16));
 	/* MDBA_MDB_EATTR_VNI */
 	if (rd->remote_vni != vxlan->default_dst.remote_vni)
@@ -987,7 +990,7 @@ vxlan_mdb_nlmsg_remote_size(const struct vxlan_dev *vxlan,
 	if (rd->remote_ifindex)
 		nlmsg_size += nla_total_size(sizeof(u32));
 	/* MDBA_MDB_EATTR_SRC_VNI */
-	if ((vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA) && group->vni)
+	if ((cfg->flags & VXLAN_F_COLLECT_METADATA) && group->vni)
 		nlmsg_size += nla_total_size(sizeof(u32));
 
 	return nlmsg_size;
@@ -1621,6 +1624,7 @@ int vxlan_mdb_get(struct net_device *dev, struct nlattr *tb[], u32 portid,
 }
 
 struct vxlan_mdb_entry *vxlan_mdb_entry_skb_get(struct vxlan_dev *vxlan,
+						const struct vxlan_config *cfg,
 						struct sk_buff *skb,
 						__be32 src_vni)
 {
@@ -1634,7 +1638,7 @@ struct vxlan_mdb_entry *vxlan_mdb_entry_skb_get(struct vxlan_dev *vxlan,
 	/* When not in collect metadata mode, 'src_vni' is zero, but MDB
 	 * entries are stored with the VNI of the VXLAN device.
 	 */
-	if (!(vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA))
+	if (!(cfg->flags & VXLAN_F_COLLECT_METADATA))
 		src_vni = vxlan->default_dst.remote_vni;
 
 	memset(&group, 0, sizeof(group));
@@ -1700,6 +1704,7 @@ struct vxlan_mdb_entry *vxlan_mdb_entry_skb_get(struct vxlan_dev *vxlan,
 }
 
 netdev_tx_t vxlan_mdb_xmit(struct vxlan_dev *vxlan,
+			   const struct vxlan_config *cfg,
 			   const struct vxlan_mdb_entry *mdb_entry,
 			   struct sk_buff *skb)
 {
@@ -1721,12 +1726,12 @@ netdev_tx_t vxlan_mdb_xmit(struct vxlan_dev *vxlan,
 
 		skb1 = skb_clone(skb, GFP_ATOMIC);
 		if (skb1)
-			vxlan_xmit_one(skb1, vxlan->dev, src_vni,
+			vxlan_xmit_one(skb1, vxlan->dev, cfg, src_vni,
 				       rcu_dereference(remote->rd), false);
 	}
 
 	if (fremote)
-		vxlan_xmit_one(skb, vxlan->dev, src_vni,
+		vxlan_xmit_one(skb, vxlan->dev, cfg, src_vni,
 			       rcu_dereference(fremote->rd), false);
 	else
 		kfree_skb_reason(skb, SKB_DROP_REASON_NO_TX_TARGET);
diff --git a/drivers/net/vxlan/vxlan_private.h b/drivers/net/vxlan/vxlan_private.h
index b1eec221636088aa1c1674221d5ef0f13698b53f..ab7216c4e41011b99f8bf72de50fc2230b43c405 100644
--- a/drivers/net/vxlan/vxlan_private.h
+++ b/drivers/net/vxlan/vxlan_private.h
@@ -195,9 +195,10 @@ int vxlan_fdb_update(struct vxlan_dev *vxlan,
 		     __u32 ifindex, __u16 ndm_flags, u32 nhid,
 		     bool swdev_notify, struct netlink_ext_ack *extack);
 void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
+		    const struct vxlan_config *cfg,
 		    __be32 default_vni, struct vxlan_rdst *rdst, bool did_rsc);
 int vxlan_vni_in_use(struct net *src_net, struct vxlan_dev *vxlan,
-		     struct vxlan_config *conf, __be32 vni);
+		     const struct vxlan_config *conf, __be32 vni);
 
 /* vxlan_vnifilter.c */
 int vxlan_vnigroup_init(struct vxlan_dev *vxlan);
@@ -205,7 +206,8 @@ void vxlan_vnigroup_uninit(struct vxlan_dev *vxlan);
 
 int vxlan_vnifilter_init(void);
 void vxlan_vnifilter_uninit(void);
-void vxlan_vnifilter_count(struct vxlan_dev *vxlan, __be32 vni,
+void vxlan_vnifilter_count(struct vxlan_dev *vxlan,
+			   const struct vxlan_config *cfg, __be32 vni,
 			   struct vxlan_vni_node *vninode,
 			   int type, unsigned int len);
 
@@ -241,9 +243,11 @@ int vxlan_mdb_del_bulk(struct net_device *dev, struct nlattr *tb[],
 int vxlan_mdb_get(struct net_device *dev, struct nlattr *tb[], u32 portid,
 		  u32 seq, struct netlink_ext_ack *extack);
 struct vxlan_mdb_entry *vxlan_mdb_entry_skb_get(struct vxlan_dev *vxlan,
+						const struct vxlan_config *cfg,
 						struct sk_buff *skb,
 						__be32 src_vni);
 netdev_tx_t vxlan_mdb_xmit(struct vxlan_dev *vxlan,
+			   const struct vxlan_config *cfg,
 			   const struct vxlan_mdb_entry *mdb_entry,
 			   struct sk_buff *skb);
 int vxlan_mdb_init(struct vxlan_dev *vxlan);
diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
index 0a18c32902da08dc2732e2aea10d58b8753fe57f..7d362c69be1bc91204ee613dbe6afbaf7af1eeca 100644
--- a/drivers/net/vxlan/vxlan_vnifilter.c
+++ b/drivers/net/vxlan/vxlan_vnifilter.c
@@ -171,13 +171,14 @@ static void vxlan_vnifilter_stats_add(struct vxlan_vni_node *vninode,
 	u64_stats_update_end(&pstats->syncp);
 }
 
-void vxlan_vnifilter_count(struct vxlan_dev *vxlan, __be32 vni,
+void vxlan_vnifilter_count(struct vxlan_dev *vxlan,
+			   const struct vxlan_config *cfg, __be32 vni,
 			   struct vxlan_vni_node *vninode,
 			   int type, unsigned int len)
 {
 	struct vxlan_vni_node *vnode;
 
-	if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER))
+	if (!cfg || !(cfg->flags & VXLAN_F_VNIFILTER))
 		return;
 
 	if (vninode) {
-- 
2.55.0.1007.g17ff1f9808-goog


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v3 net-next 3/6] vxlan: move VXLAN_F_MDB to struct vxlan_dev flags
  2026-09-11  6:21 [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps Eric Dumazet
  2026-09-11  6:21 ` [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev() Eric Dumazet
  2026-09-11  6:21 ` [PATCH v3 net-next 2/6] vxlan: pass vxlan_config pointer to helper functions Eric Dumazet
@ 2026-09-11  6:21 ` Eric Dumazet
  2026-09-15  2:01   ` Jakub Kicinski
  2026-09-11  6:21 ` [PATCH v3 net-next 4/6] vxlan: convert configuration to RCU protection Eric Dumazet
                   ` (2 subsequent siblings)
  5 siblings, 1 reply; 12+ messages in thread
From: Eric Dumazet @ 2026-09-11  6:21 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Kuniyuki Iwashima, Ido Schimmel, Andrew Lunn,
	netdev, eric.dumazet, Eric Dumazet

VXLAN_F_MDB is an internal runtime state flag indicating whether any
MDB entries are configured on the device, rather than a netlink
configuration attribute.

In preparation for converting vxlan->cfg to an RCU-protected pointer,
move VXLAN_F_MDB from struct vxlan_config to a dedicated 'flags' field
in struct vxlan_dev as VXLAN_DEV_F_MDB, using atomic bitops (set_bit(),
clear_bit(), test_bit()) to avoid KCSAN data races between the TX path
and RTNL operations.

This avoids having to dynamically reallocate and publish a new
vxlan_config structure via RCU whenever the first MDB entry is added
or the last one is removed, and prevents potential memory allocation
failures during MDB teardown under memory pressure.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 drivers/net/vxlan/vxlan_core.c | 2 +-
 drivers/net/vxlan/vxlan_mdb.c  | 6 +++---
 include/net/vxlan.h            | 6 +++++-
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 3115b056a68ddae35720bf6e25558b77f51beba0..4bb6e05379ca7835f355017c6cccd221c89c1f2c 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -2824,7 +2824,7 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (nhid)
 		return vxlan_xmit_nhid(skb, dev, nhid, vni, cfg);
 
-	if (flags & VXLAN_F_MDB) {
+	if (test_bit(VXLAN_DEV_F_MDB, &vxlan->flags)) {
 		struct vxlan_mdb_entry *mdb_entry;
 
 		rcu_read_lock();
diff --git a/drivers/net/vxlan/vxlan_mdb.c b/drivers/net/vxlan/vxlan_mdb.c
index 56ca9283283307d8b1231c3b26724474e6c838d6..cf606256d0929c4dd356ec8aa343150c10edfb82 100644
--- a/drivers/net/vxlan/vxlan_mdb.c
+++ b/drivers/net/vxlan/vxlan_mdb.c
@@ -1219,7 +1219,7 @@ vxlan_mdb_entry_get(struct vxlan_dev *vxlan,
 		goto err_free_entry;
 
 	if (hlist_is_singular_node(&mdb_entry->mdb_node, &vxlan->mdb_list))
-		vxlan->cfg.flags |= VXLAN_F_MDB;
+		set_bit(VXLAN_DEV_F_MDB, &vxlan->flags);
 
 	return mdb_entry;
 
@@ -1236,7 +1236,7 @@ static void vxlan_mdb_entry_put(struct vxlan_dev *vxlan,
 		return;
 
 	if (hlist_is_singular_node(&mdb_entry->mdb_node, &vxlan->mdb_list))
-		vxlan->cfg.flags &= ~VXLAN_F_MDB;
+		clear_bit(VXLAN_DEV_F_MDB, &vxlan->flags);
 
 	rhashtable_remove_fast(&vxlan->mdb_tbl, &mdb_entry->rhnode,
 			       vxlan_mdb_rht_params);
@@ -1762,7 +1762,7 @@ void vxlan_mdb_fini(struct vxlan_dev *vxlan)
 	struct vxlan_mdb_flush_desc desc = {};
 
 	vxlan_mdb_flush(vxlan, &desc);
-	WARN_ON_ONCE(vxlan->cfg.flags & VXLAN_F_MDB);
+	WARN_ON_ONCE(test_bit(VXLAN_DEV_F_MDB, &vxlan->flags));
 	rhashtable_free_and_destroy(&vxlan->mdb_tbl, vxlan_mdb_check_empty,
 				    NULL);
 }
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index 7b82075055237058d231d636698f640c75c521af..d323f91af2364822e148310297c978fec7664010 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h
@@ -300,6 +300,7 @@ struct vxlan_dev {
 	spinlock_t	  hash_lock;
 	unsigned int	  addrcnt;
 	struct gro_cells  gro_cells;
+	unsigned long	  flags;
 
 	struct vxlan_config	cfg;
 
@@ -313,6 +314,10 @@ struct vxlan_dev {
 	unsigned int mdb_seq;
 };
 
+enum vxlan_dev_flags {
+	VXLAN_DEV_F_MDB,
+};
+
 #define VXLAN_F_LEARN			0x01
 #define VXLAN_F_PROXY			0x02
 #define VXLAN_F_RSC			0x04
@@ -331,7 +336,6 @@ struct vxlan_dev {
 #define VXLAN_F_IPV6_LINKLOCAL		0x8000
 #define VXLAN_F_TTL_INHERIT		0x10000
 #define VXLAN_F_VNIFILTER               0x20000
-#define VXLAN_F_MDB			0x40000
 #define VXLAN_F_LOCALBYPASS		0x80000
 #define VXLAN_F_MC_ROUTE		0x100000
 
-- 
2.55.0.1007.g17ff1f9808-goog


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v3 net-next 4/6] vxlan: convert configuration to RCU protection
  2026-09-11  6:21 [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps Eric Dumazet
                   ` (2 preceding siblings ...)
  2026-09-11  6:21 ` [PATCH v3 net-next 3/6] vxlan: move VXLAN_F_MDB to struct vxlan_dev flags Eric Dumazet
@ 2026-09-11  6:21 ` Eric Dumazet
  2026-09-11  6:21 ` [PATCH v3 net-next 5/6] vxlan: remove default_dst and use vxlan_config and lowerdev Eric Dumazet
  2026-09-11  6:22 ` [PATCH v3 net-next 6/6] vxlan: no longer rely on RTNL in vxlan_fill_info() Eric Dumazet
  5 siblings, 0 replies; 12+ messages in thread
From: Eric Dumazet @ 2026-09-11  6:21 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Kuniyuki Iwashima, Ido Schimmel, Andrew Lunn,
	netdev, eric.dumazet, Eric Dumazet

Move 'struct vxlan_config' from an embedded structure inside
'struct vxlan_dev' to a dynamically allocated RCU-protected pointer
'vxlan->cfg'.

Updating configuration via vxlan_changelink() or vxlan_dev_configure()
allocates a new struct vxlan_config and publishes it with
rcu_assign_pointer(), freeing the previous config with kfree_rcu().

Readers are converted to use rcu_dereference() or rtnl_dereference().
In vxlan_xmit(), acquire rcu_read_lock() to protect config access.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 .../mellanox/mlxsw/spectrum_nve_vxlan.c       |  14 +-
 .../mellanox/mlxsw/spectrum_switchdev.c       |  57 ++--
 drivers/net/vxlan/vxlan_core.c                | 270 ++++++++++++------
 drivers/net/vxlan/vxlan_mdb.c                 |  10 +-
 drivers/net/vxlan/vxlan_multicast.c           |  12 +-
 drivers/net/vxlan/vxlan_vnifilter.c           |  21 +-
 include/net/vxlan.h                           |   3 +-
 7 files changed, 261 insertions(+), 126 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c
index 52c2fe3644d4b9b27f1d589d9f7f597748339782..50cea39323f570e04067f2f98aff4d97e4a409fc 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c
@@ -59,8 +59,11 @@ static bool mlxsw_sp_nve_vxlan_can_offload(const struct mlxsw_sp_nve *nve,
 					   const struct mlxsw_sp_nve_params *params,
 					   struct netlink_ext_ack *extack)
 {
-	struct vxlan_dev *vxlan = netdev_priv(params->dev);
-	struct vxlan_config *cfg = &vxlan->cfg;
+	const struct vxlan_config *cfg;
+	struct vxlan_dev *vxlan;
+
+	vxlan = netdev_priv(params->dev);
+	cfg = rtnl_dereference(vxlan->cfg);
 
 	if (vxlan_addr_multicast(&cfg->remote_ip)) {
 		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Multicast destination IP is not supported");
@@ -148,8 +151,11 @@ static void mlxsw_sp_nve_vxlan_config(const struct mlxsw_sp_nve *nve,
 				      const struct mlxsw_sp_nve_params *params,
 				      struct mlxsw_sp_nve_config *config)
 {
-	struct vxlan_dev *vxlan = netdev_priv(params->dev);
-	struct vxlan_config *cfg = &vxlan->cfg;
+	const struct vxlan_config *cfg;
+	struct vxlan_dev *vxlan;
+
+	vxlan = netdev_priv(params->dev);
+	cfg = rtnl_dereference(vxlan->cfg);
 
 	config->type = MLXSW_SP_NVE_TYPE_VXLAN;
 	config->ttl = cfg->ttl;
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
index fe45e533a4b2efb532b85960009c586a53ade340..de60b698bea982593f0f7550571e9a4f434dcceb 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_switchdev.c
@@ -2513,15 +2513,17 @@ mlxsw_sp_bridge_vlan_aware_vxlan_join(struct mlxsw_sp_bridge_device *bridge_devi
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_lower_get(bridge_device->dev);
 	struct vxlan_dev *vxlan = netdev_priv(vxlan_dev);
-	struct mlxsw_sp_nve_params params = {
-		.type = MLXSW_SP_NVE_TYPE_VXLAN,
-		.vni = vxlan->cfg.vni,
-		.dev = vxlan_dev,
-		.ethertype = ethertype,
-	};
+	struct mlxsw_sp_nve_params params;
+	const struct vxlan_config *cfg;
 	struct mlxsw_sp_fid *fid;
 	int err;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+	params.type = MLXSW_SP_NVE_TYPE_VXLAN;
+	params.vni = cfg->vni;
+	params.dev = vxlan_dev;
+	params.ethertype = ethertype;
+
 	/* If the VLAN is 0, we need to find the VLAN that is configured as
 	 * PVID and egress untagged on the bridge port of the VxLAN device.
 	 * It is possible no such VLAN exists
@@ -2704,15 +2706,17 @@ mlxsw_sp_bridge_8021d_vxlan_join(struct mlxsw_sp_bridge_device *bridge_device,
 {
 	struct mlxsw_sp *mlxsw_sp = mlxsw_sp_lower_get(bridge_device->dev);
 	struct vxlan_dev *vxlan = netdev_priv(vxlan_dev);
-	struct mlxsw_sp_nve_params params = {
-		.type = MLXSW_SP_NVE_TYPE_VXLAN,
-		.vni = vxlan->cfg.vni,
-		.dev = vxlan_dev,
-		.ethertype = ETH_P_8021Q,
-	};
+	struct mlxsw_sp_nve_params params;
+	const struct vxlan_config *cfg;
 	struct mlxsw_sp_fid *fid;
 	int err;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+	params.type = MLXSW_SP_NVE_TYPE_VXLAN;
+	params.vni = cfg->vni;
+	params.dev = vxlan_dev;
+	params.ethertype = ETH_P_8021Q;
+
 	fid = mlxsw_sp_fid_8021d_get(mlxsw_sp, bridge_device->dev->ifindex);
 	if (IS_ERR(fid)) {
 		NL_SET_ERR_MSG_MOD(extack, "Failed to create 802.1D FID");
@@ -2933,10 +2937,13 @@ static void __mlxsw_sp_bridge_vxlan_leave(struct mlxsw_sp *mlxsw_sp,
 					  const struct net_device *vxlan_dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(vxlan_dev);
+	const struct vxlan_config *cfg;
 	struct mlxsw_sp_fid *fid;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+
 	/* If the VxLAN device is down, then the FID does not have a VNI */
-	fid = mlxsw_sp_fid_lookup_by_vni(mlxsw_sp, vxlan->cfg.vni);
+	fid = mlxsw_sp_fid_lookup_by_vni(mlxsw_sp, cfg->vni);
 	if (!fid)
 		return;
 
@@ -3029,11 +3036,13 @@ static void mlxsw_sp_fdb_vxlan_call_notifiers(struct net_device *dev,
 	struct switchdev_notifier_vxlan_fdb_info info;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	enum switchdev_notifier_type type;
+	const struct vxlan_config *cfg;
 
+	cfg = rtnl_dereference(vxlan->cfg);
 	type = adding ? SWITCHDEV_VXLAN_FDB_ADD_TO_BRIDGE :
 			SWITCHDEV_VXLAN_FDB_DEL_TO_BRIDGE;
 	mlxsw_sp_switchdev_addr_vxlan_convert(proto, addr, &info.remote_ip);
-	info.remote_port = vxlan->cfg.dst_port;
+	info.remote_port = cfg->dst_port;
 	info.remote_vni = vni;
 	info.remote_ifindex = 0;
 	ether_addr_copy(info.eth_addr, mac);
@@ -3236,8 +3245,10 @@ __mlxsw_sp_fdb_notify_mac_uc_tunnel_process(struct mlxsw_sp *mlxsw_sp,
 
 	if (adding && netif_is_vxlan(dev)) {
 		struct vxlan_dev *vxlan = netdev_priv(dev);
+		const struct vxlan_config *cfg;
 
-		if (!(vxlan->cfg.flags & VXLAN_F_LEARN))
+		cfg = rtnl_dereference(vxlan->cfg);
+		if (!(cfg->flags & VXLAN_F_LEARN))
 			return -EINVAL;
 	}
 
@@ -3722,9 +3733,11 @@ mlxsw_sp_switchdev_vxlan_work_prepare(struct mlxsw_sp_switchdev_event_work *
 {
 	struct vxlan_dev *vxlan = netdev_priv(switchdev_work->dev);
 	struct switchdev_notifier_vxlan_fdb_info *vxlan_fdb_info;
-	struct vxlan_config *cfg = &vxlan->cfg;
+	const struct vxlan_config *cfg;
 	struct netlink_ext_ack *extack;
 
+	cfg = rcu_dereference_rtnl(vxlan->cfg);
+
 	extack = switchdev_notifier_info_to_extack(info);
 	vxlan_fdb_info = container_of(info,
 				      struct switchdev_notifier_vxlan_fdb_info,
@@ -3851,11 +3864,15 @@ mlxsw_sp_switchdev_vxlan_vlan_add(struct mlxsw_sp *mlxsw_sp,
 				  struct netlink_ext_ack *extack)
 {
 	struct vxlan_dev *vxlan = netdev_priv(vxlan_dev);
-	__be32 vni = vxlan->cfg.vni;
+	const struct vxlan_config *cfg;
 	struct mlxsw_sp_fid *fid;
 	u16 old_vid;
+	__be32 vni;
 	int err;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+	vni = cfg->vni;
+
 	/* We cannot have the same VLAN as PVID and egress untagged on multiple
 	 * VxLAN devices. Note that we get this notification before the VLAN is
 	 * actually added to the bridge's database, so it is not possible for
@@ -3935,12 +3952,16 @@ mlxsw_sp_switchdev_vxlan_vlan_del(struct mlxsw_sp *mlxsw_sp,
 				  const struct net_device *vxlan_dev, u16 vid)
 {
 	struct vxlan_dev *vxlan = netdev_priv(vxlan_dev);
-	__be32 vni = vxlan->cfg.vni;
+	const struct vxlan_config *cfg;
 	struct mlxsw_sp_fid *fid;
+	__be32 vni;
 
 	if (!netif_running(vxlan_dev))
 		return;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+	vni = cfg->vni;
+
 	fid = mlxsw_sp_fid_lookup_by_vni(mlxsw_sp, vni);
 	if (!fid)
 		return;
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 4bb6e05379ca7835f355017c6cccd221c89c1f2c..338ecddb9542dee1c46e79872b25200d7b249304 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -110,20 +110,23 @@ static struct vxlan_dev *vxlan_vs_find_vni(struct vxlan_sock *vs,
 		vni = 0;
 
 	hlist_for_each_entry_rcu(node, vni_head(vs, vni), hlist) {
+		const struct vxlan_config *cfg;
+
 		if (!node->vxlan)
 			continue;
+
+		cfg = rcu_dereference(node->vxlan->cfg);
+
 		vnode = NULL;
-		if (node->vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
+		if (cfg->flags & VXLAN_F_VNIFILTER) {
 			vnode = vxlan_vnifilter_lookup(node->vxlan, vni);
 			if (!vnode)
 				continue;
-		} else if (node->vxlan->default_dst.remote_vni != vni) {
+		} else if (cfg->vni != vni) {
 			continue;
 		}
 
 		if (IS_ENABLED(CONFIG_IPV6)) {
-			const struct vxlan_config *cfg = &node->vxlan->cfg;
-
 			if ((cfg->flags & VXLAN_F_IPV6_LINKLOCAL) &&
 			    cfg->remote_ifindex != ifindex)
 				continue;
@@ -157,6 +160,7 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
 			  u32 portid, u32 seq, int type, unsigned int flags,
 			  const struct vxlan_rdst *rdst)
 {
+	const struct vxlan_config *cfg = rcu_dereference_rtnl(vxlan->cfg);
 	unsigned long now = jiffies;
 	struct nda_cacheinfo ci;
 	bool send_ip, send_eth;
@@ -216,10 +220,10 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
 			goto nla_put_failure;
 
 		if (rdst->remote_port &&
-		    rdst->remote_port != vxlan->cfg.dst_port &&
+		    rdst->remote_port != cfg->dst_port &&
 		    nla_put_be16(skb, NDA_PORT, rdst->remote_port))
 			goto nla_put_failure;
-		if (rdst->remote_vni != vxlan->default_dst.remote_vni &&
+		if (rdst->remote_vni != cfg->vni &&
 		    nla_put_u32(skb, NDA_VNI, be32_to_cpu(rdst->remote_vni)))
 			goto nla_put_failure;
 		if (rdst->remote_ifindex &&
@@ -227,7 +231,7 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
 			goto nla_put_failure;
 	}
 
-	if ((vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA) && fdb->key.vni &&
+	if ((cfg->flags & VXLAN_F_COLLECT_METADATA) && fdb->key.vni &&
 	    nla_put_u32(skb, NDA_SRC_VNI,
 			be32_to_cpu(fdb->key.vni)))
 		goto nla_put_failure;
@@ -418,7 +422,7 @@ static struct vxlan_fdb *vxlan_find_mac(struct vxlan_dev *vxlan,
 	lockdep_assert_held_once(&vxlan->hash_lock);
 
 	rcu_read_lock();
-	f = vxlan_find_mac_rcu(vxlan, &vxlan->cfg, mac, vni);
+	f = vxlan_find_mac_rcu(vxlan, rcu_dereference(vxlan->cfg), mac, vni);
 	rcu_read_unlock();
 
 	return f;
@@ -459,7 +463,7 @@ int vxlan_fdb_find_uc(struct net_device *dev, const u8 *mac, __be32 vni,
 
 	rcu_read_lock();
 
-	f = vxlan_find_mac_rcu(vxlan, &vxlan->cfg, eth_addr, vni);
+	f = vxlan_find_mac_rcu(vxlan, rcu_dereference(vxlan->cfg), eth_addr, vni);
 	if (f)
 		rdst = first_remote_rcu(f);
 	if (!rdst) {
@@ -865,12 +869,13 @@ int vxlan_fdb_create(struct vxlan_dev *vxlan,
 		     u32 nhid, struct vxlan_fdb **fdb,
 		     struct netlink_ext_ack *extack)
 {
+	const struct vxlan_config *cfg = rcu_dereference_rtnl(vxlan->cfg);
 	struct vxlan_rdst *rd = NULL;
 	struct vxlan_fdb *f;
 	int rc;
 
-	if (vxlan->cfg.addrmax &&
-	    vxlan->addrcnt >= vxlan->cfg.addrmax)
+	if (cfg->addrmax &&
+	    vxlan->addrcnt >= cfg->addrmax)
 		return -ENOSPC;
 
 	netdev_dbg(vxlan->dev, "add %pM -> %pIS\n", mac, ip);
@@ -1156,6 +1161,7 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
 			   __be32 *vni, u32 *ifindex, u32 *nhid,
 			   struct netlink_ext_ack *extack)
 {
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	struct net *net = dev_net(vxlan->dev);
 	int err;
 
@@ -1172,7 +1178,7 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
 			return err;
 		}
 	} else {
-		union vxlan_addr *remote = &vxlan->default_dst.remote_ip;
+		const union vxlan_addr *remote = &cfg->remote_ip;
 
 		if (remote->sa.sa_family == AF_INET) {
 			ip->sin.sin_addr.s_addr = htonl(INADDR_ANY);
@@ -1192,7 +1198,7 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
 		}
 		*port = nla_get_be16(tb[NDA_PORT]);
 	} else {
-		*port = vxlan->cfg.dst_port;
+		*port = cfg->dst_port;
 	}
 
 	if (tb[NDA_VNI]) {
@@ -1202,7 +1208,7 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
 		}
 		*vni = cpu_to_be32(nla_get_u32(tb[NDA_VNI]));
 	} else {
-		*vni = vxlan->default_dst.remote_vni;
+		*vni = cfg->vni;
 	}
 
 	if (tb[NDA_SRC_VNI]) {
@@ -1212,7 +1218,7 @@ static int vxlan_fdb_parse(struct nlattr *tb[], struct vxlan_dev *vxlan,
 		}
 		*src_vni = cpu_to_be32(nla_get_u32(tb[NDA_SRC_VNI]));
 	} else {
-		*src_vni = vxlan->default_dst.remote_vni;
+		*src_vni = cfg->vni;
 	}
 
 	if (tb[NDA_IFINDEX]) {
@@ -1407,18 +1413,21 @@ static int vxlan_fdb_get(struct sk_buff *skb,
 			 struct netlink_ext_ack *extack)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
+	const struct vxlan_config *cfg;
 	struct vxlan_fdb *f;
 	__be32 vni;
 	int err;
 
+	cfg = rcu_dereference_rtnl(vxlan->cfg);
+
 	if (tb[NDA_VNI])
 		vni = cpu_to_be32(nla_get_u32(tb[NDA_VNI]));
 	else
-		vni = vxlan->default_dst.remote_vni;
+		vni = cfg->vni;
 
 	rcu_read_lock();
 
-	f = vxlan_find_mac_rcu(vxlan, &vxlan->cfg, addr, vni);
+	f = vxlan_find_mac_rcu(vxlan, cfg, addr, vni);
 	if (!f) {
 		NL_SET_ERR_MSG(extack, "Fdb entry not found");
 		err = -ENOENT;
@@ -1521,6 +1530,7 @@ static bool __vxlan_sock_release_prep(struct vxlan_sock *vs)
 
 static void vxlan_sock_release(struct vxlan_dev *vxlan)
 {
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	struct vxlan_sock *sock4 = rtnl_dereference(vxlan->vn4_sock);
 #if IS_ENABLED(CONFIG_IPV6)
 	struct vxlan_sock *sock6 = rtnl_dereference(vxlan->vn6_sock);
@@ -1530,7 +1540,7 @@ static void vxlan_sock_release(struct vxlan_dev *vxlan)
 
 	RCU_INIT_POINTER(vxlan->vn4_sock, NULL);
 
-	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+	if (cfg->flags & VXLAN_F_VNIFILTER)
 		vxlan_vs_del_vnigrp(vxlan);
 	else
 		vxlan_vs_del_dev(vxlan);
@@ -1703,7 +1713,8 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
 		goto drop;
 	}
 
-	cfg = &vxlan->cfg;
+	cfg = rcu_dereference(vxlan->cfg);
+
 	if (vh->vx_flags & cfg->reserved_bits.vx_flags ||
 	    vh->vx_vni & cfg->reserved_bits.vx_vni) {
 		/* If the header uses bits besides those enabled by the
@@ -1859,7 +1870,8 @@ static int vxlan_err_lookup(struct sock *sk, struct sk_buff *skb)
 	return 0;
 }
 
-static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni, u32 flags)
+static int arp_reduce(struct net_device *dev, struct sk_buff *skb,
+		      const struct vxlan_config *cfg, __be32 vni)
 {
 	struct neigh_table *tbl = arp_table(dev_net(dev));
 	struct vxlan_dev *vxlan = netdev_priv(dev);
@@ -1873,7 +1885,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni, u
 
 	if (!pskb_network_may_pull(skb, arp_hdr_len(dev))) {
 		dev_dstats_tx_dropped(dev);
-		vxlan_vnifilter_count(vxlan, &vxlan->cfg, vni, NULL,
+		vxlan_vnifilter_count(vxlan, cfg, vni, NULL,
 				      VXLAN_VNI_STATS_TX_DROPS, 0);
 		goto out;
 	}
@@ -1914,7 +1926,7 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni, u
 		neigh_ha_snapshot(ha, n, n->dev);
 
 		rcu_read_lock();
-		f = vxlan_find_mac_tx(vxlan, &vxlan->cfg, ha, vni);
+		f = vxlan_find_mac_tx(vxlan, cfg, ha, vni);
 		if (f)
 			rdst = first_remote_rcu(f);
 		if (rdst && vxlan_addr_any(&rdst->remote_ip)) {
@@ -1940,11 +1952,11 @@ static int arp_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni, u
 
 		if (netif_rx(reply) == NET_RX_DROP) {
 			dev_dstats_rx_dropped(dev);
-			vxlan_vnifilter_count(vxlan, &vxlan->cfg, vni, NULL,
+			vxlan_vnifilter_count(vxlan, cfg, vni, NULL,
 					      VXLAN_VNI_STATS_RX_DROPS, 0);
 		}
 
-	} else if (flags & VXLAN_F_L3MISS) {
+	} else if (cfg->flags & VXLAN_F_L3MISS) {
 		union vxlan_addr ipa = {
 			.sin.sin_addr.s_addr = tip,
 			.sin.sin_family = AF_INET,
@@ -2052,7 +2064,8 @@ static struct sk_buff *vxlan_na_create(struct sk_buff *request,
 	return reply;
 }
 
-static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni, u32 flags)
+static int neigh_reduce(struct net_device *dev, struct sk_buff *skb,
+			const struct vxlan_config *cfg, __be32 vni)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	const struct in6_addr *daddr;
@@ -2086,7 +2099,7 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni,
 		}
 
 		neigh_ha_snapshot(ha, n, n->dev);
-		f = vxlan_find_mac_tx(vxlan, &vxlan->cfg, ha, vni);
+		f = vxlan_find_mac_tx(vxlan, cfg, ha, vni);
 		if (f)
 			rdst = first_remote_rcu(f);
 		if (rdst && vxlan_addr_any(&rdst->remote_ip)) {
@@ -2105,10 +2118,10 @@ static int neigh_reduce(struct net_device *dev, struct sk_buff *skb, __be32 vni,
 
 		if (netif_rx(reply) == NET_RX_DROP) {
 			dev_dstats_rx_dropped(dev);
-			vxlan_vnifilter_count(vxlan, &vxlan->cfg, vni, NULL,
+			vxlan_vnifilter_count(vxlan, cfg, vni, NULL,
 					      VXLAN_VNI_STATS_RX_DROPS, 0);
 		}
-	} else if (flags & VXLAN_F_L3MISS) {
+	} else if (cfg->flags & VXLAN_F_L3MISS) {
 		union vxlan_addr ipa = {
 			.sin6.sin6_addr = msg->target,
 			.sin6.sin6_family = AF_INET6,
@@ -2295,7 +2308,7 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
 			       const struct vxlan_config *src_cfg,
 			       __be32 vni, bool snoop)
 {
-	const struct vxlan_config *dst_cfg = &dst_vxlan->cfg;
+	const struct vxlan_config *dst_cfg;
 	union vxlan_addr loopback;
 	unsigned int len = skb->len;
 	struct net_device *dev = dst_vxlan->dev;
@@ -2316,6 +2329,7 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
 	}
 
 	rcu_read_lock();
+	dst_cfg = rcu_dereference(dst_vxlan->cfg);
 	if (unlikely(!(dev->flags & IFF_UP))) {
 		kfree_skb_reason(skb, SKB_DROP_REASON_DEV_READY);
 		goto drop;
@@ -2781,7 +2795,8 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 	u32 nhid = 0;
 	u32 flags;
 
-	cfg = &vxlan->cfg;
+	rcu_read_lock();
+	cfg = rcu_dereference(vxlan->cfg);
 	flags = cfg->flags;
 	default_vni = cfg->vni;
 
@@ -2799,14 +2814,19 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 				vxlan_xmit_one(skb, dev, cfg, vni, NULL, false);
 			else
 				kfree_skb_reason(skb, SKB_DROP_REASON_TUNNEL_TXINFO);
+			rcu_read_unlock();
 			return NETDEV_TX_OK;
 		}
 	}
 
 	if (flags & VXLAN_F_PROXY) {
 		eth = eth_hdr(skb);
-		if (ntohs(eth->h_proto) == ETH_P_ARP)
-			return arp_reduce(dev, skb, vni, flags);
+		if (ntohs(eth->h_proto) == ETH_P_ARP) {
+			netdev_tx_t res = arp_reduce(dev, skb, cfg, vni);
+
+			rcu_read_unlock();
+			return res;
+		}
 #if IS_ENABLED(CONFIG_IPV6)
 		else if (ntohs(eth->h_proto) == ETH_P_IPV6 &&
 			 pskb_network_may_pull(skb, sizeof(struct ipv6hdr) +
@@ -2815,32 +2835,36 @@ static netdev_tx_t vxlan_xmit(struct sk_buff *skb, struct net_device *dev)
 			struct nd_msg *m = (struct nd_msg *)(ipv6_hdr(skb) + 1);
 
 			if (m->icmph.icmp6_code == 0 &&
-			    m->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION)
-				return neigh_reduce(dev, skb, vni, flags);
+			    m->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
+				netdev_tx_t res = neigh_reduce(dev, skb, cfg, vni);
+
+				rcu_read_unlock();
+				return res;
+			}
 		}
 #endif
 	}
 
-	if (nhid)
-		return vxlan_xmit_nhid(skb, dev, nhid, vni, cfg);
+	if (nhid) {
+		netdev_tx_t res = vxlan_xmit_nhid(skb, dev, nhid, vni, cfg);
+
+		rcu_read_unlock();
+		return res;
+	}
 
 	if (test_bit(VXLAN_DEV_F_MDB, &vxlan->flags)) {
 		struct vxlan_mdb_entry *mdb_entry;
 
-		rcu_read_lock();
 		mdb_entry = vxlan_mdb_entry_skb_get(vxlan, cfg, skb, vni);
 		if (mdb_entry) {
-			netdev_tx_t ret;
+			netdev_tx_t ret = vxlan_mdb_xmit(vxlan, cfg, mdb_entry, skb);
 
-			ret = vxlan_mdb_xmit(vxlan, cfg, mdb_entry, skb);
 			rcu_read_unlock();
 			return ret;
 		}
-		rcu_read_unlock();
 	}
 
 	eth = eth_hdr(skb);
-	rcu_read_lock();
 	f = vxlan_find_mac_tx(vxlan, cfg, eth->h_dest, vni);
 	did_rsc = false;
 
@@ -2899,12 +2923,15 @@ static void vxlan_cleanup(struct timer_list *t)
 {
 	struct vxlan_dev *vxlan = timer_container_of(vxlan, t, age_timer);
 	unsigned long next_timer = jiffies + FDB_AGE_INTERVAL;
+	const struct vxlan_config *cfg;
 	struct vxlan_fdb *f;
 
 	if (!netif_running(vxlan->dev))
 		return;
 
 	rcu_read_lock();
+	cfg = rcu_dereference(vxlan->cfg);
+
 	hlist_for_each_entry_rcu(f, &vxlan->fdb_list, fdb_node) {
 		unsigned long timeout;
 
@@ -2914,7 +2941,7 @@ static void vxlan_cleanup(struct timer_list *t)
 		if (f->flags & NTF_EXT_LEARNED)
 			continue;
 
-		timeout = READ_ONCE(f->updated) + vxlan->cfg.age_interval * HZ;
+		timeout = READ_ONCE(f->updated) + cfg->age_interval * HZ;
 		if (time_before_eq(timeout, jiffies)) {
 			spin_lock(&vxlan->hash_lock);
 			if (!hlist_unhashed(&f->fdb_node)) {
@@ -2958,13 +2985,16 @@ static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan,
 static int vxlan_init(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
+	const struct vxlan_config *cfg;
 	int err;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+
 	err = rhashtable_init(&vxlan->fdb_hash_tbl, &vxlan_fdb_rht_params);
 	if (err)
 		return err;
 
-	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
+	if (cfg->flags & VXLAN_F_VNIFILTER) {
 		err = vxlan_vnigroup_init(vxlan);
 		if (err)
 			goto err_rhashtable_destroy;
@@ -2984,7 +3014,7 @@ static int vxlan_init(struct net_device *dev)
 err_gro_cells_destroy:
 	gro_cells_destroy(&vxlan->gro_cells);
 err_vnigroup_uninit:
-	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+	if (cfg->flags & VXLAN_F_VNIFILTER)
 		vxlan_vnigroup_uninit(vxlan);
 err_rhashtable_destroy:
 	rhashtable_destroy(&vxlan->fdb_hash_tbl);
@@ -2994,10 +3024,13 @@ static int vxlan_init(struct net_device *dev)
 static void vxlan_uninit(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
+	const struct vxlan_config *cfg;
+
+	cfg = rtnl_dereference(vxlan->cfg);
 
 	vxlan_mdb_fini(vxlan);
 
-	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+	if (cfg->flags & VXLAN_F_VNIFILTER)
 		vxlan_vnigroup_uninit(vxlan);
 
 	gro_cells_destroy(&vxlan->gro_cells);
@@ -3009,6 +3042,7 @@ static void vxlan_uninit(struct net_device *dev)
 static int vxlan_open(struct net_device *dev)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
+	const struct vxlan_config *cfg;
 	int ret;
 
 	ret = vxlan_sock_add(vxlan);
@@ -3021,7 +3055,8 @@ static int vxlan_open(struct net_device *dev)
 		return ret;
 	}
 
-	if (vxlan->cfg.age_interval)
+	cfg = rtnl_dereference(vxlan->cfg);
+	if (cfg->age_interval)
 		mod_timer(&vxlan->age_timer, jiffies + FDB_AGE_INTERVAL);
 
 	return ret;
@@ -3043,8 +3078,10 @@ struct vxlan_fdb_flush_desc {
 static bool vxlan_fdb_is_default_entry(const struct vxlan_fdb *f,
 				       const struct vxlan_dev *vxlan)
 {
+	const struct vxlan_config *cfg = rcu_dereference_rtnl(vxlan->cfg);
+
 	return is_zero_ether_addr(f->key.eth_addr) &&
-	       f->key.vni == vxlan->cfg.vni;
+	       f->key.vni == cfg->vni;
 }
 
 static bool vxlan_fdb_nhid_matches(const struct vxlan_fdb *f, u32 nhid)
@@ -3262,14 +3299,18 @@ static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_rdst *dst = &vxlan->default_dst;
-	struct net_device *lowerdev = __dev_get_by_index(vxlan->net,
-							 dst->remote_ifindex);
+	const struct vxlan_config *cfg;
+	struct net_device *lowerdev;
+
+	cfg = rtnl_dereference(vxlan->cfg);
+
+	lowerdev = __dev_get_by_index(vxlan->net, dst->remote_ifindex);
 
 	/* This check is different than dev->max_mtu, because it looks at
 	 * the lowerdev->mtu, rather than the static dev->max_mtu
 	 */
 	if (lowerdev) {
-		int max_mtu = lowerdev->mtu - vxlan_headroom(vxlan->cfg.flags);
+		int max_mtu = lowerdev->mtu - vxlan_headroom(cfg->flags);
 		if (new_mtu > max_mtu)
 			return -EINVAL;
 	}
@@ -3282,11 +3323,14 @@ static int vxlan_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
+	const struct vxlan_config *cfg;
 	__be16 sport, dport;
 
-	sport = udp_flow_src_port(dev_net(dev), skb, vxlan->cfg.port_min,
-				  vxlan->cfg.port_max, true);
-	dport = info->key.tp_dst ? : vxlan->cfg.dst_port;
+	cfg = rcu_dereference(vxlan->cfg);
+
+	sport = udp_flow_src_port(dev_net(dev), skb, cfg->port_min,
+				  cfg->port_max, true);
+	dport = info->key.tp_dst ? : cfg->dst_port;
 
 	if (ip_tunnel_info_af(info) == AF_INET) {
 		struct vxlan_sock *sock4 = rcu_dereference(vxlan->vn4_sock);
@@ -3396,6 +3440,15 @@ static void vxlan_offload_rx_ports(struct net_device *dev, bool push)
 	}
 }
 
+static void vxlan_free_dev(struct net_device *dev)
+{
+	struct vxlan_dev *vxlan = netdev_priv(dev);
+	struct vxlan_config *cfg = rcu_dereference_protected(vxlan->cfg, 1);
+
+	RCU_INIT_POINTER(vxlan->cfg, NULL);
+	kfree(cfg);
+}
+
 /* Initialize the device structure. */
 static void vxlan_setup(struct net_device *dev)
 {
@@ -3404,6 +3457,8 @@ static void vxlan_setup(struct net_device *dev)
 	eth_hw_addr_random(dev);
 	ether_setup(dev);
 
+	dev->priv_destructor = vxlan_free_dev;
+
 	dev->needs_free_netdev = true;
 	SET_NETDEV_DEVTYPE(dev, &vxlan_type);
 
@@ -3686,21 +3741,22 @@ static struct vxlan_sock *vxlan_socket_create(struct net *net, bool ipv6,
 
 static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 {
-	bool metadata = vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA;
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
+	bool metadata = cfg->flags & VXLAN_F_COLLECT_METADATA;
 	struct vxlan_sock *vs = NULL;
 	struct vxlan_dev_node *node;
 	int l3mdev_index = 0;
 
 	ASSERT_RTNL();
 
-	if (vxlan->cfg.remote_ifindex)
+	if (cfg->remote_ifindex)
 		l3mdev_index = l3mdev_master_upper_ifindex_by_index(
-			vxlan->net, vxlan->cfg.remote_ifindex);
+			vxlan->net, cfg->remote_ifindex);
 
-	if (!vxlan->cfg.no_share) {
+	if (!cfg->no_share) {
 		rcu_read_lock();
 		vs = vxlan_find_sock(vxlan->net, ipv6 ? AF_INET6 : AF_INET,
-				     vxlan->cfg.dst_port, vxlan->cfg.flags,
+				     cfg->dst_port, cfg->flags,
 				     l3mdev_index);
 		if (vs && !refcount_inc_not_zero(&vs->refcnt)) {
 			rcu_read_unlock();
@@ -3710,7 +3766,7 @@ static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 	}
 	if (!vs)
 		vs = vxlan_socket_create(vxlan->net, ipv6,
-					 vxlan->cfg.dst_port, vxlan->cfg.flags,
+					 cfg->dst_port, cfg->flags,
 					 l3mdev_index);
 	if (IS_ERR(vs))
 		return PTR_ERR(vs);
@@ -3725,7 +3781,7 @@ static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 		node = &vxlan->hlist4;
 	}
 
-	if (metadata && (vxlan->cfg.flags & VXLAN_F_VNIFILTER))
+	if (metadata && (cfg->flags & VXLAN_F_VNIFILTER))
 		vxlan_vs_add_vnigrp(vxlan, vs, ipv6);
 	else
 		vxlan_vs_add_dev(vs, vxlan, node);
@@ -3735,11 +3791,14 @@ static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 
 static int vxlan_sock_add(struct vxlan_dev *vxlan)
 {
-	bool metadata = vxlan->cfg.flags & VXLAN_F_COLLECT_METADATA;
-	bool ipv6 = vxlan->cfg.flags & VXLAN_F_IPV6 || metadata;
-	bool ipv4 = !ipv6 || metadata;
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
+	bool metadata, ipv6, ipv4;
 	int ret = 0;
 
+	metadata = cfg->flags & VXLAN_F_COLLECT_METADATA;
+	ipv6 = (cfg->flags & VXLAN_F_IPV6) || metadata;
+	ipv4 = !ipv6 || metadata;
+
 	RCU_INIT_POINTER(vxlan->vn4_sock, NULL);
 #if IS_ENABLED(CONFIG_IPV6)
 	RCU_INIT_POINTER(vxlan->vn6_sock, NULL);
@@ -3763,22 +3822,27 @@ int vxlan_vni_in_use(struct net *src_net, struct vxlan_dev *vxlan,
 	struct vxlan_dev *tmp;
 
 	list_for_each_entry(tmp, &vn->vxlan_list, next) {
+		const struct vxlan_config *tmp_cfg;
+
 		if (tmp == vxlan)
 			continue;
-		if (tmp->cfg.flags & VXLAN_F_VNIFILTER) {
+
+		tmp_cfg = rtnl_dereference(tmp->cfg);
+
+		if (tmp_cfg->flags & VXLAN_F_VNIFILTER) {
 			if (!vxlan_vnifilter_lookup(tmp, vni))
 				continue;
-		} else if (tmp->cfg.vni != vni) {
+		} else if (tmp_cfg->vni != vni) {
 			continue;
 		}
-		if (tmp->cfg.dst_port != conf->dst_port)
+		if (tmp_cfg->dst_port != conf->dst_port)
 			continue;
-		if ((tmp->cfg.flags & (VXLAN_F_RCV_FLAGS | VXLAN_F_IPV6)) !=
+		if ((tmp_cfg->flags & (VXLAN_F_RCV_FLAGS | VXLAN_F_IPV6)) !=
 		    (conf->flags & (VXLAN_F_RCV_FLAGS | VXLAN_F_IPV6)))
 			continue;
 
 		if ((conf->flags & VXLAN_F_IPV6_LINKLOCAL) &&
-		    tmp->cfg.remote_ifindex != conf->remote_ifindex)
+		    tmp_cfg->remote_ifindex != conf->remote_ifindex)
 			continue;
 
 		return -EEXIST;
@@ -3940,7 +4004,7 @@ static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf,
 }
 
 static void vxlan_config_apply(struct net_device *dev,
-			       struct vxlan_config *conf,
+			       struct vxlan_config *new_cfg,
 			       struct net_device *lowerdev,
 			       struct net *src_net,
 			       bool changelink)
@@ -3948,8 +4012,9 @@ static void vxlan_config_apply(struct net_device *dev,
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct vxlan_rdst *dst = &vxlan->default_dst;
 	unsigned short needed_headroom = ETH_HLEN;
+	struct vxlan_config *old_cfg;
 	int max_mtu = ETH_MAX_MTU;
-	u32 flags = conf->flags;
+	u32 flags = new_cfg->flags;
 
 	if (!changelink) {
 		if (flags & VXLAN_F_GPE)
@@ -3957,18 +4022,18 @@ static void vxlan_config_apply(struct net_device *dev,
 		else
 			vxlan_ether_setup(dev);
 
-		if (conf->mtu)
-			dev->mtu = conf->mtu;
+		if (new_cfg->mtu)
+			dev->mtu = new_cfg->mtu;
 
 		vxlan->net = src_net;
 	}
 
-	dst->remote_vni = conf->vni;
+	dst->remote_vni = new_cfg->vni;
 
-	memcpy(&dst->remote_ip, &conf->remote_ip, sizeof(conf->remote_ip));
+	memcpy(&dst->remote_ip, &new_cfg->remote_ip, sizeof(new_cfg->remote_ip));
 
 	if (lowerdev) {
-		dst->remote_ifindex = conf->remote_ifindex;
+		dst->remote_ifindex = new_cfg->remote_ifindex;
 
 		netif_inherit_tso_max(dev, lowerdev);
 
@@ -3981,7 +4046,7 @@ static void vxlan_config_apply(struct net_device *dev,
 		if (max_mtu < ETH_MIN_MTU)
 			max_mtu = ETH_MIN_MTU;
 
-		if (!changelink && !conf->mtu)
+		if (!changelink && !new_cfg->mtu)
 			dev->mtu = max_mtu;
 	}
 
@@ -3993,7 +4058,10 @@ static void vxlan_config_apply(struct net_device *dev,
 	needed_headroom += vxlan_headroom(flags);
 	dev->needed_headroom = needed_headroom;
 
-	memcpy(&vxlan->cfg, conf, sizeof(*conf));
+	old_cfg = rtnl_dereference(vxlan->cfg);
+	rcu_assign_pointer(vxlan->cfg, new_cfg);
+	if (old_cfg)
+		kfree_rcu(old_cfg, rcu);
 }
 
 static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
@@ -4002,13 +4070,18 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct net_device *lowerdev;
+	struct vxlan_config *new_cfg;
 	int ret;
 
 	ret = vxlan_config_validate(src_net, conf, &lowerdev, vxlan, extack);
 	if (ret)
 		return ret;
 
-	vxlan_config_apply(dev, conf, lowerdev, src_net, false);
+	new_cfg = kmemdup(conf, sizeof(*conf), GFP_KERNEL);
+	if (!new_cfg)
+		return -ENOMEM;
+
+	vxlan_config_apply(dev, new_cfg, lowerdev, src_net, false);
 
 	return 0;
 }
@@ -4020,6 +4093,7 @@ static int vxlan_dev_create(struct net *net, struct net_device *dev,
 	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct net_device *remote_dev = NULL;
+	const struct vxlan_config *cfg;
 	struct vxlan_rdst *dst;
 	int err;
 
@@ -4028,11 +4102,15 @@ static int vxlan_dev_create(struct net *net, struct net_device *dev,
 	if (err)
 		return err;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+
 	dev->ethtool_ops = &vxlan_ethtool_ops;
 
 	err = register_netdevice(dev);
-	if (err)
+	if (err) {
+		vxlan_free_dev(dev);
 		return err;
+	}
 
 	if (dst->remote_ifindex) {
 		remote_dev = __dev_get_by_index(net, dst->remote_ifindex);
@@ -4059,7 +4137,7 @@ static int vxlan_dev_create(struct net *net, struct net_device *dev,
 				       &dst->remote_ip,
 				       NUD_REACHABLE | NUD_PERMANENT,
 				       NLM_F_EXCL | NLM_F_CREATE,
-				       vxlan->cfg.dst_port,
+				       cfg->dst_port,
 				       dst->remote_vni,
 				       dst->remote_vni,
 				       dst->remote_ifindex,
@@ -4123,8 +4201,12 @@ static int vxlan_nl2conf(struct nlattr *tb[], struct nlattr *data[],
 	memset(conf, 0, sizeof(*conf));
 
 	/* if changelink operation, start with old existing cfg */
-	if (changelink)
-		memcpy(conf, &vxlan->cfg, sizeof(*conf));
+	if (changelink) {
+		const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
+
+		if (cfg)
+			memcpy(conf, cfg, sizeof(*conf));
+	}
 
 	if (data[IFLA_VXLAN_ID]) {
 		__be32 vni = cpu_to_be32(nla_get_u32(data[IFLA_VXLAN_ID]));
@@ -4471,9 +4553,11 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 			    struct netlink_ext_ack *extack)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	bool rem_ip_changed, change_igmp;
 	struct net_device *lowerdev;
 	struct vxlan_config conf;
+	struct vxlan_config *new_cfg;
 	struct vxlan_rdst *dst;
 	int err;
 
@@ -4490,13 +4574,19 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (err)
 		return err;
 
+	new_cfg = kmemdup(&conf, sizeof(conf), GFP_KERNEL);
+	if (!new_cfg)
+		return -ENOMEM;
+
 	if (dst->remote_dev == lowerdev)
 		lowerdev = NULL;
 
 	err = netdev_adjacent_change_prepare(dst->remote_dev, lowerdev, dev,
 					     extack);
-	if (err)
+	if (err) {
+		kfree(new_cfg);
 		return err;
+	}
 
 	rem_ip_changed = !vxlan_addr_equal(&conf.remote_ip, &dst->remote_ip);
 	change_igmp = vxlan->dev->flags & IFF_UP &&
@@ -4511,7 +4601,7 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 					       &conf.remote_ip,
 					       NUD_REACHABLE | NUD_PERMANENT,
 					       NLM_F_APPEND | NLM_F_CREATE,
-					       vxlan->cfg.dst_port,
+					       cfg->dst_port,
 					       conf.vni, conf.vni,
 					       conf.remote_ifindex,
 					       NTF_SELF, 0, true, extack);
@@ -4519,13 +4609,14 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 				spin_unlock_bh(&vxlan->hash_lock);
 				netdev_adjacent_change_abort(dst->remote_dev,
 							     lowerdev, dev);
+				kfree(new_cfg);
 				return err;
 			}
 		}
 		if (!vxlan_addr_any(&dst->remote_ip))
 			__vxlan_fdb_delete(vxlan, all_zeros_mac,
 					   dst->remote_ip,
-					   vxlan->cfg.dst_port,
+					   cfg->dst_port,
 					   dst->remote_vni,
 					   dst->remote_vni,
 					   dst->remote_ifindex,
@@ -4535,12 +4626,13 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 		/* If vni filtering device, also update fdb entries of
 		 * all vnis that were using default remote ip
 		 */
-		if (vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
+		if (cfg->flags & VXLAN_F_VNIFILTER) {
 			err = vxlan_vnilist_update_group(vxlan, &dst->remote_ip,
 							 &conf.remote_ip, extack);
 			if (err) {
 				netdev_adjacent_change_abort(dst->remote_dev,
 							     lowerdev, dev);
+				kfree(new_cfg);
 				return err;
 			}
 		}
@@ -4549,13 +4641,13 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (change_igmp && vxlan_addr_multicast(&dst->remote_ip))
 		err = vxlan_multicast_leave(vxlan);
 
-	if (netif_running(dev) && conf.age_interval != vxlan->cfg.age_interval)
+	if (netif_running(dev) && conf.age_interval != cfg->age_interval)
 		mod_timer(&vxlan->age_timer, jiffies);
 
 	netdev_adjacent_change_commit(dst->remote_dev, lowerdev, dev);
 	if (lowerdev && lowerdev != dst->remote_dev)
 		dst->remote_dev = lowerdev;
-	vxlan_config_apply(dev, &conf, lowerdev, vxlan->net, true);
+	vxlan_config_apply(dev, new_cfg, lowerdev, vxlan->net, true);
 
 	if (!err && change_igmp &&
 	    vxlan_addr_multicast(&dst->remote_ip))
@@ -4622,7 +4714,7 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	struct ifla_vxlan_port_range ports;
 	const struct vxlan_config *cfg;
 
-	cfg = &vxlan->cfg;
+	cfg = rtnl_dereference(vxlan->cfg);
 
 	if (nla_put_u32(skb, IFLA_VXLAN_ID, be32_to_cpu(dst->remote_vni)))
 		goto nla_put_failure;
diff --git a/drivers/net/vxlan/vxlan_mdb.c b/drivers/net/vxlan/vxlan_mdb.c
index cf606256d0929c4dd356ec8aa343150c10edfb82..4ae6369ed4e35e307565f91d0706970f460af552 100644
--- a/drivers/net/vxlan/vxlan_mdb.c
+++ b/drivers/net/vxlan/vxlan_mdb.c
@@ -165,7 +165,7 @@ static int vxlan_mdb_entry_info_fill(const struct vxlan_dev *vxlan,
 				     const struct vxlan_mdb_entry *mdb_entry,
 				     const struct vxlan_mdb_remote *remote)
 {
-	const struct vxlan_config *cfg = &vxlan->cfg;
+	const struct vxlan_config *cfg = rcu_dereference_rtnl(vxlan->cfg);
 	struct vxlan_rdst *rd = rtnl_dereference(remote->rd);
 	struct br_mdb_entry e;
 	struct nlattr *nest;
@@ -614,7 +614,9 @@ static int vxlan_mdb_config_init(struct vxlan_mdb_config *cfg,
 {
 	struct br_mdb_entry *entry = nla_data(tb[MDBA_SET_ENTRY]);
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	const struct vxlan_config *vcfg = &vxlan->cfg;
+	const struct vxlan_config *vcfg;
+
+	vcfg = rtnl_dereference(vxlan->cfg);
 
 	memset(cfg, 0, sizeof(*cfg));
 	cfg->vxlan = vxlan;
@@ -959,12 +961,12 @@ vxlan_mdb_nlmsg_remote_size(const struct vxlan_dev *vxlan,
 			    const struct vxlan_mdb_entry *mdb_entry,
 			    const struct vxlan_mdb_remote *remote)
 {
-	const struct vxlan_config *cfg = &vxlan->cfg;
+	const struct vxlan_config *cfg = rcu_dereference_rtnl(vxlan->cfg);
 	const struct vxlan_mdb_entry_key *group = &mdb_entry->key;
 	struct vxlan_rdst *rd = rtnl_dereference(remote->rd);
 	size_t nlmsg_size;
 
-		     /* MDBA_MDB_ENTRY_INFO */
+	/* MDBA_MDB_ENTRY_INFO */
 	nlmsg_size = nla_total_size(sizeof(struct br_mdb_entry)) +
 		     /* MDBA_MDB_EATTR_TIMER */
 		     nla_total_size(sizeof(u32));
diff --git a/drivers/net/vxlan/vxlan_multicast.c b/drivers/net/vxlan/vxlan_multicast.c
index 3b75b48dc726df40cebb233095a8a046ee274c30..e2cf10da274f1b608d8bb5020d2b87ebfedeff46 100644
--- a/drivers/net/vxlan/vxlan_multicast.c
+++ b/drivers/net/vxlan/vxlan_multicast.c
@@ -147,6 +147,8 @@ bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
 #endif
 
 	list_for_each_entry(vxlan, &vn->vxlan_list, next) {
+		const struct vxlan_config *cfg;
+
 		if (!netif_running(vxlan->dev) || vxlan == dev)
 			continue;
 
@@ -158,7 +160,9 @@ bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
 		    rtnl_dereference(vxlan->vn6_sock) != sock6)
 			continue;
 #endif
-		if (vxlan->cfg.flags & VXLAN_F_VNIFILTER) {
+		cfg = rtnl_dereference(vxlan->cfg);
+
+		if (cfg->flags & VXLAN_F_VNIFILTER) {
 			if (!vxlan_group_used_by_vnifilter(vxlan, ip, ifindex))
 				continue;
 		} else {
@@ -233,6 +237,7 @@ static int vxlan_multicast_leave_vnigrp(struct vxlan_dev *vxlan)
 
 int vxlan_multicast_join(struct vxlan_dev *vxlan)
 {
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	int ret = 0;
 
 	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip)) {
@@ -244,7 +249,7 @@ int vxlan_multicast_join(struct vxlan_dev *vxlan)
 			return ret;
 	}
 
-	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+	if (cfg->flags & VXLAN_F_VNIFILTER)
 		return vxlan_multicast_join_vnigrp(vxlan);
 
 	return 0;
@@ -252,6 +257,7 @@ int vxlan_multicast_join(struct vxlan_dev *vxlan)
 
 int vxlan_multicast_leave(struct vxlan_dev *vxlan)
 {
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
 	int ret = 0;
 
@@ -263,7 +269,7 @@ int vxlan_multicast_leave(struct vxlan_dev *vxlan)
 			return ret;
 	}
 
-	if (vxlan->cfg.flags & VXLAN_F_VNIFILTER)
+	if (cfg->flags & VXLAN_F_VNIFILTER)
 		return vxlan_multicast_leave_vnigrp(vxlan);
 
 	return 0;
diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
index 7d362c69be1bc91204ee613dbe6afbaf7af1eeca..6a2d0a69d7be18d49015cc8e32d10b9533198b7d 100644
--- a/drivers/net/vxlan/vxlan_vnifilter.c
+++ b/drivers/net/vxlan/vxlan_vnifilter.c
@@ -178,7 +178,7 @@ void vxlan_vnifilter_count(struct vxlan_dev *vxlan,
 {
 	struct vxlan_vni_node *vnode;
 
-	if (!cfg || !(cfg->flags & VXLAN_F_VNIFILTER))
+	if (!(cfg->flags & VXLAN_F_VNIFILTER))
 		return;
 
 	if (vninode) {
@@ -337,6 +337,7 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
 	struct vxlan_vni_node *v, *vbegin = NULL, *vend = NULL;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct tunnel_msg *new_tmsg, *tmsg;
+	const struct vxlan_config *cfg;
 	struct vxlan_vni_group *vg;
 	struct nlmsghdr *nlh;
 	int idx = 0, s_idx;
@@ -349,7 +350,8 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
 	}
 	s_idx = cb->args[1];
 
-	if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER)) {
+	cfg = rcu_dereference(vxlan->cfg);
+	if (!(cfg->flags & VXLAN_F_VNIFILTER)) {
 		cb->args[1] = 0;
 		cb->args[2] = 0;
 		return -EINVAL;
@@ -489,6 +491,7 @@ static int vxlan_update_default_fdb_entry(struct vxlan_dev *vxlan, __be32 vni,
 					  union vxlan_addr *remote_ip,
 					  struct netlink_ext_ack *extack)
 {
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	struct vxlan_rdst *dst = &vxlan->default_dst;
 	int err = 0;
 
@@ -498,7 +501,7 @@ static int vxlan_update_default_fdb_entry(struct vxlan_dev *vxlan, __be32 vni,
 				       remote_ip,
 				       NUD_REACHABLE | NUD_PERMANENT,
 				       NLM_F_APPEND | NLM_F_CREATE,
-				       vxlan->cfg.dst_port,
+				       cfg->dst_port,
 				       vni,
 				       vni,
 				       dst->remote_ifindex,
@@ -512,7 +515,7 @@ static int vxlan_update_default_fdb_entry(struct vxlan_dev *vxlan, __be32 vni,
 	if (old_remote_ip && !vxlan_addr_any(old_remote_ip)) {
 		__vxlan_fdb_delete(vxlan, all_zeros_mac,
 				   *old_remote_ip,
-				   vxlan->cfg.dst_port,
+				   cfg->dst_port,
 				   vni, vni,
 				   dst->remote_ifindex,
 				   true);
@@ -626,6 +629,7 @@ static void vxlan_vni_delete_group(struct vxlan_dev *vxlan,
 				   struct vxlan_vni_node *vninode)
 {
 	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	struct vxlan_rdst *dst = &vxlan->default_dst;
 
 	/* if per vni remote_ip not present, delete the
@@ -637,7 +641,7 @@ static void vxlan_vni_delete_group(struct vxlan_dev *vxlan,
 		__vxlan_fdb_delete(vxlan, all_zeros_mac,
 				   (vxlan_addr_any(&vninode->remote_ip) ?
 				   dst->remote_ip : vninode->remote_ip),
-				   vxlan->cfg.dst_port,
+				   cfg->dst_port,
 				   vninode->vni, vninode->vni,
 				   dst->remote_ifindex,
 				   true);
@@ -737,6 +741,7 @@ static int vxlan_vni_add(struct vxlan_dev *vxlan,
 			 u32 vni, union vxlan_addr *group,
 			 struct netlink_ext_ack *extack)
 {
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	struct vxlan_vni_node *vninode;
 	__be32 v = cpu_to_be32(vni);
 	bool changed = false;
@@ -745,7 +750,7 @@ static int vxlan_vni_add(struct vxlan_dev *vxlan,
 	if (vxlan_vnifilter_lookup(vxlan, v))
 		return vxlan_vni_update(vxlan, vg, v, group, &changed, extack);
 
-	err = vxlan_vni_in_use(vxlan->net, vxlan, &vxlan->cfg, v);
+	err = vxlan_vni_in_use(vxlan->net, vxlan, cfg, v);
 	if (err) {
 		NL_SET_ERR_MSG(extack, "VNI in use");
 		return err;
@@ -954,6 +959,7 @@ static int vxlan_vnifilter_process(struct sk_buff *skb, struct nlmsghdr *nlh,
 				   struct netlink_ext_ack *extack)
 {
 	struct net *net = sock_net(skb->sk);
+	const struct vxlan_config *cfg;
 	struct tunnel_msg *tmsg;
 	struct vxlan_dev *vxlan;
 	struct net_device *dev;
@@ -978,8 +984,9 @@ static int vxlan_vnifilter_process(struct sk_buff *skb, struct nlmsghdr *nlh,
 	}
 
 	vxlan = netdev_priv(dev);
+	cfg = rtnl_dereference(vxlan->cfg);
 
-	if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER))
+	if (!(cfg->flags & VXLAN_F_VNIFILTER))
 		return -EOPNOTSUPP;
 
 	nlmsg_for_each_attr_type(attr, VXLAN_VNIFILTER_ENTRY, nlh,
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index d323f91af2364822e148310297c978fec7664010..7ced743ec8816d412bb14ec7ee7b422e97c38895 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h
@@ -229,6 +229,7 @@ struct vxlan_config {
 	bool				no_share;
 	enum ifla_vxlan_df		df;
 	struct vxlanhdr			reserved_bits;
+	struct rcu_head			rcu;
 };
 
 enum {
@@ -302,7 +303,7 @@ struct vxlan_dev {
 	struct gro_cells  gro_cells;
 	unsigned long	  flags;
 
-	struct vxlan_config	cfg;
+	struct vxlan_config __rcu	*cfg;
 
 	struct vxlan_vni_group  __rcu *vnigrp;
 
-- 
2.55.0.1007.g17ff1f9808-goog


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v3 net-next 5/6] vxlan: remove default_dst and use vxlan_config and lowerdev
  2026-09-11  6:21 [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps Eric Dumazet
                   ` (3 preceding siblings ...)
  2026-09-11  6:21 ` [PATCH v3 net-next 4/6] vxlan: convert configuration to RCU protection Eric Dumazet
@ 2026-09-11  6:21 ` Eric Dumazet
  2026-09-15  2:01   ` Jakub Kicinski
  2026-09-11  6:22 ` [PATCH v3 net-next 6/6] vxlan: no longer rely on RTNL in vxlan_fill_info() Eric Dumazet
  5 siblings, 1 reply; 12+ messages in thread
From: Eric Dumazet @ 2026-09-11  6:21 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Kuniyuki Iwashima, Ido Schimmel, Andrew Lunn,
	netdev, eric.dumazet, Eric Dumazet

Now that vxlan->cfg is an RCU-protected pointer, storing default
destination attributes (remote_ip, remote_vni, remote_ifindex) in
vxlan->default_dst is redundant and creates potential data races for
lockless readers.

Furthermore, several fields of struct vxlan_rdst (remote_dev,
remote_port, offloaded, list, rcu, dst_cache) in default_dst were
completely unused. Drop the now-unused remote_dev field from struct
vxlan_rdst.

Replace vxlan->default_dst with a 'struct net_device *lowerdev' pointer
in struct vxlan_dev to track adjacent upper/lower netdev topology under
RTNL, and switch all remaining users over to reading configuration
attributes from vxlan->cfg.

Also update mlx5e_tc_tun_get_remote_ifindex() to read remote_ifindex
from vxlan->cfg under rcu_read_lock().

In vxlan_changelink(), pass lowerdev to vxlan_config_apply() to preserve
needed_headroom and needed_tailroom, and update default FDB entries
(including VNI filter entries) if remote_ifindex changed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 .../mellanox/mlx5/core/en/tc_tun_vxlan.c      |  11 +-
 drivers/net/vxlan/vxlan_core.c                | 163 ++++++++++--------
 drivers/net/vxlan/vxlan_mdb.c                 |  14 +-
 drivers/net/vxlan/vxlan_multicast.c           |  64 +++----
 drivers/net/vxlan/vxlan_private.h             |  11 +-
 drivers/net/vxlan/vxlan_vnifilter.c           |  51 ++++--
 include/net/vxlan.h                           |   3 +-
 7 files changed, 178 insertions(+), 139 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_vxlan.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_vxlan.c
index 7a18a469961db809890d69f7d6d8bc656e560946..467fbe43b89e9bc3d28047a3a17a84495c3875af 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_vxlan.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_vxlan.c
@@ -241,9 +241,16 @@ static bool mlx5e_tc_tun_encap_info_equal_vxlan(struct mlx5e_encap_key *a,
 static int mlx5e_tc_tun_get_remote_ifindex(struct net_device *mirred_dev)
 {
 	const struct vxlan_dev *vxlan = netdev_priv(mirred_dev);
-	const struct vxlan_rdst *dst = &vxlan->default_dst;
+	const struct vxlan_config *cfg;
+	int ifindex = 0;
 
-	return dst->remote_ifindex;
+	rcu_read_lock();
+	cfg = rcu_dereference(vxlan->cfg);
+	if (cfg)
+		ifindex = cfg->remote_ifindex;
+	rcu_read_unlock();
+
+	return ifindex;
 }
 
 struct mlx5e_tc_tunnel vxlan_tunnel = {
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 338ecddb9542dee1c46e79872b25200d7b249304..8b7558eac049d2f83ab5f68aca2dad62bce9cbc7 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -804,6 +804,7 @@ static int vxlan_fdb_nh_update(struct vxlan_dev *vxlan, struct vxlan_fdb *fdb,
 			       u32 nhid, struct netlink_ext_ack *extack)
 {
 	struct nexthop *old_nh = rtnl_dereference(fdb->nh);
+	const struct vxlan_config *cfg;
 	struct nexthop *nh;
 	int err = -EINVAL;
 
@@ -832,7 +833,8 @@ static int vxlan_fdb_nh_update(struct vxlan_dev *vxlan, struct vxlan_fdb *fdb,
 	}
 
 	/* check nexthop group family */
-	switch (vxlan->default_dst.remote_ip.sa.sa_family) {
+	cfg = rtnl_dereference(vxlan->cfg);
+	switch (cfg->remote_ip.sa.sa_family) {
 	case AF_INET:
 		if (!nexthop_has_v4(nh)) {
 			err = -EAFNOSUPPORT;
@@ -1249,6 +1251,7 @@ static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 			 const unsigned char *addr, u16 vid, u16 flags,
 			 bool *notified, struct netlink_ext_ack *extack)
 {
+	const struct vxlan_config *cfg;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	/* struct net *net = dev_net(vxlan->dev); */
 	union vxlan_addr ip;
@@ -1276,7 +1279,8 @@ static int vxlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 		return -EINVAL;
 	}
 
-	if (vxlan->default_dst.remote_ip.sa.sa_family != ip.sa.sa_family)
+	cfg = rtnl_dereference(vxlan->cfg);
+	if (cfg->remote_ip.sa.sa_family != ip.sa.sa_family)
 		return -EAFNOSUPPORT;
 
 	spin_lock_bh(&vxlan->hash_lock);
@@ -2318,7 +2322,14 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
 	skb->dev = dev;
 	__skb_pull(skb, skb_network_offset(skb));
 
-	if (dst_vxlan->default_dst.remote_ip.sa.sa_family == AF_INET) {
+	rcu_read_lock();
+	dst_cfg = rcu_dereference(dst_vxlan->cfg);
+	if (unlikely(!(dev->flags & IFF_UP))) {
+		kfree_skb_reason(skb, SKB_DROP_REASON_DEV_READY);
+		goto drop;
+	}
+
+	if (dst_cfg->remote_ip.sa.sa_family == AF_INET) {
 		loopback.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 		loopback.sa.sa_family =  AF_INET;
 #if IS_ENABLED(CONFIG_IPV6)
@@ -2328,13 +2339,6 @@ static void vxlan_encap_bypass(struct sk_buff *skb, struct vxlan_dev *src_vxlan,
 #endif
 	}
 
-	rcu_read_lock();
-	dst_cfg = rcu_dereference(dst_vxlan->cfg);
-	if (unlikely(!(dev->flags & IFF_UP))) {
-		kfree_skb_reason(skb, SKB_DROP_REASON_DEV_READY);
-		goto drop;
-	}
-
 	if ((dst_cfg->flags & VXLAN_F_LEARN) && snoop)
 		vxlan_snoop(dev, dst_cfg, &loopback, eth_hdr(skb)->h_source, 0, vni);
 
@@ -2973,10 +2977,14 @@ static void vxlan_vs_del_dev(struct vxlan_dev *vxlan)
 static void vxlan_vs_add_dev(struct vxlan_sock *vs, struct vxlan_dev *vxlan,
 			     struct vxlan_dev_node *node)
 {
-	__be32 vni = vxlan->default_dst.remote_vni;
+	const struct vxlan_config *cfg;
+	__be32 vni;
 
 	ASSERT_RTNL();
 
+	cfg = rtnl_dereference(vxlan->cfg);
+	vni = cfg->vni;
+
 	node->vxlan = vxlan;
 	hlist_add_head_rcu(&node->hlist, vni_head(vs, vni));
 }
@@ -3298,13 +3306,12 @@ static void vxlan_set_multicast_list(struct net_device *dev)
 static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	struct vxlan_rdst *dst = &vxlan->default_dst;
 	const struct vxlan_config *cfg;
 	struct net_device *lowerdev;
 
 	cfg = rtnl_dereference(vxlan->cfg);
 
-	lowerdev = __dev_get_by_index(vxlan->net, dst->remote_ifindex);
+	lowerdev = __dev_get_by_index(vxlan->net, cfg->remote_ifindex);
 
 	/* This check is different than dev->max_mtu, because it looks at
 	 * the lowerdev->mtu, rather than the static dev->max_mtu
@@ -3633,9 +3640,11 @@ static int vxlan_get_link_ksettings(struct net_device *dev,
 				    struct ethtool_link_ksettings *cmd)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	struct vxlan_rdst *dst = &vxlan->default_dst;
-	struct net_device *lowerdev = __dev_get_by_index(vxlan->net,
-							 dst->remote_ifindex);
+	const struct vxlan_config *cfg;
+	struct net_device *lowerdev;
+
+	cfg = rtnl_dereference(vxlan->cfg);
+	lowerdev = __dev_get_by_index(vxlan->net, cfg->remote_ifindex);
 
 	if (!lowerdev) {
 		cmd->base.duplex = DUPLEX_UNKNOWN;
@@ -4010,7 +4019,6 @@ static void vxlan_config_apply(struct net_device *dev,
 			       bool changelink)
 {
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	struct vxlan_rdst *dst = &vxlan->default_dst;
 	unsigned short needed_headroom = ETH_HLEN;
 	struct vxlan_config *old_cfg;
 	int max_mtu = ETH_MAX_MTU;
@@ -4028,13 +4036,7 @@ static void vxlan_config_apply(struct net_device *dev,
 		vxlan->net = src_net;
 	}
 
-	dst->remote_vni = new_cfg->vni;
-
-	memcpy(&dst->remote_ip, &new_cfg->remote_ip, sizeof(new_cfg->remote_ip));
-
 	if (lowerdev) {
-		dst->remote_ifindex = new_cfg->remote_ifindex;
-
 		netif_inherit_tso_max(dev, lowerdev);
 
 		needed_headroom = lowerdev->hard_header_len;
@@ -4094,10 +4096,8 @@ static int vxlan_dev_create(struct net *net, struct net_device *dev,
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	struct net_device *remote_dev = NULL;
 	const struct vxlan_config *cfg;
-	struct vxlan_rdst *dst;
 	int err;
 
-	dst = &vxlan->default_dst;
 	err = vxlan_dev_configure(net, dev, conf, extack);
 	if (err)
 		return err;
@@ -4112,8 +4112,8 @@ static int vxlan_dev_create(struct net *net, struct net_device *dev,
 		return err;
 	}
 
-	if (dst->remote_ifindex) {
-		remote_dev = __dev_get_by_index(net, dst->remote_ifindex);
+	if (cfg->remote_ifindex) {
+		remote_dev = __dev_get_by_index(net, cfg->remote_ifindex);
 		if (!remote_dev) {
 			err = -ENODEV;
 			goto unregister;
@@ -4123,7 +4123,7 @@ static int vxlan_dev_create(struct net *net, struct net_device *dev,
 		if (err)
 			goto unregister;
 
-		dst->remote_dev = remote_dev;
+		vxlan->lowerdev = remote_dev;
 	}
 
 	err = rtnl_configure_link(dev, NULL, 0, NULL);
@@ -4131,16 +4131,18 @@ static int vxlan_dev_create(struct net *net, struct net_device *dev,
 		goto unlink;
 
 	/* create an fdb entry for a valid default destination */
-	if (!vxlan_addr_any(&dst->remote_ip)) {
+	if (!vxlan_addr_any(&cfg->remote_ip)) {
+		union vxlan_addr rip = cfg->remote_ip;
+
 		spin_lock_bh(&vxlan->hash_lock);
 		err = vxlan_fdb_update(vxlan, all_zeros_mac,
-				       &dst->remote_ip,
+				       &rip,
 				       NUD_REACHABLE | NUD_PERMANENT,
 				       NLM_F_EXCL | NLM_F_CREATE,
 				       cfg->dst_port,
-				       dst->remote_vni,
-				       dst->remote_vni,
-				       dst->remote_ifindex,
+				       cfg->vni,
+				       cfg->vni,
+				       cfg->remote_ifindex,
 				       NTF_SELF, 0, true, extack);
 		spin_unlock_bh(&vxlan->hash_lock);
 		if (err)
@@ -4552,19 +4554,19 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 			    struct nlattr *data[],
 			    struct netlink_ext_ack *extack)
 {
+	bool lowerdev_changed, rem_ip_changed, change_igmp;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
-	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
-	bool rem_ip_changed, change_igmp;
+	const struct vxlan_config *cfg;
+	struct vxlan_config *new_cfg;
 	struct net_device *lowerdev;
 	struct vxlan_config conf;
-	struct vxlan_config *new_cfg;
-	struct vxlan_rdst *dst;
 	int err;
 
+	cfg = rtnl_dereference(vxlan->cfg);
+
 	if (!rtnl_dev_link_net_capable(dev, vxlan->net))
 		return -EPERM;
 
-	dst = &vxlan->default_dst;
 	err = vxlan_nl2conf(tb, data, dev, &conf, true, extack);
 	if (err)
 		return err;
@@ -4578,23 +4580,23 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 	if (!new_cfg)
 		return -ENOMEM;
 
-	if (dst->remote_dev == lowerdev)
-		lowerdev = NULL;
-
-	err = netdev_adjacent_change_prepare(dst->remote_dev, lowerdev, dev,
-					     extack);
-	if (err) {
-		kfree(new_cfg);
-		return err;
+	lowerdev_changed = vxlan->lowerdev != lowerdev;
+	if (lowerdev_changed) {
+		err = netdev_adjacent_change_prepare(vxlan->lowerdev, lowerdev,
+						     dev, extack);
+		if (err) {
+			kfree(new_cfg);
+			return err;
+		}
 	}
 
-	rem_ip_changed = !vxlan_addr_equal(&conf.remote_ip, &dst->remote_ip);
+	rem_ip_changed = !vxlan_addr_equal(&conf.remote_ip, &cfg->remote_ip);
 	change_igmp = vxlan->dev->flags & IFF_UP &&
 		      (rem_ip_changed ||
-		       dst->remote_ifindex != conf.remote_ifindex);
+		       cfg->remote_ifindex != conf.remote_ifindex);
 
 	/* handle default dst entry */
-	if (rem_ip_changed) {
+	if (rem_ip_changed || cfg->remote_ifindex != conf.remote_ifindex) {
 		spin_lock_bh(&vxlan->hash_lock);
 		if (!vxlan_addr_any(&conf.remote_ip)) {
 			err = vxlan_fdb_update(vxlan, all_zeros_mac,
@@ -4607,19 +4609,20 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 					       NTF_SELF, 0, true, extack);
 			if (err) {
 				spin_unlock_bh(&vxlan->hash_lock);
-				netdev_adjacent_change_abort(dst->remote_dev,
-							     lowerdev, dev);
+				if (lowerdev_changed)
+					netdev_adjacent_change_abort(vxlan->lowerdev,
+								     lowerdev, dev);
 				kfree(new_cfg);
 				return err;
 			}
 		}
-		if (!vxlan_addr_any(&dst->remote_ip))
+		if (!vxlan_addr_any(&cfg->remote_ip))
 			__vxlan_fdb_delete(vxlan, all_zeros_mac,
-					   dst->remote_ip,
+					   cfg->remote_ip,
 					   cfg->dst_port,
-					   dst->remote_vni,
-					   dst->remote_vni,
-					   dst->remote_ifindex,
+					   cfg->vni,
+					   cfg->vni,
+					   cfg->remote_ifindex,
 					   true);
 		spin_unlock_bh(&vxlan->hash_lock);
 
@@ -4627,30 +4630,39 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 		 * all vnis that were using default remote ip
 		 */
 		if (cfg->flags & VXLAN_F_VNIFILTER) {
-			err = vxlan_vnilist_update_group(vxlan, &dst->remote_ip,
-							 &conf.remote_ip, extack);
+			err = vxlan_vnilist_update_group(vxlan, &cfg->remote_ip,
+							 &conf.remote_ip,
+							 cfg->remote_ifindex,
+							 conf.remote_ifindex,
+							 extack);
 			if (err) {
-				netdev_adjacent_change_abort(dst->remote_dev,
-							     lowerdev, dev);
+				if (lowerdev_changed)
+					netdev_adjacent_change_abort(vxlan->lowerdev,
+								     lowerdev, dev);
 				kfree(new_cfg);
 				return err;
 			}
 		}
 	}
 
-	if (change_igmp && vxlan_addr_multicast(&dst->remote_ip))
+	if (change_igmp && vxlan_addr_multicast(&cfg->remote_ip))
 		err = vxlan_multicast_leave(vxlan);
 
 	if (netif_running(dev) && conf.age_interval != cfg->age_interval)
 		mod_timer(&vxlan->age_timer, jiffies);
 
-	netdev_adjacent_change_commit(dst->remote_dev, lowerdev, dev);
-	if (lowerdev && lowerdev != dst->remote_dev)
-		dst->remote_dev = lowerdev;
+	if (lowerdev_changed) {
+		if (lowerdev)
+			netdev_adjacent_change_commit(vxlan->lowerdev, lowerdev,
+						      dev);
+		else
+			netdev_upper_dev_unlink(vxlan->lowerdev, dev);
+		vxlan->lowerdev = lowerdev;
+	}
 	vxlan_config_apply(dev, new_cfg, lowerdev, vxlan->net, true);
 
 	if (!err && change_igmp &&
-	    vxlan_addr_multicast(&dst->remote_ip))
+	    vxlan_addr_multicast(&new_cfg->remote_ip))
 		err = vxlan_multicast_join(vxlan);
 
 	return err;
@@ -4665,8 +4677,8 @@ static void vxlan_dellink(struct net_device *dev, struct list_head *head)
 
 	list_del(&vxlan->next);
 	unregister_netdevice_queue(dev, head);
-	if (vxlan->default_dst.remote_dev)
-		netdev_upper_dev_unlink(vxlan->default_dst.remote_dev, dev);
+	if (vxlan->lowerdev)
+		netdev_upper_dev_unlink(vxlan->lowerdev, dev);
 }
 
 static size_t vxlan_get_size(const struct net_device *dev)
@@ -4710,30 +4722,29 @@ static size_t vxlan_get_size(const struct net_device *dev)
 static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 {
 	const struct vxlan_dev *vxlan = netdev_priv(dev);
-	const struct vxlan_rdst *dst = &vxlan->default_dst;
 	struct ifla_vxlan_port_range ports;
 	const struct vxlan_config *cfg;
 
 	cfg = rtnl_dereference(vxlan->cfg);
 
-	if (nla_put_u32(skb, IFLA_VXLAN_ID, be32_to_cpu(dst->remote_vni)))
+	if (nla_put_u32(skb, IFLA_VXLAN_ID, be32_to_cpu(cfg->vni)))
 		goto nla_put_failure;
 
-	if (!vxlan_addr_any(&dst->remote_ip)) {
-		if (dst->remote_ip.sa.sa_family == AF_INET) {
+	if (!vxlan_addr_any(&cfg->remote_ip)) {
+		if (cfg->remote_ip.sa.sa_family == AF_INET) {
 			if (nla_put_in_addr(skb, IFLA_VXLAN_GROUP,
-					    dst->remote_ip.sin.sin_addr.s_addr))
+					    cfg->remote_ip.sin.sin_addr.s_addr))
 				goto nla_put_failure;
 #if IS_ENABLED(CONFIG_IPV6)
 		} else {
 			if (nla_put_in6_addr(skb, IFLA_VXLAN_GROUP6,
-					     &dst->remote_ip.sin6.sin6_addr))
+					     &cfg->remote_ip.sin6.sin6_addr))
 				goto nla_put_failure;
 #endif
 		}
 	}
 
-	if (dst->remote_ifindex && nla_put_u32(skb, IFLA_VXLAN_LINK, dst->remote_ifindex))
+	if (cfg->remote_ifindex && nla_put_u32(skb, IFLA_VXLAN_LINK, cfg->remote_ifindex))
 		goto nla_put_failure;
 
 	if (!vxlan_addr_any(&cfg->saddr)) {
@@ -4848,7 +4859,7 @@ static void vxlan_handle_lowerdev_unregister(struct vxlan_net *vn,
 	LIST_HEAD(list_kill);
 
 	list_for_each_entry_safe(vxlan, next, &vn->vxlan_list, next) {
-		struct vxlan_rdst *dst = &vxlan->default_dst;
+		const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 
 		/* In case we created vxlan device with carrier
 		 * and we loose the carrier due to module unload
@@ -4856,7 +4867,7 @@ static void vxlan_handle_lowerdev_unregister(struct vxlan_net *vn,
 		 * cases, it's not necessary and remote_ifindex
 		 * is 0 here, so no matches.
 		 */
-		if (dst->remote_ifindex == dev->ifindex)
+		if (cfg->remote_ifindex == dev->ifindex)
 			vxlan_dellink(vxlan->dev, &list_kill);
 	}
 
diff --git a/drivers/net/vxlan/vxlan_mdb.c b/drivers/net/vxlan/vxlan_mdb.c
index 4ae6369ed4e35e307565f91d0706970f460af552..c1a0551990555ce3e1dca81a9b5df7196a2a5fdf 100644
--- a/drivers/net/vxlan/vxlan_mdb.c
+++ b/drivers/net/vxlan/vxlan_mdb.c
@@ -195,7 +195,7 @@ static int vxlan_mdb_entry_info_fill(const struct vxlan_dev *vxlan,
 			be16_to_cpu(rd->remote_port)))
 		goto nest_err;
 
-	if (rd->remote_vni != vxlan->default_dst.remote_vni &&
+	if (rd->remote_vni != cfg->vni &&
 	    nla_put_u32(skb, MDBA_MDB_EATTR_VNI, be32_to_cpu(rd->remote_vni)))
 		goto nest_err;
 
@@ -620,12 +620,12 @@ static int vxlan_mdb_config_init(struct vxlan_mdb_config *cfg,
 
 	memset(cfg, 0, sizeof(*cfg));
 	cfg->vxlan = vxlan;
-	cfg->group.vni = vxlan->default_dst.remote_vni;
+	cfg->group.vni = vcfg->vni;
 	INIT_LIST_HEAD(&cfg->src_list);
 	cfg->nlflags = nlmsg_flags;
 	cfg->filter_mode = MCAST_EXCLUDE;
 	cfg->rt_protocol = RTPROT_STATIC;
-	cfg->remote_vni = vxlan->default_dst.remote_vni;
+	cfg->remote_vni = vcfg->vni;
 	cfg->remote_port = vcfg->dst_port;
 
 	if (entry->ifindex != dev->ifindex) {
@@ -986,7 +986,7 @@ vxlan_mdb_nlmsg_remote_size(const struct vxlan_dev *vxlan,
 	if (rd->remote_port && rd->remote_port != cfg->dst_port)
 		nlmsg_size += nla_total_size(sizeof(u16));
 	/* MDBA_MDB_EATTR_VNI */
-	if (rd->remote_vni != vxlan->default_dst.remote_vni)
+	if (rd->remote_vni != cfg->vni)
 		nlmsg_size += nla_total_size(sizeof(u32));
 	/* MDBA_MDB_EATTR_IFINDEX */
 	if (rd->remote_ifindex)
@@ -1488,11 +1488,13 @@ static int vxlan_mdb_get_parse(struct net_device *dev, struct nlattr *tb[],
 {
 	struct br_mdb_entry *entry = nla_data(tb[MDBA_GET_ENTRY]);
 	struct nlattr *mdbe_attrs[MDBE_ATTR_MAX + 1];
+	const struct vxlan_config *cfg;
 	struct vxlan_dev *vxlan = netdev_priv(dev);
 	int err;
 
+	cfg = rtnl_dereference(vxlan->cfg);
 	memset(group, 0, sizeof(*group));
-	group->vni = vxlan->default_dst.remote_vni;
+	group->vni = cfg->vni;
 
 	if (!tb[MDBA_GET_ENTRY_ATTRS]) {
 		vxlan_mdb_group_set(group, entry, NULL);
@@ -1641,7 +1643,7 @@ struct vxlan_mdb_entry *vxlan_mdb_entry_skb_get(struct vxlan_dev *vxlan,
 	 * entries are stored with the VNI of the VXLAN device.
 	 */
 	if (!(cfg->flags & VXLAN_F_COLLECT_METADATA))
-		src_vni = vxlan->default_dst.remote_vni;
+		src_vni = cfg->vni;
 
 	memset(&group, 0, sizeof(group));
 	group.vni = src_vni;
diff --git a/drivers/net/vxlan/vxlan_multicast.c b/drivers/net/vxlan/vxlan_multicast.c
index e2cf10da274f1b608d8bb5020d2b87ebfedeff46..6fcc4a36734361c28563d487d4ec108ca22d9e4f 100644
--- a/drivers/net/vxlan/vxlan_multicast.c
+++ b/drivers/net/vxlan/vxlan_multicast.c
@@ -14,11 +14,12 @@
 /* Update multicast group membership when first VNI on
  * multicast address is brought up
  */
-int vxlan_igmp_join(struct vxlan_dev *vxlan, union vxlan_addr *rip,
+int vxlan_igmp_join(struct vxlan_dev *vxlan, const union vxlan_addr *rip,
 		    int rifindex)
 {
-	union vxlan_addr *ip = (rip ? : &vxlan->default_dst.remote_ip);
-	int ifindex = (rifindex ? : vxlan->default_dst.remote_ifindex);
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
+	const union vxlan_addr *ip = (rip ? : &cfg->remote_ip);
+	int ifindex = (rifindex ? : cfg->remote_ifindex);
 	int ret = -EINVAL;
 	struct sock *sk;
 
@@ -47,11 +48,12 @@ int vxlan_igmp_join(struct vxlan_dev *vxlan, union vxlan_addr *rip,
 	return ret;
 }
 
-int vxlan_igmp_leave(struct vxlan_dev *vxlan, union vxlan_addr *rip,
+int vxlan_igmp_leave(struct vxlan_dev *vxlan, const union vxlan_addr *rip,
 		     int rifindex)
 {
-	union vxlan_addr *ip = (rip ? : &vxlan->default_dst.remote_ip);
-	int ifindex = (rifindex ? : vxlan->default_dst.remote_ifindex);
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
+	const union vxlan_addr *ip = (rip ? : &cfg->remote_ip);
+	int ifindex = (rifindex ? : cfg->remote_ifindex);
 	int ret = -EINVAL;
 	struct sock *sk;
 
@@ -80,8 +82,8 @@ int vxlan_igmp_leave(struct vxlan_dev *vxlan, union vxlan_addr *rip,
 	return ret;
 }
 
-static bool vxlan_group_used_match(union vxlan_addr *ip, int ifindex,
-				   union vxlan_addr *rip, int rifindex)
+static bool vxlan_group_used_match(const union vxlan_addr *ip, int ifindex,
+				   const union vxlan_addr *rip, int rifindex)
 {
 	if (!vxlan_addr_multicast(rip))
 		return false;
@@ -96,14 +98,16 @@ static bool vxlan_group_used_match(union vxlan_addr *ip, int ifindex,
 }
 
 static bool vxlan_group_used_by_vnifilter(struct vxlan_dev *vxlan,
-					  union vxlan_addr *ip, int ifindex)
+					  const struct vxlan_config *cfg,
+					  const union vxlan_addr *ip,
+					  int ifindex)
 {
 	struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
 	struct vxlan_vni_node *v, *tmp;
 
 	if (vxlan_group_used_match(ip, ifindex,
-				   &vxlan->default_dst.remote_ip,
-				   vxlan->default_dst.remote_ifindex))
+				   &cfg->remote_ip,
+				   cfg->remote_ifindex))
 		return true;
 
 	list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
@@ -112,7 +116,7 @@ static bool vxlan_group_used_by_vnifilter(struct vxlan_dev *vxlan,
 
 		if (vxlan_group_used_match(ip, ifindex,
 					   &v->remote_ip,
-					   vxlan->default_dst.remote_ifindex))
+					   cfg->remote_ifindex))
 			return true;
 	}
 
@@ -121,16 +125,17 @@ static bool vxlan_group_used_by_vnifilter(struct vxlan_dev *vxlan,
 
 /* See if multicast group is already in use by other ID */
 bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
-		      __be32 vni, union vxlan_addr *rip, int rifindex)
+		      __be32 vni, const union vxlan_addr *rip, int rifindex)
 {
-	union vxlan_addr *ip = (rip ? : &dev->default_dst.remote_ip);
-	int ifindex = (rifindex ? : dev->default_dst.remote_ifindex);
+	const struct vxlan_config *dev_cfg = rtnl_dereference(dev->cfg);
+	const union vxlan_addr *ip = (rip ? : &dev_cfg->remote_ip);
+	int ifindex = (rifindex ? : dev_cfg->remote_ifindex);
 	struct vxlan_dev *vxlan;
 	struct vxlan_sock *sock4;
 #if IS_ENABLED(CONFIG_IPV6)
 	struct vxlan_sock *sock6;
 #endif
-	unsigned short family = dev->default_dst.remote_ip.sa.sa_family;
+	unsigned short family = dev_cfg->remote_ip.sa.sa_family;
 
 	sock4 = rtnl_dereference(dev->vn4_sock);
 
@@ -163,12 +168,12 @@ bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
 		cfg = rtnl_dereference(vxlan->cfg);
 
 		if (cfg->flags & VXLAN_F_VNIFILTER) {
-			if (!vxlan_group_used_by_vnifilter(vxlan, ip, ifindex))
+			if (!vxlan_group_used_by_vnifilter(vxlan, cfg, ip, ifindex))
 				continue;
 		} else {
 			if (!vxlan_group_used_match(ip, ifindex,
-						    &vxlan->default_dst.remote_ip,
-						    vxlan->default_dst.remote_ifindex))
+						    &cfg->remote_ip,
+						    cfg->remote_ifindex))
 				continue;
 		}
 
@@ -178,7 +183,8 @@ bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
 	return false;
 }
 
-static int vxlan_multicast_join_vnigrp(struct vxlan_dev *vxlan)
+static int vxlan_multicast_join_vnigrp(struct vxlan_dev *vxlan,
+				       const struct vxlan_config *cfg)
 {
 	struct vxlan_vni_group *vg = rtnl_dereference(vxlan->vnigrp);
 	struct vxlan_vni_node *v, *tmp, *vgood = NULL;
@@ -189,7 +195,7 @@ static int vxlan_multicast_join_vnigrp(struct vxlan_dev *vxlan)
 			continue;
 		/* skip if address is same as default address */
 		if (vxlan_addr_equal(&v->remote_ip,
-				     &vxlan->default_dst.remote_ip))
+				     &cfg->remote_ip))
 			continue;
 		ret = vxlan_igmp_join(vxlan, &v->remote_ip, 0);
 		if (ret == -EADDRINUSE)
@@ -204,7 +210,7 @@ static int vxlan_multicast_join_vnigrp(struct vxlan_dev *vxlan)
 			if (!vxlan_addr_multicast(&v->remote_ip))
 				continue;
 			if (vxlan_addr_equal(&v->remote_ip,
-					     &vxlan->default_dst.remote_ip))
+					     &cfg->remote_ip))
 				continue;
 			vxlan_igmp_leave(vxlan, &v->remote_ip, 0);
 			if (v == vgood)
@@ -240,9 +246,9 @@ int vxlan_multicast_join(struct vxlan_dev *vxlan)
 	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
 	int ret = 0;
 
-	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip)) {
-		ret = vxlan_igmp_join(vxlan, &vxlan->default_dst.remote_ip,
-				      vxlan->default_dst.remote_ifindex);
+	if (vxlan_addr_multicast(&cfg->remote_ip)) {
+		ret = vxlan_igmp_join(vxlan, &cfg->remote_ip,
+				      cfg->remote_ifindex);
 		if (ret == -EADDRINUSE)
 			ret = 0;
 		if (ret)
@@ -250,7 +256,7 @@ int vxlan_multicast_join(struct vxlan_dev *vxlan)
 	}
 
 	if (cfg->flags & VXLAN_F_VNIFILTER)
-		return vxlan_multicast_join_vnigrp(vxlan);
+		return vxlan_multicast_join_vnigrp(vxlan, cfg);
 
 	return 0;
 }
@@ -261,10 +267,10 @@ int vxlan_multicast_leave(struct vxlan_dev *vxlan)
 	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
 	int ret = 0;
 
-	if (vxlan_addr_multicast(&vxlan->default_dst.remote_ip) &&
+	if (vxlan_addr_multicast(&cfg->remote_ip) &&
 	    !vxlan_group_used(vn, vxlan, 0, NULL, 0)) {
-		ret = vxlan_igmp_leave(vxlan, &vxlan->default_dst.remote_ip,
-				       vxlan->default_dst.remote_ifindex);
+		ret = vxlan_igmp_leave(vxlan, &cfg->remote_ip,
+				       cfg->remote_ifindex);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/net/vxlan/vxlan_private.h b/drivers/net/vxlan/vxlan_private.h
index ab7216c4e41011b99f8bf72de50fc2230b43c405..6ba0fb6400d102bdb58c2717d0d101e4b11ebb04 100644
--- a/drivers/net/vxlan/vxlan_private.h
+++ b/drivers/net/vxlan/vxlan_private.h
@@ -216,8 +216,9 @@ void vxlan_vs_add_vnigrp(struct vxlan_dev *vxlan,
 			 bool ipv6);
 void vxlan_vs_del_vnigrp(struct vxlan_dev *vxlan);
 int vxlan_vnilist_update_group(struct vxlan_dev *vxlan,
-			       union vxlan_addr *old_remote_ip,
-			       union vxlan_addr *new_remote_ip,
+			       const union vxlan_addr *old_remote_ip,
+			       const union vxlan_addr *new_remote_ip,
+			       u32 old_ifindex, u32 new_ifindex,
 			       struct netlink_ext_ack *extack);
 
 
@@ -225,10 +226,10 @@ int vxlan_vnilist_update_group(struct vxlan_dev *vxlan,
 int vxlan_multicast_join(struct vxlan_dev *vxlan);
 int vxlan_multicast_leave(struct vxlan_dev *vxlan);
 bool vxlan_group_used(struct vxlan_net *vn, struct vxlan_dev *dev,
-		      __be32 vni, union vxlan_addr *rip, int rifindex);
-int vxlan_igmp_join(struct vxlan_dev *vxlan, union vxlan_addr *rip,
+		      __be32 vni, const union vxlan_addr *rip, int rifindex);
+int vxlan_igmp_join(struct vxlan_dev *vxlan, const union vxlan_addr *rip,
 		    int rifindex);
-int vxlan_igmp_leave(struct vxlan_dev *vxlan, union vxlan_addr *rip,
+int vxlan_igmp_leave(struct vxlan_dev *vxlan, const union vxlan_addr *rip,
 		     int rifindex);
 
 /* vxlan_mdb.c */
diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
index 6a2d0a69d7be18d49015cc8e32d10b9533198b7d..55a07c20e7649d262e9f2c5c649a17da2649e1c5 100644
--- a/drivers/net/vxlan/vxlan_vnifilter.c
+++ b/drivers/net/vxlan/vxlan_vnifilter.c
@@ -487,24 +487,31 @@ static const struct nla_policy vni_filter_policy[VXLAN_VNIFILTER_MAX + 1] = {
 };
 
 static int vxlan_update_default_fdb_entry(struct vxlan_dev *vxlan, __be32 vni,
-					  union vxlan_addr *old_remote_ip,
-					  union vxlan_addr *remote_ip,
+					  const union vxlan_addr *old_remote_ip,
+					  const union vxlan_addr *remote_ip,
+					  u32 old_ifindex, u32 new_ifindex,
 					  struct netlink_ext_ack *extack)
 {
 	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
-	struct vxlan_rdst *dst = &vxlan->default_dst;
 	int err = 0;
 
+	if (old_remote_ip && remote_ip &&
+	    vxlan_addr_equal(old_remote_ip, remote_ip) &&
+	    old_ifindex == new_ifindex)
+		return 0;
+
 	spin_lock_bh(&vxlan->hash_lock);
 	if (remote_ip && !vxlan_addr_any(remote_ip)) {
+		union vxlan_addr rip = *remote_ip;
+
 		err = vxlan_fdb_update(vxlan, all_zeros_mac,
-				       remote_ip,
+				       &rip,
 				       NUD_REACHABLE | NUD_PERMANENT,
 				       NLM_F_APPEND | NLM_F_CREATE,
 				       cfg->dst_port,
 				       vni,
 				       vni,
-				       dst->remote_ifindex,
+				       new_ifindex,
 				       NTF_SELF, 0, true, extack);
 		if (err) {
 			spin_unlock_bh(&vxlan->hash_lock);
@@ -517,7 +524,7 @@ static int vxlan_update_default_fdb_entry(struct vxlan_dev *vxlan, __be32 vni,
 				   *old_remote_ip,
 				   cfg->dst_port,
 				   vni, vni,
-				   dst->remote_ifindex,
+				   old_ifindex,
 				   true);
 	}
 	spin_unlock_bh(&vxlan->hash_lock);
@@ -532,8 +539,8 @@ static int vxlan_vni_update_group(struct vxlan_dev *vxlan,
 				  struct netlink_ext_ack *extack)
 {
 	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
-	struct vxlan_rdst *dst = &vxlan->default_dst;
-	union vxlan_addr *newrip = NULL, *oldrip = NULL;
+	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
+	const union vxlan_addr *newrip = NULL, *oldrip = NULL;
 	union vxlan_addr old_remote_ip;
 	int ret = 0;
 
@@ -545,8 +552,8 @@ static int vxlan_vni_update_group(struct vxlan_dev *vxlan,
 	if (group && !vxlan_addr_any(group)) {
 		newrip = group;
 	} else {
-		if (!vxlan_addr_any(&dst->remote_ip))
-			newrip = &dst->remote_ip;
+		if (!vxlan_addr_any(&cfg->remote_ip))
+			newrip = &cfg->remote_ip;
 	}
 
 	/* if old rip exists, and no newrip,
@@ -563,6 +570,8 @@ static int vxlan_vni_update_group(struct vxlan_dev *vxlan,
 
 	ret = vxlan_update_default_fdb_entry(vxlan, vninode->vni,
 					     oldrip, newrip,
+					     cfg->remote_ifindex,
+					     cfg->remote_ifindex,
 					     extack);
 	if (ret)
 		goto out;
@@ -574,7 +583,7 @@ static int vxlan_vni_update_group(struct vxlan_dev *vxlan,
 		if (vxlan_addr_multicast(&old_remote_ip) &&
 		    !vxlan_group_used(vn, vxlan, vninode->vni,
 				      &old_remote_ip,
-				      vxlan->default_dst.remote_ifindex)) {
+				      cfg->remote_ifindex)) {
 			ret = vxlan_igmp_leave(vxlan, &old_remote_ip,
 					       0);
 			if (ret)
@@ -598,8 +607,9 @@ static int vxlan_vni_update_group(struct vxlan_dev *vxlan,
 }
 
 int vxlan_vnilist_update_group(struct vxlan_dev *vxlan,
-			       union vxlan_addr *old_remote_ip,
-			       union vxlan_addr *new_remote_ip,
+			       const union vxlan_addr *old_remote_ip,
+			       const union vxlan_addr *new_remote_ip,
+			       u32 old_ifindex, u32 new_ifindex,
 			       struct netlink_ext_ack *extack)
 {
 	struct list_head *headp, *hpos;
@@ -616,6 +626,8 @@ int vxlan_vnilist_update_group(struct vxlan_dev *vxlan,
 			ret = vxlan_update_default_fdb_entry(vxlan, vent->vni,
 							     old_remote_ip,
 							     new_remote_ip,
+							     old_ifindex,
+							     new_ifindex,
 							     extack);
 			if (ret)
 				return ret;
@@ -630,20 +642,19 @@ static void vxlan_vni_delete_group(struct vxlan_dev *vxlan,
 {
 	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
 	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
-	struct vxlan_rdst *dst = &vxlan->default_dst;
 
 	/* if per vni remote_ip not present, delete the
 	 * default dst remote_ip previously added for this vni
 	 */
 	if (!vxlan_addr_any(&vninode->remote_ip) ||
-	    !vxlan_addr_any(&dst->remote_ip)) {
+	    !vxlan_addr_any(&cfg->remote_ip)) {
 		spin_lock_bh(&vxlan->hash_lock);
 		__vxlan_fdb_delete(vxlan, all_zeros_mac,
 				   (vxlan_addr_any(&vninode->remote_ip) ?
-				   dst->remote_ip : vninode->remote_ip),
+				   cfg->remote_ip : vninode->remote_ip),
 				   cfg->dst_port,
 				   vninode->vni, vninode->vni,
-				   dst->remote_ifindex,
+				   cfg->remote_ifindex,
 				   true);
 		spin_unlock_bh(&vxlan->hash_lock);
 	}
@@ -652,7 +663,7 @@ static void vxlan_vni_delete_group(struct vxlan_dev *vxlan,
 		if (vxlan_addr_multicast(&vninode->remote_ip) &&
 		    !vxlan_group_used(vn, vxlan, vninode->vni,
 				      &vninode->remote_ip,
-				      dst->remote_ifindex)) {
+				      cfg->remote_ifindex)) {
 			vxlan_igmp_leave(vxlan, &vninode->remote_ip, 0);
 		}
 	}
@@ -863,6 +874,7 @@ static int vxlan_process_vni_filter(struct vxlan_dev *vxlan,
 				    int cmd, struct netlink_ext_ack *extack)
 {
 	struct nlattr *vattrs[VXLAN_VNIFILTER_ENTRY_MAX + 1];
+	const struct vxlan_config *cfg;
 	u32 vni_start = 0, vni_end = 0;
 	union vxlan_addr group;
 	int err;
@@ -900,7 +912,8 @@ static int vxlan_process_vni_filter(struct vxlan_dev *vxlan,
 		memset(&group, 0, sizeof(group));
 	}
 
-	if (vxlan_addr_multicast(&group) && !vxlan->default_dst.remote_ifindex) {
+	cfg = rtnl_dereference(vxlan->cfg);
+	if (vxlan_addr_multicast(&group) && !cfg->remote_ifindex) {
 		NL_SET_ERR_MSG(extack,
 			       "Local interface required for multicast remote group");
 
diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index 7ced743ec8816d412bb14ec7ee7b422e97c38895..c3c9f2ccc3d1bfdf661312482856e0714e9ea3a6 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h
@@ -204,7 +204,6 @@ struct vxlan_rdst {
 	u8			 offloaded:1;
 	__be32			 remote_vni;
 	u32			 remote_ifindex;
-	struct net_device	 *remote_dev;
 	struct list_head	 list;
 	struct rcu_head		 rcu;
 	struct dst_cache	 dst_cache;
@@ -295,7 +294,7 @@ struct vxlan_dev {
 #endif
 	struct net_device *dev;
 	struct net	  *net;		/* netns for packet i/o */
-	struct vxlan_rdst default_dst;	/* default destination */
+	struct net_device *lowerdev;
 
 	struct timer_list age_timer;
 	spinlock_t	  hash_lock;
-- 
2.55.0.1007.g17ff1f9808-goog


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* [PATCH v3 net-next 6/6] vxlan: no longer rely on RTNL in vxlan_fill_info()
  2026-09-11  6:21 [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps Eric Dumazet
                   ` (4 preceding siblings ...)
  2026-09-11  6:21 ` [PATCH v3 net-next 5/6] vxlan: remove default_dst and use vxlan_config and lowerdev Eric Dumazet
@ 2026-09-11  6:22 ` Eric Dumazet
  5 siblings, 0 replies; 12+ messages in thread
From: Eric Dumazet @ 2026-09-11  6:22 UTC (permalink / raw)
  To: David S . Miller, Jakub Kicinski, Paolo Abeni
  Cc: Simon Horman, Kuniyuki Iwashima, Ido Schimmel, Andrew Lunn,
	netdev, eric.dumazet, Eric Dumazet

Now that vxlan->cfg is RCU-protected, we can update vxlan_fill_info()
to run under RCU read lock instead of relying on RTNL.

This completes the transition to RTNL-less link info dumping for VXLAN.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 drivers/net/vxlan/vxlan_core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 8b7558eac049d2f83ab5f68aca2dad62bce9cbc7..8f008ec6d2e98dc015649fd6e26a1346012c2238 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -4725,7 +4725,8 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 	struct ifla_vxlan_port_range ports;
 	const struct vxlan_config *cfg;
 
-	cfg = rtnl_dereference(vxlan->cfg);
+	rcu_read_lock();
+	cfg = rcu_dereference(vxlan->cfg);
 
 	if (nla_put_u32(skb, IFLA_VXLAN_ID, be32_to_cpu(cfg->vni)))
 		goto nla_put_failure;
@@ -4824,9 +4825,11 @@ static int vxlan_fill_info(struct sk_buff *skb, const struct net_device *dev)
 		    &cfg->reserved_bits))
 		goto nla_put_failure;
 
+	rcu_read_unlock();
 	return 0;
 
 nla_put_failure:
+	rcu_read_unlock();
 	return -EMSGSIZE;
 }
 
-- 
2.55.0.1007.g17ff1f9808-goog


^ permalink raw reply related	[flat|nested] 12+ messages in thread

* Re: [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()
  2026-09-11  6:21 ` [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev() Eric Dumazet
@ 2026-09-15  2:00   ` Jakub Kicinski
  2026-09-15  7:53     ` Paolo Abeni
  0 siblings, 1 reply; 12+ messages in thread
From: Jakub Kicinski @ 2026-09-15  2:00 UTC (permalink / raw)
  To: edumazet
  Cc: Jakub Kicinski, davem, pabeni, horms, kuniyu, idosch,
	andrew+netdev, netdev, eric.dumazet

This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.
---
vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()

This switches the vg->vni_list walk in vxlan_vnifilter_dump_dev() to
list_for_each_entry_rcu(), clears the saved VNI offset on the early
return paths, and adds cb->args[2] to track the ifindex of the device
currently being dumped so the VNI offset is reset when the device
changes.

> diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
> index dd94085e08865..0a18c32902da0 100644
> --- a/drivers/net/vxlan/vxlan_vnifilter.c
> +++ b/drivers/net/vxlan/vxlan_vnifilter.c
> @@ -333,22 +333,34 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
>  				    struct sk_buff *skb,
>  				    struct netlink_callback *cb)
>  {
> -	struct vxlan_vni_node *tmp, *v, *vbegin = NULL, *vend = NULL;
> +	struct vxlan_vni_node *v, *vbegin = NULL, *vend = NULL;
>  	struct vxlan_dev *vxlan = netdev_priv(dev);
>  	struct tunnel_msg *new_tmsg, *tmsg;
> -	int idx = 0, s_idx = cb->args[1];
>  	struct vxlan_vni_group *vg;
>  	struct nlmsghdr *nlh;
> +	int idx = 0, s_idx;
>  	bool dump_stats;
>  	int err = 0;
>  
> -	if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER))
> +	if (cb->args[2] != dev->ifindex) {
> +		cb->args[1] = 0;
> +		cb->args[2] = dev->ifindex;
> +	}
> +	s_idx = cb->args[1];

[Severity: High]
The commit message says the ifindex tracking handles the case where
"devices are added or removed between dump calls, ordinal device indexes
can shift".  Can this new check actually observe that case?

In vxlan_vnifilter_dump() the device cursor is still a bare ordinal, and
devices below it are skipped before vxlan_vnifilter_dump_dev() is ever
called:

	int idx = 0, err = 0, s_idx = cb->args[0];
	...
		for_each_netdev_rcu(net, dev) {
			if (!netif_is_vxlan(dev))
				continue;
			if (idx < s_idx)
				goto skip;
			err = vxlan_vnifilter_dump_dev(dev, skb, cb);
			if (err == -EMSGSIZE)
				break;
skip:
			idx++;
		}
	}
	cb->args[0] = idx;

On -EMSGSIZE the loop breaks before idx++, so cb->args[0] is the ordinal
of the partially dumped device A while cb->args[1]/cb->args[2] hold A's
VNI offset and ifindex.  RTM_GETTUNNEL is registered with flags 0:

	{THIS_MODULE, PF_BRIDGE, RTM_GETTUNNEL, NULL, vxlan_vnifilter_dump, 0},

so rtnl_dumpit takes and releases RTNL per dump skb.  If a vxlan device
preceding A is unregistered in that window, A shifts down to ordinal
s_idx - 1 and is skipped by the "if (idx < s_idx) goto skip" test, so
vxlan_vnifilter_dump_dev() never runs for A and the new cb->args[2]
comparison never happens.  A's remaining VNIs then disappear from the
dump and the dump ends looking complete.  Would an ifindex-keyed device
walk (for_each_netdev_dump()) be needed to close that?

There is also the same-device case.  The commit message says the stale
offset "silently skipp[ed] their first N VNIs", but s_idx here is still a
plain count of entries to skip in a freshly re-walked list, and the
writers mutate that list while RTNL is dropped:

	__vxlan_vni_add_list()
		list_add_rcu(&v->vlist, hpos);	/* sorted by vni */
		vg->num_vnis++;

	__vxlan_vni_del_list()
		list_del_rcu(&v->vlist);
		vg->num_vnis--;

Since the insertion is sorted by VNI it can land before the resume point,
shifting ordinals up so an already dumped entry is emitted a second time;
a deletion before the resume point shifts them down so an entry that was
never dumped is skipped.  In both cases cb->args[2] still equals
dev->ifindex, so the new reset does not fire.  Would resuming from the
last dumped VNI value rather than an ordinal offset avoid this?

Finally, nothing signals the tear to user space.  vxlan_vnifilter_dump_dev()
calls nlmsg_end() without assigning cb->seq or calling
nl_dump_check_consistent(), and the VNI list writers bump no generation
counter, so NLM_F_DUMP_INTR is never set.  The MDB dump in the same driver
does do this:

drivers/net/vxlan/vxlan_mdb.c:vxlan_mdb_dump() {
	...
	nlmsg_end(skb, nlh);

	cb->seq = vxlan->mdb_seq;
	nl_dump_check_consistent(cb, nlh);
	...
}

Should the vnifilter dump publish a similar generation counter so a
skipped or repeated VNI is at least visible to user space?

>  
>  	/* RCU needed because of the vni locking rules (rcu || rtnl) */
>  	vg = rcu_dereference(vxlan->vnigrp);

[ ... ]

> @@ -362,7 +374,7 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
>  	new_tmsg->family = PF_BRIDGE;
>  	new_tmsg->ifindex = dev->ifindex;
>  
> -	list_for_each_entry_safe(v, tmp, &vg->vni_list, vlist) {
> +	list_for_each_entry_rcu(v, &vg->vni_list, vlist) {
>  		if (idx < s_idx) {
>  			idx++;
>  			continue;
> @@ -394,6 +406,7 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
>  	}
>  
>  	cb->args[1] = err ? idx : 0;
> +	cb->args[2] = err ? dev->ifindex : 0;
>  
>  	nlmsg_end(skb, nlh);
>  

For reference, the ordinal cursors and the missing cb->seq /
nl_dump_check_consistent() are still present at the end of the series
(1c77987f9ffa), so no later patch appears to change this.

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3 net-next 3/6] vxlan: move VXLAN_F_MDB to struct vxlan_dev flags
  2026-09-11  6:21 ` [PATCH v3 net-next 3/6] vxlan: move VXLAN_F_MDB to struct vxlan_dev flags Eric Dumazet
@ 2026-09-15  2:01   ` Jakub Kicinski
  0 siblings, 0 replies; 12+ messages in thread
From: Jakub Kicinski @ 2026-09-15  2:01 UTC (permalink / raw)
  To: edumazet
  Cc: Jakub Kicinski, davem, pabeni, horms, kuniyu, idosch,
	andrew+netdev, netdev, eric.dumazet

This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.
---
vxlan: move VXLAN_F_MDB to struct vxlan_dev flags

This moves the internal VXLAN_F_MDB runtime state out of struct
vxlan_config.flags into a new unsigned long flags field in struct
vxlan_dev, accessed with set_bit()/clear_bit()/test_bit(), in
preparation for making vxlan->cfg an RCU-protected pointer.

One question about an out-of-tree-of-this-patch consumer of
cfg->flags below.

> diff --git a/drivers/net/vxlan/vxlan_mdb.c b/drivers/net/vxlan/vxlan_mdb.c
> index 56ca928328330..cf606256d0929 100644
> --- a/drivers/net/vxlan/vxlan_mdb.c
> +++ b/drivers/net/vxlan/vxlan_mdb.c
> @@ -1219,7 +1219,7 @@ vxlan_mdb_entry_get(struct vxlan_dev *vxlan,
>  		goto err_free_entry;
>  
>  	if (hlist_is_singular_node(&mdb_entry->mdb_node, &vxlan->mdb_list))
> -		vxlan->cfg.flags |= VXLAN_F_MDB;
> +		set_bit(VXLAN_DEV_F_MDB, &vxlan->flags);

[Severity: Medium]
Does this change relax the mlxsw NVE offload validation?

mlxsw checks cfg->flags with a deny-by-default mask, so the 0x40000 bit
used to land in the "unsupported flag" test:

drivers/net/ethernet/mellanox/mlxsw/spectrum_nve_vxlan.c:
#define MLXSW_SP_NVE_VXLAN_IPV4_SUPPORTED_FLAGS (VXLAN_F_UDP_ZERO_CSUM_TX | \
						 VXLAN_F_LEARN | \
						 VXLAN_F_LOCALBYPASS)

static bool mlxsw_sp_nve_vxlan_ipv4_flags_check(const struct vxlan_config *cfg,
						struct netlink_ext_ack *extack)
{
	...
	if (cfg->flags & ~MLXSW_SP_NVE_VXLAN_IPV4_SUPPORTED_FLAGS) {
		NL_SET_ERR_MSG_MOD(extack, "VxLAN: Unsupported flag");
		return false;
	}

The same mask exists for the IPv6 underlay in
mlxsw_sp_nve_vxlan_ipv6_flags_check(), and both are reached from
mlxsw_sp_nve_vxlan_can_offload(), which only looks at &vxlan->cfg.

So for a device that already has an MDB entry:

  bridge mdb add dev vxlan0 port vxlan0 grp 239.1.1.1 permanent \
      dst 198.51.100.1
    -> vxlan_mdb_add() -> __vxlan_mdb_add() -> vxlan_mdb_entry_get()

before this patch that set VXLAN_F_MDB in cfg->flags, and a later
enslavement to an mlxsw-offloaded bridge was refused with "VxLAN:
Unsupported flag". After the move, mlxsw_sp_nve_vxlan_can_offload() has
no way to observe the MDB state, since nothing outside vxlan_core.c and
vxlan_mdb.c tests VXLAN_DEV_F_MDB, and the device is accepted for
offload while the configured MDB entries are not honoured by the
hardware forwarding plane.

Note the previous rejection was already order-dependent: MDB entries
added after the FID was enabled were never re-validated, because vxlan
MDB emits no switchdev notification at all (git grep switchdev
drivers/net/vxlan/ matches only vxlan_core.c).

Would it make sense to add a test_bit(VXLAN_DEV_F_MDB, &vxlan->flags)
check in mlxsw_sp_nve_vxlan_can_offload(), or to state in the commit
message that MDB presence is intentionally no longer a bar to offload?

>  
>  	return mdb_entry;
>  

[ ... ]

> diff --git a/include/net/vxlan.h b/include/net/vxlan.h
> index 7b82075055237..d323f91af2364 100644
> --- a/include/net/vxlan.h
> +++ b/include/net/vxlan.h

[ ... ]

> @@ -313,6 +314,10 @@ struct vxlan_dev {
>  	unsigned int mdb_seq;
>  };
>  
> +enum vxlan_dev_flags {
> +	VXLAN_DEV_F_MDB,
> +};
> +
>  #define VXLAN_F_LEARN			0x01
>  #define VXLAN_F_PROXY			0x02
>  #define VXLAN_F_RSC			0x04
> @@ -331,7 +336,6 @@ struct vxlan_dev {
>  #define VXLAN_F_IPV6_LINKLOCAL		0x8000
>  #define VXLAN_F_TTL_INHERIT		0x10000
>  #define VXLAN_F_VNIFILTER               0x20000
> -#define VXLAN_F_MDB			0x40000
>  #define VXLAN_F_LOCALBYPASS		0x80000
>  #define VXLAN_F_MC_ROUTE		0x100000

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3 net-next 5/6] vxlan: remove default_dst and use vxlan_config and lowerdev
  2026-09-11  6:21 ` [PATCH v3 net-next 5/6] vxlan: remove default_dst and use vxlan_config and lowerdev Eric Dumazet
@ 2026-09-15  2:01   ` Jakub Kicinski
  0 siblings, 0 replies; 12+ messages in thread
From: Jakub Kicinski @ 2026-09-15  2:01 UTC (permalink / raw)
  To: edumazet
  Cc: Jakub Kicinski, davem, pabeni, horms, kuniyu, idosch,
	andrew+netdev, netdev, eric.dumazet

This is an AI-generated review of your patch. The human sending this
email has considered the AI review valid, or at least plausible.
---
vxlan: remove default_dst and use vxlan_config and lowerdev

This removes vxlan->default_dst, moving the default destination attributes
(remote_ip, remote_vni, remote_ifindex) over to the RCU-protected
vxlan->cfg, and adds a plain struct net_device *lowerdev to struct
vxlan_dev for upper/lower adjacency tracking under RTNL.  It also drops
the remote_dev field from struct vxlan_rdst and updates
mlx5e_tc_tun_get_remote_ifindex() to read remote_ifindex from vxlan->cfg.

A few questions below.

> diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
> index 338ecddb9542d..8b7558eac049d 100644
> --- a/drivers/net/vxlan/vxlan_core.c
> +++ b/drivers/net/vxlan/vxlan_core.c

[ ... ]

> @@ -4010,7 +4019,6 @@ static void vxlan_config_apply(struct net_device *dev,
>  			       bool changelink)
>  {
>  	struct vxlan_dev *vxlan = netdev_priv(dev);
> -	struct vxlan_rdst *dst = &vxlan->default_dst;
>  	unsigned short needed_headroom = ETH_HLEN;
>  	struct vxlan_config *old_cfg;
>  	int max_mtu = ETH_MAX_MTU;
> @@ -4028,13 +4036,7 @@ static void vxlan_config_apply(struct net_device *dev,
>  		vxlan->net = src_net;
>  	}
>  
> -	dst->remote_vni = new_cfg->vni;
> -
> -	memcpy(&dst->remote_ip, &new_cfg->remote_ip, sizeof(new_cfg->remote_ip));
> -
>  	if (lowerdev) {
> -		dst->remote_ifindex = new_cfg->remote_ifindex;
> -
>  		netif_inherit_tso_max(dev, lowerdev);
>  
>  		needed_headroom = lowerdev->hard_header_len;

[ ... ]

> @@ -4578,23 +4580,23 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
>  	if (!new_cfg)
>  		return -ENOMEM;
>  
> -	if (dst->remote_dev == lowerdev)
> -		lowerdev = NULL;
> -
> -	err = netdev_adjacent_change_prepare(dst->remote_dev, lowerdev, dev,
> -					     extack);
> -	if (err) {
> -		kfree(new_cfg);
> -		return err;
> +	lowerdev_changed = vxlan->lowerdev != lowerdev;
> +	if (lowerdev_changed) {
> +		err = netdev_adjacent_change_prepare(vxlan->lowerdev, lowerdev,
> +						     dev, extack);
> +		if (err) {
> +			kfree(new_cfg);
> +			return err;
> +		}
>  	}

[Severity: Medium]
Can dropping the "lowerdev = NULL" shortcut here silently shrink the MTU of a
live vxlan device?

Previously, when the lower device was unchanged, lowerdev was set to NULL, so
vxlan_config_apply() skipped its whole "if (lowerdev)" block, max_mtu stayed at
ETH_MAX_MTU and the trailing clamp was a no-op:

	if (lowerdev) {
		...
		max_mtu = lowerdev->mtu - vxlan_headroom(flags);
		if (max_mtu < ETH_MIN_MTU)
			max_mtu = ETH_MIN_MTU;
		...
	}

	if (dev->mtu > max_mtu)
		dev->mtu = max_mtu;

Now the real lower device is always passed on changelink, so max_mtu is
recomputed every time.  vxlan_change_mtu() only validates against lowerdev->mtu
at the time of the request, and vxlan_netdevice_event() handles only
NETDEV_UNREGISTER and the udp tunnel port events, so nothing reacts to a lower
device MTU reduction:

	ip link add vxlan0 type vxlan id 10 dev eth0 dstport 4789 [mtu 1450]
	ip link set eth0 mtu 1000		# vxlan0 mtu unchanged
	ip link set dev vxlan0 type vxlan ageing 100

The last command inherits IFLA_VXLAN_LINK from the old config, so lowerdev is
non-NULL and unchanged, and dev->mtu is clamped down to
1000 - vxlan_headroom(flags).

The commit message describes passing lowerdev only as needed "to preserve
needed_headroom and needed_tailroom" and says nothing about MTU or the TSO
limits from netif_inherit_tso_max().  Was the MTU effect intended?

>  
> -	rem_ip_changed = !vxlan_addr_equal(&conf.remote_ip, &dst->remote_ip);
> +	rem_ip_changed = !vxlan_addr_equal(&conf.remote_ip, &cfg->remote_ip);
>  	change_igmp = vxlan->dev->flags & IFF_UP &&
>  		      (rem_ip_changed ||
> -		       dst->remote_ifindex != conf.remote_ifindex);
> +		       cfg->remote_ifindex != conf.remote_ifindex);
>  
>  	/* handle default dst entry */
> -	if (rem_ip_changed) {
> +	if (rem_ip_changed || cfg->remote_ifindex != conf.remote_ifindex) {
>  		spin_lock_bh(&vxlan->hash_lock);
>  		if (!vxlan_addr_any(&conf.remote_ip)) {
>  			err = vxlan_fdb_update(vxlan, all_zeros_mac,

[Severity: Medium]
Should this widened condition come with a Fixes: tag in a separate patch?

Before this change, a changelink that altered only the lower device
(for example "ip link set dev vxlan0 type vxlan group 239.1.1.1 dev eth1")
skipped this block because rem_ip_changed was false, while
vxlan_config_apply() updated dst->remote_ifindex.  The all-zeros-MAC rdst kept
the old ifindex, and vxlan_xmit_one() uses it as the route oif:

	ifindex = rdst->remote_ifindex;

so traffic kept leaving the old device.  The same applies to the
old_ifindex/new_ifindex plumbing added to vxlan_update_default_fdb_entry() in
vxlan_vnifilter.c.  These look like fixes of user-visible misbehaviour bundled
into a refactor, so they will not be picked up for stable.

The same is true of needed_headroom/needed_tailroom no longer being reset to
ETH_HLEN + vxlan_headroom() on changelink, which is mentioned only as an
implementation detail.

There is also an undocumented behaviour change further down in this function:
when IFLA_VXLAN_LINK is explicitly set to 0, the new "else
netdev_upper_dev_unlink(vxlan->lowerdev, dev);" branch now tears down the
old upper/lower adjacency, whereas netdev_adjacent_change_prepare() and
netdev_adjacent_change_commit() returned early for a NULL new device and the
adjacency survived.  Could that be called out in the changelog?

> @@ -4607,19 +4609,20 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
>  					       NTF_SELF, 0, true, extack);
>  			if (err) {
>  				spin_unlock_bh(&vxlan->hash_lock);
> -				netdev_adjacent_change_abort(dst->remote_dev,
> -							     lowerdev, dev);
> +				if (lowerdev_changed)
> +					netdev_adjacent_change_abort(vxlan->lowerdev,
> +								     lowerdev, dev);
>  				kfree(new_cfg);
>  				return err;
>  			}
>  		}
> -		if (!vxlan_addr_any(&dst->remote_ip))
> +		if (!vxlan_addr_any(&cfg->remote_ip))
>  			__vxlan_fdb_delete(vxlan, all_zeros_mac,
> -					   dst->remote_ip,
> +					   cfg->remote_ip,
>  					   cfg->dst_port,
> -					   dst->remote_vni,
> -					   dst->remote_vni,
> -					   dst->remote_ifindex,
> +					   cfg->vni,
> +					   cfg->vni,
> +					   cfg->remote_ifindex,
>  					   true);
>  		spin_unlock_bh(&vxlan->hash_lock);
>  
> @@ -4627,30 +4630,39 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
>  		 * all vnis that were using default remote ip
>  		 */
>  		if (cfg->flags & VXLAN_F_VNIFILTER) {
> -			err = vxlan_vnilist_update_group(vxlan, &dst->remote_ip,
> -							 &conf.remote_ip, extack);
> +			err = vxlan_vnilist_update_group(vxlan, &cfg->remote_ip,
> +							 &conf.remote_ip,
> +							 cfg->remote_ifindex,
> +							 conf.remote_ifindex,
> +							 extack);
>  			if (err) {
> -				netdev_adjacent_change_abort(dst->remote_dev,
> -							     lowerdev, dev);
> +				if (lowerdev_changed)
> +					netdev_adjacent_change_abort(vxlan->lowerdev,
> +								     lowerdev, dev);
>  				kfree(new_cfg);
>  				return err;
>  			}
>  		}
>  	}

[Severity: Low]
Can this error path leave forwarding state half applied for an ifindex-only
change?

By the time vxlan_vnilist_update_group() runs, the default destination has
already been appended with the new remote/ifindex and the old one deleted, and
the loop in vxlan_vnilist_update_group() commits each per-VNI update in turn
and returns on the first failure without undoing the earlier ones.
vxlan_fdb_append() can fail:

	rd = kmalloc_obj(*rd, GFP_ATOMIC);
	if (rd == NULL)
		return -ENOMEM;

On that failure this branch only aborts the adjacency change and frees new_cfg,
so vxlan_config_apply() is never reached: vxlan->cfg and vxlan->lowerdev keep
the old values while the default fdb entry and some per-VNI entries already
carry the requested ifindex.  The rdsts allocated for the ifindex that was
never committed stay linked until explicit fdb or device teardown.  The
append-then-delete rollback gap already existed for remote-IP changes, but
ifindex-only changes are newly routed through it.

>  
> -	if (change_igmp && vxlan_addr_multicast(&dst->remote_ip))
> +	if (change_igmp && vxlan_addr_multicast(&cfg->remote_ip))
>  		err = vxlan_multicast_leave(vxlan);
>  
>  	if (netif_running(dev) && conf.age_interval != cfg->age_interval)
>  		mod_timer(&vxlan->age_timer, jiffies);
>  
> -	netdev_adjacent_change_commit(dst->remote_dev, lowerdev, dev);
> -	if (lowerdev && lowerdev != dst->remote_dev)
> -		dst->remote_dev = lowerdev;
> +	if (lowerdev_changed) {
> +		if (lowerdev)
> +			netdev_adjacent_change_commit(vxlan->lowerdev, lowerdev,
> +						      dev);
> +		else
> +			netdev_upper_dev_unlink(vxlan->lowerdev, dev);
> +		vxlan->lowerdev = lowerdev;
> +	}
>  	vxlan_config_apply(dev, new_cfg, lowerdev, vxlan->net, true);

[ ... ]

> diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
> index 6a2d0a69d7be1..55a07c20e7649 100644
> --- a/drivers/net/vxlan/vxlan_vnifilter.c
> +++ b/drivers/net/vxlan/vxlan_vnifilter.c
> @@ -487,24 +487,31 @@ static const struct nla_policy vni_filter_policy[VXLAN_VNIFILTER_MAX + 1] = {
>  };
>  
>  static int vxlan_update_default_fdb_entry(struct vxlan_dev *vxlan, __be32 vni,
> -					  union vxlan_addr *old_remote_ip,
> -					  union vxlan_addr *remote_ip,
> +					  const union vxlan_addr *old_remote_ip,
> +					  const union vxlan_addr *remote_ip,
> +					  u32 old_ifindex, u32 new_ifindex,
>  					  struct netlink_ext_ack *extack)
>  {
>  	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
> -	struct vxlan_rdst *dst = &vxlan->default_dst;
>  	int err = 0;
>  
> +	if (old_remote_ip && remote_ip &&
> +	    vxlan_addr_equal(old_remote_ip, remote_ip) &&
> +	    old_ifindex == new_ifindex)
> +		return 0;
> +

[ ... ]

> @@ -563,6 +570,8 @@ static int vxlan_vni_update_group(struct vxlan_dev *vxlan,
>  
>  	ret = vxlan_update_default_fdb_entry(vxlan, vninode->vni,
>  					     oldrip, newrip,
> +					     cfg->remote_ifindex,
> +					     cfg->remote_ifindex,
>  					     extack);
>  	if (ret)
>  		goto out;

[ ... ]

> @@ -616,6 +626,8 @@ int vxlan_vnilist_update_group(struct vxlan_dev *vxlan,
>  			ret = vxlan_update_default_fdb_entry(vxlan, vent->vni,
>  							     old_remote_ip,
>  							     new_remote_ip,
> +							     old_ifindex,
> +							     new_ifindex,
>  							     extack);
>  			if (ret)
>  				return ret;

[Severity: Medium]
Is the new ifindex refresh complete for VNI entries that carry their own group
address?

The loop in vxlan_vnilist_update_group() only visits nodes whose remote_ip is
"any":

	if (vxlan_addr_any(&vent->remote_ip)) {
		ret = vxlan_update_default_fdb_entry(...);

But vxlan_vni_update_group() creates entries with an explicit group using the
device configuration ifindex, as seen in the hunk above
(cfg->remote_ifindex passed for both old and new), so those rdsts also store
the device's remote_ifindex and are skipped here.  After a changelink that
alters remote_ifindex, vxlan_config_apply() publishes the new cfg while those
rdsts keep the old value.

	bridge vni add vni 100 group 239.1.1.1 dev vx	# rdst ifindex = eth0
	ip link set dev vxlan0 type vxlan dev eth1	# or IFLA_VXLAN_LINK = 0
	bridge vni del vni 100 dev vx

vxlan_vni_delete_group() then calls __vxlan_fdb_delete() with the new
cfg->remote_ifindex, and vxlan_fdb_find_rdst() requires an exact match:

		if (vxlan_addr_equal(&rd->remote_ip, ip) &&
		    rd->remote_port == port &&
		    rd->remote_vni == vni &&
		    rd->remote_ifindex == ifindex)
			return rd;

so no rdst is found, __vxlan_fdb_delete() takes the "goto out; return 0" path
and the all-zeros-MAC entry survives the vni delete.  Re-adding the same vni
appends a second rdst, duplicating transmitted BUM traffic.  Meanwhile
vxlan_xmit_one() keeps using the stale "ifindex = rdst->remote_ifindex" as
route oif, and the vxlan_igmp_leave(vxlan, &vninode->remote_ip, 0) in the same
function resolves rifindex 0 to the new cfg->remote_ifindex although the group
was joined on the old one.

The IFLA_VXLAN_LINK = 0 variant looks newly broken: previously
default_dst.remote_ifindex was left untouched when lowerdev was NULL, so the
delete still matched.  Given the commit message says default fdb entries
"including VNI filter entries" are updated if remote_ifindex changed, should
this loop also handle nodes with their own group?

> @@ -630,20 +642,19 @@ static void vxlan_vni_delete_group(struct vxlan_dev *vxlan,
>  {
>  	struct vxlan_net *vn = net_generic(vxlan->net, vxlan_net_id);
>  	const struct vxlan_config *cfg = rtnl_dereference(vxlan->cfg);
> -	struct vxlan_rdst *dst = &vxlan->default_dst;
>  
>  	/* if per vni remote_ip not present, delete the
>  	 * default dst remote_ip previously added for this vni
>  	 */
>  	if (!vxlan_addr_any(&vninode->remote_ip) ||
> -	    !vxlan_addr_any(&dst->remote_ip)) {
> +	    !vxlan_addr_any(&cfg->remote_ip)) {
>  		spin_lock_bh(&vxlan->hash_lock);
>  		__vxlan_fdb_delete(vxlan, all_zeros_mac,
>  				   (vxlan_addr_any(&vninode->remote_ip) ?
> -				   dst->remote_ip : vninode->remote_ip),
> +				   cfg->remote_ip : vninode->remote_ip),
>  				   cfg->dst_port,
>  				   vninode->vni, vninode->vni,
> -				   dst->remote_ifindex,
> +				   cfg->remote_ifindex,
>  				   true);
>  		spin_unlock_bh(&vxlan->hash_lock);
>  	}

[ ... ]

> diff --git a/include/net/vxlan.h b/include/net/vxlan.h
> index 7ced743ec8816..c3c9f2ccc3d1b 100644
> --- a/include/net/vxlan.h
> +++ b/include/net/vxlan.h
> @@ -204,7 +204,6 @@ struct vxlan_rdst {
>  	u8			 offloaded:1;
>  	__be32			 remote_vni;
>  	u32			 remote_ifindex;
> -	struct net_device	 *remote_dev;
>  	struct list_head	 list;
>  	struct rcu_head		 rcu;
>  	struct dst_cache	 dst_cache;

[Severity: Low]
The commit message says:

    Furthermore, several fields of struct vxlan_rdst (remote_dev,
    remote_port, offloaded, list, rcu, dst_cache) in default_dst were
    completely unused.

Is that accurate for remote_dev?  In the baseline, default_dst.remote_dev was
the only user of that field: vxlan_dev_create() assigned it
("dst->remote_dev = remote_dev;"), vxlan_changelink() compared it
("if (dst->remote_dev == lowerdev) lowerdev = NULL;") and passed it to
netdev_adjacent_change_prepare()/commit()/abort(), and vxlan_dellink() used it
for netdev_upper_dev_unlink().  The patch moves that active role to
vxlan->lowerdev rather than removing dead state, and changes the surrounding
changelink logic along the way.

> @@ -295,7 +294,7 @@ struct vxlan_dev {
>  #endif
>  	struct net_device *dev;
>  	struct net	  *net;		/* netns for packet i/o */
> -	struct vxlan_rdst default_dst;	/* default destination */
> +	struct net_device *lowerdev;
>  
>  	struct timer_list age_timer;
>  	spinlock_t	  hash_lock;

^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()
  2026-09-15  2:00   ` Jakub Kicinski
@ 2026-09-15  7:53     ` Paolo Abeni
  2026-09-15 11:48       ` Eric Dumazet
  0 siblings, 1 reply; 12+ messages in thread
From: Paolo Abeni @ 2026-09-15  7:53 UTC (permalink / raw)
  To: Jakub Kicinski, edumazet
  Cc: davem, horms, kuniyu, idosch, andrew+netdev, netdev, eric.dumazet

On 9/15/26 4:00 AM, Jakub Kicinski wrote:
> This is an AI-generated review of your patch. The human sending this
> email has considered the AI review valid, or at least plausible.
> ---
> vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()
> 
> This switches the vg->vni_list walk in vxlan_vnifilter_dump_dev() to
> list_for_each_entry_rcu(), clears the saved VNI offset on the early
> return paths, and adds cb->args[2] to track the ifindex of the device
> currently being dumped so the VNI offset is reset when the device
> changes.
> 
>> diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
>> index dd94085e08865..0a18c32902da0 100644
>> --- a/drivers/net/vxlan/vxlan_vnifilter.c
>> +++ b/drivers/net/vxlan/vxlan_vnifilter.c
>> @@ -333,22 +333,34 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
>>  				    struct sk_buff *skb,
>>  				    struct netlink_callback *cb)
>>  {
>> -	struct vxlan_vni_node *tmp, *v, *vbegin = NULL, *vend = NULL;
>> +	struct vxlan_vni_node *v, *vbegin = NULL, *vend = NULL;
>>  	struct vxlan_dev *vxlan = netdev_priv(dev);
>>  	struct tunnel_msg *new_tmsg, *tmsg;
>> -	int idx = 0, s_idx = cb->args[1];
>>  	struct vxlan_vni_group *vg;
>>  	struct nlmsghdr *nlh;
>> +	int idx = 0, s_idx;
>>  	bool dump_stats;
>>  	int err = 0;
>>  
>> -	if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER))
>> +	if (cb->args[2] != dev->ifindex) {
>> +		cb->args[1] = 0;
>> +		cb->args[2] = dev->ifindex;
>> +	}
>> +	s_idx = cb->args[1];
> 
> [Severity: High]
> The commit message says the ifindex tracking handles the case where
> "devices are added or removed between dump calls, ordinal device indexes
> can shift".  Can this new check actually observe that case?

I think this is the only comment possibly actionable. AFAICS addressing
sashiko comments for good would require a significant refactor switching to
ifindex based index. That in turn feels slightly overkill.

Possibly implementing a nl_dump_check_consistent() check would make sense?

/P


^ permalink raw reply	[flat|nested] 12+ messages in thread

* Re: [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()
  2026-09-15  7:53     ` Paolo Abeni
@ 2026-09-15 11:48       ` Eric Dumazet
  0 siblings, 0 replies; 12+ messages in thread
From: Eric Dumazet @ 2026-09-15 11:48 UTC (permalink / raw)
  To: Paolo Abeni
  Cc: Jakub Kicinski, davem, horms, kuniyu, idosch, andrew+netdev,
	netdev, eric.dumazet

On Tue, Sep 15, 2026 at 12:53 AM Paolo Abeni <pabeni@redhat.com> wrote:
>
> On 9/15/26 4:00 AM, Jakub Kicinski wrote:
> > This is an AI-generated review of your patch. The human sending this
> > email has considered the AI review valid, or at least plausible.
> > ---
> > vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()
> >
> > This switches the vg->vni_list walk in vxlan_vnifilter_dump_dev() to
> > list_for_each_entry_rcu(), clears the saved VNI offset on the early
> > return paths, and adds cb->args[2] to track the ifindex of the device
> > currently being dumped so the VNI offset is reset when the device
> > changes.
> >
> >> diff --git a/drivers/net/vxlan/vxlan_vnifilter.c b/drivers/net/vxlan/vxlan_vnifilter.c
> >> index dd94085e08865..0a18c32902da0 100644
> >> --- a/drivers/net/vxlan/vxlan_vnifilter.c
> >> +++ b/drivers/net/vxlan/vxlan_vnifilter.c
> >> @@ -333,22 +333,34 @@ static int vxlan_vnifilter_dump_dev(const struct net_device *dev,
> >>                                  struct sk_buff *skb,
> >>                                  struct netlink_callback *cb)
> >>  {
> >> -    struct vxlan_vni_node *tmp, *v, *vbegin = NULL, *vend = NULL;
> >> +    struct vxlan_vni_node *v, *vbegin = NULL, *vend = NULL;
> >>      struct vxlan_dev *vxlan = netdev_priv(dev);
> >>      struct tunnel_msg *new_tmsg, *tmsg;
> >> -    int idx = 0, s_idx = cb->args[1];
> >>      struct vxlan_vni_group *vg;
> >>      struct nlmsghdr *nlh;
> >> +    int idx = 0, s_idx;
> >>      bool dump_stats;
> >>      int err = 0;
> >>
> >> -    if (!(vxlan->cfg.flags & VXLAN_F_VNIFILTER))
> >> +    if (cb->args[2] != dev->ifindex) {
> >> +            cb->args[1] = 0;
> >> +            cb->args[2] = dev->ifindex;
> >> +    }
> >> +    s_idx = cb->args[1];
> >
> > [Severity: High]
> > The commit message says the ifindex tracking handles the case where
> > "devices are added or removed between dump calls, ordinal device indexes
> > can shift".  Can this new check actually observe that case?
>
> I think this is the only comment possibly actionable. AFAICS addressing
> sashiko comments for good would require a significant refactor switching to
> ifindex based index. That in turn feels slightly overkill.
>
> Possibly implementing a nl_dump_check_consistent() check would make sense?

I started looking at this and added a patch after the first one to
implement this idea.
Thanks.

^ permalink raw reply	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2026-09-15 11:49 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-09-11  6:21 [PATCH v3 net-next 0/6] vxlan: convert configuration to RCU and enable lockless dumps Eric Dumazet
2026-09-11  6:21 ` [PATCH v3 net-next 1/6] vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev() Eric Dumazet
2026-09-15  2:00   ` Jakub Kicinski
2026-09-15  7:53     ` Paolo Abeni
2026-09-15 11:48       ` Eric Dumazet
2026-09-11  6:21 ` [PATCH v3 net-next 2/6] vxlan: pass vxlan_config pointer to helper functions Eric Dumazet
2026-09-11  6:21 ` [PATCH v3 net-next 3/6] vxlan: move VXLAN_F_MDB to struct vxlan_dev flags Eric Dumazet
2026-09-15  2:01   ` Jakub Kicinski
2026-09-11  6:21 ` [PATCH v3 net-next 4/6] vxlan: convert configuration to RCU protection Eric Dumazet
2026-09-11  6:21 ` [PATCH v3 net-next 5/6] vxlan: remove default_dst and use vxlan_config and lowerdev Eric Dumazet
2026-09-15  2:01   ` Jakub Kicinski
2026-09-11  6:22 ` [PATCH v3 net-next 6/6] vxlan: no longer rely on RTNL in vxlan_fill_info() Eric Dumazet

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