[PATCH v5 net-next 02/10] geneve: expose gso partial features for tunnel offload
From: Paolo Abeni <pabeni@redhat.com>
Date: 2026-01-21 16:12:39
Subsystem:
networking drivers, networking [general], the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
GSO partial features for tunnels do not require any kind of support from the underlying device: we can safely add them to the geneve UDP tunnel. The only point of attention is the skb required features propagation in the device xmit op: partial features must be stripped, except for UDP_TUNNEL*. Keep partial features disabled by default. Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- drivers/net/geneve.c | 11 ++++++++++- include/net/udp_tunnel.h | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 77b0c3d52041..64ea4b970376 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c@@ -774,6 +774,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb, bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags); struct genevehdr *gnvh; __be16 inner_proto; + bool double_encap; int min_headroom; int err;
@@ -786,6 +787,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb, if (unlikely(err)) goto free_dst; + double_encap = udp_tunnel_handle_partial(skb); err = udp_tunnel_handle_offloads(skb, udp_sum); if (err) goto free_dst;
@@ -793,7 +795,7 @@ static int geneve_build_skb(struct dst_entry *dst, struct sk_buff *skb, gnvh = __skb_push(skb, sizeof(*gnvh) + info->options_len); inner_proto = inner_proto_inherit ? skb->protocol : htons(ETH_P_TEB); geneve_build_header(gnvh, info, inner_proto); - skb_set_inner_protocol(skb, inner_proto); + udp_tunnel_set_inner_protocol(skb, double_encap, inner_proto); return 0; free_dst:
@@ -1211,9 +1213,16 @@ static void geneve_setup(struct net_device *dev) dev->features |= NETIF_F_RXCSUM; dev->features |= NETIF_F_GSO_SOFTWARE; + /* Partial features are disabled by default. */ dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST; dev->hw_features |= NETIF_F_RXCSUM; dev->hw_features |= NETIF_F_GSO_SOFTWARE; + dev->hw_features |= UDP_TUNNEL_PARTIAL_FEATURES; + dev->hw_features |= NETIF_F_GSO_PARTIAL; + + dev->hw_enc_features = dev->hw_features; + dev->gso_partial_features = UDP_TUNNEL_PARTIAL_FEATURES; + dev->mangleid_features = NETIF_F_GSO_PARTIAL; dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS; /* MTU range: 68 - (something less than 65535) */
diff --git a/include/net/udp_tunnel.h b/include/net/udp_tunnel.h
index 9acef2fbd2fd..d9c6d04bb3b5 100644
--- a/include/net/udp_tunnel.h
+++ b/include/net/udp_tunnel.h@@ -10,6 +10,11 @@ #include <net/ipv6_stubs.h> #endif +#define UDP_TUNNEL_PARTIAL_FEATURES NETIF_F_GSO_ENCAP_ALL +#define UDP_TUNNEL_STRIPPED_GSO_TYPES ((UDP_TUNNEL_PARTIAL_FEATURES | \ + NETIF_F_GSO_PARTIAL) >> \ + NETIF_F_GSO_SHIFT) + struct udp_port_cfg { u8 family;
@@ -145,6 +150,33 @@ void udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk, __be16 src_port, __be16 dst_port, bool nocheck, u16 ip6cb_flags); +static inline bool udp_tunnel_handle_partial(struct sk_buff *skb) +{ + bool double_encap = !!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL); + + /* + * If the skb went through partial segmentation, lower devices + * will not need to offload the related features - except for + * UDP_TUNNEL, that will be re-added by the later + * udp_tunnel_handle_offloads(). + */ + if (double_encap) + skb_shinfo(skb)->gso_type &= ~UDP_TUNNEL_STRIPPED_GSO_TYPES; + return double_encap; +} + +static inline void udp_tunnel_set_inner_protocol(struct sk_buff *skb, + bool double_encap, + __be16 inner_proto) +{ + /* + * The inner protocol has been set by the nested tunnel, don't + * overraid it. + */ + if (!double_encap) + skb_set_inner_protocol(skb, inner_proto); +} + void udp_tunnel_sock_release(struct socket *sock); struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
--
2.52.0