Re: [PATCH net-next V2 3/3] net: Add GRO support for vxlan traffic

Add gro handlers for vxlan using the udp gro infrastructure

On my setup, which is net-next (now with the mlx4 vxlan offloads patches) --
for single TCP session that goes through vxlan tunneling I got nice improvement
from 6.8Gbs to 11.5Gbs

--> UDP/VXLAN GRO disabled
$ netperf  -H 192.168.52.147 -c -C

$ netperf -t TCP_STREAM -H 192.168.52.147 -c -C
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.52.147 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  65536  65536    10.00      6799.75   12.54    24.79    0.604   1.195

--> UDP/VXLAN GRO enabled

$ netperf -t TCP_STREAM -H 192.168.52.147 -c -C
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.52.147 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  65536  65536    10.00      11562.72   24.90    20.34    0.706   0.577

Signed-off-by: Or Gerlitz <redacted>
---
 drivers/net/vxlan.c |  101 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 99 insertions(+), 2 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 481f85d..b51823b 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c

@@ -40,6 +40,7 @@
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 #include <net/vxlan.h>
+#include <net/protocol.h>
 #if IS_ENABLED(CONFIG_IPV6)
 #include <net/ipv6.h>
 #include <net/addrconf.h>

@@ -554,6 +555,98 @@ static int vxlan_fdb_append(struct vxlan_fdb *f,
        return 1;
 }

+static struct sk_buff **vxlan_gro_receive(struct sk_buff **head, struct sk_buff *skb)
+{
+       struct sk_buff *p, **pp = NULL;
+       struct vxlanhdr *vh, *vh2;
+       struct ethhdr *eh;
+       unsigned int hlen, off, off_eth;
+       const struct packet_offload *ptype;
+       __be16 type;
+       int flush = 1;
+
+       off  = skb_gro_offset(skb);
+       hlen = off + sizeof(*vh);
+       vh   = skb_gro_header_fast(skb, off);
+       if (skb_gro_header_hard(skb, hlen)) {
+               vh = skb_gro_header_slow(skb, hlen, off);
+               if (unlikely(!vh))
+                       goto out;
+       }
+
+       flush = 0;
+
+       for (p = *head; p; p = p->next) {
+               if (!NAPI_GRO_CB(p)->same_flow)
+                       continue;
+
+               vh2 = (struct vxlanhdr   *)(p->data + off);
+               if (vh->vx_vni ^ vh2->vx_vni) {

+                       NAPI_GRO_CB(p)->same_flow = 0;
+                       continue;
+               }
+               goto found;
+       }
+
+found:
+       skb_gro_pull(skb, sizeof(struct vxlanhdr)); /* pull vxlan header */
+
+       off_eth = skb_gro_offset(skb);
+       hlen = off_eth + sizeof(*eh);
+       eh   = skb_gro_header_fast(skb, off_eth);
+       if (skb_gro_header_hard(skb, hlen)) {
+               eh = skb_gro_header_slow(skb, hlen, off_eth);
+               if (unlikely(!eh))
+                       goto out;
+       }
+       type = eh->h_proto;
+
+       rcu_read_lock();
+       ptype = gro_find_receive_by_type(type);
+       if (ptype == NULL) {
+               flush = 1;
+               goto out_unlock;
+       }
+
+       skb_gro_pull(skb, sizeof(*eh)); /* pull inner eth header */
+       pp = ptype->callbacks.gro_receive(head, skb);
+
+out_unlock:
+       rcu_read_unlock();
+out:
+       NAPI_GRO_CB(skb)->flush |= flush;
+
+       return pp;
+}
+
+static int vxlan_gro_complete(struct sk_buff *skb, int nhoff)
+{
+       struct ethhdr *eh;
+       struct packet_offload *ptype;
+       __be16 type;
+       /* 22 = 8 bytes for the vlxan header + 14 bytes for the inner eth header */
+       int vxlan_len  = 22;
+       int err = -ENOSYS;
+
+       eh = (struct ethhdr *)(skb->data + nhoff + sizeof (struct vxlanhdr));
+       type = eh->h_proto;
+
+       rcu_read_lock();
+       ptype = gro_find_complete_by_type(type);
+       if (ptype != NULL)
+               err = ptype->callbacks.gro_complete(skb, nhoff + vxlan_len);
+
+       rcu_read_unlock();
+       return err;
+}
+
+static const struct net_offload vxlan_offload = {
+       .callbacks = {
+               .gro_receive  = vxlan_gro_receive,
+               .gro_complete = vxlan_gro_complete,
+       },
+};
+
 /* Notify netdevs that UDP port started listening */
 static void vxlan_notify_add_rx_port(struct sock *sk)
 {

@@ -568,6 +661,8 @@ static void vxlan_notify_add_rx_port(struct sock *sk)
                        dev->netdev_ops->ndo_add_vxlan_port(dev, sa_family,
                                                            port);
        }
+       if (sa_family == AF_INET)
+               udp_add_offload(&vxlan_offload, port);
        rcu_read_unlock();
 }

@@ -585,6 +680,8 @@ static void vxlan_notify_del_rx_port(struct sock *sk)
                        dev->netdev_ops->ndo_del_vxlan_port(dev, sa_family,
                                                            port);
        }
+       if (sa_family == AF_INET)
+               udp_del_offload(&vxlan_offload, port);
        rcu_read_unlock();
 }

@@ -1125,8 +1222,8 @@ static void vxlan_rcv(struct vxlan_sock *vs,
         * leave the CHECKSUM_UNNECESSARY, the device checksummed it
         * for us. Otherwise force the upper layers to verify it.
         */
-       if (skb->ip_summed != CHECKSUM_UNNECESSARY || !skb->encapsulation ||
-           !(vxlan->dev->features & NETIF_F_RXCSUM))
+       if ((skb->ip_summed != CHECKSUM_UNNECESSARY && skb->ip_summed != CHECKSUM_PARTIAL) ||
+           !skb->encapsulation || !(vxlan->dev->features & NETIF_F_RXCSUM))
                skb->ip_summed = CHECKSUM_NONE;

        skb->encapsulation = 0;
--

1.7.1

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