From e069ba07e6c7af69e119316bc87ff44869095f49 Mon Sep 17 00:00:00 2001 From: Aaron Conole Date: Fri, 9 Jun 2023 09:59:55 -0400 Subject: [PATCH] net: openvswitch: add support for l4 symmetric hashing Since its introduction, the ovs module execute_hash action allowed hash algorithms other than the skb->l4_hash to be used. However, additional hash algorithms were not implemented. This means flows requiring different hash distributions weren't able to use the kernel datapath. Now, introduce support for symmetric hashing algorithm as an alternative hash supported by the ovs module using the flow dissector. Output of flow using l4_sym hash: recirc_id(0),in_port(3),eth(),eth_type(0x0800), ipv4(dst=64.0.0.0/192.0.0.0,proto=6,frag=no), packets:30473425, bytes:45902883702, used:0.000s, flags:SP., actions:hash(sym_l4(0)),recirc(0xd) Some performance testing with no GRO/GSO, two veths, single flow: hash(l4(0)): 4.35 GBits/s hash(l4_sym(0)): 4.24 GBits/s Signed-off-by: Aaron Conole Signed-off-by: David S. Miller --- include/uapi/linux/openvswitch.h | 1 + net/openvswitch/actions.c | 12 ++++++++++-- net/openvswitch/flow_netlink.c | 2 ++ 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h index c5d62ee82567..e94870e77ee9 100644 --- a/include/uapi/linux/openvswitch.h +++ b/include/uapi/linux/openvswitch.h @@ -765,6 +765,7 @@ struct ovs_action_push_vlan { */ enum ovs_hash_alg { OVS_HASH_ALG_L4, + OVS_HASH_ALG_SYM_L4, }; /* diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c index 8074ea00d577..cab1e02b63e0 100644 --- a/net/openvswitch/actions.c +++ b/net/openvswitch/actions.c @@ -1073,8 +1073,16 @@ static void execute_hash(struct sk_buff *skb, struct sw_flow_key *key, struct ovs_action_hash *hash_act = nla_data(attr); u32 hash = 0; - /* OVS_HASH_ALG_L4 is the only possible hash algorithm. */ - hash = skb_get_hash(skb); + if (hash_act->hash_alg == OVS_HASH_ALG_L4) { + /* OVS_HASH_ALG_L4 hasing type. */ + hash = skb_get_hash(skb); + } else if (hash_act->hash_alg == OVS_HASH_ALG_SYM_L4) { + /* OVS_HASH_ALG_SYM_L4 hashing type. NOTE: this doesn't + * extend past an encapsulated header. + */ + hash = __skb_get_hash_symmetric(skb); + } + hash = jhash_1word(hash, hash_act->hash_basis); if (!hash) hash = 0x1; diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c index ead5418c126e..41116361433d 100644 --- a/net/openvswitch/flow_netlink.c +++ b/net/openvswitch/flow_netlink.c @@ -3221,6 +3221,8 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr, switch (act_hash->hash_alg) { case OVS_HASH_ALG_L4: + fallthrough; + case OVS_HASH_ALG_SYM_L4: break; default: return -EINVAL; -- 2.20.1