diff mbox series

[ovs-dev,net-next] net: openvswitch: add support for l4 symmetric hashing

Message ID 20230609135955.3024931-1-aconole@redhat.com
State Handled Elsewhere
Headers show
Series [ovs-dev,net-next] net: openvswitch: add support for l4 symmetric hashing | expand

Commit Message

Aaron Conole June 9, 2023, 1:59 p.m. UTC
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 <aconole@redhat.com>
---
 include/uapi/linux/openvswitch.h |  1 +
 net/openvswitch/actions.c        | 12 ++++++++++--
 net/openvswitch/flow_netlink.c   |  2 ++
 3 files changed, 13 insertions(+), 2 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org June 12, 2023, 8:50 a.m. UTC | #1
Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Fri,  9 Jun 2023 09:59:55 -0400 you wrote:
> 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.
> 
> [...]

Here is the summary with links:
  - [net-next] net: openvswitch: add support for l4 symmetric hashing
    https://git.kernel.org/netdev/net-next/c/e069ba07e6c7

You are awesome, thank you!
diff mbox series

Patch

diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index c5d62ee825673..e94870e77ee96 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 a8cf9a88758ef..35b20d03c14a6 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -1072,8 +1072,16 @@  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 ead5418c126e3..41116361433da 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;