[ovs-dev] [PATCH] datapath: Optimize recirc action.

Andy Zhou azhou at nicira.com
Thu Aug 7 21:01:07 UTC 2014


On Thu, Aug 7, 2014 at 12:32 PM, Pravin B Shelar <pshelar at nicira.com> wrote:
> OVS need to flow key for flow lookup in recic action. OVS
> does key extract in recic action. Most of cases we could
> use OVS_CB packet key directly and can avoid packet flow key
> extract. SET action we can update flow-key along with packet
> to keep it consistent. But there are some action like MPLS
> pop which forces OVS to do flow-extract. In such cases we
> can mark flow key as invalid so that subsequent recirc
> action can do full flow extract.

Does this optimization apply to sample action as well?

>
> Signed-off-by: Pravin B Shelar <pshelar at nicira.com>
> ---
>  datapath/actions.c | 197 +++++++++++++++++++++++++++++++++++++++++++----------
>  1 file changed, 160 insertions(+), 37 deletions(-)
>
> diff --git a/datapath/actions.c b/datapath/actions.c
> index efc64f1..3c004a8 100644
> --- a/datapath/actions.c
> +++ b/datapath/actions.c
> @@ -40,6 +40,90 @@
>  #include "vlan.h"
>  #include "vport.h"
>
> +static void flow_key_set_priority(struct sk_buff *skb, u32 priority)

Why not just pass in pkt_key, instead of skb?

> +{
> +       OVS_CB(skb)->pkt_key->phy.priority = priority;
> +}
> +
> +static void flow_key_set_skb_mark(struct sk_buff *skb, u32 skb_mark)
> +{
> +       OVS_CB(skb)->pkt_key->phy.skb_mark = skb_mark;
> +}
> +
> +static void flow_key_set_eth_src(struct sk_buff *skb, const u8 addr[])
> +{
> +       ether_addr_copy(OVS_CB(skb)->pkt_key->eth.src, addr);
> +}
> +
> +static void flow_key_set_eth_dst(struct sk_buff *skb, const u8 addr[])
> +{
> +       ether_addr_copy(OVS_CB(skb)->pkt_key->eth.dst, addr);
> +}
> +
> +static void flow_key_set_vlan_tci(struct sk_buff *skb, __be16 tci)
> +{
> +       OVS_CB(skb)->pkt_key->eth.tci = tci;
> +}
> +
> +static void flow_key_set_ipv4_src(struct sk_buff *skb, __be32 addr)
> +{
> +       OVS_CB(skb)->pkt_key->ipv4.addr.src = addr;
> +}
> +
> +static void flow_key_set_ipv4_dst(struct sk_buff *skb, __be32 addr)
> +{
> +       OVS_CB(skb)->pkt_key->ipv4.addr.src = addr;
> +}
> +
> +static void flow_key_set_ipv4_tos(struct sk_buff *skb, const struct iphdr *nh)
> +{
> +       OVS_CB(skb)->pkt_key->ip.tos = nh->tos;
> +}
> +
> +static void flow_key_set_ip_ttl(struct sk_buff *skb, u8 ttl)
> +{
> +       OVS_CB(skb)->pkt_key->ip.ttl = ttl;
> +}
> +
> +static void flow_key_set_ipv6_src(struct sk_buff *skb,
> +                                 const __be32 addr[4])
> +{
> +       memcpy(&OVS_CB(skb)->pkt_key->ipv6.addr.src, addr, sizeof(__be32[4]));
> +}
> +
> +static void flow_key_set_ipv6_dst(struct sk_buff *skb,
> +                                 const __be32 addr[4])
> +{
> +       memcpy(&OVS_CB(skb)->pkt_key->ipv6.addr.dst, addr, sizeof(__be32[4]));
> +}
> +
> +static void flow_key_set_ipv6_fl(struct sk_buff *skb,
> +                                const struct ipv6hdr *nh)
> +{
> +       OVS_CB(skb)->pkt_key->ipv6.label = *(__be32 *)nh &
> +                                          htonl(IPV6_FLOWINFO_FLOWLABEL);
> +}
> +
> +static void flow_key_set_tp_src(struct sk_buff *skb, __be16 port)
> +{
> +       OVS_CB(skb)->pkt_key->tp.src = port;
> +}
> +
> +static void flow_key_set_tp_dst(struct sk_buff *skb, __be16 port)
> +{
> +       OVS_CB(skb)->pkt_key->tp.dst = port;
> +}
> +
> +static void invalidate_skb_flow_key(struct sk_buff *skb)
> +{
> +       OVS_CB(skb)->pkt_key->eth.type = 0;
> +}
> +
> +static bool is_skb_flow_key_valid(struct sk_buff *skb)
> +{
> +       return !!OVS_CB(skb)->pkt_key->eth.type;
> +}
> +
>  static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
>                               const struct nlattr *attr, int len);
>
> @@ -90,6 +174,7 @@ static int push_mpls(struct sk_buff *skb,
>         if (!ovs_skb_get_inner_protocol(skb))
>                 ovs_skb_set_inner_protocol(skb, skb->protocol);
>         skb->protocol = mpls->mpls_ethertype;
> +       invalidate_skb_flow_key(skb);
>         return 0;
>  }
>
> @@ -120,6 +205,7 @@ static int pop_mpls(struct sk_buff *skb, const __be16 ethertype)
>         hdr->h_proto = ethertype;
>         if (eth_p_mpls(skb->protocol))
>                 skb->protocol = ethertype;
> +       invalidate_skb_flow_key(skb);
>         return 0;
>  }
>
> @@ -139,7 +225,7 @@ static int set_mpls(struct sk_buff *skb, const __be32 *mpls_lse)
>         }
>
>         *stack = *mpls_lse;
> -
> +       invalidate_skb_flow_key(skb);
>         return 0;
>  }
>
> @@ -189,9 +275,12 @@ static int pop_vlan(struct sk_buff *skb)
>         }
>         /* move next vlan tag to hw accel tag */
>         if (likely(skb->protocol != htons(ETH_P_8021Q) ||
> -                  skb->len < VLAN_ETH_HLEN))
> +                  skb->len < VLAN_ETH_HLEN)) {
> +               flow_key_set_vlan_tci(skb, 0);
>                 return 0;
> +       }
>
> +       invalidate_skb_flow_key(skb);
>         err = __pop_vlan_tci(skb, &tci);
>         if (unlikely(err))
>                 return err;
> @@ -220,6 +309,7 @@ static int push_vlan(struct sk_buff *skb, const struct ovs_action_push_vlan *vla
>
>         }
>         __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT);
> +       invalidate_skb_flow_key(skb);
>         return 0;
>  }
>
> @@ -238,11 +328,13 @@ static int set_eth_addr(struct sk_buff *skb,
>
>         ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
>
> +       flow_key_set_eth_src(skb, eth_key->eth_src);
> +       flow_key_set_eth_dst(skb, eth_key->eth_dst);
>         return 0;
>  }
>
>  static void set_ip_addr(struct sk_buff *skb, struct iphdr *nh,
> -                               __be32 *addr, __be32 new_addr)
> +                       __be32 *addr, __be32 new_addr)
>  {
>         int transport_len = skb->len - skb_transport_offset(skb);
>
> @@ -333,17 +425,25 @@ static int set_ipv4(struct sk_buff *skb, const struct ovs_key_ipv4 *ipv4_key)
>
>         nh = ip_hdr(skb);
>
> -       if (ipv4_key->ipv4_src != nh->saddr)
> +       if (ipv4_key->ipv4_src != nh->saddr) {
>                 set_ip_addr(skb, nh, &nh->saddr, ipv4_key->ipv4_src);
> +               flow_key_set_ipv4_src(skb, ipv4_key->ipv4_src);
> +       }
>
> -       if (ipv4_key->ipv4_dst != nh->daddr)
> +       if (ipv4_key->ipv4_dst != nh->daddr) {
>                 set_ip_addr(skb, nh, &nh->daddr, ipv4_key->ipv4_dst);
> +               flow_key_set_ipv4_dst(skb, ipv4_key->ipv4_dst);
> +       }
>
> -       if (ipv4_key->ipv4_ != nh->tos)
> +       if (ipv4_key->ipv4_tos != nh->tos) {
>                 ipv4_change_dsfield(nh, 0, ipv4_key->ipv4_tos);
> +               flow_key_set_ipv4_tos(skb, nh);

why not pass ipv4_key->ipv4_tos instead of nh?

> +       }
>
> -       if (ipv4_key->ipv4_ttl != nh->ttl)
> +       if (ipv4_key->ipv4_ttl != nh->ttl) {
>                 set_ip_ttl(skb, nh, ipv4_key->ipv4_ttl);
> +               flow_key_set_ip_ttl(skb, ipv4_key->ipv4_ttl);
> +       }
>
>         return 0;
>  }
> @@ -364,9 +464,11 @@ static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
>         saddr = (__be32 *)&nh->saddr;
>         daddr = (__be32 *)&nh->daddr;
>
> -       if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src)))
> +       if (memcmp(ipv6_key->ipv6_src, saddr, sizeof(ipv6_key->ipv6_src))) {
>                 set_ipv6_addr(skb, ipv6_key->ipv6_proto, saddr,
>                               ipv6_key->ipv6_src, true);
> +               flow_key_set_ipv6_src(skb, ipv6_key->ipv6_src);
> +       }
>
>         if (memcmp(ipv6_key->ipv6_dst, daddr, sizeof(ipv6_key->ipv6_dst))) {
>                 unsigned int offset = 0;
> @@ -380,12 +482,15 @@ static int set_ipv6(struct sk_buff *skb, const struct ovs_key_ipv6 *ipv6_key)
>
>                 set_ipv6_addr(skb, ipv6_key->ipv6_proto, daddr,
>                               ipv6_key->ipv6_dst, recalc_csum);
> +               flow_key_set_ipv6_dst(skb, ipv6_key->ipv6_dst);
>         }
>
>         set_ipv6_tc(nh, ipv6_key->ipv6_tclass);
>         set_ipv6_fl(nh, ntohl(ipv6_key->ipv6_label));
> -       nh->hop_limit = ipv6_key->ipv6_hlimit;
> +       flow_key_set_ipv6_fl(skb, nh);
>
> +       nh->hop_limit = ipv6_key->ipv6_hlimit;
> +       flow_key_set_ip_ttl(skb, ipv6_key->ipv6_hlimit);
>         return 0;
>  }
>
> @@ -424,11 +529,15 @@ static int set_udp(struct sk_buff *skb, const struct ovs_key_udp *udp_port_key)
>                 return err;
>
>         uh = udp_hdr(skb);
> -       if (udp_port_key->udp_src != uh->source)
> +       if (udp_port_key->udp_src != uh->source) {
>                 set_udp_port(skb, &uh->source, udp_port_key->udp_src);
> +               flow_key_set_tp_src(skb, udp_port_key->udp_src);
> +       }
>
> -       if (udp_port_key->udp_dst != uh->dest)
> +       if (udp_port_key->udp_dst != uh->dest) {
>                 set_udp_port(skb, &uh->dest, udp_port_key->udp_dst);
> +               flow_key_set_tp_dst(skb, udp_port_key->udp_dst);
> +       }
>
>         return 0;
>  }
> @@ -444,17 +553,21 @@ static int set_tcp(struct sk_buff *skb, const struct ovs_key_tcp *tcp_port_key)
>                 return err;
>
>         th = tcp_hdr(skb);
> -       if (tcp_port_key->tcp_src != th->source)
> +       if (tcp_port_key->tcp_src != th->source) {
>                 set_tp_port(skb, &th->source, tcp_port_key->tcp_src, &th->check);
> +               flow_key_set_tp_src(skb, tcp_port_key->tcp_src);
> +       }
>
> -       if (tcp_port_key->tcp_dst != th->dest)
> +       if (tcp_port_key->tcp_dst != th->dest) {
>                 set_tp_port(skb, &th->dest, tcp_port_key->tcp_dst, &th->check);
> +               flow_key_set_tp_dst(skb, tcp_port_key->tcp_dst);
> +       }
>
>         return 0;
>  }
>
>  static int set_sctp(struct sk_buff *skb,
> -                    const struct ovs_key_sctp *sctp_port_key)
> +                   const struct ovs_key_sctp *sctp_port_key)
>  {
>         struct sctphdr *sh;
>         int err;
> @@ -481,6 +594,8 @@ static int set_sctp(struct sk_buff *skb,
>                 sh->checksum = old_csum ^ old_correct_csum ^ new_csum;
>
>                 skb_clear_hash(skb);
> +               flow_key_set_tp_src(skb, sctp_port_key->sctp_src);
> +               flow_key_set_tp_dst(skb, sctp_port_key->sctp_dst);
>         }
>
>         return 0;
> @@ -603,10 +718,12 @@ static int execute_set_action(struct sk_buff *skb,
>         switch (nla_type(nested_attr)) {
>         case OVS_KEY_ATTR_PRIORITY:
>                 skb->priority = nla_get_u32(nested_attr);
> +               flow_key_set_priority(skb, skb->priority);
>                 break;
>
>         case OVS_KEY_ATTR_SKB_MARK:
>                 skb->mark = nla_get_u32(nested_attr);
> +               flow_key_set_skb_mark(skb, skb->mark);
>                 break;
>
>         case OVS_KEY_ATTR_TUNNEL_INFO:
> @@ -646,20 +763,40 @@ static int execute_set_action(struct sk_buff *skb,
>  }
>
>  static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
> -                         const struct nlattr *a)
> +                         const struct nlattr *a, int rem)
>  {
>         struct sw_flow_key recirc_key;
>         int err;
>
> -       err = ovs_flow_key_extract_recirc(nla_get_u32(a), OVS_CB(skb)->pkt_key,
> -                                         skb, &recirc_key);
> -       if (err) {
> -               kfree_skb(skb);
> -               return err;
> +       if (!last_action(a, rem)) {
> +               /* Recirc action is the not the last action
> +                * of the action list. */
> +               skb = skb_clone(skb, GFP_ATOMIC);
> +
> +               /* Skip the recirc action when out of memory, but
> +                * continue on with the rest of the action list. */
> +               if (!skb)
> +                       return 0;
>         }
>
> -       ovs_dp_process_packet(skb, true);
> +       if (is_skb_flow_key_valid(skb)) {
> +               if (!last_action(a, rem)) {
> +                       recirc_key = *OVS_CB(skb)->pkt_key;
> +                       OVS_CB(skb)->pkt_key = &recirc_key;
> +               }
> +               OVS_CB(skb)->pkt_key->recirc_id = nla_get_u32(a);

How about adding two new static inline functions:
  * flow_key_clone_recirc(nla_get_n32(a), skb, &recirc_key);
  * flow_key_set_recirc_id(skb, nla_get_n32(a));

The above logic will become even easier to understand and more consistent with
the API usage in this function. It should also help with the follow on
non-recursive changes.

> +       } else {
> +               struct sw_flow_key *pkt_key = OVS_CB(skb)->pkt_key;
>
> +               err = ovs_flow_key_extract_recirc(nla_get_u32(a), pkt_key,
> +                                                 skb, &recirc_key);
> +               if (err) {
> +                       kfree_skb(skb);
> +                       return err;
> +               }
> +       }
> +
> +       ovs_dp_process_packet(skb, true);
>         return 0;
>  }
>
> @@ -719,23 +856,9 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb,
>                         err = pop_vlan(skb);
>                         break;
>
> -               case OVS_ACTION_ATTR_RECIRC: {
> -                       struct sk_buff *recirc_skb;
> -
> -                       if (last_action(a, rem))
> -                               return execute_recirc(dp, skb, a);
> -
> -                       /* Recirc action is the not the last action
> -                        * of the action list. */
> -                       recirc_skb = skb_clone(skb, GFP_ATOMIC);
> -
> -                       /* Skip the recirc action when out of memory, but
> -                        * continue on with the rest of the action list. */
> -                       if (recirc_skb)
> -                               err = execute_recirc(dp, recirc_skb, a);
> -
> +               case OVS_ACTION_ATTR_RECIRC:
> +                       err = execute_recirc(dp, skb, a, rem);
>                         break;
> -               }
>
>                 case OVS_ACTION_ATTR_SET:
>                         err = execute_set_action(skb, nla_data(a));
> --
> 1.9.3
>
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