[ovs-dev] [PATCH v8 2/6] dpif-netdev: retrieve flow directly from the flow mark

Shahaf Shuler shahafs at mellanox.com
Wed Apr 11 12:18:02 UTC 2018


Tuesday, April 10, 2018 10:58 PM, Stokes, Ian:
> Subject: RE: [PATCH v8 2/6] dpif-netdev: retrieve flow directly from the flow
> mark
> 
> > Subject: [PATCH v8 2/6] dpif-netdev: retrieve flow directly from the
> > flow mark
> >
> > From: Yuanhan Liu <yliu at fridaylinux.org>
> >
> > So that we could skip some very costly CPU operations, including but
> > not limiting to miniflow_extract, emc lookup, dpcls lookup, etc. Thus,
> > performance could be greatly improved.
> >
> > A PHY-PHY forwarding with 1000 mega flows (udp,tp_src=1000-1999) and
> > 1 million streams (tp_src=1000-1999, tp_dst=2000-2999) show more that
> > 260% performance boost.
> >
> > Note that though the heavy miniflow_extract is skipped, we still have
> > to do per packet checking, due to we have to check the tcp_flags.
> >
> > Co-authored-by: Finn Christensen <fc at napatech.com>
> > Signed-off-by: Yuanhan Liu <yliu at fridaylinux.org>
> > Signed-off-by: Finn Christensen <fc at napatech.com>
> > Signed-off-by: Shahaf Shuler <shahafs at mellanox.com>
> > ---
> >  lib/dp-packet.h   |  13 +++++
> >  lib/dpif-netdev.c |  44 ++++++++++++--
> >  lib/flow.c        | 155 +++++++++++++++++++++++++++++++++++++++-----
> -----
> >  lib/flow.h        |   1 +
> >  4 files changed, 175 insertions(+), 38 deletions(-)
> >
> > diff --git a/lib/dp-packet.h b/lib/dp-packet.h index 21c8ca5..dd3f17b
> > 100644
> > --- a/lib/dp-packet.h
> > +++ b/lib/dp-packet.h
> > @@ -691,6 +691,19 @@ reset_dp_packet_checksum_ol_flags(struct
> > dp_packet
> > *p)  #define reset_dp_packet_checksum_ol_flags(arg)
> >  #endif
> >
> > +static inline bool
> > +dp_packet_has_flow_mark(struct dp_packet *p OVS_UNUSED,
> > +                        uint32_t *mark OVS_UNUSED) { #ifdef DPDK_NETDEV
> > +    if (p->mbuf.ol_flags & PKT_RX_FDIR_ID) {
> > +        *mark = p->mbuf.hash.fdir.hi;
> > +        return true;
> > +    }
> > +#endif
> > +    return false;
> > +}
> > +
> >  enum { NETDEV_MAX_BURST = 32 }; /* Maximum number packets in a
> batch.
> > */
> >
> >  struct dp_packet_batch {
> > diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c index
> > 2fdb6ef..7489a2f
> > 100644
> > --- a/lib/dpif-netdev.c
> > +++ b/lib/dpif-netdev.c
> > @@ -2015,6 +2015,23 @@ flow_mark_flush(struct
> dp_netdev_pmd_thread *pmd)
> >      }
> >  }
> >
> > +static struct dp_netdev_flow *
> > +mark_to_flow_find(const struct dp_netdev_pmd_thread *pmd,
> > +                  const uint32_t mark) {
> > +    struct dp_netdev_flow *flow;
> > +
> > +    CMAP_FOR_EACH_WITH_HASH (flow, mark_node, hash_int(mark, 0),
> > +                             &flow_mark.mark_to_flow) {
> > +        if (flow->mark == mark && flow->pmd_id == pmd->core_id &&
> > +            flow->dead == false) {
> > +            return flow;
> > +        }
> > +    }
> > +
> > +    return NULL;
> > +}
> > +
> >  static void
> >  dp_netdev_pmd_remove_flow(struct dp_netdev_pmd_thread *pmd,
> >                            struct dp_netdev_flow *flow) @@ -5204,10
> > +5221,10 @@ struct packet_batch_per_flow {  static inline void
> > packet_batch_per_flow_update(struct packet_batch_per_flow *batch,
> >                               struct dp_packet *packet,
> > -                             const struct miniflow *mf)
> > +                             uint16_t tcp_flags)
> >  {
> >      batch->byte_count += dp_packet_size(packet);
> > -    batch->tcp_flags |= miniflow_get_tcp_flags(mf);
> > +    batch->tcp_flags |= tcp_flags;
> >      batch->array.packets[batch->array.count++] = packet;  }
> >
> > @@ -5241,7 +5258,7 @@ packet_batch_per_flow_execute(struct
> > packet_batch_per_flow *batch,
> >
> >  static inline void
> >  dp_netdev_queue_batches(struct dp_packet *pkt,
> > -                        struct dp_netdev_flow *flow, const struct
> > miniflow *mf,
> > +                        struct dp_netdev_flow *flow, uint16_t
> > + tcp_flags,
> >                          struct packet_batch_per_flow *batches,
> >                          size_t *n_batches)  { @@ -5252,7 +5269,7 @@
> > dp_netdev_queue_batches(struct dp_packet *pkt,
> >          packet_batch_per_flow_init(batch, flow);
> >      }
> >
> > -    packet_batch_per_flow_update(batch, pkt, mf);
> > +    packet_batch_per_flow_update(batch, pkt, tcp_flags);
> >  }
> >
> >  /* Try to process all ('cnt') the 'packets' using only the exact
> > match cache @@ -5283,6 +5300,7 @@ emc_processing(struct
> > dp_netdev_pmd_thread *pmd,
> >      const size_t cnt = dp_packet_batch_size(packets_);
> >      uint32_t cur_min;
> >      int i;
> > +    uint16_t tcp_flags;
> >
> >      atomic_read_relaxed(&pmd->dp->emc_insert_min, &cur_min);
> >      pmd_perf_update_counter(&pmd->perf_stats,
> > @@ -5291,6 +5309,7 @@ emc_processing(struct dp_netdev_pmd_thread
> *pmd,
> >
> >      DP_PACKET_BATCH_REFILL_FOR_EACH (i, cnt, packet, packets_) {
> >          struct dp_netdev_flow *flow;
> > +        uint32_t mark;
> >
> >          if (OVS_UNLIKELY(dp_packet_size(packet) < ETH_HEADER_LEN)) {
> >              dp_packet_delete(packet); @@ -5298,6 +5317,16 @@
> > emc_processing(struct dp_netdev_pmd_thread *pmd,
> >              continue;
> >          }
> >
> > +        if (dp_packet_has_flow_mark(packet, &mark)) {
> > +            flow = mark_to_flow_find(pmd, mark);
> > +            if (flow) {
> > +                tcp_flags = parse_tcp_flags(packet);
> > +                dp_netdev_queue_batches(packet, flow, tcp_flags, batches,
> > +                                        n_batches);
> > +                continue;
> > +            }
> > +        }
> > +
> >          if (i != cnt - 1) {
> >              struct dp_packet **packets = packets_->packets;
> >              /* Prefetch next packet data and metadata. */ @@ -5323,7
> > +5352,8 @@ emc_processing(struct dp_netdev_pmd_thread *pmd,
> >              flow = NULL;
> >          }
> >          if (OVS_LIKELY(flow)) {
> > -            dp_netdev_queue_batches(packet, flow, &key->mf, batches,
> > +            tcp_flags = miniflow_get_tcp_flags(&key->mf);
> > +            dp_netdev_queue_batches(packet, flow, tcp_flags, batches,
> >                                      n_batches);
> >          } else {
> >              /* Exact match cache missed. Group missed packets
> > together at @@ -5501,7 +5531,9 @@ fast_path_processing(struct
> > dp_netdev_pmd_thread *pmd,
> >          flow = dp_netdev_flow_cast(rules[i]);
> >
> >          emc_probabilistic_insert(pmd, &keys[i], flow);
> > -        dp_netdev_queue_batches(packet, flow, &keys[i].mf, batches,
> > n_batches);
> > +        dp_netdev_queue_batches(packet, flow,
> > +                                miniflow_get_tcp_flags(&keys[i].mf),
> > +                                batches, n_batches);
> >      }
> >
> >      pmd_perf_update_counter(&pmd->perf_stats,
> PMD_STAT_MASKED_HIT,
> > diff - -git a/lib/flow.c b/lib/flow.c index 38ff29c..6c74dd3 100644
> > --- a/lib/flow.c
> > +++ b/lib/flow.c
> > @@ -624,6 +624,70 @@ flow_extract(struct dp_packet *packet, struct
> > flow
> > *flow)
> >      miniflow_expand(&m.mf, flow);
> >  }
> >
> > +static inline bool
> > +ipv4_sanity_check(const struct ip_header *nh, size_t size,
> > +                  int *ip_lenp, uint16_t *tot_lenp) {
> > +    int ip_len;
> > +    uint16_t tot_len;
> > +
> > +    if (OVS_UNLIKELY(size < IP_HEADER_LEN)) {
> > +        return false;
> > +    }
> > +    ip_len = IP_IHL(nh->ip_ihl_ver) * 4;
> > +
> > +    if (OVS_UNLIKELY(ip_len < IP_HEADER_LEN || size < ip_len)) {
> > +        return false;
> > +    }
> > +
> > +    tot_len = ntohs(nh->ip_tot_len);
> > +    if (OVS_UNLIKELY(tot_len > size || ip_len > tot_len ||
> > +                size - tot_len > UINT8_MAX)) {
> > +        return false;
> > +    }
> > +
> > +    *ip_lenp = ip_len;
> > +    *tot_lenp = tot_len;
> > +
> > +    return true;
> > +}
> > +
> > +static inline uint8_t
> > +ipv4_get_nw_frag(const struct ip_header *nh) {
> > +    uint8_t nw_frag = 0;
> > +
> > +    if (OVS_UNLIKELY(IP_IS_FRAGMENT(nh->ip_frag_off))) {
> > +        nw_frag = FLOW_NW_FRAG_ANY;
> > +        if (nh->ip_frag_off & htons(IP_FRAG_OFF_MASK)) {
> > +            nw_frag |= FLOW_NW_FRAG_LATER;
> > +        }
> > +    }
> > +
> > +    return nw_frag;
> > +}
> > +
> > +static inline bool
> > +ipv6_sanity_check(const struct ovs_16aligned_ip6_hdr *nh, size_t
> > +size) {
> > +    uint16_t plen;
> > +
> > +    if (OVS_UNLIKELY(size < sizeof *nh)) {
> > +        return false;
> > +    }
> > +
> > +    plen = ntohs(nh->ip6_plen);
> > +    if (OVS_UNLIKELY(plen > size)) {
> > +        return false;
> > +    }
> > +    /* Jumbo Payload option not supported yet. */
> > +    if (OVS_UNLIKELY(size - plen > UINT8_MAX)) {
> > +        return false;
> > +    }
> > +
> > +    return true;
> > +}
> > +
> >  /* Caller is responsible for initializing 'dst' with enough storage for
> >   * FLOW_U64S * 8 bytes. */
> >  void
> > @@ -748,22 +812,7 @@ miniflow_extract(struct dp_packet *packet, struct
> > miniflow *dst)
> >          int ip_len;
> >          uint16_t tot_len;
> >
> > -        if (OVS_UNLIKELY(size < IP_HEADER_LEN)) {
> > -            goto out;
> > -        }
> > -        ip_len = IP_IHL(nh->ip_ihl_ver) * 4;
> > -
> > -        if (OVS_UNLIKELY(ip_len < IP_HEADER_LEN)) {
> > -            goto out;
> > -        }
> > -        if (OVS_UNLIKELY(size < ip_len)) {
> > -            goto out;
> > -        }
> > -        tot_len = ntohs(nh->ip_tot_len);
> > -        if (OVS_UNLIKELY(tot_len > size || ip_len > tot_len)) {
> > -            goto out;
> > -        }
> > -        if (OVS_UNLIKELY(size - tot_len > UINT8_MAX)) {
> > +        if (OVS_UNLIKELY(!ipv4_sanity_check(nh, size, &ip_len,
> > + &tot_len))) {
> 
> You may have missed my comment in the v7 regarding this.
> 
> There's no mention in commit message of the introduction of
> IPv4/IPv6/fragmentation sanity checks.
> 
> This affects minflow extract regardless of HWOL usage. The miniflow extract
> refactor should  to use these should be introduced as a separate patch to this
> series so it's clear that it is being modified.
> 
> >              goto out;
> >          }
> >          dp_packet_set_l2_pad_size(packet, size - tot_len); @@ -786,31
> > +835,19 @@ miniflow_extract(struct dp_packet *packet, struct miniflow
> > *dst)
> >          nw_tos = nh->ip_tos;
> >          nw_ttl = nh->ip_ttl;
> >          nw_proto = nh->ip_proto;
> > -        if (OVS_UNLIKELY(IP_IS_FRAGMENT(nh->ip_frag_off))) {
> > -            nw_frag = FLOW_NW_FRAG_ANY;
> > -            if (nh->ip_frag_off & htons(IP_FRAG_OFF_MASK)) {
> > -                nw_frag |= FLOW_NW_FRAG_LATER;
> > -            }
> > -        }
> > +        nw_frag = ipv4_get_nw_frag(nh);
> >          data_pull(&data, &size, ip_len);
> >      } else if (dl_type == htons(ETH_TYPE_IPV6)) {
> > -        const struct ovs_16aligned_ip6_hdr *nh;
> > +        const struct ovs_16aligned_ip6_hdr *nh = data;
> >          ovs_be32 tc_flow;
> >          uint16_t plen;
> >
> > -        if (OVS_UNLIKELY(size < sizeof *nh)) {
> > +        if (OVS_UNLIKELY(!ipv6_sanity_check(nh, size))) {
> >              goto out;
> >          }
> > -        nh = data_pull(&data, &size, sizeof *nh);
> > +        data_pull(&data, &size, sizeof *nh);
> >
> >          plen = ntohs(nh->ip6_plen);
> > -        if (OVS_UNLIKELY(plen > size)) {
> > -            goto out;
> > -        }
> > -        /* Jumbo Payload option not supported yet. */
> > -        if (OVS_UNLIKELY(size - plen > UINT8_MAX)) {
> > -            goto out;
> > -        }
> >          dp_packet_set_l2_pad_size(packet, size - plen);
> >          size = plen;   /* Never pull padding. */
> >
> > @@ -982,6 +1019,60 @@ parse_dl_type(const struct eth_header *data_,
> > size_t
> > size)
> >      return parse_ethertype(&data, &size);  }
> >
> > +uint16_t
> > +parse_tcp_flags(struct dp_packet *packet) {
> > +    const void *data = dp_packet_data(packet);
> > +    size_t size = dp_packet_size(packet);
> > +    ovs_be16 dl_type;
> > +    uint8_t nw_frag = 0, nw_proto = 0;
> > +
> > +    if (packet->packet_type != htonl(PT_ETH)) {
> > +        return 0;
> > +    }
> > +
> > +    data_pull(&data, &size, ETH_ADDR_LEN * 2);
> > +    dl_type = parse_ethertype(&data, &size);
> > +    if (OVS_LIKELY(dl_type == htons(ETH_TYPE_IP))) {
> > +        const struct ip_header *nh = data;
> > +        int ip_len;
> > +        uint16_t tot_len;
> > +
> > +        if (OVS_UNLIKELY(!ipv4_sanity_check(nh, size, &ip_len,
> > &tot_len))) {
> > +            return 0;
> > +        }
> > +        nw_proto = nh->ip_proto;
> > +        nw_frag = ipv4_get_nw_frag(nh);
> > +
> > +        size = tot_len;   /* Never pull padding. */
> > +        data_pull(&data, &size, ip_len);
> > +    } else if (dl_type == htons(ETH_TYPE_IPV6)) {
> > +        const struct ovs_16aligned_ip6_hdr *nh = data;
> > +
> > +        if (OVS_UNLIKELY(!ipv6_sanity_check(nh, size))) {
> > +            return 0;
> > +        }
> > +        data_pull(&data, &size, sizeof *nh);
> > +
> > +        size = ntohs(nh->ip6_plen); /* Never pull padding. */
> > +        if (!parse_ipv6_ext_hdrs__(&data, &size, &nw_proto, &nw_frag)) {
> > +            return 0;
> > +        }
> > +        nw_proto = nh->ip6_nxt;
> > +    } else {
> > +        return 0;
> > +    }
> > +
> > +    if (!(nw_frag & FLOW_NW_FRAG_LATER) && nw_proto ==
> IPPROTO_TCP &&
> > +        size >= TCP_HEADER_LEN) {
> > +        const struct tcp_header *tcp = data;
> > +
> > +        return TCP_FLAGS_BE32(tcp->tcp_ctl);
> 
> Will cause compilation failure with sparse when compiling without DPDK.
> 
> lib/flow.c:1070:16: error: incorrect type in return expression (different base
> types)
> lib/flow.c:1070:16:    expected unsigned short
> lib/flow.c:1070:16:    got restricted ovs_be32 [usertype] <noident>

Thanks,

Is there a way for me to re-run travis build so I can verify it is fixed? 

> 
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftra
> vis-
> ci.org%2Fistokes%2Fovs%2Fjobs%2F364709985&data=02%7C01%7Cshahafs%
> 40mellanox.com%7C624a50f6dcd64230e11c08d59f1d6f66%7Ca652971c7d2e4
> d9ba6a4d149256f461b%7C0%7C0%7C636589871173668041&sdata=bZ6FwLkX
> B0%2FphhOaQBb6tBjAkNaA8to%2BSWiuK6zdBew%3D&reserved=0
> 
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> >  /* For every bit of a field that is wildcarded in 'wildcards', sets the
> >   * corresponding bit in 'flow' to zero. */  void diff --git
> > a/lib/flow.h b/lib/flow.h index 770a07a..0adecbf 100644
> > --- a/lib/flow.h
> > +++ b/lib/flow.h
> > @@ -132,6 +132,7 @@ bool parse_ipv6_ext_hdrs(const void **datap,
> > size_t *sizep, uint8_t *nw_proto,
> >                           uint8_t *nw_frag);
> >  ovs_be16 parse_dl_type(const struct eth_header *data_, size_t size);
> > bool parse_nsh(const void **datap, size_t *sizep, struct ovs_key_nsh
> > *key);
> > +uint16_t parse_tcp_flags(struct dp_packet *packet);
> >
> >  static inline uint64_t
> >  flow_get_xreg(const struct flow *flow, int idx)
> > --
> > 2.7.4



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