From 4199fdea60c36f3ef0529a61896fd5ab0cc0ba1f Mon Sep 17 00:00:00 2001 From: Olivier Matz Date: Wed, 26 Nov 2014 16:04:52 +0100 Subject: [PATCH] mbuf: generic support for TCP segmentation offload Some of the NICs supported by DPDK have a possibility to accelerate TCP traffic by using segmentation offload. The application prepares a packet with valid TCP header with size up to 64K and deleguates the segmentation to the NIC. Implement the generic part of TCP segmentation offload in rte_mbuf. It introduces 2 new fields in rte_mbuf: l4_len (length of L4 header in bytes) and tso_segsz (MSS of packets). To delegate the TCP segmentation to the hardware, the user has to: - set the PKT_TX_TCP_SEG flag in mbuf->ol_flags (this flag implies PKT_TX_TCP_CKSUM) - set the flag PKT_TX_IPV4 or PKT_TX_IPV6 - set PKT_TX_IP_CKSUM if it's IPv4, and set the IP checksum to 0 in the packet - fill the mbuf offload information: l2_len, l3_len, l4_len, tso_segsz - calculate the pseudo header checksum without taking ip_len in account, and set it in the TCP header, for instance by using rte_ipv4_phdr_cksum(ip_hdr, ol_flags) The API is inspired from ixgbe hardware (the next commit adds the support for ixgbe), but it seems generic enough to be used for other hw/drivers in the future. This commit also reworks the way l2_len and l3_len are used in igb and ixgbe drivers as the l2_l3_len is not available anymore in mbuf. Signed-off-by: Mirek Walukiewicz Signed-off-by: Olivier Matz Acked-by: Konstantin Ananyev --- app/test-pmd/testpmd.c | 2 +- examples/ipv4_multicast/main.c | 2 +- lib/librte_mbuf/rte_mbuf.c | 1 + lib/librte_mbuf/rte_mbuf.h | 45 ++++++++++++++++++------------- lib/librte_net/rte_ip.h | 39 ++++++++++++++++++++++----- lib/librte_pmd_e1000/igb_rxtx.c | 11 +++++++- lib/librte_pmd_ixgbe/ixgbe_rxtx.c | 11 +++++++- 7 files changed, 82 insertions(+), 29 deletions(-) diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index 8a4190b73b..d2d127df1f 100644 --- a/app/test-pmd/testpmd.c +++ b/app/test-pmd/testpmd.c @@ -408,7 +408,7 @@ testpmd_mbuf_ctor(struct rte_mempool *mp, mb->ol_flags = 0; mb->data_off = RTE_PKTMBUF_HEADROOM; mb->nb_segs = 1; - mb->l2_l3_len = 0; + mb->tx_offload = 0; mb->vlan_tci = 0; mb->hash.rss = 0; } diff --git a/examples/ipv4_multicast/main.c b/examples/ipv4_multicast/main.c index 590d11a326..80c5140b7c 100644 --- a/examples/ipv4_multicast/main.c +++ b/examples/ipv4_multicast/main.c @@ -302,7 +302,7 @@ mcast_out_pkt(struct rte_mbuf *pkt, int use_clone) /* copy metadata from source packet*/ hdr->port = pkt->port; hdr->vlan_tci = pkt->vlan_tci; - hdr->l2_l3_len = pkt->l2_l3_len; + hdr->tx_offload = pkt->tx_offload; hdr->hash = pkt->hash; hdr->ol_flags = pkt->ol_flags; diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c index 9b57b3a750..87c29633aa 100644 --- a/lib/librte_mbuf/rte_mbuf.c +++ b/lib/librte_mbuf/rte_mbuf.c @@ -241,6 +241,7 @@ const char *rte_get_tx_ol_flag_name(uint64_t mask) case PKT_TX_UDP_CKSUM: return "PKT_TX_UDP_CKSUM"; case PKT_TX_IEEE1588_TMST: return "PKT_TX_IEEE1588_TMST"; case PKT_TX_VXLAN_CKSUM: return "PKT_TX_VXLAN_CKSUM"; + case PKT_TX_TCP_SEG: return "PKT_TX_TCP_SEG"; default: return NULL; } } diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h index 2a07f58cd7..6cf0ead264 100644 --- a/lib/librte_mbuf/rte_mbuf.h +++ b/lib/librte_mbuf/rte_mbuf.h @@ -2,6 +2,7 @@ * BSD LICENSE * * Copyright(c) 2010-2014 Intel Corporation. All rights reserved. + * Copyright 2014 6WIND S.A. * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -132,6 +133,20 @@ extern "C" { #define PKT_TX_VLAN_PKT (1ULL << 55) /**< TX packet is a 802.1q VLAN packet. */ +/** + * TCP segmentation offload. To enable this offload feature for a + * packet to be transmitted on hardware supporting TSO: + * - set the PKT_TX_TCP_SEG flag in mbuf->ol_flags (this flag implies + * PKT_TX_TCP_CKSUM) + * - if it's IPv4, set the PKT_TX_IP_CKSUM flag and write the IP checksum + * to 0 in the packet + * - fill the mbuf offload information: l2_len, l3_len, l4_len, tso_segsz + * - calculate the pseudo header checksum without taking ip_len in accound, + * and set it in the TCP header. Refer to rte_ipv4_phdr_cksum() and + * rte_ipv6_phdr_cksum() that can be used as helpers. + */ +#define PKT_TX_TCP_SEG (1ULL << 49) + /* Use final bit of flags to indicate a control mbuf */ #define CTRL_MBUF_FLAG (1ULL << 63) /**< Mbuf contains control data */ @@ -242,22 +257,18 @@ struct rte_mbuf { /* fields to support TX offloads */ union { - uint16_t l2_l3_len; /**< combined l2/l3 lengths as single var */ + uint64_t tx_offload; /**< combined for easy fetch */ struct { - uint16_t l3_len:9; /**< L3 (IP) Header Length. */ - uint16_t l2_len:7; /**< L2 (MAC) Header Length. */ - }; - }; + uint64_t l2_len:7; /**< L2 (MAC) Header Length. */ + uint64_t l3_len:9; /**< L3 (IP) Header Length. */ + uint64_t l4_len:8; /**< L4 (TCP/UDP) Header Length. */ + uint64_t tso_segsz:16; /**< TCP TSO segment size */ - /* fields for TX offloading of tunnels */ - union { - uint16_t inner_l2_l3_len; - /**< combined inner l2/l3 lengths as single var */ - struct { - uint16_t inner_l3_len:9; - /**< inner L3 (IP) Header Length. */ - uint16_t inner_l2_len:7; - /**< inner L2 (MAC) Header Length. */ + /* fields for TX offloading of tunnels */ + uint64_t inner_l3_len:9; /**< inner L3 (IP) Hdr Length. */ + uint64_t inner_l2_len:7; /**< inner L2 (MAC) Hdr Length. */ + + /* uint64_t unused:8; */ }; }; } __rte_cache_aligned; @@ -609,8 +620,7 @@ static inline void rte_pktmbuf_reset(struct rte_mbuf *m) { m->next = NULL; m->pkt_len = 0; - m->l2_l3_len = 0; - m->inner_l2_l3_len = 0; + m->tx_offload = 0; m->vlan_tci = 0; m->nb_segs = 1; m->port = 0xff; @@ -679,8 +689,7 @@ static inline void rte_pktmbuf_attach(struct rte_mbuf *mi, struct rte_mbuf *md) mi->data_len = md->data_len; mi->port = md->port; mi->vlan_tci = md->vlan_tci; - mi->l2_l3_len = md->l2_l3_len; - mi->inner_l2_l3_len = md->inner_l2_l3_len; + mi->tx_offload = md->tx_offload; mi->hash = md->hash; mi->next = NULL; diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h index 387b06c71d..20c3ae17e1 100644 --- a/lib/librte_net/rte_ip.h +++ b/lib/librte_net/rte_ip.h @@ -81,6 +81,7 @@ #include #include +#include #ifdef __cplusplus extern "C" { @@ -312,13 +313,21 @@ rte_ipv4_cksum(const struct ipv4_hdr *ipv4_hdr) * * The checksum field must be set to 0 by the caller. * + * Depending on the ol_flags, the pseudo-header checksum expected by the + * drivers is not the same. For instance, when TSO is enabled, the IP + * payload length must not be included in the packet. + * + * When ol_flags is 0, it computes the standard pseudo-header checksum. + * * @param ipv4_hdr * The pointer to the contiguous IPv4 header. + * @param ol_flags + * The ol_flags of the associated mbuf. * @return * The non-complemented checksum to set in the L4 header. */ static inline uint16_t -rte_ipv4_phdr_cksum(const struct ipv4_hdr *ipv4_hdr) +rte_ipv4_phdr_cksum(const struct ipv4_hdr *ipv4_hdr, uint64_t ol_flags) { struct ipv4_psd_header { uint32_t src_addr; /* IP address of source host. */ @@ -332,9 +341,13 @@ rte_ipv4_phdr_cksum(const struct ipv4_hdr *ipv4_hdr) psd_hdr.dst_addr = ipv4_hdr->dst_addr; psd_hdr.zero = 0; psd_hdr.proto = ipv4_hdr->next_proto_id; - psd_hdr.len = rte_cpu_to_be_16( - (uint16_t)(rte_be_to_cpu_16(ipv4_hdr->total_length) - - sizeof(struct ipv4_hdr))); + if (ol_flags & PKT_TX_TCP_SEG) { + psd_hdr.len = 0; + } else { + psd_hdr.len = rte_cpu_to_be_16( + (uint16_t)(rte_be_to_cpu_16(ipv4_hdr->total_length) + - sizeof(struct ipv4_hdr))); + } return rte_raw_cksum((const char *)&psd_hdr, sizeof(psd_hdr)); } @@ -361,7 +374,7 @@ rte_ipv4_udptcp_cksum(const struct ipv4_hdr *ipv4_hdr, const void *l4_hdr) sizeof(struct ipv4_hdr); cksum = rte_raw_cksum(l4_hdr, l4_len); - cksum += rte_ipv4_phdr_cksum(ipv4_hdr); + cksum += rte_ipv4_phdr_cksum(ipv4_hdr, 0); cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff); cksum = (~cksum) & 0xffff; @@ -386,13 +399,21 @@ struct ipv6_hdr { /** * Process the pseudo-header checksum of an IPv6 header. * + * Depending on the ol_flags, the pseudo-header checksum expected by the + * drivers is not the same. For instance, when TSO is enabled, the IPv6 + * payload length must not be included in the packet. + * + * When ol_flags is 0, it computes the standard pseudo-header checksum. + * * @param ipv6_hdr * The pointer to the contiguous IPv6 header. + * @param ol_flags + * The ol_flags of the associated mbuf. * @return * The non-complemented checksum to set in the L4 header. */ static inline uint16_t -rte_ipv6_phdr_cksum(const struct ipv6_hdr *ipv6_hdr) +rte_ipv6_phdr_cksum(const struct ipv6_hdr *ipv6_hdr, uint64_t ol_flags) { struct ipv6_psd_header { uint8_t src_addr[16]; /* IP address of source host. */ @@ -404,7 +425,11 @@ rte_ipv6_phdr_cksum(const struct ipv6_hdr *ipv6_hdr) rte_memcpy(&psd_hdr.src_addr, ipv6_hdr->src_addr, sizeof(ipv6_hdr->src_addr) + sizeof(ipv6_hdr->dst_addr)); psd_hdr.proto = (ipv6_hdr->proto << 24); - psd_hdr.len = ipv6_hdr->payload_len; + if (ol_flags & PKT_TX_TCP_SEG) { + psd_hdr.len = 0; + } else { + psd_hdr.len = ipv6_hdr->payload_len; + } return rte_raw_cksum((const char *)&psd_hdr, sizeof(psd_hdr)); } diff --git a/lib/librte_pmd_e1000/igb_rxtx.c b/lib/librte_pmd_e1000/igb_rxtx.c index 433c61605d..848d5d1ef9 100644 --- a/lib/librte_pmd_e1000/igb_rxtx.c +++ b/lib/librte_pmd_e1000/igb_rxtx.c @@ -367,6 +367,13 @@ eth_igb_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, struct rte_mbuf *tx_pkt; struct rte_mbuf *m_seg; union igb_vlan_macip vlan_macip_lens; + union { + uint16_t u16; + struct { + uint16_t l3_len:9; + uint16_t l2_len:7; + }; + } l2_l3_len; uint64_t buf_dma_addr; uint32_t olinfo_status; uint32_t cmd_type_len; @@ -404,8 +411,10 @@ eth_igb_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, tx_last = (uint16_t) (tx_id + tx_pkt->nb_segs - 1); ol_flags = tx_pkt->ol_flags; + l2_l3_len.l2_len = tx_pkt->l2_len; + l2_l3_len.l3_len = tx_pkt->l3_len; vlan_macip_lens.f.vlan_tci = tx_pkt->vlan_tci; - vlan_macip_lens.f.l2_l3_len = tx_pkt->l2_l3_len; + vlan_macip_lens.f.l2_l3_len = l2_l3_len.u16; tx_ol_req = ol_flags & IGB_TX_OFFLOAD_MASK; /* If a Context Descriptor need be built . */ diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c index ca35db283f..2df3385770 100644 --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c @@ -546,6 +546,13 @@ ixgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, struct rte_mbuf *tx_pkt; struct rte_mbuf *m_seg; union ixgbe_vlan_macip vlan_macip_lens; + union { + uint16_t u16; + struct { + uint16_t l3_len:9; + uint16_t l2_len:7; + }; + } l2_l3_len; uint64_t buf_dma_addr; uint32_t olinfo_status; uint32_t cmd_type_len; @@ -588,8 +595,10 @@ ixgbe_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, /* If hardware offload required */ tx_ol_req = ol_flags & IXGBE_TX_OFFLOAD_MASK; if (tx_ol_req) { + l2_l3_len.l2_len = tx_pkt->l2_len; + l2_l3_len.l3_len = tx_pkt->l3_len; vlan_macip_lens.f.vlan_tci = tx_pkt->vlan_tci; - vlan_macip_lens.f.l2_l3_len = tx_pkt->l2_l3_len; + vlan_macip_lens.f.l2_l3_len = l2_l3_len.u16; /* If new context need be built or reuse the exist ctx. */ ctx = what_advctx_update(txq, tx_ol_req, -- 2.20.1