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 <miroslaw.walukiewicz at intel.com>
Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
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 8a4190b..d2d127d 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 590d11a..80c5140 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 9b57b3a..87c2963 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 832fe0a..04cbf41 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 387b06c..20c3ae1 100644
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -81,6 +81,7 @@
#include <rte_memcpy.h>
#include <rte_byteorder.h>
+#include <rte_mbuf.h>
#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 433c616..848d5d1 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 ca35db2..2df3385 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,
--
2.1.0
