Re: [PATCH 2/2] app/testpmd: support TCP TSO in Tx only mode

[Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>]

On 10/19/22 19:41, Ferruh Yigit wrote:
> On 10/17/2022 3:41 PM, Andrew Rybchenko wrote:
>> Add '--txonly-tso-mss=N' option that enables TSO offload
>> and generates packets with specified MSS in txonly mode.
>>
>> Signed-off-by: Georgiy Levashov <georgiy.levashov@oktetlabs.ru>
>> Signed-off-by: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
>> Signed-off-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
>> ---
>>   app/test-pmd/parameters.c             | 10 +++++++++
>>   app/test-pmd/testpmd.c                | 12 +++++++++++
>>   app/test-pmd/testpmd.h                |  1 +
>>   app/test-pmd/txonly.c                 | 31 ++++++++++++++++++++++++++-
>>   doc/guides/testpmd_app_ug/run_app.rst |  4 ++++
>>   5 files changed, 57 insertions(+), 1 deletion(-)
>>
>> diff --git a/app/test-pmd/parameters.c b/app/test-pmd/parameters.c
>> index 545ebee16b..eba0c658c2 100644
>> --- a/app/test-pmd/parameters.c
>> +++ b/app/test-pmd/parameters.c
>> @@ -156,6 +156,7 @@ usage(char* progname)
>>       printf("  --txpkts=X[,Y]*: set TX segment sizes"
>>           " or total packet length.\n");
>>       printf("  --txonly-multi-flow: generate multiple flows in txonly 
>> mode\n");
>> +    printf("  --txonly-tso-mss=N: enable TSO offload and generate 
>> packets with specified MSS in txonly mode\n");
>>       printf("  --tx-ip=src,dst: IP addresses in Tx-only mode\n");
>>       printf("  --tx-udp=src[,dst]: UDP ports in Tx-only mode\n");
>>       printf("  --eth-link-speed: force link speed.\n");
>> @@ -671,6 +672,7 @@ launch_args_parse(int argc, char** argv)
>>           { "rxhdrs",            1, 0, 0 },
>>           { "txpkts",            1, 0, 0 },
>>           { "txonly-multi-flow",        0, 0, 0 },
>> +        { "txonly-tso-mss",        1, 0, 0 },
>>           { "rxq-share",            2, 0, 0 },
>>           { "eth-link-speed",        1, 0, 0 },
>>           { "disable-link-check",        0, 0, 0 },
>> @@ -1299,6 +1301,14 @@ launch_args_parse(int argc, char** argv)
>>               }
>>               if (!strcmp(lgopts[opt_idx].name, "txonly-multi-flow"))
>>                   txonly_multi_flow = 1;
>> +            if (!strcmp(lgopts[opt_idx].name, "txonly-tso-mss")) {
>> +                n = atoi(optarg);
>> +                if (n >= 0 && n <= UINT16_MAX)
>> +                    txonly_tso_segsz = n;
>> +                else
>> +                    rte_exit(EXIT_FAILURE,
>> +                         "TSO MSS must be >= 0 and <= UINT16_MAX\n");
>> +            }
>>               if (!strcmp(lgopts[opt_idx].name, "rxq-share")) {
>>                   if (optarg == NULL) {
>>                       rxq_share = UINT32_MAX;
>> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
>> index 97adafacd0..076f1b3740 100644
>> --- a/app/test-pmd/testpmd.c
>> +++ b/app/test-pmd/testpmd.c
>> @@ -264,6 +264,9 @@ enum tx_pkt_split tx_pkt_split = TX_PKT_SPLIT_OFF;
>>   uint8_t txonly_multi_flow;
>>   /**< Whether multiple flows are generated in TXONLY mode. */
>> +uint16_t txonly_tso_segsz;
>> +/**< TSO MSS for generated packets in TXONLY mode. */
>> +
>>   uint32_t tx_pkt_times_inter;
>>   /**< Timings for send scheduling in TXONLY mode, time between 
>> bursts. */
>> @@ -1619,6 +1622,15 @@ init_config_port_offloads(portid_t pid, 
>> uint32_t socket_id)
>>           port->dev_conf.txmode.offloads &=
>>               ~RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE;
>> +    if (txonly_tso_segsz > 0) {
>> +        if ((ports[pid].dev_info.tx_offload_capa &
>> +            RTE_ETH_TX_OFFLOAD_TCP_TSO) == 0) {
>> +            rte_exit(EXIT_FAILURE,
>> +                 "TSO isn't supported for port %d\n", pid);
>> +        }
>> +        port->dev_conf.txmode.offloads |= RTE_ETH_TX_OFFLOAD_TCP_TSO;
>> +    }
>> +
>>       /* Apply Rx offloads configuration */
>>       for (i = 0; i < port->dev_info.max_rx_queues; i++)
>>           port->rxq[i].conf.offloads = port->dev_conf.rxmode.offloads;
>> diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
>> index 30915bd84b..bb47bdb490 100644
>> --- a/app/test-pmd/testpmd.h
>> +++ b/app/test-pmd/testpmd.h
>> @@ -605,6 +605,7 @@ enum tx_pkt_split {
>>   extern enum tx_pkt_split tx_pkt_split;
>>   extern uint8_t txonly_multi_flow;
>> +extern uint16_t txonly_tso_segsz;
>>   extern uint32_t rxq_share;
>> diff --git a/app/test-pmd/txonly.c b/app/test-pmd/txonly.c
>> index 44bda752bc..858cc73ab4 100644
>> --- a/app/test-pmd/txonly.c
>> +++ b/app/test-pmd/txonly.c
>> @@ -60,6 +60,7 @@ RTE_DEFINE_PER_LCORE(uint8_t, _ip_var); /**< IP 
>> address variation */
>>   static union pkt_l4_hdr_t {
>>       struct rte_udp_hdr udp;    /**< UDP header of tx packets. */
>> +    struct rte_tcp_hdr tcp; /**< TCP header of tx packets. */
>>   } pkt_l4_hdr; /**< Layer 4 header of tx packets. */
>>   static uint64_t timestamp_mask; /**< Timestamp dynamic flag mask */
>> @@ -112,8 +113,19 @@ setup_pkt_l4_ip_headers(uint8_t ip_proto, struct 
>> rte_ipv4_hdr *ip_hdr,
>>       uint32_t ip_cksum;
>>       uint16_t pkt_len;
>>       struct rte_udp_hdr *udp_hdr;
>> +    struct rte_tcp_hdr *tcp_hdr;
>>       switch (ip_proto) {
>> +    case IPPROTO_TCP:
>> +        /*
>> +         * Initialize TCP header.
>> +         */
>> +        pkt_len = (uint16_t)(pkt_data_len + sizeof(struct rte_tcp_hdr));
>> +        tcp_hdr = &l4_hdr->tcp;
>> +        tcp_hdr->src_port = rte_cpu_to_be_16(tx_l4_src_port);
>> +        tcp_hdr->dst_port = rte_cpu_to_be_16(tx_l4_dst_port);
>> +        tcp_hdr->data_off = (sizeof(struct rte_tcp_hdr) << 2) & 0xF0;
>> +        break;
>>       case IPPROTO_UDP:
>>           /*
>>            * Initialize UDP header.
>> @@ -189,6 +201,8 @@ update_pkt_header(struct rte_mbuf *pkt, uint32_t 
>> total_pkt_len)
>>       ip_hdr->hdr_checksum = rte_ipv4_cksum(ip_hdr);
>>       switch (ip_hdr->next_proto_id) {
>> +    case IPPROTO_TCP:
>> +        break;
> 
> Why packet length is updated for UDP, but not for TCP packets?
> 

There is no length in TCP header.

>>       case IPPROTO_UDP:
>>           /* update UDP packet length */
>>           udp_hdr = rte_pktmbuf_mtod_offset(pkt, struct rte_udp_hdr *,
>> @@ -232,6 +246,12 @@ pkt_burst_prepare(struct rte_mbuf *pkt, struct 
>> rte_mempool *mbp,
>>       pkt->l2_len = sizeof(struct rte_ether_hdr);
>>       pkt->l3_len = sizeof(struct rte_ipv4_hdr);
>> +    if (txonly_tso_segsz > 0) {
>> +        pkt->tso_segsz = txonly_tso_segsz;
>> +        pkt->ol_flags |= RTE_MBUF_F_TX_TCP_SEG | RTE_MBUF_F_TX_IPV4 |
>> +                 RTE_MBUF_F_TX_IP_CKSUM;
>> +    }
>> +
>>       pkt_len = pkt->data_len;
>>       pkt_seg = pkt;
>>       for (i = 1; i < nb_segs; i++) {
>> @@ -267,6 +287,12 @@ pkt_burst_prepare(struct rte_mbuf *pkt, struct 
>> rte_mempool *mbp,
>>           RTE_PER_LCORE(_ip_var) = ip_var;
>>       }
>>       switch (ip_hdr->next_proto_id) {
>> +    case IPPROTO_TCP:
>> +        copy_buf_to_pkt(&pkt_l4_hdr.tcp, sizeof(pkt_l4_hdr.tcp), pkt,
>> +                sizeof(struct rte_ether_hdr) +
>> +                sizeof(struct rte_ipv4_hdr));
>> +        l4_hdr_size = sizeof(pkt_l4_hdr.tcp);
>> +        break;
>>       case IPPROTO_UDP:
>>           copy_buf_to_pkt(&pkt_l4_hdr.udp, sizeof(pkt_l4_hdr.udp), pkt,
>>                   sizeof(struct rte_ether_hdr) +
>> @@ -277,6 +303,7 @@ pkt_burst_prepare(struct rte_mbuf *pkt, struct 
>> rte_mempool *mbp,
>>           l4_hdr_size = 0;
>>           break;
>>       }
>> +    pkt->l4_len = l4_hdr_size;
>>       if (unlikely(tx_pkt_split == TX_PKT_SPLIT_RND) || 
>> txonly_multi_flow)
>>           update_pkt_header(pkt, pkt_len);
>> @@ -459,6 +486,7 @@ tx_only_begin(portid_t pi)
>>   {
>>       uint16_t pkt_hdr_len, pkt_data_len;
>>       int dynf;
>> +    uint8_t ip_proto;
>>       pkt_hdr_len = (uint16_t)(sizeof(struct rte_ether_hdr) +
>>                    sizeof(struct rte_ipv4_hdr) +
>> @@ -474,7 +502,8 @@ tx_only_begin(portid_t pi)
>>           return -EINVAL;
>>       }
>> -    setup_pkt_l4_ip_headers(IPPROTO_UDP, &pkt_ip_hdr, &pkt_l4_hdr,
>> +    ip_proto = txonly_tso_segsz > 0 ? IPPROTO_TCP : IPPROTO_UDP;
>> +    setup_pkt_l4_ip_headers(ip_proto, &pkt_ip_hdr, &pkt_l4_hdr,
>>                   pkt_data_len);
> 
> please check comment in previous patch to have more explict way to 
> detect the protocol type.
> 

Thanks a lot. Will be fixed in v2.

>>       timestamp_enable = false;
>> diff --git a/doc/guides/testpmd_app_ug/run_app.rst 
>> b/doc/guides/testpmd_app_ug/run_app.rst
>> index ed53b4fb1f..b7d1a07346 100644
>> --- a/doc/guides/testpmd_app_ug/run_app.rst
>> +++ b/doc/guides/testpmd_app_ug/run_app.rst
>> @@ -369,6 +369,10 @@ The command line options are:
>>       Generate multiple flows in txonly mode.
>> +*   ``--txonly-tso-mss=N```
>> +
>> +    Enable TSO offload and generate TCP packets with specified MSS in 
>> txonly mode.
>> +
>>   *   ``--rxq-share=[X]``
>>       Create queues in shared Rx queue mode if device supports.
>