Re: [dpdk-dev] [PATCH v4 02/22] app/testpmd: fix max rx packet length for VLAN packets

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 1/21/2021 3:27 PM, Lance Richardson wrote:
> On Mon, Jan 18, 2021 at 2:08 AM Steve Yang <stevex.yang@intel.com> wrote:
>>
>> When the max rx packet length is smaller than the sum of mtu size and
>> ether overhead size, it should be enlarged, otherwise the VLAN packets
>> will be dropped.
>>
>> Removed the rx_offloads assignment for jumbo frame during command line
>> parsing, and set the correct jumbo frame flag if MTU size is larger than
>> the default value 'RTE_ETHER_MTU' within 'init_config()'.
>>
>> Fixes: 384161e00627 ("app/testpmd: adjust on the fly VLAN configuration")
>> Fixes: 35b2d13fd6fd ("net: add rte prefix to ether defines")
>> Fixes: ce17eddefc20 ("ethdev: introduce Rx queue offloads API")
>> Fixes: 150c9ac2df13 ("app/testpmd: update Rx offload after setting MTU")
>>
>> Cc: Wenzhuo Lu <wenzhuo.lu@intel.com>
>> Cc: Beilei Xing <beilei.xing@intel.com>
>> Cc: Bernard Iremonger <bernard.iremonger@intel.com>
>>
>> Signed-off-by: Steve Yang <stevex.yang@intel.com>
>> ---
>>   app/test-pmd/cmdline.c    |  6 ------
>>   app/test-pmd/config.c     |  2 +-
>>   app/test-pmd/parameters.c |  7 ++-----
>>   app/test-pmd/testpmd.c    | 18 ++++++++++++++++++
>>   4 files changed, 21 insertions(+), 12 deletions(-)
>>
>> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
>> index 2ccbaa039e..65042fcff5 100644
>> --- a/app/test-pmd/cmdline.c
>> +++ b/app/test-pmd/cmdline.c
>> @@ -1886,7 +1886,6 @@ cmd_config_max_pkt_len_parsed(void *parsed_result,
>>
>>          RTE_ETH_FOREACH_DEV(pid) {
>>                  struct rte_port *port = &ports[pid];
>> -               uint64_t rx_offloads = port->dev_conf.rxmode.offloads;
>>
>>                  if (!strcmp(res->name, "max-pkt-len")) {
>>                          if (res->value < RTE_ETHER_MIN_LEN) {
>> @@ -1898,11 +1897,6 @@ cmd_config_max_pkt_len_parsed(void *parsed_result,
>>                                  return;
>>
>>                          port->dev_conf.rxmode.max_rx_pkt_len = res->value;
>> -                       if (res->value > RTE_ETHER_MAX_LEN)
>> -                               rx_offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
>> -                       else
>> -                               rx_offloads &= ~DEV_RX_OFFLOAD_JUMBO_FRAME;
>> -                       port->dev_conf.rxmode.offloads = rx_offloads;
>>                  } else {
>>                          printf("Unknown parameter\n");
>>                          return;
>> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
>> index 3f6c8642b1..1195f054f3 100644
>> --- a/app/test-pmd/config.c
>> +++ b/app/test-pmd/config.c
>> @@ -1434,7 +1434,7 @@ port_mtu_set(portid_t port_id, uint16_t mtu)
>>                   * device supports jumbo frame.
>>                   */
>>                  eth_overhead = dev_info.max_rx_pktlen - dev_info.max_mtu;
>> -               if (mtu > RTE_ETHER_MAX_LEN - eth_overhead) {
>> +               if (mtu > RTE_ETHER_MTU) {
>>                          rte_port->dev_conf.rxmode.offloads |=
>>                                                  DEV_RX_OFFLOAD_JUMBO_FRAME;
>>                          rte_port->dev_conf.rxmode.max_rx_pkt_len =
>> diff --git a/app/test-pmd/parameters.c b/app/test-pmd/parameters.c
>> index 414a0068fb..df5eb10d84 100644
>> --- a/app/test-pmd/parameters.c
>> +++ b/app/test-pmd/parameters.c
>> @@ -834,12 +834,9 @@ launch_args_parse(int argc, char** argv)
>>                          }
>>                          if (!strcmp(lgopts[opt_idx].name, "max-pkt-len")) {
>>                                  n = atoi(optarg);
>> -                               if (n >= RTE_ETHER_MIN_LEN) {
>> +                               if (n >= RTE_ETHER_MIN_LEN)
>>                                          rx_mode.max_rx_pkt_len = (uint32_t) n;
>> -                                       if (n > RTE_ETHER_MAX_LEN)
>> -                                               rx_offloads |=
>> -                                                       DEV_RX_OFFLOAD_JUMBO_FRAME;
>> -                               } else
>> +                               else
>>                                          rte_exit(EXIT_FAILURE,
>>                                                   "Invalid max-pkt-len=%d - should be > %d\n",
>>                                                   n, RTE_ETHER_MIN_LEN);
>> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
>> index 2b60f6c5d3..c256e719ae 100644
>> --- a/app/test-pmd/testpmd.c
>> +++ b/app/test-pmd/testpmd.c
>> @@ -1410,6 +1410,7 @@ init_config(void)
>>          struct rte_gro_param gro_param;
>>          uint32_t gso_types;
>>          uint16_t data_size;
>> +       uint16_t eth_overhead;
>>          bool warning = 0;
>>          int k;
>>          int ret;
>> @@ -1446,6 +1447,23 @@ init_config(void)
>>                          rte_exit(EXIT_FAILURE,
>>                                   "rte_eth_dev_info_get() failed\n");
>>
>> +               /* Update the max_rx_pkt_len to have MTU as RTE_ETHER_MTU */
>> +               if (port->dev_info.max_mtu != UINT16_MAX &&
>> +                   port->dev_info.max_rx_pktlen > port->dev_info.max_mtu)
>> +                       eth_overhead = port->dev_info.max_rx_pktlen -
>> +                               port->dev_info.max_mtu;
>> +               else
>> +                       eth_overhead =
>> +                               RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN;
>> +
>> +               if (port->dev_conf.rxmode.max_rx_pkt_len <=
>> +                       (uint32_t)(RTE_ETHER_MTU + eth_overhead))
>> +                       port->dev_conf.rxmode.max_rx_pkt_len =
>> +                                       RTE_ETHER_MTU + eth_overhead;
>> +               else
>> +                       port->dev_conf.rxmode.offloads |=
>> +                                       DEV_RX_OFFLOAD_JUMBO_FRAME;
>> +
>>                  if (!(port->dev_info.tx_offload_capa &
>>                        DEV_TX_OFFLOAD_MBUF_FAST_FREE))
>>                          port->dev_conf.txmode.offloads &=
>> --
>> 2.17.1
>>
> 
> Moving the setting of DEV_RX_OFFLOAD_JUMBO_FRAME from
> cmd_config_max_pkt_len_parsed() to init_config() doesn't seem to
> be correct for the case where max_rx_pkt_len is changed from the
> command line via "port config all max-pkt-len".
> 
> The init_config() function is only called when testpmd is started,
> but the DEV_RX_OFFLOAD_JUMBO_FRAME setting needs to
> be recomputed whenever max_rx_pkt_len changes.
> 

Hi Lance,

You are right, there is a patch trying to fix the command, can you please review it?
https://patches.dpdk.org/project/dpdk/list/?series=14925


> (Of course this won't matter when DEV_RX_OFFLOAD_JUMBO_FRAME
> is removed, which seems like a great idea, but for now this is impacting
> some test automation with 21.02-rc1.)
>