[dpdk-stable] [PATCH v5] app/testpmd: fix setting maximum packet length

[Wisam Monther]

Hi Ferruh,


> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit at intel.com>
> Sent: Monday, January 25, 2021 8:16 PM
> To: Wenzhuo Lu <wenzhuo.lu at intel.com>; Xiaoyun Li
> <xiaoyun.li at intel.com>; Bernard Iremonger
> <bernard.iremonger at intel.com>; Steve Yang <stevex.yang at intel.com>
> Cc: Ferruh Yigit <ferruh.yigit at intel.com>; dev at dpdk.org; stable at dpdk.org;
> lance.richardson at broadcom.com; oulijun at huawei.com; Wisam Monther
> <wisamm at nvidia.com>; lihuisong at huawei.com
> Subject: [PATCH v5] app/testpmd: fix setting maximum packet length
> 
> From: Steve Yang <stevex.yang at intel.com>
> 
> "port config all max-pkt-len" command fails because it doesn't set the
> 'DEV_RX_OFFLOAD_JUMBO_FRAME' offload flag properly.
> 
> Commit in the fixes line moved the 'DEV_RX_OFFLOAD_JUMBO_FRAME'
> offload flag update from 'cmd_config_max_pkt_len_parsed()' to
> 'init_config()'.
> 'init_config()' function is only called during testpmd startup, but the flag
> status needs to be calculated whenever 'max_rx_pkt_len' changes.
> 
> The issue can be reproduce as [1], where the 'max-pkt-len' reduced and
> 'DEV_RX_OFFLOAD_JUMBO_FRAME' offload flag should be cleared but it
> didn't.
> 
> Adding the 'update_jumbo_frame_offload()' helper function to update
> 'DEV_RX_OFFLOAD_JUMBO_FRAME' offload flag and 'max_rx_pkt_len'. This
> function is called both by 'init_config()' and
> 'cmd_config_max_pkt_len_parsed()'.
> 
> Default 'max-pkt-len' value set to zero, 'update_jumbo_frame_offload()'
> updates it to "RTE_ETHER_MTU + PMD specific Ethernet overhead" when it is
> zero.
> If '--max-pkt-len=N' argument provided, it will be used instead.
> And with each "port config all max-pkt-len" command, the
> 'DEV_RX_OFFLOAD_JUMBO_FRAME' offload flag, 'max-pkt-len' and MTU is
> updated.
> 
> [1]
> --------------------------------------------------------------------------
> dpdk-testpmd -c 0xf -n 4 -- -i --max-pkt-len=9000 --tx-offloads=0x8000
> 	--rxq=4 --txq=4 --disable-rss
> testpmd>  set verbose 3
> testpmd>  port stop all
> testpmd>  port config all max-pkt-len 1518  port start all
> 
> // Got fail error info without this patch Configuring Port 0 (socket 1) Ethdev
> port_id=0 rx_queue_id=0, new added offloads 0x800 must be within per-
> queue offload capabilities 0x0 in rte_eth_rx_queue_setup() Fail to configure
> port 0 rx queues //<-- Fail error info;
> --------------------------------------------------------------------------
> 
> Fixes: 761c4d66900f ("app/testpmd: fix max Rx packet length for VLAN
> packets")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Steve Yang <stevex.yang at intel.com>
> Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
> ---
> 
> v5:
> * 'update_jumbo_frame_offload()' helper updated
>   * check zero 'max-pkt-len' value
>   * Update how queue offload flags updated
>   * Update MTU if JUMBO_FRAME flag is not set
> * Default testpmd 'max-pkt-len' value set to zero
> 
> Cc: lance.richardson at broadcom.com
> Cc: oulijun at huawei.com
> Cc: wisamm at mellanox.com
> Cc: lihuisong at huawei.com
> ---

I think we need to have https://bugs.dpdk.org/show_bug.cgi?id=625 ID in the commit log as fix,
In order to allow the scripts to close related bugs directly from Bugzilla.

BRs,
Wisam Jaddo