Re: [dpdk-dev] [PATCH] net/e1000: fix nic ops function was no initialized in secondary process

[Tengfei Zhang <zypscode@outlook.com>]

On 2021/6/22 上午10:16, Wang, Haiyue wrote:
> From: 张 杨 <zypscode@outlook.com>
> Sent: Monday, June 21, 2021 16:35
> To: Wang, Haiyue <haiyue.wang@intel.com>
> Cc: dev@dpdk.org; Zhang, Qi Z <qi.z.zhang@intel.com>; Lin, Xueqin <xueqin.lin@intel.com>
> Subject: Re: [PATCH] net/e1000: fix nic ops function was no initialized in secondary process
>
> 发件人: Wang, Haiyue <mailto:haiyue.wang@intel.com>
> 发送时间: 2021年6月21日星期一 15:31
> 收件人: Tengfei Zhang
> 抄送: mailto:dev@dpdk.org; Zhang, Qi Z; Lin, Xueqin
> 主题: RE: [PATCH] net/e1000: fix nic ops function was no initialized in secondary process
>
>
>> -----Original Message-----
>> From: Tengfei Zhang <mailto:zypscode@outlook.com>
>> Sent: Saturday, June 19, 2021 01:27
>> To: Wang, Haiyue <mailto:haiyue.wang@intel.com>
>> Cc: mailto:dev@dpdk.org; Tengfei Zhang <mailto:zypscode@outlook.com>
>> Subject: [PATCH] net/e1000: fix nic ops function was no initialized in secondary process
>>
>> 'e1000_setup_init_funcs' was not called in secondary process,
>> it initialize mac,phy,nvm ops.
>> when secondary process get link status,it will coredump.
>> Thanks, Tengfei.
>> Since primary / secondary is so complicated, AFAIK, the control path is in
>> primary, the secondary is mainly for rx/tx ops officially, like new Intel
>> ice PMD:
>>          if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
>>                  ice_set_rx_function(dev);
>>                  ice_set_tx_function(dev);
>>                  return 0;
>>          }
>>
>> So you can keep your patch as private for special secondary usage. ;-)
>> Signed-off-by: Tengfei Zhang <mailto:zypscode@outlook.com>
>> ---
>>    drivers/net/e1000/em_ethdev.c  | 1 +
>>    drivers/net/e1000/igb_ethdev.c | 2 ++
>>    2 files changed, 3 insertions(+)
>>
>> diff --git a/drivers/net/e1000/em_ethdev.c b/drivers/net/e1000/em_ethdev.c
>> index a0ca371b02..cd5faa4228 100644
>> --- a/drivers/net/e1000/em_ethdev.c
>> +++ b/drivers/net/e1000/em_ethdev.c
>> @@ -258,6 +258,7 @@ eth_em_dev_init(struct rte_eth_dev *eth_dev)
>>           * has already done this work. Only check we don't need a different
>>           * RX function */
>>          if (rte_eal_process_type() != RTE_PROC_PRIMARY){
>> +             e1000_setup_init_funcs(hw, TRUE);
>>                  if (eth_dev->data->scattered_rx)
>>                          eth_dev->rx_pkt_burst =
>>                                  (eth_rx_burst_t)&eth_em_recv_scattered_pkts;
>> diff --git a/drivers/net/e1000/igb_ethdev.c b/drivers/net/e1000/igb_ethdev.c
>> index 10ee0f3341..7d9d60497d 100644
>> --- a/drivers/net/e1000/igb_ethdev.c
>> +++ b/drivers/net/e1000/igb_ethdev.c
>> @@ -737,6 +737,7 @@ eth_igb_dev_init(struct rte_eth_dev *eth_dev)
>>           * has already done this work. Only check we don't need a different
>>           * RX function */
>>          if (rte_eal_process_type() != RTE_PROC_PRIMARY){
>> +             e1000_setup_init_funcs(hw, TRUE);
>>                  if (eth_dev->data->scattered_rx)
>>                          eth_dev->rx_pkt_burst = &eth_igb_recv_scattered_pkts;
>>                  return 0;
>> @@ -931,6 +932,7 @@ eth_igbvf_dev_init(struct rte_eth_dev *eth_dev)
>>           * has already done this work. Only check we don't need a different
>>           * RX function */
>>          if (rte_eal_process_type() != RTE_PROC_PRIMARY){
>> +             e1000_setup_init_funcs(hw, TRUE);
>>                  if (eth_dev->data->scattered_rx)
>>                          eth_dev->rx_pkt_burst = &eth_igb_recv_scattered_pkts;
>>                  return 0;
>> --
>> 2.26.2
>
>
>
>> this issue does not appear in  ice, i40e, vmxnet3 PMD drivers. Only in e1000 , ixgbe drivers.
>> Ice  pmd driver gets link status by read reg directly.
> For making primary & secondary working well, these drivers try to avoid save
> the global data and ops function in shared data at the design of beginning.
>
>
>> I agree with what you said "primary, the secondary is mainly for rx/tx ops officially".
>> My opinion is the "set actions" shouldn't called in secondary process, but "get actions" was very common operation, they shouldn't be banned.
> It's not banned, just because e1000's design introduces the global data ops in the
> shared data, which is not good for sharing and accessing, since the address of the
> global data ops is changed in secondary process.
>
> As you can see in " e1000_setup_init_funcs", they not only set function pointers,
> but also call them, not sure this will break other things or not. ;-)
>
>> Thanks for your reply
>
>
I think "get" operation should not crash  in  any  process.

and on different  nics ,  this operation  should  be consistent.


Yes , "e1000_setup_init_funcs" not only set function pointers, this 
patch is not good enough,  just happens to  work.

I look forward to   a better solution