Re: [PATCH] net/tap: do not include l2 header in gso size when compared with mtu

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

On 3/8/2022 2:35 PM, Harold Huang wrote:
> On Mon, Feb 28, 2022 at 4:27 PM Harold Huang <baymaxhuang@gmail.com> wrote:
>>
>> The gso size is calculated with all of the headers and payload. As a
>> result, the l2 header should not be included when comparing gso size
>> with mtu.
>>
>> Fixes: 050316a88313 ("net/tap: support TSO (TCP Segment Offload)")
>> Cc: stable@dpdk.org
>> Signed-off-by: Harold Huang <baymaxhuang@gmail.com>
>> ---
>>   drivers/net/tap/rte_eth_tap.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
>> index f1b48cae82..2b561d232c 100644
>> --- a/drivers/net/tap/rte_eth_tap.c
>> +++ b/drivers/net/tap/rte_eth_tap.c
>> @@ -731,7 +731,7 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
>>                                          mbuf_in->l4_len;
>>                          tso_segsz = mbuf_in->tso_segsz + hdrs_len;
>>                          if (unlikely(tso_segsz == hdrs_len) ||
>> -                               tso_segsz > *txq->mtu) {
>> +                               tso_segsz > *txq->mtu + mbuf_in->l2_len) {
>>                                  txq->stats.errs++;
>>                                  break;
>>                          }
>> --
>> 2.27.0
>>
> 
> Hi, Jiayu,
> 
> This is the only example in the driver to use GSO. I think it is
> important for us to calculate a correct GSO size. I see you are the
> GSO lib maintainer, could you please help review this patch?


Hi Jiayu, Ophir,

Can you please review this patch?

For reference, patchwork link:
https://patches.dpdk.org/project/dpdk/patch/20220228082724.1646930-1-baymaxhuang@gmail.com/

Thanks,
ferruh