[dpdk-dev] [PATCH v4 3/3] app/testpmd: fix Tx offload on tunneling packet

[Tan, Jianfeng]

Hi Konstantin,


On 9/21/2016 11:47 PM, Ananyev, Konstantin wrote:
> Hi Jianfeng,
>
>> Hi Konstantin,
>>
>>
>> On 9/19/2016 8:09 PM, Ananyev, Konstantin wrote:
>>> Hi Jainfeng,
>>>
>>>> -----Original Message-----
>>>> From: Tan, Jianfeng
>>>> Sent: Monday, August 1, 2016 4:57 AM
>>>> To: dev at dpdk.org
>>>> Cc: thomas.monjalon at 6wind.com; De Lara Guarch, Pablo
>>>> <pablo.de.lara.guarch at intel.com>; Ananyev, Konstantin
>>>> <konstantin.ananyev at intel.com>; Wu, Jingjing <jingjing.wu at intel.com>;
>>>> Zhang, Helin <helin.zhang at intel.com>; Tan, Jianfeng
>>>> <jianfeng.tan at intel.com>; Tao, Zhe <zhe.tao at intel.com>
>>>> Subject: [PATCH v4 3/3] app/testpmd: fix Tx offload on tunneling
>>>> packet
>>>>
>>>> Tx offload on tunneling packet now requires applications to correctly
>>>> set tunneling type. Without setting it, i40e driver does not parse
>>>> tunneling parameters. Besides that, add a check to see if NIC supports TSO on tunneling packet when executing "csum
>> parse_tunnel on _port"
>>>> after "tso set _size _port" or the other way around.
>>>>
>>>> Fixes: b51c47536a9e ("app/testpmd: support TSO in checksum forward
>>>> engine")
>>>>
>>>> Signed-off-by: Zhe Tao <zhe.tao at intel.com>
>>>> Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
>>>> ---
>>>>    app/test-pmd/cmdline.c  | 42 ++++++++++++++++++++++++++++++++++++------
>>>>    app/test-pmd/csumonly.c | 37 +++++++++++++++++++++++++++++--------
>>>>    2 files changed, 65 insertions(+), 14 deletions(-)
>>>>
>>>> [...]
>>>>
>>>> @@ -745,7 +762,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
>>>>    		 * processed in hardware. */
>>>>    		if (info.is_tunnel == 1) {
>>>>    			ol_flags |= process_outer_cksums(outer_l3_hdr, &info,
>>>> -				testpmd_ol_flags);
>>>> +				testpmd_ol_flags, ol_flags & PKT_TX_TCP_SEG);
>>>>    		}
>>>>
>>>>    		/* step 4: fill the mbuf meta data (flags and header lengths) */
>>>> @@ -806,6 +823,10 @@
>>> It was a while since I looked a t it closely, but shouldn't you also update step 4 below:
>>>
>>> if (info.is_tunnel == 1) {
>>>                           if (testpmd_ol_flags & TESTPMD_TX_OFFLOAD_OUTER_IP_CKSUM) {
>>>                                   m->outer_l2_len = info.outer_l2_len;
>>>                                   m->outer_l3_len = info.outer_l3_len;
>>>                                   m->l2_len = info.l2_len;
>>>                                   m->l3_len = info.l3_len;
>>>                                   m->l4_len = info.l4_len;
>>>                           }
>>>                           else {
>>>                                   /* if there is a outer UDP cksum
>>>                                      processed in sw and the inner in hw,
>>>                                      the outer checksum will be wrong as
>>>                                      the payload will be modified by the
>>>                                      hardware */
>>>                                   m->l2_len = info.outer_l2_len +
>>>                                           info.outer_l3_len + info.l2_len;
>>>                                   m->l3_len = info.l3_len;
>>>                                   m->l4_len = info.l4_len;
>>>                           }
>>>
>>>
>>> ?
>>>
>>> In particular shouldn't it be something like:
>>> if ((testpmd_ol_flags & TESTPMD_TX_OFFLOAD_OUTER_IP_CKSUM) != 0 ||
>>>         ((testmpd_ol_flags & TESTPMD_TX_OFFLOAD_PARSE_TUNNEL) != 0 &&
>>> info.tso_segsz != 0)) { ....
>>> ?
>> Sorry for late response, because I also take some time to refresh memory. And, you are right, I missed this corner case. After applying
>> your way above, it works!
>>
>> The case below settings in testpmd:
>> $ set fwd csum
>> $ csum parse_tunnel on 0
>> $ tso set 800 0
>> <keep outer-ip checksum offload is sw>
> Great :)
>
>> And unfortunately, our previous verification is based on "outer-ip checksum offload is hw".
>>
>>> Another thought, might be it is worth to introduce new flag:
>>> TESTPMD_TX_OFFLOAD_TSO_TUNNEL, and new command in cmdline.c, that would set/clear that flag.
>>> Instead of trying to make assumptions does user wants tso for tunneled
>>> packets based on 2 different things:
>>> - enable/disable tso
>>> - enable/disable tunneled packets parsing ?
>> Currently, if we do parse_tunnel is based on the command "csum parse_tunnel on/off <port>".
>> If we add a command like "tso_tunnel set <length> <port>", it's a little duplicated with "tso set <length> <port>", and there is too
>> much info to just set a flag like TESTPMD_TX_OFFLOAD_TSO_TUNNEL; If we add a command like "csum tunnel_tso on <port>", it also
>> depends on "csum parse_tunnel on <port>" so that tunnel packets are parsed.
> But I thought in some cases user might want to enable tunnel parsing, but do tso for non-tunneled packets only.
> I.E.
>   - enable tunnel parsing
> - for non-tunneled packets do tso
> - for tunneled packets don't do tso
> My understanding that with current set commands/flags this is not possible, correct?
> Konstantin

Yes, correct, above case is not supported now. A twin case would be:
- for non-tunneled packets, don't do tso
- for tunneled packets, do tso

Considering above two cases, so how about adding a command like;
$ tunnel_tso set 800 0
which needs "csum parse_tunnel on 0" has been set before it.

And original "tso set 800 0" will only control tso of non-tunneled packets.
?


Thanks,
Jianfeng