Re: [dpdk-dev] [PATCH v3 1/8] app/testpmd: store VXLAN/NVGRE encap data globally

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

On 4/7/2021 9:35 AM, Salem Sol wrote:
> 
> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Wednesday, April 7, 2021 11:24 AM
> To: Salem Sol <salems@nvidia.com>; Jiawei(Jonny) Wang <jiaweiw@nvidia.com>; dev@dpdk.org
> Cc: Ori Kam <orika@nvidia.com>; Xiaoyun Li <xiaoyun.li@intel.com>
> Subject: Re: [dpdk-dev] [PATCH v3 1/8] app/testpmd: store VXLAN/NVGRE encap data globally
> 
> External email: Use caution opening links or attachments
> 
> 
> On 4/7/2021 9:19 AM, Salem Sol wrote:
>> Hi Ferruh,
>>
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>> Sent: Tuesday, April 6, 2021 5:44 PM
>> To: Jiawei(Jonny) Wang <jiaweiw@nvidia.com>; Salem Sol
>> <salems@nvidia.com>; dev@dpdk.org
>> Cc: Ori Kam <orika@nvidia.com>; Xiaoyun Li <xiaoyun.li@intel.com>
>> Subject: Re: [dpdk-dev] [PATCH v3 1/8] app/testpmd: store VXLAN/NVGRE
>> encap data globally
>>
>> External email: Use caution opening links or attachments
>>
>>
>> On 4/1/2021 5:13 AM, Jiawei(Jonny) Wang wrote:
>>> Hello Ferruh,
>>>
>>>> -----Original Message-----
>>>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>>>> Sent: Wednesday, March 31, 2021 8:08 PM
>>>> To: Salem Sol <salems@nvidia.com>; dev@dpdk.org
>>>> Cc: Jiawei(Jonny) Wang <jiaweiw@nvidia.com>; Ori Kam
>>>> <orika@nvidia.com>; Xiaoyun Li <xiaoyun.li@intel.com>
>>>> Subject: Re: [dpdk-dev] [PATCH v3 1/8] app/testpmd: store
>>>> VXLAN/NVGRE encap data globally
>>>>
>>>> On 3/17/2021 9:26 AM, Salem Sol wrote:
>>>>> From: Jiawei Wang <jiaweiw@nvidia.com>
>>>>>
>>>>> With the current code the VXLAN/NVGRE parsing routine stored the
>>>>> configuration of the header on stack, this might lead to
>>>>> overwriting the data on the stack.
>>>>>
>>>>> This patch stores the external data of vxlan and nvgre encap into
>>>>> global data as a pre-step to supporting vxlan and nvgre encap as a
>>>>> sample actions.
>>>>>
>>>>
>>>> I didn't get what was on stack and moved in to the global data, can
>>>> you please elaborate.
>>>>
>>>
>>> This patch split the function and saved input data into input parameter:
>>> So it mentioned here "pre-step" for next store the data of vxlan/nvgre into global.
>>>
>>> The global var for sample action is defined in:
>>> (https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpa
>>> t
>>> ches.dpdk.org%2Fproject%2Fdpdk%2Fpatch%2F20210317092610.71000-5-salem
>>> s
>>> %40nvidia.com%2F&amp;data=04%7C01%7Csalems%40nvidia.com%7Cd9baadbc48f
>>> c
>>> 44caf4fc08d8f90a7553%7C43083d15727340c1b7db39efd9ccc17a%7C0%7C0%7C637
>>> 5
>>> 33170601193210%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2
>>> l
>>> uMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=olwLyRnHnM7TyKDF
>>> I
>>> xVH3Dj6KhWtUzdXgAyGgON4M9M%3D&amp;reserved=0)
>>> struct action_vxlan_encap_data
>>> sample_vxlan_encap[RAW_SAMPLE_CONFS_MAX_NUM];
>>>
>>
>> Commit log says:
>>
>> "
>> This patch stores the external data of vxlan and nvgre encap into global data as a pre-step to supporting vxlan and nvgre encap as a sample actions.
>> "
>>
>> It says this patch does storing into the global data, but as far as I can see from code and above description, this patch is just preparation for it.
>> I can see there is a new version which has same commit log, can you please update it in new version?
>>
>> I will update in the next series.
>>
>>>> For example for nvgre, 'action_nvgre_encap_data' is pointer in stack
>>>> but the actual object is 'ctx->object', so it is not really in the stack.
>>>>
>>>
>>> After call 'set sample 0 nvgre .. ', the data be stored into
>>> 'ctx->object', the 'ctx->object' will be reused for the following CLI
>>> command, After that, while we try to use previous 'sample action' to fetch nvgre data, these data may be lost.
>>>
>>> For sample action, use global data can save the previous nvgre configurations data.
>>>
>>
>> Got it, the target is to use "set sample_actions ..." testpmd command to store vxlan/nvgre encap sample actions.
>> For record, can you please document what was the way to the same before this support, can you please document the old testpmd command.
>>
>> Can you please elaborate regarding where did you want this documentation?
>> Prior to this support it is already documented, in
>> http://patches.dpdk.org/project/dpdk/patch/1617244796-358287-1-git-sen
>> d-email-jiaweiw@nvidia.com/
>> With the "raw_encap"
>>
> 
>> I was just thinking putting it in the commit log, for reference. To record how it was previously done.
> 
> Does this seem acceptable?
> " app/testpmd: prepare storing VXLAN/NVGRE encap data globally
>   
>   With the current code the VXLAN/NVGRE parsing routine
>   stored the configuration of the header on stack, this
>   might lead to overwriting the data on the stack.
>   
>   Currently having VXLAN/NVGRE encap as sample actions
>   is done using RAW_ENCAP, for example:
>   1. set raw_encap 1 eth src.../ vxlan vni.../ ipv4.../ ...
>      set sample_actions 0 raw_encap / port_id id 0 / end
>      flow create 0 ... pattern eth / end actions
>         sample ration 1 index 0 / jump group 1 / end
>   
>   The goal is to utilize the rte_flow_action_vxlan_encap
>   and rte_flow_action_nvgre_encap for sample actions.
>   
>   This patch prepares storing the external data of vxlan and
>   nvgre encap into global data as a pre-step to supporting
>   vxlan and nvgre encap as a sample actions."
> 

Sounds good, thank you.

>>>> Tough, OK to refactor and split the function as preparation to
>>>> support the sample action.
>>>>
>>>>> Signed-off-by: Jiawei Wang <jiaweiw@nvidia.com>
>>>>
>>>> <...>
>>>>
>>>>> -/** Parse VXLAN encap action. */
>>>>> +/** Setup VXLAN encap configuration. */
>>>>>      static int
>>>>> -parse_vc_action_vxlan_encap(struct context *ctx, const struct
>>>>> token
>>>> *token,
>>>>> -                       const char *str, unsigned int len,
>>>>> -                       void *buf, unsigned int size)
>>>>> +parse_setup_vxlan_encap_data
>>>>> +           (struct action_vxlan_encap_data
>>>>> +*action_vxlan_encap_data)
>>>>
>>>> Can you please fix the syntax, I guess this is done to keep within
>>>> in
>>>> 80 column limit, but from readability perspective I think better to
>>>> go over the 80 column a little instead of breaking the line like this.
>>>>
>>>
>>> Ok, will change into one line.
>>>
>>>> <...>
>>>>
>>>>> +/** Setup NVGRE encap configuration. */ static int
>>>>> +parse_setup_nvgre_encap_data
>>>>> +           (struct action_nvgre_encap_data
>>>>> +*action_nvgre_encap_data)
>>>> {
>>>>> +   if (!action_nvgre_encap_data)
>>>>> +           return -1;
>>>>
>>>> This is a static function, and the input of it is in our control, so
>>>> not sure if we should verify the input here.
>>>> But if we need to, can you please check the return value of this
>>>> function where it is called.
>>>
>>> I agree with you that can remove this checking inside, since we make sure it's valid before call.
>>>
>>> Thanks.
>>>
>>
>