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

[Salem Sol <salems@nvidia.com>]

-----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."

>>> 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.
>>
>