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From: Andrew Rybchenko <arybchenko@solarflare.com>
To: Gregory Etelson <getelson@nvidia.com>,
	Ajit Khaparde <ajit.khaparde@broadcom.com>
Cc: dpdk-dev <dev@dpdk.org>, Matan Azrad <matan@nvidia.com>,
	Raslan Darawsheh <rasland@nvidia.com>, Ori Kam <orika@nvidia.com>,
	Ori Kam <orika@mellanox.com>,
	NBU-Contact-Thomas Monjalon <thomas@monjalon.net>,
	Ferruh Yigit <ferruh.yigit@intel.com>
Subject: Re: [dpdk-dev] [PATCH v2 1/4] ethdev: allow negative values in flow rule types
Date: Thu, 17 Sep 2020 18:18:01 +0300
Message-ID: <0e19026c-db3d-9896-7b73-3efb39d1107b@solarflare.com> (raw)
In-Reply-To: <BY5PR12MB36684CE3AD488A77B631884EA53E0@BY5PR12MB3668.namprd12.prod.outlook.com>

On 9/17/20 10:56 AM, Gregory Etelson wrote:
>> On 9/16/20 8:21 PM, Gregory Etelson wrote:
>>> From: Gregory Etelson
>>> Sent: Tuesday, September 15, 2020 13:27
>>> To: Andrew Rybchenko <arybchenko@solarflare.com>; Ajit Khaparde
>>> <ajit.khaparde@broadcom.com>
>>> Cc: dpdk-dev <dev@dpdk.org>; Matan Azrad <matan@nvidia.com>; Raslan
>>> Darawsheh <rasland@nvidia.com>; Ori Kam <orika@nvidia.com>; Gregory
>>> Etelson <getelson@mellanox.com>; Ori Kam <orika@mellanox.com>;
>>> NBU-Contact-Thomas Monjalon <thomas@monjalon.net>; Ferruh Yigit
>>> <ferruh.yigit@intel.com>
>>> Subject: RE: [dpdk-dev] [PATCH v2 1/4] ethdev: allow negative values
>>> in flow rule types
>>>
>>> Subject: Re: [dpdk-dev] [PATCH v2 1/4] ethdev: allow negative values
>>> in flow rule types On 9/15/20 7:36 AM, Ajit Khaparde wrote:
>>> On Tue, Sep 8, 2020 at 1:16 PM Gregory Etelson
>> <mailto:getelson@nvidia.com> wrote:
>>> From: Gregory Etelson <mailto:getelson@mellanox.com>
>>>
>>> RTE flow items & actions use positive values in item & action type.
>>> Negative values are reserved for PMD private types. PMD items &
>>> actions usually are not exposed to application and are not used to
>>> create RTE flows.
>>>
>>> The patch allows applications with access to PMD flow items & actions
>>> ability to integrate RTE and PMD items & actions and use them to
>>> create flow rule.
>>> While we are reviewing this, some quick comment/questions..
>>>
>>> Doesn't this go against the above "PMD items & actions usually are not
>>> exposed to application and are not used to create RTE flows."?
>>> Why would an application try to use PMD specific private types?
>>> Isn't this contrary to having a standard API?
>>>
>>> +1
>>>
>>> I would like to clarify the purpose and use of private elements patch.
>>> That patch is prerequisite for  [PATCH v2 2/4] ethdev: tunnel offload model
>> patch.
>>> The tunnel offload API provides unified hardware independent model to
>>> offload tunneled packets, match on packet headers in hardware and to
>> restore outer headers of partially offloaded packets.
>>> The model implementation depends on hardware capabilities. For
>>> example,  if hardware supports inner nat, it can do nat first and
>>> postpone decap to the end, while other hardware that cannot do inner
>>> nat must decap first and run nat actions afterwards. Such hardware has
>>> to save outer header in some hardware context, register or memory, for
>> application to restore a packet later, if needed. Also, in this case the exact
>> solution depends on PMD because of limited number of hardware contexts.
>>> Although application working with DKDK can implement all these
>>> requirements with existing flow rules API, it will have to address each
>> hardware specifications separately.
>>> To solve this limitation we selected design where application quires
>>> PMD for actions, or items, that are optimal for a hardware that PMD
>>> represents. Result can be a mixture of RTE and PMD private elements -
>>> it's up to PMD implementation. Application passes these elements back to
>> PMD as a flow rule recipe that's already optimal for underlying hardware.
>>> If PMD has private elements in such rule items or actions, these private
>> elements must not be rejected by RTE layer.
>>>
>>> I hope it helps to understand what this model is trying to achieve.
>>> Did that clarify your concerns ?
>>
>> There is a very simple question which I can't answer after reading it.
>> Why these PMD specific actions and items do not bind application to a
>> specific vendor. If it binds, it should be clearly stated in the description. If no,
>> I'd like to understand why since opaque actions/items are not really well
>> defined and hardly portable across vendors.
> 
> Tunnel Offload API does not bind application to a vendor.
> One of the main goals of that model is to provide application with vendor/hardware independent solution.
> PMD transfer to application an array of items. Application passes that array back to PMD as opaque data,
> in rte_flow_create(), without reviewing the array content. Therefore, if there are internal PMD actions in the array,
> they have no effect on application.
> Consider the following application code example:
> 
> /* get PMD actions that implement tunnel offload */
> rte_tunnel_decap_set(&tunnel, &pmd_actions, pmd_actions_num, error);
> 
> /* compile an array of actions to create flow rule */
> memcpy(actions, pmd_actions,  pmd_actions_num * sizeof(actions[0]));
> memcpy(actions + pmd_actions_num, app_actions, app_actions_num * sizeof(actions[0]));
> 
> /* create flow rule*/
> rte_flow_create(port_id, attr, pattern, actions, error);
> 
> vendor A provides pmd_actions_A = {va1, va2 …. vaN}
> vendor B provides pmd_actions_B = {vb1}
> Regardless of pmd_actions content, application code will not change.
> However, each PMD will receive exact, hardware related, actions for tunnel offload.
> 

Many thanks for explanations. I got it. I'll wait for the next version
to take a look at code once again.

  reply index

Thread overview: 90+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-25 16:03 [dpdk-dev] [PATCH 0/2] ethdev: tunnel offload model Gregory Etelson
2020-06-25 16:03 ` [dpdk-dev] [PATCH 1/2] ethdev: allow negative values in flow rule types Gregory Etelson
2020-07-05 13:34   ` Andrew Rybchenko
2020-08-19 14:33     ` Gregory Etelson
2020-06-25 16:03 ` [dpdk-dev] [PATCH 2/2] ethdev: tunnel offload model Gregory Etelson
     [not found]   ` <DB8PR05MB6761ED02BCD188771BDCDE64A86F0@DB8PR05MB6761.eurprd05.prod.outlook.com>
     [not found]     ` <38d3513f-1261-0fbc-7c56-f83ced61f97a@ashroe.eu>
2020-07-01  6:52       ` Gregory Etelson
2020-07-13  8:21         ` Thomas Monjalon
2020-07-13 13:23           ` Gregory Etelson
2020-07-05 14:50   ` Andrew Rybchenko
2020-08-19 14:30     ` Gregory Etelson
2020-07-05 13:39 ` [dpdk-dev] [PATCH 0/2] " Andrew Rybchenko
2020-09-08 20:15 ` [dpdk-dev] [PATCH v2 0/4] Tunnel Offload API Gregory Etelson
2020-09-08 20:15   ` [dpdk-dev] [PATCH v2 1/4] ethdev: allow negative values in flow rule types Gregory Etelson
2020-09-15  4:36     ` Ajit Khaparde
2020-09-15  8:46       ` Andrew Rybchenko
2020-09-15 10:27         ` Gregory Etelson
2020-09-16 17:21           ` Gregory Etelson
2020-09-17  6:49             ` Andrew Rybchenko
2020-09-17  7:47               ` Ori Kam
2020-09-17 15:15                 ` Andrew Rybchenko
2020-09-17  7:56               ` Gregory Etelson
2020-09-17 15:18                 ` Andrew Rybchenko [this message]
2020-09-15  8:45     ` Andrew Rybchenko
2020-09-15 16:17       ` Gregory Etelson
2020-09-08 20:15   ` [dpdk-dev] [PATCH v2 2/4] ethdev: tunnel offload model Gregory Etelson
2020-09-08 20:15   ` [dpdk-dev] [PATCH v2 3/4] net/mlx5: implement tunnel offload API Gregory Etelson
2020-09-08 20:15   ` [dpdk-dev] [PATCH v2 4/4] app/testpmd: support " Gregory Etelson
2020-09-15  4:47     ` Ajit Khaparde
2020-09-15 10:44       ` Gregory Etelson
2020-09-30  9:18 ` [dpdk-dev] [PATCH v3 0/4] Tunnel Offload API Gregory Etelson
2020-09-30  9:18   ` [dpdk-dev] [PATCH v3 1/4] ethdev: allow negative values in flow rule types Gregory Etelson
2020-10-04  5:40     ` Ajit Khaparde
2020-10-04  9:24       ` Gregory Etelson
2020-09-30  9:18   ` [dpdk-dev] [PATCH v3 2/4] ethdev: tunnel offload model Gregory Etelson
2020-09-30  9:18   ` [dpdk-dev] [PATCH v3 3/4] net/mlx5: implement tunnel offload API Gregory Etelson
2020-09-30  9:18   ` [dpdk-dev] [PATCH v3 4/4] app/testpmd: add commands for " Gregory Etelson
2020-10-01  5:32     ` Ajit Khaparde
2020-10-01  9:05       ` Gregory Etelson
2020-10-04  5:40         ` Ajit Khaparde
2020-10-04  9:29           ` Gregory Etelson
2020-10-04 13:50 ` [dpdk-dev] [PATCH v4 0/4] Tunnel Offload API Gregory Etelson
2020-10-04 13:50   ` [dpdk-dev] [PATCH v4 1/4] ethdev: allow negative values in flow rule types Gregory Etelson
2020-10-14 23:40     ` Thomas Monjalon
2020-10-04 13:50   ` [dpdk-dev] [PATCH v4 2/4] ethdev: tunnel offload model Gregory Etelson
2020-10-06  9:47     ` Sriharsha Basavapatna
2020-10-07 12:36       ` Gregory Etelson
2020-10-14 17:23         ` Ferruh Yigit
2020-10-16  9:15           ` Gregory Etelson
2020-10-14 23:55     ` Thomas Monjalon
2020-10-04 13:50   ` [dpdk-dev] [PATCH v4 3/4] net/mlx5: implement tunnel offload API Gregory Etelson
2020-10-04 13:50   ` [dpdk-dev] [PATCH v4 4/4] app/testpmd: add commands for " Gregory Etelson
2020-10-04 13:59     ` Ori Kam
2020-10-14 17:25   ` [dpdk-dev] [PATCH v4 0/4] Tunnel Offload API Ferruh Yigit
2020-10-15 12:41 ` [dpdk-dev] [PATCH v5 0/3] " Gregory Etelson
2020-10-15 12:41   ` [dpdk-dev] [PATCH v5 1/3] ethdev: allow negative values in flow rule types Gregory Etelson
2020-10-15 12:41   ` [dpdk-dev] [PATCH v5 2/3] ethdev: tunnel offload model Gregory Etelson
2020-10-15 12:41   ` [dpdk-dev] [PATCH v5 3/3] app/testpmd: add commands for tunnel offload API Gregory Etelson
2020-10-15 22:47   ` [dpdk-dev] [PATCH v5 0/3] Tunnel Offload API Ferruh Yigit
2020-10-16  8:55 ` [dpdk-dev] [PATCH v6 " Gregory Etelson
2020-10-16  8:55   ` [dpdk-dev] [PATCH v6 1/3] ethdev: allow negative values in flow rule types Gregory Etelson
2020-10-16  8:55   ` [dpdk-dev] [PATCH v6 2/3] ethdev: tunnel offload model Gregory Etelson
2020-10-16  8:55   ` [dpdk-dev] [PATCH v6 3/3] app/testpmd: add commands for tunnel offload API Gregory Etelson
2020-10-16 10:33 ` [dpdk-dev] [PATCH v7 0/3] Tunnel Offload API Gregory Etelson
2020-10-16 10:33   ` [dpdk-dev] [PATCH v7 1/3] ethdev: allow negative values in flow rule types Gregory Etelson
2020-10-16 10:33   ` [dpdk-dev] [PATCH v7 2/3] ethdev: tunnel offload model Gregory Etelson
2020-10-16 10:34   ` [dpdk-dev] [PATCH v7 3/3] app/testpmd: add commands for tunnel offload API Gregory Etelson
2020-10-16 12:10   ` [dpdk-dev] [PATCH v7 0/3] Tunnel Offload API Ferruh Yigit
2020-10-16 12:51 ` [dpdk-dev] [PATCH v8 " Gregory Etelson
2020-10-16 12:51   ` [dpdk-dev] [PATCH v8 1/3] ethdev: allow negative values in flow rule types Gregory Etelson
2020-10-16 12:51   ` [dpdk-dev] [PATCH v8 2/3] ethdev: tunnel offload model Gregory Etelson
2020-10-16 15:41     ` Kinsella, Ray
2020-10-16 12:51   ` [dpdk-dev] [PATCH v8 3/3] app/testpmd: add commands for tunnel offload API Gregory Etelson
2020-10-16 13:19   ` [dpdk-dev] [PATCH v8 0/3] Tunnel Offload API Ferruh Yigit
2020-10-16 14:20     ` Ferruh Yigit
2020-10-18 12:15 ` [dpdk-dev] [PATCH] ethdev: rename tunnel offload callbacks Gregory Etelson
2020-10-19  8:31   ` Ferruh Yigit
2020-10-19  9:56     ` Kinsella, Ray
2020-10-19 21:29       ` Thomas Monjalon
2020-10-21  9:22 ` [dpdk-dev] [PATCH] net/mlx5: implement tunnel offload API Gregory Etelson
2020-10-22 16:00 ` [dpdk-dev] [PATCH v2] " Gregory Etelson
2020-10-23 13:49 ` [dpdk-dev] [PATCH v3] " Gregory Etelson
2020-10-23 13:57 ` [dpdk-dev] [PATCH v4] " Gregory Etelson
2020-10-25 14:08 ` [dpdk-dev] [PATCH v5] " Gregory Etelson
2020-10-25 15:01   ` Raslan Darawsheh
2020-10-27 16:12 ` [dpdk-dev] [PATCH] net/mlx5: tunnel offload code cleanup Gregory Etelson
2020-10-27 16:29   ` Slava Ovsiienko
2020-10-27 17:16   ` Raslan Darawsheh
2020-10-28 12:33     ` Andrew Rybchenko
2020-10-28  4:58 ` [dpdk-dev] [PATCH] net/mlx5: fix tunnel flow destroy Gregory Etelson
2020-11-02 16:27   ` Raslan Darawsheh

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