Re: [dpdk-dev] [PATCH v4 1/3] ethdev: add raw encapsulation action

[Ori Kam <orika@mellanox.com>]

> -----Original Message-----
> From: Andrew Rybchenko <arybchenko@solarflare.com>
> Sent: Monday, October 22, 2018 4:28 PM
> To: Ori Kam <orika@mellanox.com>; wenzhuo.lu@intel.com;
> jingjing.wu@intel.com; bernard.iremonger@intel.com; ferruh.yigit@intel.com;
> stephen@networkplumber.org; Adrien Mazarguil
> <adrien.mazarguil@6wind.com>
> Cc: dev@dpdk.org; Dekel Peled <dekelp@mellanox.com>; Thomas Monjalon
> <thomas@monjalon.net>; Nélio Laranjeiro <nelio.laranjeiro@6wind.com>;
> Yongseok Koh <yskoh@mellanox.com>; Shahaf Shuler
> <shahafs@mellanox.com>
> Subject: Re: [dpdk-dev] [PATCH v4 1/3] ethdev: add raw encapsulation action
> 
> On 10/22/18 4:19 PM, Ori Kam wrote:
> >> -----Original Message-----
> >> From: Andrew Rybchenko <arybchenko@solarflare.com>
> >> Sent: Monday, October 22, 2018 4:06 PM
> >> To: Ori Kam <orika@mellanox.com>; wenzhuo.lu@intel.com;
> >> jingjing.wu@intel.com; bernard.iremonger@intel.com;
> ferruh.yigit@intel.com;
> >> stephen@networkplumber.org; Adrien Mazarguil
> >> <adrien.mazarguil@6wind.com>
> >> Cc: dev@dpdk.org; Dekel Peled <dekelp@mellanox.com>; Thomas Monjalon
> >> <thomas@monjalon.net>; Nélio Laranjeiro <nelio.laranjeiro@6wind.com>;
> >> Yongseok Koh <yskoh@mellanox.com>; Shahaf Shuler
> >> <shahafs@mellanox.com>
> >> Subject: Re: [dpdk-dev] [PATCH v4 1/3] ethdev: add raw encapsulation action
> >>
> >> On 10/17/18 11:43 AM, Ori Kam wrote:
> >>>> -----Original Message-----
> >>>> From: Andrew Rybchenko <arybchenko@solarflare.com>
> >>>> Sent: Wednesday, October 17, 2018 10:56 AM
> >>>> To: Ori Kam <orika@mellanox.com>; wenzhuo.lu@intel.com;
> >>>> jingjing.wu@intel.com; bernard.iremonger@intel.com;
> >> ferruh.yigit@intel.com;
> >>>> stephen@networkplumber.org; Adrien Mazarguil
> >>>> <adrien.mazarguil@6wind.com>
> >>>> Cc: dev@dpdk.org; Dekel Peled <dekelp@mellanox.com>; Thomas
> Monjalon
> >>>> <thomas@monjalon.net>; Nélio Laranjeiro
> <nelio.laranjeiro@6wind.com>;
> >>>> Yongseok Koh <yskoh@mellanox.com>; Shahaf Shuler
> >>>> <shahafs@mellanox.com>
> >>>> Subject: Re: [dpdk-dev] [PATCH v4 1/3] ethdev: add raw encapsulation
> action
> >>>>
> >>>> On 10/17/18 12:41 AM, Ori Kam wrote:
> >>>> Currenlty the encap/decap actions only support encapsulation
> >>>> of VXLAN and NVGRE L2 packets (L2 encapsulation is where
> >>>> the inner packet has a valid Ethernet header, while L3 encapsulation
> >>>> is where the inner packet doesn't have the Ethernet header).
> >>>> In addtion the parameter to to the encap action is a list of rte items,
> >>>> this results in 2 extra translation, between the application to the
> >>>> actioni and from the action to the NIC. This results in negetive impact
> >>>> on the insertion performance.
> >>>>
> >>>> Looking forward there are going to be a need to support many more
> tunnel
> >>>> encapsulations. For example MPLSoGRE, MPLSoUDP.
> >>>> Adding the new encapsulation will result in duplication of code.
> >>>> For example the code for handling NVGRE and VXLAN are exactly the
> same,
> >>>> and each new tunnel will have the same exact structure.
> >>>>
> >>>> This patch introduce a raw encapsulation that can support L2 tunnel types
> >>>> and L3 tunnel types. In addtion the new
> >>>> encapsulations commands are using raw buffer inorder to save the
> >>>> converstion time, both for the application and the PMD.
> >>>>
> >>>> In order to encapsulate L3 tunnel type there is a need to use both
> >>>> actions in the same rule: The decap to remove the L2 of the original
> >>>> packet, and then encap command to encapsulate the packet with the
> >>>> tunnel.
> >>>> For decap L3 there is also a need to use both commands in the same flow
> >>>> first the decap command to remove the outer tunnel header and then
> encap
> >>>> to add the L2 header.
> >>>>
> >>>> Signed-off-by: Ori Kam mailto:orika@mellanox.com
> >> [...]
> >>
> >>>> +
> >>>> +This action modifies the payload of matched flows. The data supplied
> must
> >>>> +be a valid header, either holding layer 2 data in case of removing layer 2
> >>>> +before incapsulation of layer 3 tunnel (for example MPLSoGRE) or
> >> complete
> >>>> +tunnel definition starting from layer 2 and moving to the tunel item
> itself.
> >>>> +When applied to the original packet the resulting packet must be a
> >>>> +valid packet.
> >>>> +
> >>>> +.. _table_rte_flow_action_raw_decap:
> >>>> +
> >>>> +.. table:: RAW_DECAP
> >>>> +
> >>>> +   +----------------+----------------------------------------+
> >>>> +   | Field          | Value                                  |
> >>>> +
> +================+========================================+
> >>>> +   | ``data``       | Decapsulation data                     |
> >>>>
> >>>> Sorry, I've missed the point why it is here. Is it used for matching?
> >>>> Why is the size insufficient?
> >>>>
> >>> No it is not used for matching this is only for the encapsulation data.
> >>> The data is for PMD that needs to validate that they can decapsulate
> >>> The packet, and on some PMD there might need the specify which headers
> >>> to remove and not just number of bytes.
> >> Sorry, but I still don't understand. How should PMD or HW use it?
> >> I guess the main problem here is that it is a generic action.
> >> If it is VXLAN_DECAP, it would not be a problem and neither
> >> size nor data would be required.
> >>
> > The data is buffer of the encap/decap headers, so the PMD can parse the this
> data
> > and check the validity and if the HW supports it.
> > Some NICs will not use this others can check if the tunnel request is valid.
> > For example let's assume that some tunnel encapsulation is supported on
> some FW version
> > and not supported in other version so the PMD can check the encapsulation
> data to see
> > what is the requested tunnel type and the FW capabilities to return success or
> fail.
> 
> OK, I see. Could you improve the action description to make it clear.
> Right now the description says nothing about it.
> 

Sure I will update it.

Ori