Re: [dpdk-dev] [PATCH 1/2] cryptodev: add min headroom and tailroom requirement

[Akhil Goyal <akhil.goyal@nxp.com>]

Hi Anoob,


On 6/22/2018 12:22 PM, Joseph, Anoob wrote:
> Hi Akhil,
>
> The change adds couple of entries in cryptodev_info structure. I was 
> under the impression this will be an ABI change and would need one 
> release cycle. If we can get this through in 18.08, it would be great. 
> Do you want me to revise the patch stating it that way?

If you are adding a deprecation notice for next release, then you cannot add code in that release.

To add this in current release, I think Pablo can take a decision on this.


>
> Thanks,
> Anoob
> On 21-06-2018 19:54, Akhil Goyal wrote:
>>
>> On 6/19/2018 11:56 AM, Anoob Joseph wrote:
>>> Enabling crypto devs to specify the minimum headroom and tailroom it
>>> expects in the mbuf. For net PMDs, standard headroom has to be honoured
>>> by applications, which is not strictly followed for crypto devs. This
>>> prevents crypto devs from using free space in mbuf (available as
>>> head/tailroom) for internal requirements in crypto operations. Addition
>>> of head/tailroom requirement will help PMDs to communicate such
>>> requirements to the application.
>>>
>>> The availability and use of head/tailroom is an optimization if the
>>> hardware supports use of head/tailroom for crypto-op info. For devices
>>> that do not support using the head/tailroom, they can continue to 
>>> operate
>>> without any performance-drop.
>>>
>>> Signed-off-by: Anoob Joseph <anoob.joseph@caviumnetworks.com>
>>> ---
>>>   doc/guides/rel_notes/deprecation.rst | 4 ++++
>>>   lib/librte_cryptodev/rte_cryptodev.h | 6 ++++++
>>>   2 files changed, 10 insertions(+)
>>>
>>> diff --git a/doc/guides/rel_notes/deprecation.rst 
>>> b/doc/guides/rel_notes/deprecation.rst
>>> index 1ce692e..a547289 100644
>>> --- a/doc/guides/rel_notes/deprecation.rst
>>> +++ b/doc/guides/rel_notes/deprecation.rst
>>> @@ -122,3 +122,7 @@ Deprecation Notices
>>>     - Function ``rte_cryptodev_get_private_session_size()`` will be 
>>> deprecated
>>>       in 18.05, and it gets replaced with 
>>> ``rte_cryptodev_sym_get_private_session_size()``.
>>>       It will be removed in 18.08.
>>> +  - New field, ``min_headroom_req``, added in 
>>> ``rte_cryptodev_info`` structure. It will be
>>> +    added in 18.11.
>>> +  - New field, ``min_tailroom_req``, added in 
>>> ``rte_cryptodev_info`` structure. It will be
>>> +    added in 18.11.
>>
>> Is this targeted for 18.08 or 18.11?
>>
>>> diff --git a/lib/librte_cryptodev/rte_cryptodev.h 
>>> b/lib/librte_cryptodev/rte_cryptodev.h
>>> index 92ce6d4..fa944b8 100644
>>> --- a/lib/librte_cryptodev/rte_cryptodev.h
>>> +++ b/lib/librte_cryptodev/rte_cryptodev.h
>>> @@ -382,6 +382,12 @@ struct rte_cryptodev_info {
>>>       unsigned max_nb_queue_pairs;
>>>       /**< Maximum number of queues pairs supported by device. */
>>>
>>> +     uint32_t min_headroom_req;
>>> +     /**< Minimum mbuf headroom required by device */
>>> +
>>> +     uint32_t min_tailroom_req;
>>> +     /**< Minimum mbuf tailroom required by device */
>>> +
>>>       struct {
>>>               unsigned max_nb_sessions;
>>>               /**< Maximum number of sessions supported by device. */
>>
>