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

["Joseph, Anoob" <Anoob.Joseph@caviumnetworks.com>]

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?

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. */
>