Re: [dpdk-dev] [PATCH] cryptodev: extend api of asymmetric crypto by sessionless

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

Hi Fiona,

> 
> Hi Akhil, Arek, Shally,
> 
> > -----Original Message-----
> > From: Akhil Goyal [mailto:akhil.goyal@nxp.com]
> > Sent: Thursday, June 20, 2019 3:17 PM
> > To: Kusztal, ArkadiuszX <arkadiuszx.kusztal@intel.com>; dev@dpdk.org
> > Cc: Trahe, Fiona <fiona.trahe@intel.com>;
> shally.verma@caviumnetworks.com
> > Subject: RE: [PATCH] cryptodev: extend api of asymmetric crypto by
> sessionless
> > >
> > > Asymmetric cryptography algorithms may more likely use
> > > sessionless API so there is need to extend API.
> > >
> > > Signed-off-by: Arek Kusztal <arkadiuszx.kusztal@intel.com>
> > > ---
> > Acked-by: Akhil Goyal <akhil.goyal@nxp.com>
> 
> [Fiona] The code is ok but I think a little more is needed.
> As all PMDs don't support sessionless, this needs to be handled as an optional
> capability.
> And in future some PMDs may only support SESSIONLESS and some only support
> WITH_SESSION.


I believe this holds true for symmetric crypto as well. But adding a feature flag for everything may beat the purpose
Of adding a feature flag. Sessionless crypto operations in symmetric crypto is being used without any issue for a long
And nobody feel the need of that as of today. So my question is how asymmetric crypto pmds are different that they 
Need feature flag?

If the driver does not support sessionless, then it may give an error while creating it. I don't think that is an issue. It is
Already being handled in the rte_crypto_op by an enum which denote that the 'op' need to be processed with some
Session or with xform.

> So I propose adding 2 feature flags to the API
> RTE_CRYPTODEV_FF_ASYM_WTH_SESSION
> RTE_CRYPTODEV_FF_ASYM_SESSIONLESS
> and including in this patch the PMD and UT changes to set and test the first flag.
> We'll follow up with SESSIONLESS QAT implementation and UTs in a separate
> patchset.
> 
> Also documentation updates should go with this API patch, i.e.
>  - update section 16.7.2 in the cryptodev programmers guide - and review that
> doc in case other sections need updating.
Yes this needs to be updated if the implementation is complete and we have some PMD supporting that.

>  - fix comment in rte_crypto.h under STATUS_INVALID_SESSION
>  - release note
> 
> 


-Akhil