[dpdk-dev] [PATCH 1/2] lib/cryptodev: add support to set session private data

[Gujjar, Abhinandan S]

Hi All,

> -----Original Message-----
> From: Gujjar, Abhinandan S
> Sent: Thursday, January 18, 2018 12:22 PM
> To: Akhil Goyal <akhil.goyal at nxp.com>; De Lara Guarch, Pablo
> <pablo.de.lara.guarch at intel.com>; Doherty, Declan
> <declan.doherty at intel.com>; Jacob, Jerin
> <Jerin.JacobKollanukkaran at cavium.com>
> Cc: dev at dpdk.org; Vangati, Narender <narender.vangati at intel.com>; Rao,
> Nikhil <nikhil.rao at intel.com>
> Subject: RE: [PATCH 1/2] lib/cryptodev: add support to set session private data
> 
> Hi Akhil,
> 
> > -----Original Message-----
> > From: Akhil Goyal [mailto:akhil.goyal at nxp.com]
> > Sent: Wednesday, January 17, 2018 4:23 PM
> > To: Gujjar, Abhinandan S <abhinandan.gujjar at intel.com>; De Lara
> > Guarch, Pablo <pablo.de.lara.guarch at intel.com>; Doherty, Declan
> > <declan.doherty at intel.com>; Jacob, Jerin
> > <Jerin.JacobKollanukkaran at cavium.com>
> > Cc: dev at dpdk.org; Vangati, Narender <narender.vangati at intel.com>; Rao,
> > Nikhil <nikhil.rao at intel.com>
> > Subject: Re: [PATCH 1/2] lib/cryptodev: add support to set session
> > private data
> >
> > Hi Abhinandan,
> > On 1/17/2018 3:35 PM, Gujjar, Abhinandan S wrote:
> > > Hi Akhil,
> > >
> > >> -----Original Message-----
> > >> From: De Lara Guarch, Pablo
> > >> Sent: Wednesday, January 17, 2018 3:16 PM
> > >> To: Gujjar, Abhinandan S <abhinandan.gujjar at intel.com>; Akhil Goyal
> > >> <akhil.goyal at nxp.com>; Doherty, Declan <declan.doherty at intel.com>;
> > >> Jacob, Jerin <Jerin.JacobKollanukkaran at cavium.com>
> > >> Cc: dev at dpdk.org; Vangati, Narender <narender.vangati at intel.com>;
> > >> Rao, Nikhil <nikhil.rao at intel.com>
> > >> Subject: RE: [PATCH 1/2] lib/cryptodev: add support to set session
> > >> private data
> > >>
> > >> Hi Abhinandan,
> > >>
> > >>> -----Original Message-----
> > >>> From: Gujjar, Abhinandan S
> > >>> Sent: Wednesday, January 17, 2018 6:35 AM
> > >>> To: Akhil Goyal <akhil.goyal at nxp.com>; Doherty, Declan
> > >>> <declan.doherty at intel.com>; De Lara Guarch, Pablo
> > >>> <pablo.de.lara.guarch at intel.com>; Jacob, Jerin
> > >>> <Jerin.JacobKollanukkaran at cavium.com>
> > >>> Cc: dev at dpdk.org; Vangati, Narender <narender.vangati at intel.com>;
> > >>> Rao, Nikhil <nikhil.rao at intel.com>
> > >>> Subject: RE: [PATCH 1/2] lib/cryptodev: add support to set session
> > >>> private data
> > >>>
> > >>> Hi Akhil,
> > >>>
> > >>
> > >> ...
> > >>
> > >>> I guess, you are suggesting below changes:
> > >>> diff --git a/lib/librte_cryptodev/rte_cryptodev.h
> > >>> b/lib/librte_cryptodev/rte_cryptodev.h
> > >>> index 56958a6..057c39a 100644
> > >>> --- a/lib/librte_cryptodev/rte_cryptodev.h
> > >>> +++ b/lib/librte_cryptodev/rte_cryptodev.h
> > >>> @@ -892,6 +892,8 @@ struct rte_cryptodev_data {
> > >>>
> > >>>   /** Cryptodev symmetric crypto session */  struct
> > >>> rte_cryptodev_sym_session {
> > >>> +       uint16_t private_data_offset;
> > >>> +       /**< Private data offset */
> > >>>          __extension__ void *sess_private_data[0];
> > >>>          /**< Private session material */  }; I am ok with this.
> > >>>
> > >>> Declan/Pablo,
> > >>> Is this ok? Do you see any impact on performance or anything else
> > >>> has to be considered?
> > >>
> > >> This is breaking ABI, and since there is a zero length array, this
> > >> latter has to be at the end of the structure.
> > >> Therefore, this is not a valid option unless ABI deprecation is
> > >> announced and then it could be merged in the next release.
> > > What is your opinion on this?
> > > Should we consider retaining the enum rte_crypto_op_private_data_type?
> >
> > As per our previous discussion we are anyway pushing crypto adapter to
> > next release, then we do have time for the deprecation notice to be sent.
> Not sure, it is really worth breaking ABI or have an enum.
> > Or you can reserve the first byte of private data (internal to
> > library) in the session to check whether the private data is valid or not.
> Regarding reserving the first byte which validates the rest of the metadata data,
> unless this byte is also included part of rte_cryptodev_sym_session_create()
> i.e.
> memset(sess, 0, (sizeof(void *) * nb_drivers + private_data_flag)); and in
> rte_cryptodev_get_header_session_size(void)
> {
> 	/*
> 	 * Header contains pointers to the private data
> 	 * of all registered drivers
> 	 */
> 	return (sizeof(void *) * nb_drivers + private_data_flag); } Without above
> changes, the flag content can't be just trusted. Do you agree?
I will send the next patch based on above approach.
> 
> Pablo/Declan,
> Hope the changes are ok? ABI breakage or anything has to be considered again?
> >
> > IMO, private data offset in session is a better approach instead of
> > adding one more enum. Others can suggest.
> @Others, please provide your inputs so that I can prepare the next patch.
> 
> -Abhinandan
> >
> > -Akhil
> > >>
> > >> Pablo
> > > Abhinandan
> > >