Hi Akhil, Konstantin,
Wouldn't the new element, userdata, conflict with the one referred by
rte_cryptodev_sym_session_set_user_data()
rte_cryptodev_sym_session_get_user_data()
Do you mind a name change for either? Or do you have a clear picture of when
one should be used over the other?
Thanks,
Anoob
> -----Original Message-----
> From: Akhil Goyal <akhil.go...@nxp.com>
> Sent: 12 November 2018 17:34
> To: Konstantin Ananyev <konstantin.anan...@intel.com>; dev@dpdk.org; Ravi
> Kumar <ravi1.ku...@amd.com>; Jacob, Jerin
> <jerin.jacobkollanukka...@cavium.com>; Joseph, Anoob
> <anoob.jos...@cavium.com>; Declan Doherty <declan.dohe...@intel.com>;
> Fiona Trahe <fiona.tr...@intel.com>; Tomasz Duszynski <t...@semihalf.com>;
> Dmitri Epshtein <d...@marvell.com>; Natalie Samsonov
> <nsams...@marvell.com>; Jay Zhou <jianjay.z...@huawei.com>
> Subject: Re: [dpdk-dev] [PATCH] doc: cryptodev deprecation notice for sym
> session changes
>
> External Email
>
> On 10/11/2018 7:50 PM, Konstantin Ananyev wrote:
> > Below are details and reasoning for proposed changes.
> >
> > 1.rte_cryptodev_sym_session_init()/ rte_cryptodev_sym_session_clear()
> > operate based on cytpodev device id, though inside
> > rte_cryptodev_sym_session device specific data is addressed
> > by driver id (not device id).
> > That creates a problem with current implementation when we have
> > two or more devices with the same driver used by the same session.
> > Consider the following example:
> >
> > struct rte_cryptodev_sym_session *sess;
> > rte_cryptodev_sym_session_init(dev_id=X, sess, ...);
> > rte_cryptodev_sym_session_init(dev_id=Y, sess, ...);
> > rte_cryptodev_sym_session_clear(dev_id=X, sess);
> >
> > After that point if X and Y uses the same driver,
> > then sess can't be used by device Y any more.
> > The reason for that - driver specific (not device specific)
> > data per session, plus there is no information
> > how many device instances use that data.
> > Probably the simplest way to deal with that issue -
> > add a reference counter per each driver data.
> >
> > 2.rte_cryptodev_sym_session_set_user_data() and
> > rte_cryptodev_sym_session_get_user_data() -
> > with current implementation there is no defined way for the user to
> > determine what is the max allowed size of the private data.
> > rte_cryptodev_sym_session_set_user_data() just blindly copies
> > user provided data without checking memory boundaries violation.
> > To overcome that issue propose to add 'uint16_t priv_size' into
> > rte_cryptodev_sym_session structure.
> >
> > 3.rte_cryptodev_sym_session contains an array of variable size for
> > driver specific data.
> > Though number of elements in that array is determined by static
> > variable nb_drivers, that could be modified by
> > rte_cryptodev_allocate_driver().
> > That construction seems to work ok so far, as right now users register
> > all their PMDs at startup, though it doesn't mean that it would always
> > remain like that.
> > To make it less error prone propose to add 'uint16_t nb_drivers'
> > into the rte_cryptodev_sym_session structure.
> > At least that allows related functions to check that provided
> > driver id wouldn't overrun variable array boundaries,
> > again it allows to determine size of already allocated session
> > without accessing global variable.
> >
> > 4.#2 and #3 above implies that now each struct rte_cryptodev_sym_session
> > would have sort of readonly type data (init once at allocation time,
> > keep unmodified through session life-time).
> > That requires more changes in current cryptodev implementation:
> > Right now inside cryptodev framework both rte_cryptodev_sym_session
> > and driver specific session data are two completely different sctrucures
> > (e.g. struct cryptodev_sym_session and struct null_crypto_session).
> > Though current cryptodev implementation implicitly assumes that driver
> > will allocate both of them from within the same mempool.
> > Plus this is done in a manner that they override each other fields
> > (reuse the same space - sort of implicit C union).
> > That's probably not the best programming practice,
> > plus make impossible to have readonly fields inside both of them.
> > To overcome that situation propose to changed an API a bit, to allow
> > to use two different mempools for these two distinct data structures.
> >
> > 5. Add 'uint64_t userdata' inside struct rte_cryptodev_sym_session.
> > I suppose that self-explanatory, and might be used in a lot of places
> > (would be quite useful for ipsec library we develop).
> >
> > The new proposed layout for rte_cryptodev_sym_session:
> > struct rte_cryptodev_sym_session {
> > uint64_t userdata;
> > /**< Can be used for external metadata */
> > uint16_t nb_drivers;
> > /**< number of elements in sess_data array */
> > uint16_t priv_size;
> > /**< session private data will be placed after sess_data */
> > __extension__ struct {
> > void *data;
> > uint16_t refcnt;
> > } sess_data[0];
> > /**< Driver specific session material, variable size */ };
> >
> > Signed-off-by: Konstantin Ananyev <konstantin.anan...@intel.com>
>
> Adding maintainers to ack this deprecation notice. These changes will impact
> all
> the PMDs and everyone should agree to these changes.
>
> from NXP dpaa_sec, dpaa2_sec, caam_jr PMDs:
>
> Acked-by: Akhil Goyal <akhil.go...@nxp.com>
> > ---
> > doc/guides/rel_notes/deprecation.rst | 9 +++++++++
> > 1 file changed, 9 insertions(+)
> >
> > diff --git a/doc/guides/rel_notes/deprecation.rst
> > b/doc/guides/rel_notes/deprecation.rst
> > index d2aec64d1..998a0d92c 100644
> > --- a/doc/guides/rel_notes/deprecation.rst
> > +++ b/doc/guides/rel_notes/deprecation.rst
> > @@ -74,3 +74,12 @@ Deprecation Notices
> >
> > This is due to a lack of flexibility and reliance on a type unusable
> > with
> > C++ programs (struct rte_flow_desc).
> > +
> > +* cryptodev: several API and ABI changes are planned for
> > +rte_cryptodev
> > + in v19.02:
> > +
> > + - The size and layout of ``rte_cryptodev_sym_session`` will change
> > + to fix existing issues.
> > + - The size and layout of ``rte_cryptodev_qp_conf`` and syntax of
> > + ``rte_cryptodev_queue_pair_setup`` will change to to allow to use
> > + two different mempools for crypto and device private sessions.
