Re: [dpdk-dev] [PATCH v2 1/2] lib/crypto: add callback handlers for crypto

["Varghese, Vipin" <vipin.varghese@intel.com>]

Thanks Akhil, I will work on the suggested inputs.

> -----Original Message-----
> From: Akhil Goyal <akhil.goyal@nxp.com>
> Sent: Thursday, June 27, 2019 7:55 PM
> To: Varghese, Vipin <vipin.varghese@intel.com>; Wiles, Keith
> <keith.wiles@intel.com>; dev@dpdk.org; De Lara Guarch, Pablo
> <pablo.de.lara.guarch@intel.com>; Doherty, Declan
> <declan.doherty@intel.com>
> Cc: Padubidri, Sanjay A <sanjay.padubidri@intel.com>
> Subject: RE: [PATCH v2 1/2] lib/crypto: add callback handlers for crypto
> 
> Hi Vipin,
> 
> >
> > Add callback handlers for enqueue-dequeue operation on crypto device.
> > The pre-enqueue and post-dequeue are selected on invoke user
> > registered callback functions.
> >
> > Use cases:
> >  - allow user to investigate the contents pre-enqueue.
> >  - allow user to investigate the contents post-dequeue.
> >  - modify pre-enqueue and post-dequeue stage content.
> >  - investigate PMD meta data.
> >
> > Signed-off-by: Vipin Varghese <vipin.varghese@intel.com>
> > ---
> 
> [..]
> 
> > @@ -907,6 +926,19 @@ rte_cryptodev_dequeue_burst(uint8_t dev_id,
> > uint16_t qp_id,
> >  	nb_ops = (*dev->dequeue_burst)
> >  			(dev->data->queue_pairs[qp_id], ops, nb_ops);
> >
> > +#ifdef RTE_CRYPTODEV_ENQDEQ_CALLBACKS
> > +	struct rte_cryptodev_enqdeq_callback *cb = NULL;
> > +
> > +	TAILQ_FOREACH(cb, &(dev->deq_cbs), next) {
> > +		if (cb->cb_fn == NULL)
> > +			continue;
> > +
> > +		cb->active = 1;
> > +		nb_ops = cb->cb_fn(dev_id, qp_id, ops, nb_ops, cb->cb_arg);
> > +		cb->active = 0;
> > +	}
> 
> Shouldn't this cb->active be set atomically.
> 
> Will it be thread safe? There may be multiple threads enqueuing on the same
> device.
> One may be executing while the other finished and set the active to 0, and may
> unregister While the some other thread is still executing.
> 
> One more thing, it would be better to have a debug prints about how many
> nb_ops have been Successfully passed through each of the callback.
> And in the callback, it should be assumed that it will return back just after the first
> failed ops, so that The application can free the remaining one. This should be
> documented in the callback API.
> 
> > +#endif
> > +
> >  	return nb_ops;
> >  }
> >