Re: [dpdk-dev] [dpdk-dev v10 2/4] cryptodev: add raw crypto data-path APIs

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

> > > +During the enqueue, the cryptodev driver only sets the enqueued
> > descriptors
> > > +into the device queue but not initiates the device to start processing them.
> > > +The temporary queue pair data changes in relation to the enqueued
> > descriptors
> > > +may be recorded in the ``struct rte_crypto_raw_dp_ctx`` buffer as the
> > > reference
> > > +to the next enqueue function call. When
> > ``rte_cryptodev_raw_enqueue_done``
> > > is
> > > +called, the driver will initiate the processing of all enqueued descriptors
> > and
> > > +merge the temporary queue pair data changes into the driver's private
> > queue
> > > +pair data. Calling ``rte_cryptodev_raw_configure_dp_context`` twice
> > without
> > > +``rte_cryptodev_dp_enqueue_done`` call in between will invalidate the
> > > temporary
> > > +data stored in ``struct rte_crypto_raw_dp_ctx`` buffer. This feature is
> > useful
> > > +when the user wants to abandon partially enqueued data for a failed
> > enqueue
> > > +burst operation and try enqueuing in a whole later.
> >
> > This feature may not be supported by all the HW PMDs, Can there be a way
> > to bypass
> > this done API?
> 
> We can add another feature flag
> "RTE_CRYPTODEV_FF_SYM_HW_RAW_DP_ALLOW_CACHE". The PMDs who
> do not support this feature can simply return "- ENOTSUP" when calling
> enqueue_done and dequeue_done function. What do you think?

Can the enqueue/dequeue API return a flag which decide whether
to call done API or not?
Returning ENOTSUP will break the execution.


> > > +int
> > > +rte_cryptodev_raw_configure_dp_context(uint8_t dev_id, uint16_t
> > qp_id,
> > > +	struct rte_crypto_raw_dp_ctx *ctx)
> >
> > rte_cryptodev_configure_raw_dp_ctx
> >
> > > +{
> > > +	struct rte_cryptodev *dev;
> > > +	union rte_cryptodev_session_ctx sess_ctx = {NULL};
> > > +
> > > +	if (!rte_cryptodev_get_qp_status(dev_id, qp_id))
> > > +		return -EINVAL;
> > > +
> > > +	dev = rte_cryptodev_pmd_get_dev(dev_id);
> > > +	if (!(dev->feature_flags & RTE_CRYPTODEV_FF_SYM_HW_RAW_DP)
> > > +			|| dev->dev_ops->configure_dp_ctx == NULL)
> > > +		return -ENOTSUP;
> > > +
> > > +	return (*dev->dev_ops->configure_dp_ctx)(dev, qp_id,
> > > +			RTE_CRYPTO_OP_WITH_SESSION, sess_ctx, ctx);
> > > +}
> > > +
> > > +int
> > > +rte_cryptodev_raw_attach_session(uint8_t dev_id, uint16_t qp_id,
> > > +	struct rte_crypto_raw_dp_ctx *ctx,
> > > +	enum rte_crypto_op_sess_type sess_type,
> > > +	union rte_cryptodev_session_ctx session_ctx)
> > > +{
> > > +	struct rte_cryptodev *dev;
> > > +
> > > +	if (!rte_cryptodev_get_qp_status(dev_id, qp_id))
> > > +		return -EINVAL;
> > > +
> > > +	dev = rte_cryptodev_pmd_get_dev(dev_id);
> > > +	if (!(dev->feature_flags & RTE_CRYPTODEV_FF_SYM_HW_RAW_DP)
> > > +			|| dev->dev_ops->configure_dp_ctx == NULL)
> > > +		return -ENOTSUP;
> > > +	return (*dev->dev_ops->configure_dp_ctx)(dev, qp_id, sess_type,
> > > +			session_ctx, ctx);
> >
> > What is the difference between rte_cryptodev_raw_configure_dp_context
> > and
> > rte_cryptodev_raw_attach_session?
> > And if at all it is needed, then it should be
> > rte_cryptodev_attach_raw_dp_session.
> > IMO attach is not needed, I am not clear about it.
> >
> > You are calling the same dev_ops for both - one with explicit session time
> > and other
> > From an argument.
> 
> rte_cryptodev_raw_configure_dp_context creates a shadow copy of the queue
> pair data with in ctx, where rte_cryptodev_raw_attach_session sets the function
> handler based on the session data. Using of the same PMD callback function is
> to
> save one function pointer stored in the dev_ops. If you don't like it I can create
> 2 callback functions no problem.

I don't like the idea of having 2 APIs.

Why do you need to create a shadow copy of the queue data? Why it can't be
Done in the attach API by the driver? In v9 it was doing that, why is it changed?