Re: [dpdk-dev] [PATCH v7 1/2] cryptodev: support enqueue and dequeue callback functions

["Gujjar, Abhinandan S" <abhinandan.gujjar@intel.com>]

Hi Akhil,

Could you please review the patches?

Regards
Abhinandan

> -----Original Message-----
> From: Gujjar, Abhinandan S <abhinandan.gujjar@intel.com>
> Sent: Tuesday, December 22, 2020 8:13 PM
> To: dev@dpdk.org; akhil.goyal@nxp.com; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>
> Cc: Gujjar, Abhinandan S <abhinandan.gujjar@intel.com>
> Subject: [PATCH v7 1/2] cryptodev: support enqueue and dequeue callback
> functions
> 
> This patch adds APIs to add/remove callback functions on crypto
> enqueue/dequeue burst. The callback function will be called for each burst of
> crypto ops received/sent on a given crypto device queue pair.
> 
> Signed-off-by: Abhinandan Gujjar <abhinandan.gujjar@intel.com>
> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> ---
>  config/rte_config.h                     |   1 +
>  doc/guides/prog_guide/cryptodev_lib.rst |  44 +++
>  doc/guides/rel_notes/release_21_02.rst  |   9 +
>  lib/librte_cryptodev/meson.build        |   2 +-
>  lib/librte_cryptodev/rte_cryptodev.c    | 398 +++++++++++++++++++++++-
>  lib/librte_cryptodev/rte_cryptodev.h    | 246 ++++++++++++++-
>  lib/librte_cryptodev/version.map        |   7 +
>  7 files changed, 702 insertions(+), 5 deletions(-)
> 
> diff --git a/config/rte_config.h b/config/rte_config.h index
> a0b5160ff..87f9786d7 100644
> --- a/config/rte_config.h
> +++ b/config/rte_config.h
> @@ -62,6 +62,7 @@
>  /* cryptodev defines */
>  #define RTE_CRYPTO_MAX_DEVS 64
>  #define RTE_CRYPTODEV_NAME_LEN 64
> +#define RTE_CRYPTO_CALLBACKS 1
> 
>  /* compressdev defines */
>  #define RTE_COMPRESS_MAX_DEVS 64
> diff --git a/doc/guides/prog_guide/cryptodev_lib.rst
> b/doc/guides/prog_guide/cryptodev_lib.rst
> index 473b014a1..9b1cf8d49 100644
> --- a/doc/guides/prog_guide/cryptodev_lib.rst
> +++ b/doc/guides/prog_guide/cryptodev_lib.rst
> @@ -338,6 +338,50 @@ start of private data information. The offset is counted
> from the start of the  rte_crypto_op including other crypto information such as
> the IVs (since there can  be an IV also for authentication).
> 
> +User callback APIs
> +~~~~~~~~~~~~~~~~~~
> +The add APIs configures a user callback function to be called for each
> +burst of crypto ops received/sent on a given crypto device queue pair.
> +The return value is a pointer that can be used later to remove the
> +callback using remove API. Application is expected to register a
> +callback function of type ``rte_cryptodev_callback_fn``. Multiple
> +callback functions can be added for a given queue pair. API does not restrict
> on maximum number of callbacks.
> +
> +Callbacks registered by application would not survive
> +``rte_cryptodev_configure`` as it reinitializes the callback list. It
> +is user responsibility to remove all installed callbacks before calling
> ``rte_cryptodev_configure`` to avoid possible memory leakage.
> +
> +So, the application is expected to add user callback after
> ``rte_cryptodev_configure``.
> +The callbacks can also be added at the runtime. These callbacks get
> +executed when
> ``rte_cryptodev_enqueue_burst``/``rte_cryptodev_dequeue_burst`` is called.
> +
> +.. code-block:: c
> +
> +	struct rte_cryptodev_cb *
> +		rte_cryptodev_add_enq_callback(uint8_t dev_id, uint16_t
> qp_id,
> +					       rte_cryptodev_callback_fn cb_fn,
> +					       void *cb_arg);
> +
> +	struct rte_cryptodev_cb *
> +		rte_cryptodev_add_deq_callback(uint8_t dev_id, uint16_t
> qp_id,
> +					       rte_cryptodev_callback_fn cb_fn,
> +					       void *cb_arg);
> +
> +	uint16_t (* rte_cryptodev_callback_fn)(uint16_t dev_id, uint16_t qp_id,
> +					       struct rte_crypto_op **ops,
> +					       uint16_t nb_ops, void
> *user_param);
> +
> +The remove API removes a callback function added by
> +``rte_cryptodev_add_enq_callback``/``rte_cryptodev_add_deq_callback``.
> +
> +.. code-block:: c
> +
> +	int rte_cryptodev_remove_enq_callback(uint8_t dev_id, uint16_t
> qp_id,
> +					      struct rte_cryptodev_cb *cb);
> +
> +	int rte_cryptodev_remove_deq_callback(uint8_t dev_id, uint16_t
> qp_id,
> +					      struct rte_cryptodev_cb *cb);
> +
> 
>  Enqueue / Dequeue Burst APIs
>  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> diff --git a/doc/guides/rel_notes/release_21_02.rst
> b/doc/guides/rel_notes/release_21_02.rst
> index 638f98168..8c7866401 100644
> --- a/doc/guides/rel_notes/release_21_02.rst
> +++ b/doc/guides/rel_notes/release_21_02.rst
> @@ -55,6 +55,13 @@ New Features
>       Also, make sure to start the actual text at the margin.
>       =======================================================
> 
> +* **Added enqueue & dequeue callback APIs for cryptodev library.**
> +
> +  Cryptodev library is added with enqueue & dequeue callback APIs to
> + enable applications to add/remove user callbacks which gets called
> + for every enqueue/dequeue operation.
> +
> +
> 
>  Removed Items
>  -------------
> @@ -84,6 +91,8 @@ API Changes
>     Also, make sure to start the actual text at the margin.
>     =======================================================
> 
> +* cryptodev: The structure ``rte_cryptodev`` has been updated with
> +pointers
> +  for adding enqueue and dequeue callbacks.
> 
>  ABI Changes
>  -----------
> diff --git a/lib/librte_cryptodev/meson.build b/lib/librte_cryptodev/meson.build
> index c4c6b3b6a..8c5493f4c 100644
> --- a/lib/librte_cryptodev/meson.build
> +++ b/lib/librte_cryptodev/meson.build
> @@ -9,4 +9,4 @@ headers = files('rte_cryptodev.h',
>  	'rte_crypto.h',
>  	'rte_crypto_sym.h',
>  	'rte_crypto_asym.h')
> -deps += ['kvargs', 'mbuf']
> +deps += ['kvargs', 'mbuf', 'rcu']
> diff --git a/lib/librte_cryptodev/rte_cryptodev.c
> b/lib/librte_cryptodev/rte_cryptodev.c
> index 3d95ac6ea..40f55a3cd 100644
> --- a/lib/librte_cryptodev/rte_cryptodev.c
> +++ b/lib/librte_cryptodev/rte_cryptodev.c
> @@ -448,6 +448,122 @@
> rte_cryptodev_asym_xform_capability_check_modlen(
>  	return 0;
>  }
> 
> +/* spinlock for crypto device enq callbacks */ static rte_spinlock_t
> +rte_cryptodev_callback_lock = RTE_SPINLOCK_INITIALIZER;
> +
> +static void
> +cryptodev_cb_cleanup(struct rte_cryptodev *dev) {
> +	struct rte_cryptodev_cb_rcu *list;
> +	struct rte_cryptodev_cb *cb, *next;
> +	uint16_t qp_id;
> +
> +	if (dev->enq_cbs == NULL && dev->deq_cbs == NULL)
> +		return;
> +
> +	for (qp_id = 0; qp_id < dev->data->nb_queue_pairs; qp_id++) {
> +		list = &dev->enq_cbs[qp_id];
> +		cb = list->next;
> +		while (cb != NULL) {
> +			next = cb->next;
> +			rte_free(cb);
> +			cb = next;
> +		}
> +
> +		rte_free(list->qsbr);
> +	}
> +
> +	for (qp_id = 0; qp_id < dev->data->nb_queue_pairs; qp_id++) {
> +		list = &dev->deq_cbs[qp_id];
> +		cb = list->next;
> +		while (cb != NULL) {
> +			next = cb->next;
> +			rte_free(cb);
> +			cb = next;
> +		}
> +
> +		rte_free(list->qsbr);
> +	}
> +
> +	rte_free(dev->enq_cbs);
> +	dev->enq_cbs = NULL;
> +	rte_free(dev->deq_cbs);
> +	dev->deq_cbs = NULL;
> +}
> +
> +static int
> +cryptodev_cb_init(struct rte_cryptodev *dev) {
> +	struct rte_cryptodev_cb_rcu *list;
> +	struct rte_rcu_qsbr *qsbr;
> +	uint16_t qp_id;
> +	size_t size;
> +
> +	/* Max thread set to 1, as one DP thread accessing a queue-pair */
> +	const uint32_t max_threads = 1;
> +
> +	dev->enq_cbs = rte_zmalloc(NULL,
> +				   sizeof(struct rte_cryptodev_cb_rcu) *
> +				   dev->data->nb_queue_pairs, 0);
> +	if (dev->enq_cbs == NULL) {
> +		CDEV_LOG_ERR("Failed to allocate memory for enq
> callbacks");
> +		return -ENOMEM;
> +	}
> +
> +	dev->deq_cbs = rte_zmalloc(NULL,
> +				   sizeof(struct rte_cryptodev_cb_rcu) *
> +				   dev->data->nb_queue_pairs, 0);
> +	if (dev->deq_cbs == NULL) {
> +		CDEV_LOG_ERR("Failed to allocate memory for deq
> callbacks");
> +		rte_free(dev->enq_cbs);
> +		return -ENOMEM;
> +	}
> +
> +	/* Create RCU QSBR variable */
> +	size = rte_rcu_qsbr_get_memsize(max_threads);
> +
> +	for (qp_id = 0; qp_id < dev->data->nb_queue_pairs; qp_id++) {
> +		list = &dev->enq_cbs[qp_id];
> +		qsbr = rte_zmalloc(NULL, size, RTE_CACHE_LINE_SIZE);
> +		if (qsbr == NULL) {
> +			CDEV_LOG_ERR("Failed to allocate memory for RCU
> on "
> +				"queue_pair_id=%d", qp_id);
> +			goto cb_init_err;
> +		}
> +
> +		if (rte_rcu_qsbr_init(qsbr, max_threads)) {
> +			CDEV_LOG_ERR("Failed to initialize for RCU on "
> +				"queue_pair_id=%d", qp_id);
> +			goto cb_init_err;
> +		}
> +
> +		list->qsbr = qsbr;
> +	}
> +
> +	for (qp_id = 0; qp_id < dev->data->nb_queue_pairs; qp_id++) {
> +		list = &dev->deq_cbs[qp_id];
> +		qsbr = rte_zmalloc(NULL, size, RTE_CACHE_LINE_SIZE);
> +		if (qsbr == NULL) {
> +			CDEV_LOG_ERR("Failed to allocate memory for RCU
> on "
> +				"queue_pair_id=%d", qp_id);
> +			goto cb_init_err;
> +		}
> +
> +		if (rte_rcu_qsbr_init(qsbr, max_threads)) {
> +			CDEV_LOG_ERR("Failed to initialize for RCU on "
> +				"queue_pair_id=%d", qp_id);
> +			goto cb_init_err;
> +		}
> +
> +		list->qsbr = qsbr;
> +	}
> +
> +	return 0;
> +
> +cb_init_err:
> +	cryptodev_cb_cleanup(dev);
> +	return -ENOMEM;
> +}
> 
>  const char *
>  rte_cryptodev_get_feature_name(uint64_t flag) @@ -927,6 +1043,10 @@
> rte_cryptodev_configure(uint8_t dev_id, struct rte_cryptodev_config *config)
> 
>  	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_configure, -
> ENOTSUP);
> 
> +	rte_spinlock_lock(&rte_cryptodev_callback_lock);
> +	cryptodev_cb_cleanup(dev);
> +	rte_spinlock_unlock(&rte_cryptodev_callback_lock);
> +
>  	/* Setup new number of queue pairs and reconfigure device. */
>  	diag = rte_cryptodev_queue_pairs_config(dev, config-
> >nb_queue_pairs,
>  			config->socket_id);
> @@ -936,11 +1056,18 @@ rte_cryptodev_configure(uint8_t dev_id, struct
> rte_cryptodev_config *config)
>  		return diag;
>  	}
> 
> +	rte_spinlock_lock(&rte_cryptodev_callback_lock);
> +	diag = cryptodev_cb_init(dev);
> +	rte_spinlock_unlock(&rte_cryptodev_callback_lock);
> +	if (diag) {
> +		CDEV_LOG_ERR("Callback init failed for dev_id=%d", dev_id);
> +		return diag;
> +	}
> +
>  	rte_cryptodev_trace_configure(dev_id, config);
>  	return (*dev->dev_ops->dev_configure)(dev, config);  }
> 
> -
>  int
>  rte_cryptodev_start(uint8_t dev_id)
>  {
> @@ -1136,6 +1263,275 @@ rte_cryptodev_queue_pair_setup(uint8_t dev_id,
> uint16_t queue_pair_id,
>  			socket_id);
>  }
> 
> +struct rte_cryptodev_cb *
> +rte_cryptodev_add_enq_callback(uint8_t dev_id,
> +			       uint16_t qp_id,
> +			       rte_cryptodev_callback_fn cb_fn,
> +			       void *cb_arg)
> +{
> +	struct rte_cryptodev *dev;
> +	struct rte_cryptodev_cb_rcu *list;
> +	struct rte_cryptodev_cb *cb, *tail;
> +
> +	if (!cb_fn) {
> +		CDEV_LOG_ERR("Callback is NULL on dev_id=%d", dev_id);
> +		rte_errno = EINVAL;
> +		return NULL;
> +	}
> +
> +	if (!rte_cryptodev_pmd_is_valid_dev(dev_id)) {
> +		CDEV_LOG_ERR("Invalid dev_id=%d", dev_id);
> +		rte_errno = ENODEV;
> +		return NULL;
> +	}
> +
> +	dev = &rte_crypto_devices[dev_id];
> +	if (qp_id >= dev->data->nb_queue_pairs) {
> +		CDEV_LOG_ERR("Invalid queue_pair_id=%d", qp_id);
> +		rte_errno = ENODEV;
> +		return NULL;
> +	}
> +
> +	cb = rte_zmalloc(NULL, sizeof(*cb), 0);
> +	if (cb == NULL) {
> +		CDEV_LOG_ERR("Failed to allocate memory for callback on "
> +			     "dev=%d, queue_pair_id=%d", dev_id, qp_id);
> +		rte_errno = ENOMEM;
> +		return NULL;
> +	}
> +
> +	rte_spinlock_lock(&rte_cryptodev_callback_lock);
> +
> +	cb->fn = cb_fn;
> +	cb->arg = cb_arg;
> +
> +	/* Add the callbacks in fifo order. */
> +	list = &dev->enq_cbs[qp_id];
> +	tail = list->next;
> +
> +	if (tail) {
> +		while (tail->next)
> +			tail = tail->next;
> +		/* Stores to cb->fn and cb->param should complete before
> +		 * cb is visible to data plane.
> +		 */
> +		__atomic_store_n(&tail->next, cb, __ATOMIC_RELEASE);
> +	} else {
> +		/* Stores to cb->fn and cb->param should complete before
> +		 * cb is visible to data plane.
> +		 */
> +		__atomic_store_n(&list->next, cb, __ATOMIC_RELEASE);
> +	}
> +
> +	rte_spinlock_unlock(&rte_cryptodev_callback_lock);
> +
> +	return cb;
> +}
> +
> +int
> +rte_cryptodev_remove_enq_callback(uint8_t dev_id,
> +				  uint16_t qp_id,
> +				  struct rte_cryptodev_cb *cb)
> +{
> +	struct rte_cryptodev *dev;
> +	struct rte_cryptodev_cb **prev_cb, *curr_cb;
> +	struct rte_cryptodev_cb_rcu *list;
> +	int ret;
> +
> +	ret = -EINVAL;
> +
> +	if (!cb) {
> +		CDEV_LOG_ERR("Callback is NULL");
> +		return -EINVAL;
> +	}
> +
> +	if (!rte_cryptodev_pmd_is_valid_dev(dev_id)) {
> +		CDEV_LOG_ERR("Invalid dev_id=%d", dev_id);
> +		return -ENODEV;
> +	}
> +
> +	dev = &rte_crypto_devices[dev_id];
> +	if (qp_id >= dev->data->nb_queue_pairs) {
> +		CDEV_LOG_ERR("Invalid queue_pair_id=%d", qp_id);
> +		return -ENODEV;
> +	}
> +
> +	rte_spinlock_lock(&rte_cryptodev_callback_lock);
> +	if (dev->enq_cbs == NULL) {
> +		CDEV_LOG_ERR("Callback not initialized");
> +		goto cb_err;
> +	}
> +
> +	list = &dev->enq_cbs[qp_id];
> +	if (list == NULL) {
> +		CDEV_LOG_ERR("Callback list is NULL");
> +		goto cb_err;
> +	}
> +
> +	if (list->qsbr == NULL) {
> +		CDEV_LOG_ERR("Rcu qsbr is NULL");
> +		goto cb_err;
> +	}
> +
> +	prev_cb = &list->next;
> +	for (; *prev_cb != NULL; prev_cb = &curr_cb->next) {
> +		curr_cb = *prev_cb;
> +		if (curr_cb == cb) {
> +			/* Remove the user cb from the callback list. */
> +			__atomic_store_n(prev_cb, curr_cb->next,
> +				__ATOMIC_RELAXED);
> +			ret = 0;
> +			break;
> +		}
> +	}
> +
> +	if (!ret) {
> +		/* Call sync with invalid thread id as this is part of
> +		 * control plane API
> +		 */
> +		rte_rcu_qsbr_synchronize(list->qsbr,
> RTE_QSBR_THRID_INVALID);
> +		rte_free(cb);
> +	}
> +
> +cb_err:
> +	rte_spinlock_unlock(&rte_cryptodev_callback_lock);
> +	return ret;
> +}
> +
> +struct rte_cryptodev_cb *
> +rte_cryptodev_add_deq_callback(uint8_t dev_id,
> +			       uint16_t qp_id,
> +			       rte_cryptodev_callback_fn cb_fn,
> +			       void *cb_arg)
> +{
> +	struct rte_cryptodev *dev;
> +	struct rte_cryptodev_cb_rcu *list;
> +	struct rte_cryptodev_cb *cb, *tail;
> +
> +	if (!cb_fn) {
> +		CDEV_LOG_ERR("Callback is NULL on dev_id=%d", dev_id);
> +		rte_errno = EINVAL;
> +		return NULL;
> +	}
> +
> +	if (!rte_cryptodev_pmd_is_valid_dev(dev_id)) {
> +		CDEV_LOG_ERR("Invalid dev_id=%d", dev_id);
> +		rte_errno = ENODEV;
> +		return NULL;
> +	}
> +
> +	dev = &rte_crypto_devices[dev_id];
> +	if (qp_id >= dev->data->nb_queue_pairs) {
> +		CDEV_LOG_ERR("Invalid queue_pair_id=%d", qp_id);
> +		rte_errno = ENODEV;
> +		return NULL;
> +	}
> +
> +	cb = rte_zmalloc(NULL, sizeof(*cb), 0);
> +	if (cb == NULL) {
> +		CDEV_LOG_ERR("Failed to allocate memory for callback on "
> +			     "dev=%d, queue_pair_id=%d", dev_id, qp_id);
> +		rte_errno = ENOMEM;
> +		return NULL;
> +	}
> +
> +	rte_spinlock_lock(&rte_cryptodev_callback_lock);
> +
> +	cb->fn = cb_fn;
> +	cb->arg = cb_arg;
> +
> +	/* Add the callbacks in fifo order. */
> +	list = &dev->deq_cbs[qp_id];
> +	tail = list->next;
> +
> +	if (tail) {
> +		while (tail->next)
> +			tail = tail->next;
> +		/* Stores to cb->fn and cb->param should complete before
> +		 * cb is visible to data plane.
> +		 */
> +		__atomic_store_n(&tail->next, cb, __ATOMIC_RELEASE);
> +	} else {
> +		/* Stores to cb->fn and cb->param should complete before
> +		 * cb is visible to data plane.
> +		 */
> +		__atomic_store_n(&list->next, cb, __ATOMIC_RELEASE);
> +	}
> +
> +	rte_spinlock_unlock(&rte_cryptodev_callback_lock);
> +
> +	return cb;
> +}
> +
> +int
> +rte_cryptodev_remove_deq_callback(uint8_t dev_id,
> +				  uint16_t qp_id,
> +				  struct rte_cryptodev_cb *cb)
> +{
> +	struct rte_cryptodev *dev;
> +	struct rte_cryptodev_cb **prev_cb, *curr_cb;
> +	struct rte_cryptodev_cb_rcu *list;
> +	int ret;
> +
> +	ret = -EINVAL;
> +
> +	if (!cb) {
> +		CDEV_LOG_ERR("Callback is NULL");
> +		return -EINVAL;
> +	}
> +
> +	if (!rte_cryptodev_pmd_is_valid_dev(dev_id)) {
> +		CDEV_LOG_ERR("Invalid dev_id=%d", dev_id);
> +		return -ENODEV;
> +	}
> +
> +	dev = &rte_crypto_devices[dev_id];
> +	if (qp_id >= dev->data->nb_queue_pairs) {
> +		CDEV_LOG_ERR("Invalid queue_pair_id=%d", qp_id);
> +		return -ENODEV;
> +	}
> +
> +	rte_spinlock_lock(&rte_cryptodev_callback_lock);
> +	if (dev->enq_cbs == NULL) {
> +		CDEV_LOG_ERR("Callback not initialized");
> +		goto cb_err;
> +	}
> +
> +	list = &dev->deq_cbs[qp_id];
> +	if (list == NULL) {
> +		CDEV_LOG_ERR("Callback list is NULL");
> +		goto cb_err;
> +	}
> +
> +	if (list->qsbr == NULL) {
> +		CDEV_LOG_ERR("Rcu qsbr is NULL");
> +		goto cb_err;
> +	}
> +
> +	prev_cb = &list->next;
> +	for (; *prev_cb != NULL; prev_cb = &curr_cb->next) {
> +		curr_cb = *prev_cb;
> +		if (curr_cb == cb) {
> +			/* Remove the user cb from the callback list. */
> +			__atomic_store_n(prev_cb, curr_cb->next,
> +				__ATOMIC_RELAXED);
> +			ret = 0;
> +			break;
> +		}
> +	}
> +
> +	if (!ret) {
> +		/* Call sync with invalid thread id as this is part of
> +		 * control plane API
> +		 */
> +		rte_rcu_qsbr_synchronize(list->qsbr,
> RTE_QSBR_THRID_INVALID);
> +		rte_free(cb);
> +	}
> +
> +cb_err:
> +	rte_spinlock_unlock(&rte_cryptodev_callback_lock);
> +	return ret;
> +}
> 
>  int
>  rte_cryptodev_stats_get(uint8_t dev_id, struct rte_cryptodev_stats *stats) diff
> --git a/lib/librte_cryptodev/rte_cryptodev.h
> b/lib/librte_cryptodev/rte_cryptodev.h
> index 0935fd587..ae34f33f6 100644
> --- a/lib/librte_cryptodev/rte_cryptodev.h
> +++ b/lib/librte_cryptodev/rte_cryptodev.h
> @@ -23,6 +23,7 @@ extern "C" {
>  #include "rte_dev.h"
>  #include <rte_common.h>
>  #include <rte_config.h>
> +#include <rte_rcu_qsbr.h>
> 
>  #include "rte_cryptodev_trace_fp.h"
> 
> @@ -522,6 +523,30 @@ struct rte_cryptodev_qp_conf {
>  	/**< The mempool for creating sess private data in sessionless mode
> */  };
> 
> +/**
> + * Function type used for processing crypto ops when enqueue/dequeue
> +burst is
> + * called.
> + *
> + * The callback function is called on enqueue/dequeue burst immediately.
> + *
> + * @param	dev_id		The identifier of the device.
> + * @param	qp_id		The index of the queue pair on which ops are
> + *				enqueued/dequeued. The value must be in the
> + *				range [0, nb_queue_pairs - 1] previously
> + *				supplied to *rte_cryptodev_configure*.
> + * @param	ops		The address of an array of *nb_ops* pointers
> + *				to *rte_crypto_op* structures which contain
> + *				the crypto operations to be processed.
> + * @param	nb_ops		The number of operations to process.
> + * @param	user_param	The arbitrary user parameter passed in by the
> + *				application when the callback was originally
> + *				registered.
> + * @return			The number of ops to be enqueued to the
> + *				crypto device.
> + */
> +typedef uint16_t (*rte_cryptodev_callback_fn)(uint16_t dev_id, uint16_t
> qp_id,
> +		struct rte_crypto_op **ops, uint16_t nb_ops, void
> *user_param);
> +
>  /**
>   * Typedef for application callback function to be registered by application
>   * software for notification of device events @@ -822,7 +847,6 @@
> rte_cryptodev_callback_unregister(uint8_t dev_id,
>  		enum rte_cryptodev_event_type event,
>  		rte_cryptodev_cb_fn cb_fn, void *cb_arg);
> 
> -
>  typedef uint16_t (*dequeue_pkt_burst_t)(void *qp,
>  		struct rte_crypto_op **ops,	uint16_t nb_ops);
>  /**< Dequeue processed packets from queue pair of a device. */ @@ -839,6
> +863,30 @@ struct rte_cryptodev_callback;
>  /** Structure to keep track of registered callbacks */
> TAILQ_HEAD(rte_cryptodev_cb_list, rte_cryptodev_callback);
> 
> +/**
> + * Structure used to hold information about the callbacks to be called
> +for a
> + * queue pair on enqueue/dequeue.
> + */
> +struct rte_cryptodev_cb {
> +	struct rte_cryptodev_cb *next;
> +	/**< Pointer to next callback */
> +	rte_cryptodev_callback_fn fn;
> +	/**< Pointer to callback function */
> +	void *arg;
> +	/**< Pointer to argument */
> +};
> +
> +/**
> + * @internal
> + * Structure used to hold information about the RCU for a queue pair.
> + */
> +struct rte_cryptodev_cb_rcu {
> +	struct rte_cryptodev_cb *next;
> +	/**< Pointer to next callback */
> +	struct rte_rcu_qsbr *qsbr;
> +	/**< RCU QSBR variable per queue pair */ };
> +
>  /** The data structure associated with each crypto device. */  struct
> rte_cryptodev {
>  	dequeue_pkt_burst_t dequeue_burst;
> @@ -867,6 +915,12 @@ struct rte_cryptodev {
>  	__extension__
>  	uint8_t attached : 1;
>  	/**< Flag indicating the device is attached */
> +
> +	struct rte_cryptodev_cb_rcu *enq_cbs;
> +	/**< User application callback for pre enqueue processing */
> +
> +	struct rte_cryptodev_cb_rcu *deq_cbs;
> +	/**< User application callback for post dequeue processing */
>  } __rte_cache_aligned;
> 
>  void *
> @@ -945,10 +999,33 @@ rte_cryptodev_dequeue_burst(uint8_t dev_id,
> uint16_t qp_id,  {
>  	struct rte_cryptodev *dev = &rte_cryptodevs[dev_id];
> 
> +	rte_cryptodev_trace_dequeue_burst(dev_id, qp_id, (void **)ops,
> +nb_ops);
>  	nb_ops = (*dev->dequeue_burst)
>  			(dev->data->queue_pairs[qp_id], ops, nb_ops);
> -
> -	rte_cryptodev_trace_dequeue_burst(dev_id, qp_id, (void **)ops,
> nb_ops);
> +#ifdef RTE_CRYPTO_CALLBACKS
> +	if (unlikely(dev->deq_cbs != NULL)) {
> +		struct rte_cryptodev_cb_rcu *list;
> +		struct rte_cryptodev_cb *cb;
> +
> +		/* __ATOMIC_RELEASE memory order was used when the
> +		 * call back was inserted into the list.
> +		 * Since there is a clear dependency between loading
> +		 * cb and cb->fn/cb->next, __ATOMIC_ACQUIRE memory order
> is
> +		 * not required.
> +		 */
> +		list = &dev->deq_cbs[qp_id];
> +		rte_rcu_qsbr_thread_online(list->qsbr, 0);
> +		cb = __atomic_load_n(&list->next, __ATOMIC_RELAXED);
> +
> +		while (cb != NULL) {
> +			nb_ops = cb->fn(dev_id, qp_id, ops, nb_ops,
> +					cb->arg);
> +			cb = cb->next;
> +		};
> +
> +		rte_rcu_qsbr_thread_offline(list->qsbr, 0);
> +	}
> +#endif
>  	return nb_ops;
>  }
> 
> @@ -989,6 +1066,31 @@ rte_cryptodev_enqueue_burst(uint8_t dev_id,
> uint16_t qp_id,  {
>  	struct rte_cryptodev *dev = &rte_cryptodevs[dev_id];
> 
> +#ifdef RTE_CRYPTO_CALLBACKS
> +	if (unlikely(dev->enq_cbs != NULL)) {
> +		struct rte_cryptodev_cb_rcu *list;
> +		struct rte_cryptodev_cb *cb;
> +
> +		/* __ATOMIC_RELEASE memory order was used when the
> +		 * call back was inserted into the list.
> +		 * Since there is a clear dependency between loading
> +		 * cb and cb->fn/cb->next, __ATOMIC_ACQUIRE memory order
> is
> +		 * not required.
> +		 */
> +		list = &dev->enq_cbs[qp_id];
> +		rte_rcu_qsbr_thread_online(list->qsbr, 0);
> +		cb = __atomic_load_n(&list->next, __ATOMIC_RELAXED);
> +
> +		while (cb != NULL) {
> +			nb_ops = cb->fn(dev_id, qp_id, ops, nb_ops,
> +					cb->arg);
> +			cb = cb->next;
> +		};
> +
> +		rte_rcu_qsbr_thread_offline(list->qsbr, 0);
> +	}
> +#endif
> +
>  	rte_cryptodev_trace_enqueue_burst(dev_id, qp_id, (void **)ops,
> nb_ops);
>  	return (*dev->enqueue_burst)(
>  			dev->data->queue_pairs[qp_id], ops, nb_ops); @@ -
> 1730,6 +1832,144 @@ int  rte_cryptodev_raw_dequeue_done(struct
> rte_crypto_raw_dp_ctx *ctx,
>  		uint32_t n);
> 
> +/**
> + * Add a user callback for a given crypto device and queue pair which
> +will be
> + * called on crypto ops enqueue.
> + *
> + * This API configures a function to be called for each burst of crypto
> +ops
> + * received on a given crypto device queue pair. The return value is a
> +pointer
> + * that can be used later to remove the callback using
> + * rte_cryptodev_remove_enq_callback().
> + *
> + * Callbacks registered by application would not survive
> + * rte_cryptodev_configure() as it reinitializes the callback list.
> + * It is user responsibility to remove all installed callbacks before
> + * calling rte_cryptodev_configure() to avoid possible memory leakage.
> + * Application is expected to call add API after rte_cryptodev_configure().
> + *
> + * Multiple functions can be registered per queue pair & they are
> +called
> + * in the order they were added. The API does not restrict on maximum
> +number
> + * of callbacks.
> + *
> + * @param	dev_id		The identifier of the device.
> + * @param	qp_id		The index of the queue pair on which ops are
> + *				to be enqueued for processing. The value
> + *				must be in the range [0, nb_queue_pairs - 1]
> + *				previously supplied to
> + *				*rte_cryptodev_configure*.
> + * @param	cb_fn		The callback function
> + * @param	cb_arg		A generic pointer parameter which will be
> passed
> + *				to each invocation of the callback function on
> + *				this crypto device and queue pair.
> + *
> + * @return
> + *  - NULL on error & rte_errno will contain the error code.
> + *  - On success, a pointer value which can later be used to remove the
> + *    callback.
> + */
> +
> +__rte_experimental
> +struct rte_cryptodev_cb *
> +rte_cryptodev_add_enq_callback(uint8_t dev_id,
> +			       uint16_t qp_id,
> +			       rte_cryptodev_callback_fn cb_fn,
> +			       void *cb_arg);
> +
> +/**
> + * Remove a user callback function for given crypto device and queue pair.
> + *
> + * This function is used to remove enqueue callbacks that were added to
> +a
> + * crypto device queue pair using rte_cryptodev_add_enq_callback().
> + *
> + *
> + *
> + * @param	dev_id		The identifier of the device.
> + * @param	qp_id		The index of the queue pair on which ops are
> + *				to be enqueued. The value must be in the
> + *				range [0, nb_queue_pairs - 1] previously
> + *				supplied to *rte_cryptodev_configure*.
> + * @param	cb		Pointer to user supplied callback created via
> + *				rte_cryptodev_add_enq_callback().
> + *
> + * @return
> + *   -  0: Success. Callback was removed.
> + *   - <0: The dev_id or the qp_id is out of range, or the callback
> + *         is NULL or not found for the crypto device queue pair.
> + */
> +
> +__rte_experimental
> +int rte_cryptodev_remove_enq_callback(uint8_t dev_id,
> +				      uint16_t qp_id,
> +				      struct rte_cryptodev_cb *cb);
> +
> +/**
> + * Add a user callback for a given crypto device and queue pair which
> +will be
> + * called on crypto ops dequeue.
> + *
> + * This API configures a function to be called for each burst of crypto
> +ops
> + * received on a given crypto device queue pair. The return value is a
> +pointer
> + * that can be used later to remove the callback using
> + * rte_cryptodev_remove_deq_callback().
> + *
> + * Callbacks registered by application would not survive
> + * rte_cryptodev_configure() as it reinitializes the callback list.
> + * It is user responsibility to remove all installed callbacks before
> + * calling rte_cryptodev_configure() to avoid possible memory leakage.
> + * Application is expected to call add API after rte_cryptodev_configure().
> + *
> + * Multiple functions can be registered per queue pair & they are
> +called
> + * in the order they were added. The API does not restrict on maximum
> +number
> + * of callbacks.
> + *
> + * @param	dev_id		The identifier of the device.
> + * @param	qp_id		The index of the queue pair on which ops are
> + *				to be dequeued. The value must be in the
> + *				range [0, nb_queue_pairs - 1] previously
> + *				supplied to *rte_cryptodev_configure*.
> + * @param	cb_fn		The callback function
> + * @param	cb_arg		A generic pointer parameter which will be
> passed
> + *				to each invocation of the callback function on
> + *				this crypto device and queue pair.
> + *
> + * @return
> + *   - NULL on error & rte_errno will contain the error code.
> + *   - On success, a pointer value which can later be used to remove the
> + *     callback.
> + */
> +
> +__rte_experimental
> +struct rte_cryptodev_cb *
> +rte_cryptodev_add_deq_callback(uint8_t dev_id,
> +			       uint16_t qp_id,
> +			       rte_cryptodev_callback_fn cb_fn,
> +			       void *cb_arg);
> +
> +/**
> + * Remove a user callback function for given crypto device and queue pair.
> + *
> + * This function is used to remove dequeue callbacks that were added to
> +a
> + * crypto device queue pair using rte_cryptodev_add_deq_callback().
> + *
> + *
> + *
> + * @param	dev_id		The identifier of the device.
> + * @param	qp_id		The index of the queue pair on which ops are
> + *				to be dequeued. The value must be in the
> + *				range [0, nb_queue_pairs - 1] previously
> + *				supplied to *rte_cryptodev_configure*.
> + * @param	cb		Pointer to user supplied callback created via
> + *				rte_cryptodev_add_deq_callback().
> + *
> + * @return
> + *   -  0: Success. Callback was removed.
> + *   - <0: The dev_id or the qp_id is out of range, or the callback
> + *         is NULL or not found for the crypto device queue pair.
> + */
> +__rte_experimental
> +int rte_cryptodev_remove_deq_callback(uint8_t dev_id,
> +				      uint16_t qp_id,
> +				      struct rte_cryptodev_cb *cb);
> +
>  #ifdef __cplusplus
>  }
>  #endif
> diff --git a/lib/librte_cryptodev/version.map b/lib/librte_cryptodev/version.map
> index 7e4360ff0..9f04737ae 100644
> --- a/lib/librte_cryptodev/version.map
> +++ b/lib/librte_cryptodev/version.map
> @@ -109,4 +109,11 @@ EXPERIMENTAL {
>  	rte_cryptodev_raw_enqueue;
>  	rte_cryptodev_raw_enqueue_burst;
>  	rte_cryptodev_raw_enqueue_done;
> +
> +	# added in 21.02
> +	rte_cryptodev_add_deq_callback;
> +	rte_cryptodev_add_enq_callback;
> +	rte_cryptodev_remove_deq_callback;
> +	rte_cryptodev_remove_enq_callback;
> +
>  };
> --
> 2.25.1