[dpdk-users] Memory requirements for crypto devices (QAT and AESNI) (using DPDK-17.02)

[Chinmaya Dwibedy <ckdwibedy@gmail.com>]

Hi All,


We are using DPK-17.02.  We use crypto via hardware (QAT) and software
acceleration (AESNI).  There is one to one mapping between crypto Dev and
worker core. What are the memory requirements for the below stated

1)           Creation of one physical Crypto device.

2)           Creation of one AESNI MB virtual Crypto device.

Thereafter we configure a device with the default number of queue pairs to
set up for the device as shown below.


#define CDEV_MP_CACHE_SZ 64

rte_cryptodev_info_get(cdev_id, &info);

                dev_conf.nb_queue_pairs = info.max_nb_queue_pairs;

                dev_conf.session_mp.nb_objs = info.sym.max_nb_sessions;

                  dev_conf.socket_id = SOCKET_ID_ANY;

                dev_conf.session_mp.cache_size = CDEV_MP_CACHE_SZ;

rte_cryptodev_configure (cdev_id, &dev_conf);


How to calculate the minimum memory required to configure per HW and per SW
crypto device. Then we allocate and set up a receive queue pair for a
device as follows. As of now we use one queue per device and number of
descriptors per queue pair is set to 2k. If we increase the number of
descriptors, will it improve the performance in terms of throughput?


#define CDEV_MP_NB_OBJS 2048

qp_conf.nb_descriptors = CDEV_MP_NB_OBJS;

rte_cryptodev_queue_pair_setup (cdev_id, 0, &qp_conf, dev_conf.socket_id)


We create a session for symmetric cryptographic operations per IPsec
Security association.  What is the memory required to hold session data
structure?


The intent behind this is to calculate the memory requirements in advance
(before EAL initialization) and based upon the available memory, figure out
how many crypto devices (note: our application initializes AESNI vdev
without using EAL command line option) can be initialized? Say there are 24
worker cores and we need 24 crypto AESNI vdevs. But there is no sufficient
hugepage memory for creating 24 crypto AESNI vdevs. In such case, we will
allocate more hugepages , then call rte_eal_init() and expect it to be
passed.


Thank you in advance for your suggestion and time.



Regards,

Chinmaya