[dpdk-dev] [PATCH v2 10/10] doc: update prog guide and sample app guid

[Fan Zhang]

Signed-off-by: Fan Zhang <roy.fan.zhang at intel.com>
---
 doc/guides/prog_guide/vhost_lib.rst       | 27 ++++++++++
 doc/guides/sample_app_ug/index.rst        |  1 +
 doc/guides/sample_app_ug/vhost_crypto.rst | 83 +++++++++++++++++++++++++++++++
 3 files changed, 111 insertions(+)
 create mode 100644 doc/guides/sample_app_ug/vhost_crypto.rst

diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
index 18227b6a3..f03b9aad8 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -160,6 +160,33 @@ The following is an overview of some key Vhost API functions:
 
   Receives (dequeues) ``count`` packets from guest, and stored them at ``pkts``.
 
+* ``rte_vhost_crypto_create(vid, cryptodev_id, sess_mempool, socket_id)``
+
+  As an extension of `new_device()`, this function adds virtio-crypto workload
+  acceleration capability to the device. All crypto workload is processed by
+  DPDK cryptodev with the device ID of `cryptodev_id`.
+
+* ``rte_vhost_crypto_free(vid)``
+
+  As an extension of `destroy_device()`, this function frees up the memory
+  created in `rte_vhost_crypto_create()`.
+
+* ``rte_vhost_crypto_fetch_requests(vid, queue_id, ops, nb_ops)``
+
+  Receives (dequeues) `nb_ops` virtio-crypto requests from the virt-queue
+  `queue_id` of the guest `vid`, converts them to DPDK Crypto Operations, and
+  fills the `ops` with conversion results.
+
+* ``rte_vhost_crypto_finalize_requests(queue_id, ops, nb_ops, callfds, nb_fds)``
+
+  After the `ops` are dequeued from Cryptodev, updates the used ring
+  of the virtqueue, copy back the data (if zero-copy is disabled), and updates
+  the callfd numbers for the application to notify the guest(s).
+
+* ``rte_vhost_crypto_set_zero_copy(vid, enable_zc)``
+  This function enables/disables the zero copy feature of the vhost crypto
+  acceleration engine.
+
 Vhost-user Implementations
 --------------------------
 
diff --git a/doc/guides/sample_app_ug/index.rst b/doc/guides/sample_app_ug/index.rst
index e87afda80..57e8354d4 100644
--- a/doc/guides/sample_app_ug/index.rst
+++ b/doc/guides/sample_app_ug/index.rst
@@ -44,6 +44,7 @@ Sample Applications User Guides
     vmdq_dcb_forwarding
     vhost
     vhost_scsi
+    vhost_crypto
     netmap_compatibility
     ip_pipeline
     test_pipeline
diff --git a/doc/guides/sample_app_ug/vhost_crypto.rst b/doc/guides/sample_app_ug/vhost_crypto.rst
new file mode 100644
index 000000000..5051064dc
--- /dev/null
+++ b/doc/guides/sample_app_ug/vhost_crypto.rst
@@ -0,0 +1,83 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2010-2014 Intel Corporation.
+
+
+Vhost_Crypto Sample Application
+===============================
+
+The vhost_crypto sample application implemented a simple Crypto device,
+which used as the  backend of Qemu vhost-user-crypto device. Similar with
+vhost-user-net and vhost-user-scsi device, the sample application used
+domain socket to communicate with Qemu, and the virtio ring was processed
+by vhost_crypto sample application.
+
+Testing steps
+-------------
+
+This section shows the steps how to start a VM with the crypto device as
+fast data path for critical application.
+
+Compiling the Application
+-------------------------
+
+To compile the sample application see :doc:`compiling`.
+
+The application is located in the ``examples`` sub-directory.
+
+Start the vhost_crypto example
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. code-block:: console
+
+    ./vhost_crypto [EAL options] -- [--socket-file PATH]
+        [--cdev-id ID] [--cdev-queue-id ID] [--zero-copy] [--guest-polling]
+
+where,
+
+* socket-file PATH: the path of UNIX socket file to be created, multiple
+  instances of this config item is supported. Upon absence of this item,
+  the default socket-file `/tmp/vhost_crypto1.socket` is used.
+
+* cdev-id ID: the target DPDK Cryptodev's ID to process the actual crypto
+  workload. Upon absence of this item the default value of `0` will be used.
+  For details of DPDK Cryptodev, please refer to DPDK Cryptodev Library
+  Programmers' Guide.
+
+* cdev-queue-id ID: the target DPDK Cryptodev's queue ID to process the
+  actual crypto workload. Upon absence of this item the default value of `0`
+  will be used. For details of DPDK Cryptodev, please refer to DPDK Cryptodev
+  Library Programmers' Guide.
+
+* zero-copy: the presence of this item means the ZERO-COPY feature will be
+  enabled. Otherwise it is disabled. PLEASE NOTE the ZERO-COPY feature is still
+  in experimental stage and may cause the problem like segmentation fault. If
+  the user wants to use LKCF in the guest, this feature shall be turned off.
+
+* guest-polling: the presence of this item means the application assumes the
+  guest works in polling mode, thus will NOT notify the guest completion of
+  processing.
+
+The application requires that crypto devices capable of performing
+the specified crypto operation are available on application initialization.
+This means that HW crypto device/s must be bound to a DPDK driver or
+a SW crypto device/s (virtual crypto PMD) must be created (using --vdev).
+
+.. _vhost_crypto_app_run_vm:
+
+Start the VM
+~~~~~~~~~~~~
+
+.. code-block:: console
+
+    qemu-system-x86_64 -machine accel=kvm \
+        -m $mem -object memory-backend-file,id=mem,size=$mem,\
+        mem-path=/dev/hugepages,share=on -numa node,memdev=mem \
+        -drive file=os.img,if=none,id=disk \
+        -device ide-hd,drive=disk,bootindex=0 \
+        -chardev socket,id={chardev_id},path={PATH} \
+        -object cryptodev-vhost-user,id={obj_id},chardev={chardev_id} \
+        -device virtio-crypto-pci,id={dev_id},cryptodev={obj_id} \
+        ...
+
+.. note::
+    You must check whether your Qemu can support "vhost-user-crypto" or not.
-- 
2.13.6