The vdpa sample application creates vhost-user sockets by using the
vDPA backend. vDPA stands for vhost Data Path Acceleration which utilizes
virtio ring compatible devices to serve virtio driver directly to enable
datapath acceleration. As vDPA driver can help to set up vhost datapath,
this application doesn't need to launch dedicated worker threads for vhost
enqueue/dequeue operations.

Signed-off-by: Xiao Wang <redacted>
Signed-off-by: Xiaolong Ye <redacted>
---
  MAINTAINERS                            |   2 +
  doc/guides/rel_notes/release_18_11.rst |   8 +
  doc/guides/sample_app_ug/index.rst     |   1 +
  doc/guides/sample_app_ug/vdpa.rst      | 120 +++++++
  examples/Makefile                      |   2 +-
  examples/vdpa/Makefile                 |  32 ++
  examples/vdpa/main.c                   | 466 +++++++++++++++++++++++++
  examples/vdpa/meson.build              |  16 +
  8 files changed, 646 insertions(+), 1 deletion(-)
  create mode 100644 doc/guides/sample_app_ug/vdpa.rst
  create mode 100644 examples/vdpa/Makefile
  create mode 100644 examples/vdpa/main.c
  create mode 100644 examples/vdpa/meson.build

diff --git a/MAINTAINERS b/MAINTAINERS
index 5967c1dd3..5656f18e8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS

@@ -683,6 +683,8 @@ F: doc/guides/sample_app_ug/vhost.rst
  F: examples/vhost_scsi/
  F: doc/guides/sample_app_ug/vhost_scsi.rst
  F: examples/vhost_crypto/
+F: examples/vdpa/
+F: doc/guides/sample_app_ug/vdpa.rst
  
  Vhost PMD
  M: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst
index bc9b74ec4..dd53a9ecf 100644
--- a/doc/guides/rel_notes/release_18_11.rst
+++ b/doc/guides/rel_notes/release_18_11.rst

@@ -67,6 +67,14 @@ New Features
    SR-IOV option in Hyper-V and Azure. This is an alternative to the previous
    vdev_netvsc, tap, and failsafe drivers combination.
  
+* **Add a new sample for vDPA**
+
+  The vdpa sample application creates vhost-user sockets by using the
+  vDPA backend. vDPA stands for vhost Data Path Acceleration which utilizes
+  virtio ring compatible devices to serve virtio driver directly to enable
+  datapath acceleration. As vDPA driver can help to set up vhost datapath,
+  this application doesn't need to launch dedicated worker threads for vhost
+  enqueue/dequeue operations.
  
  API Changes
  -----------

diff --git a/doc/guides/sample_app_ug/index.rst b/doc/guides/sample_app_ug/index.rst
index 5bedf4f6f..74b12af85 100644
--- a/doc/guides/sample_app_ug/index.rst
+++ b/doc/guides/sample_app_ug/index.rst

@@ -45,6 +45,7 @@ Sample Applications User Guides
      vhost
      vhost_scsi
      vhost_crypto
+    vdpa
      netmap_compatibility
      ip_pipeline
      test_pipeline

diff --git a/doc/guides/sample_app_ug/vdpa.rst b/doc/guides/sample_app_ug/vdpa.rst
new file mode 100644
index 000000000..745f196ca
--- /dev/null
+++ b/doc/guides/sample_app_ug/vdpa.rst

@@ -0,0 +1,120 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2018 Intel Corporation.
+
+Vdpa Sample Application
+=======================
+
+The vdpa sample application creates vhost-user sockets by using the
+vDPA backend. vDPA stands for vhost Data Path Acceleration which utilizes
+virtio ring compatible devices to serve virtio driver directly to enable
+datapath acceleration. As vDPA driver can help to set up vhost datapath,
+this application doesn't need to launch dedicated worker threads for vhost
+enqueue/dequeue operations.
+
+Testing steps
+-------------
+
+This section shows the steps of how to start VMs with vDPA vhost-user
+backend and verify network connection & live migration.
+
+Build
+~~~~~
+
+To compile the sample application see :doc:`compiling`.
+
+The application is located in the ``vdpa`` sub-directory.
+
+Start the vdpa example
+~~~~~~~~~~~~~~~~~~~~~~
+
+.. code-block:: console
+
+        ./vdpa [EAL options]  -- [--client] [--interactive|-i] or [--iface SOCKET_PATH]
+
+where
+
+* --client means running vdpa app in client mode, in the client mode, QEMU needs
+  to run as the server mode and take charge of socket file creation.
+* --iface specifies the path prefix of the UNIX domain socket file, e.g.
+  /tmp/vhost-user-, then the socket files will be named as /tmp/vhost-user-<n>
+  (n starts from 0).
+* --interactive means run the vdpa sample in interactive mode, currently 4
+  internal cmds are supported:
+
+  1. help: show help message
+  2. list: list all available vdpa devices
+  3. create: create a new vdpa port with socket file and vdpa device address
+  4. quit: unregister vhost driver and exit the application
+
+Take IFCVF driver for example:
+
+.. code-block:: console
+
+        ./vdpa -c 0x2 -n 4 --socket-mem 1024,1024 \
+                -w 0000:06:00.3,vdpa=1 -w 0000:06:00.4,vdpa=1 \
+                -- --interactive
+
+.. note::
+    Here 0000:06:00.3 and 0000:06:00.4 refer to virtio ring compatible devices,
+    and we need to bind vfio-pci to them before running vdpa sample.
+
+    * modprobe vfio-pci
+    * ./usertools/dpdk-devbind.py -b vfio-pci 06:00.3 06:00.4
+
+Then we can create 2 vdpa ports in interactive cmdline.
+
+.. code-block:: console
+
+        vdpa> list
+        device id       device address  queue num       supported features
+        0               0000:06:00.3    1               0x14c238020
+        1               0000:06:00.4    1               0x14c238020
+        2               0000:06:00.5    1               0x14c238020
+
+        vdpa> create /tmp/vdpa-socket0 0000:06:00.3
+        vdpa> create /tmp/vdpa-socket1 0000:06:00.4
+
+.. _vdpa_app_run_vm:
+
+Start the VMs
+~~~~~~~~~~~~~
+
+.. code-block:: console
+
+       qemu-system-x86_64 -cpu host -enable-kvm \
+       <snip>
+       -mem-prealloc \
+       -chardev socket,id=char0,path=<socket_file created in above steps> \
+       -netdev type=vhost-user,id=vdpa,chardev=char0 \
+       -device virtio-net-pci,netdev=vdpa,mac=00:aa:bb:cc:dd:ee,page-per-vq=on \
+
+After the VMs launches, we can login the VMs and configure the ip, verify the
+network connection via ping or netperf.
+
+.. note::
+    Suggest to use QEMU 3.0.0 which extends vhost-user for vDPA.
+
+Live Migration
+~~~~~~~~~~~~~~
+vDPA supports cross-backend live migration, user can migrate SW vhost backend
+VM to vDPA backend VM and vice versa. Here are the detailed steps. Assume A is
+the source host with SW vhost VM and B is the destination host with vDPA.
+
+1. Start vdpa sample and launch a VM with exact same parameters as the VM on A,
+   in migration-listen mode:
+
+.. code-block:: console
+
+        B: <qemu-command-line> -incoming tcp:0:4444 (or other PORT))
+
+2. Start the migration (on source host):
+
+.. code-block:: console
+
+        A: (qemu) migrate -d tcp:<B ip>:4444 (or other PORT)
+
+3. Check the status (on source host):
+
+.. code-block:: console
+
+        A: (qemu) info migrate

diff --git a/examples/Makefile b/examples/Makefile
index 481720cb6..356fcb1cd 100644
--- a/examples/Makefile
+++ b/examples/Makefile

@@ -65,7 +65,7 @@ ifeq ($(CONFIG_RTE_LIBRTE_HASH),y)
  DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += tep_termination
  endif
  DIRS-$(CONFIG_RTE_LIBRTE_TIMER) += timer
-DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost vhost_scsi
+DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost vhost_scsi vdpa
  ifeq ($(CONFIG_RTE_LIBRTE_CRYPTODEV),y)
  DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += vhost_crypto
  endif

diff --git a/examples/vdpa/Makefile b/examples/vdpa/Makefile
new file mode 100644
index 000000000..42672a2bc
--- /dev/null
+++ b/examples/vdpa/Makefile

@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2018 Intel Corporation
+
+ifeq ($(RTE_SDK),)
+$(error "Please define RTE_SDK environment variable")
+endif
+
+# Default target, can be overridden by command line or environment
+RTE_TARGET ?= x86_64-native-linuxapp-gcc
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+ifneq ($(CONFIG_RTE_EXEC_ENV),"linuxapp")
+$(info This application can only operate in a linuxapp environment, \
+please change the definition of the RTE_TARGET environment variable)
+all:
+else
+
+# binary name
+APP = vdpa
+
+# all source are stored in SRCS-y
+SRCS-y := main.c
+
+CFLAGS += -O2 -D_FILE_OFFSET_BITS=64
+CFLAGS += $(WERROR_FLAGS)
+CFLAGS += -D_GNU_SOURCE
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+
+include $(RTE_SDK)/mk/rte.extapp.mk
+
+endif

diff --git a/examples/vdpa/main.c b/examples/vdpa/main.c
new file mode 100644
index 000000000..898286e30
--- /dev/null
+++ b/examples/vdpa/main.c

@@ -0,0 +1,466 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2018 Intel Corporation
+ */
+
+#include <getopt.h>
+#include <signal.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rte_ethdev.h>
+#include <rte_malloc.h>
+#include <rte_vhost.h>
+#include <rte_vdpa.h>
+#include <rte_pci.h>
+
+#include <cmdline_parse.h>
+#include <cmdline_socket.h>
+#include <cmdline_parse_string.h>
+#include <cmdline.h>
+
+#define MAX_PATH_LEN 128
+#define MAX_VDPA_SAMPLE_PORTS 1024
+#define RTE_LOGTYPE_VDPA RTE_LOGTYPE_USER1
+
+struct vdpa_port {
+	char ifname[MAX_PATH_LEN];
+	int did;
+	int vid;
+	uint64_t flags;
+};
+
+struct vdpa_port vports[MAX_VDPA_SAMPLE_PORTS];