[dpdk-dev] [PATCH v3 1/4] ena: Amazon ENA documentation

[Jan Medala <jan@semihalf.com>]

Signed-off-by: Evgeny Schemeilin <evgenys@amazon.com>
Signed-off-by: Alexander Matushevsky <matua@amazon.com>
Signed-off-by: Jan Medala <jan@semihalf.com>
Signed-off-by: Jakub Palider <jpa@semihalf.com>
---
 doc/guides/nics/ena.rst | 238 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 238 insertions(+)
 create mode 100644 doc/guides/nics/ena.rst

diff --git a/doc/guides/nics/ena.rst b/doc/guides/nics/ena.rst
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+.. BSD LICENSE
+
+    Copyright (c) 2015-2016 Amazon.com, Inc. or its affiliates.
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+    * Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+    * Neither the name of Amazon.com, Inc. nor the names of its
+    contributors may be used to endorse or promote products derived
+    from this software without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+ENA Poll Mode Driver
+=====================
+ENA PMD is the DPDK poll-mode driver for the Amazon Elastic
+Network Adapter (ENA) family.
+
+Overview
+--------
+The ENA driver exposes a lightweight management interface with a
+minimal set of memory mapped registers and extendable command set
+through an Admin Queue.
+
+The driver supports a wide range of ENA adapter, is link-speed
+independent (i.e., the same driver is used for 10GbE, 25GbE, 40GbE,
+etc.), and it negotiates and supports extendable feature set.
+
+ENA adapters allow high speed and low overhead Ethernet traffic
+processing by providing a dedicated Tx/Rx queue pair per CPU core.
+
+The ENA driver supports industry standard TCP/IP offload features such
+as checksum offload and TCP transmit segmentation offload (TSO).
+
+Receive-side scaling (RSS) is supported for multi-core scaling.
+
+Some of the ENA devices support a working mode called Low-latency
+Queue (LLQ), which saves several more microseconds.
+
+Management Interface
+----------------------
+ENA management interface is exposed by means of:
+- Device Registers
+- Admin Queue (AQ) and Admin Completion Queue (ACQ)
+
+ENA device memory-mapped PCIe space for registers (MMIO registers)
+are accessed only during driver initialization and are not involved
+in further normal device operation.
+
+AQ is used for submitting management commands, and the
+results/responses are reported asynchronously through ACQ.
+
+ENA introduces a very small set of management commands with room for
+vendor-specific extensions. Most of the management operations are
+framed in a generic Get/Set feature command.
+
+The following admin queue commands are supported:
+- Create I/O submission queue
+- Create I/O completion queue
+- Destroy I/O submission queue
+- Destroy I/O completion queue
+- Get feature
+- Set feature
+- Get statistics
+
+Refer to ena_admin_defs.h for the list of supported Get/Set Feature
+properties.
+
+Data Path Interface
+-------------------
+I/O operations are based on Tx and Rx Submission Queues (Tx SQ and Rx
+SQ correspondingly). Each SQ has a completion queue (CQ) associated
+with it.
+
+The SQs and CQs are implemented as descriptor rings in contiguous
+physical memory.
+
+Refer to ena_eth_io_defs.h for the detailed structure of the descriptor
+
+The driver supports multi-queue for both Tx and Rx.
+
+Configuration information
+-------------------------
+- **DPDK Configuration Parameters**
+
+  The following configuration options are available for the ENIC PMD:
+
+  - **CONFIG_RTE_LIBRTE_ENA_PMD** (default y): Enables or disables inclusion
+    of the ENA PMD driver in the DPDK compilation.
+
+  - **CONFIG_RTE_LIBRTE_ENA_DEBUG_INIT** (default y): Enables or disables debug
+    logging of device initialization within the ENA PMD driver.
+
+  - **CONFIG_RTE_LIBRTE_ENA_DEBUG_RX** (default n): Enables or disables debug
+    logging of RX logic within the ENA PMD driver.
+
+  - **CONFIG_RTE_LIBRTE_ENA_DEBUG_TX** (default n): Enables or disables debug
+    logging of TX logic within the ENA PMD driver.
+
+  - **CONFIG_RTE_LIBRTE_ENA_COM_DEBUG** (default n): Enables or disables debug
+    logging of low level tx/rx logic in ena_com(base) within the ENA PMD driver.
+
+- **ENA Configuration Parameters**
+
+  - **Number of Queues**
+
+    This is the requested number of queues upon initialization, however, the actual number of receive and transmit queues to be created will be the minimum between the maximal number supported by the device and number of queues requested.
+
+  - **Size of Queues**
+
+    This is the requested size of receive/transmit queues, while the actual size will be the minimum between the requested size and the maximal receive/transmit supported by the device.
+
+How to build the suite?
+-----------------------
+The build instructions for the DPDK suite should as follows:
+
+By default the ENA PMD library will be built into the DPDK library.
+
+For configuring and using UIO and VFIO frameworks, please refer the
+documentation that comes with DPDK suite.
+
+Supported ENA adapters
+----------------------------
+Current ENA PMD supports the following ENA adapters including:
+
+- 1d0f:ec20 - ENA VF
+- 1d0f:1ec2 - ENA LLQ VF
+
+Supported Operating Systems
+---------------------------
+Any Linux distribution fulfilling the conditions described in Dependencies
+section of DPDK documentation.
+
+Supported features
+------------------
+- Jumbo frames up to 9K
+- Port Hardware Statistics
+- IPv4/TCP/UDP checksum offload
+- TSO offload
+- Multiple receive and transmit queues
+- RSS
+- Low Latency Queue for Tx
+
+Known bugs and Unsupported features in this release
+---------------------------------------------------
+The features supported by the device and not yet supported by this PMD include:
+- Asynchronous Event Notification Queue (AENQ)
+
+Prerequisites
+-------------
+- Prepare the system as recommended by DPDK suite.  This includes environment
+  variables, hugepages configuration, tool-chains and configuration
+- Insert igb_uio kernel module using the command 'modprobe igb_uio'
+- Bind the intended ENA device to igb_uio module
+
+At this point the system should be ready to run DPDK applications. Once the
+application runs to completion, the ENA can be detached from igb_uio if necessary.
+
+Usage example
+-------------
+
+This section demonstrates how to launch **testpmd** with Amazon ENA
+devices managed by librte_pmd_ena.
+
+#. Load the kernel modules:
+
+   .. code-block:: console
+
+      modprobe uio
+      insmod ./x86_64-native-linuxapp-gcc/kmod/igb_uio.ko
+
+   .. note::
+
+      Currently Amazon ENA PMD driver depends on igb_uio user space I/O kernel module
+
+#. Mount and request huge pages:
+
+   .. code-block:: console
+
+      mount -t hugetlbfs nodev /mnt/hugepages
+      echo 1024 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
+
+#. Bind UIO driver to ENA device (using provided by DPDK binding tool):
+
+   .. code-block:: console
+
+      ./tools/dpdk_nic_bind.py --bind=igb_uio 0000:02:00.1
+
+#. Start testpmd with basic parameters:
+
+   .. code-block:: console
+
+      ./x86_64-native-linuxapp-gcc/app/testpmd -c 0xf -n 4 -- -i
+
+   Example output:
+
+   .. code-block:: console
+
+      [...]
+      EAL: PCI device 0000:02:00.1 on NUMA socket -1
+      EAL:   probe driver: 1d0f:ec20 rte_ena_pmd
+      EAL:   PCI memory mapped at 0x7f9b6c400000
+      PMD: eth_ena_dev_init(): Initializing 0:2:0.1
+      Interactive-mode selected
+      Configuring Port 0 (socket 0)
+      Port 0: 00:00:00:11:00:01
+      Checking link statuses...
+      Port 0 Link Up - speed 10000 Mbps - full-duplex
+      Done
+      testpmd>
+
+Contact Information
+-------------------
+Any questions or bugs should be reported to DPDK community and to the ENA PMD
+maintainers:
+
+- Jan Medala <jan@semihalf.com>
+- Jakub Palider <jpa@semihalf.com>
+- Netanel Belgazal <netanel@amazon.com>
+- Evgeny Schemeilin <evgenys@amazon.com>
-- 
1.9.1