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numam-dpdk/doc/guides/nics/enic.rst
John Daley d4f954b166 doc: fix enic guide syntax 
Fixes: 211f9a9ce2 ("enic: add guide")
Cc: stable@dpdk.org

Signed-off-by: John Daley <johndale@cisco.com>
Acked-by: John McNamara <john.mcnamara@intel.com>
2017-04-28 14:46:18 +02:00

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.. BSD LICENSE
Copyright (c) 2017, Cisco Systems, Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. 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.
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 HOLDER 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.
ENIC Poll Mode Driver
=====================
ENIC PMD is the DPDK poll-mode driver for the Cisco System Inc. VIC Ethernet
NICs. These adapters are also referred to as vNICs below. If you are running
or would like to run DPDK software applications on Cisco UCS servers using
Cisco VIC adapters the following documentation is relevant.
How to obtain ENIC PMD integrated DPDK
--------------------------------------
ENIC PMD support is integrated into the DPDK suite. dpdk-<version>.tar.gz
should be downloaded from http://dpdk.org
Configuration information
-------------------------
- **DPDK Configuration Parameters**
The following configuration options are available for the ENIC PMD:
- **CONFIG_RTE_LIBRTE_ENIC_PMD** (default y): Enables or disables inclusion
of the ENIC PMD driver in the DPDK compilation.
- **CONFIG_RTE_LIBRTE_ENIC_DEBUG** (default n): Enables or disables debug
logging within the ENIC PMD driver.
- **vNIC Configuration Parameters**
- **Number of Queues**
The maximum number of receive queues (RQs), work queues (WQs) and
completion queues (CQs) are configurable on a per vNIC basis
through the Cisco UCS Manager (CIMC or UCSM).
These values should be configured as follows:
- The number of WQs should be greater or equal to the value of the
expected nb_tx_q parameter in the call to the
rte_eth_dev_configure()
- The number of RQs configured in the vNIC should be greater or
equal to *twice* the value of the expected nb_rx_q parameter in
the call to rte_eth_dev_configure(). With the addition of Rx
scatter, a pair of RQs on the vnic is needed for each receive
queue used by DPDK, even if Rx scatter is not being used.
Having a vNIC with only 1 RQ is not a valid configuration, and
will fail with an error message.
- The number of CQs should set so that there is one CQ for each
WQ, and one CQ for each pair of RQs.
For example: If the application requires 3 Rx queues, and 3 Tx
queues, the vNIC should be configured to have at least 3 WQs, 6
RQs (3 pairs), and 6 CQs (3 for use by WQs + 3 for use by the 3
pairs of RQs).
- **Size of Queues**
Likewise, the number of receive and transmit descriptors are configurable on
a per vNIC bases via the UCS Manager and should be greater than or equal to
the nb_rx_desc and nb_tx_desc parameters expected to be used in the calls
to rte_eth_rx_queue_setup() and rte_eth_tx_queue_setup() respectively.
An application requesting more than the set size will be limited to that
size.
Unless there is a lack of resources due to creating many vNICs, it
is recommended that the WQ and RQ sizes be set to the maximum. This
gives the application the greatest amount of flexibility in its
queue configuration.
- *Note*: Since the introduction of Rx scatter, for performance
reasons, this PMD uses two RQs on the vNIC per receive queue in
DPDK. One RQ holds descriptors for the start of a packet the
second RQ holds the descriptors for the rest of the fragments of
a packet. This means that the nb_rx_desc parameter to
rte_eth_rx_queue_setup() can be a greater than 4096. The exact
amount will depend on the size of the mbufs being used for
receives, and the MTU size.
For example: If the mbuf size is 2048, and the MTU is 9000, then
receiving a full size packet will take 5 descriptors, 1 from the
start of packet queue, and 4 from the second queue. Assuming
that the RQ size was set to the maximum of 4096, then the
application can specify up to 1024 + 4096 as the nb_rx_desc
parameter to rte_eth_rx_queue_setup().
- **Interrupts**
Only one interrupt per vNIC interface should be configured in the UCS
manager regardless of the number receive/transmit queues. The ENIC PMD
uses this interrupt to get information about link status and errors
in the fast path.
.. _enic-flow-director:
Flow director support
---------------------
Advanced filtering support was added to 1300 series VIC firmware starting
with version 2.0.13 for C-series UCS servers and version 3.1.2 for UCSM
managed blade servers. In order to enable advanced filtering the 'Advanced
filter' radio button should be enabled via CIMC or UCSM followed by a reboot
of the server.
With advanced filters, perfect matching of all fields of IPv4, IPv6 headers
as well as TCP, UDP and SCTP L4 headers is available through flow director.
Masking of these fields for partial match is also supported.
Without advanced filter support, the flow director is limited to IPv4
perfect filtering of the 5-tuple with no masking of fields supported.
SR-IOV mode utilization
-----------------------
UCS blade servers configured with dynamic vNIC connection policies in UCS
manager are capable of supporting assigned devices on virtual machines (VMs)
through a KVM hypervisor. Assigned devices, also known as 'passthrough'
devices, are SR-IOV virtual functions (VFs) on the host which are exposed
to VM instances.
The Cisco Virtual Machine Fabric Extender (VM-FEX) gives the VM a dedicated
interface on the Fabric Interconnect (FI). Layer 2 switching is done at
the FI. This may eliminate the requirement for software switching on the
host to route intra-host VM traffic.
Please refer to `Creating a Dynamic vNIC Connection Policy
<http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/sw/vm_fex/vmware/gui/config_guide/b_GUI_VMware_VM-FEX_UCSM_Configuration_Guide/b_GUI_VMware_VM-FEX_UCSM_Configuration_Guide_chapter_010.html#task_433E01651F69464783A68E66DA8A47A5>`_
for information on configuring SR-IOV Adapter policies using UCS manager.
Once the policies are in place and the host OS is rebooted, VFs should be
visible on the host, E.g.:
.. code-block:: console
# lspci | grep Cisco | grep Ethernet
0d:00.0 Ethernet controller: Cisco Systems Inc VIC Ethernet NIC (rev a2)
0d:00.1 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
0d:00.2 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
0d:00.3 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
0d:00.4 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
0d:00.5 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
0d:00.6 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
0d:00.7 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
Enable Intel IOMMU on the host and install KVM and libvirt. A VM instance should
be created with an assigned device. When using libvirt, this configuration can
be done within the domain (i.e. VM) config file. For example this entry maps
host VF 0d:00:01 into the VM.
.. code-block:: console
<interface type='hostdev' managed='yes'>
<mac address='52:54:00:ac:ff:b6'/>
<source>
<address type='pci' domain='0x0000' bus='0x0d' slot='0x00' function='0x1'/>
</source>
Alternatively, the configuration can be done in a separate file using the
``network`` keyword. These methods are described in the libvirt documentation for
`Network XML format <https://libvirt.org/formatnetwork.html>`_.
When the VM instance is started, the ENIC KVM driver will bind the host VF to
vfio, complete provisioning on the FI and bring up the link.
.. note::
It is not possible to use a VF directly from the host because it is not
fully provisioned until the hypervisor brings up the VM that it is assigned
to.
In the VM instance, the VF will now be visible. E.g., here the VF 00:04.0 is
seen on the VM instance and should be available for binding to a DPDK.
.. code-block:: console
# lspci | grep Ether
00:04.0 Ethernet controller: Cisco Systems Inc VIC SR-IOV VF (rev a2)
Follow the normal DPDK install procedure, binding the VF to either ``igb_uio``
or ``vfio`` in non-IOMMU mode.
Please see :ref:`Limitations <enic_limitations>` for limitations in
the use of SR-IOV.
.. _enic_limitations:
Limitations
-----------
- **VLAN 0 Priority Tagging**
If a vNIC is configured in TRUNK mode by the UCS manager, the adapter will
priority tag egress packets according to 802.1Q if they were not already
VLAN tagged by software. If the adapter is connected to a properly configured
switch, there will be no unexpected behavior.
In test setups where an Ethernet port of a Cisco adapter in TRUNK mode is
connected point-to-point to another adapter port or connected though a router
instead of a switch, all ingress packets will be VLAN tagged. Programs such
as l3fwd which do not account for VLAN tags in packets will misbehave. The
solution is to enable VLAN stripping on ingress. The follow code fragment is
example of how to accomplish this:
.. code-block:: console
vlan_offload = rte_eth_dev_get_vlan_offload(port);
vlan_offload |= ETH_VLAN_STRIP_OFFLOAD;
rte_eth_dev_set_vlan_offload(port, vlan_offload);
- Limited flow director support on 1200 series and 1300 series Cisco VIC
adapters with old firmware. Please see :ref:`enic-flow-director`.
- Flow director features are not supported on generation 1 Cisco VIC adapters
(M81KR and P81E)
- **SR-IOV**
- KVM hypervisor support only. VMware has not been tested.
- Requires VM-FEX, and so is only available on UCS managed servers connected
to Fabric Interconnects. It is not on standalone C-Series servers.
- VF devices are not usable directly from the host. They can only be used
as assigned devices on VM instances.
- Currently, unbind of the ENIC kernel mode driver 'enic.ko' on the VM
instance may hang. As a workaround, enic.ko should blacklisted or removed
from the boot process.
- pci_generic cannot be used as the uio module in the VM. igb_uio or
vfio in non-IOMMU mode can be used.
- The number of RQs in UCSM dynamic vNIC configurations must be at least 2.
- The number of SR-IOV devices is limited to 256. Components on target system
might limit this number to fewer than 256.
How to build the suite
----------------------
Refer to the document :ref:`compiling and testing a PMD for a NIC
<pmd_build_and_test>` for details.
By default the ENIC PMD library will be built into the DPDK library.
For configuring and using UIO and VFIO frameworks, please refer to the
documentation that comes with DPDK suite.
Supported Cisco VIC adapters
----------------------------
ENIC PMD supports all recent generations of Cisco VIC adapters including:
- VIC 1280
- VIC 1240
- VIC 1225
- VIC 1285
- VIC 1225T
- VIC 1227
- VIC 1227T
- VIC 1380
- VIC 1340
- VIC 1385
- VIC 1387
Supported Operating Systems
---------------------------
Any Linux distribution fulfilling the conditions described in Dependencies
section of DPDK documentation.
Supported features
------------------
- Unicast, multicast and broadcast transmission and reception
- Receive queue polling
- Port Hardware Statistics
- Hardware VLAN acceleration
- IP checksum offload
- Receive side VLAN stripping
- Multiple receive and transmit queues
- Flow Director ADD, UPDATE, DELETE, STATS operation support IPv4 and IPv6
- Promiscuous mode
- Setting RX VLAN (supported via UCSM/CIMC only)
- VLAN filtering (supported via UCSM/CIMC only)
- Execution of application by unprivileged system users
- IPV4, IPV6 and TCP RSS hashing
- Scattered Rx
- MTU update
- SR-IOV on UCS managed servers connected to Fabric Interconnects.
Known bugs and unsupported features in this release
---------------------------------------------------
- Signature or flex byte based flow direction
- Drop feature of flow direction
- VLAN based flow direction
- non-IPV4 flow direction
- Setting of extended VLAN
- UDP RSS hashing
- MTU update only works if Scattered Rx mode is disabled
Prerequisites
-------------
- Prepare the system as recommended by DPDK suite. This includes environment
variables, hugepages configuration, tool-chains and configuration
- Insert vfio-pci kernel module using the command 'modprobe vfio-pci' if the
user wants to use VFIO framework
- Insert uio kernel module using the command 'modprobe uio' if the user wants
to use UIO framework
- DPDK suite should be configured based on the user's decision to use VFIO or
UIO framework
- If the vNIC device(s) to be used is bound to the kernel mode Ethernet driver
use 'ifconfig' to bring the interface down. The dpdk-devbind.py tool can
then be used to unbind the device's bus id from the ENIC kernel mode driver.
- Bind the intended vNIC to vfio-pci in case the user wants ENIC PMD to use
VFIO framework using dpdk-devbind.py.
- Bind the intended vNIC to igb_uio in case the user wants ENIC PMD to use
UIO framework using dpdk-devbind.py.
At this point the system should be ready to run DPDK applications. Once the
application runs to completion, the vNIC can be detached from vfio-pci or
igb_uio if necessary.
Root privilege is required to bind and unbind vNICs to/from VFIO/UIO.
VFIO framework helps an unprivileged user to run the applications.
For an unprivileged user to run the applications on DPDK and ENIC PMD,
it may be necessary to increase the maximum locked memory of the user.
The following command could be used to do this.
.. code-block:: console
sudo sh -c "ulimit -l <value in Kilo Bytes>"
The value depends on the memory configuration of the application, DPDK and
PMD. Typically, the limit has to be raised to higher than 2GB.
e.g., 2621440
The compilation of any unused drivers can be disabled using the
configuration file in config/ directory (e.g., config/common_linuxapp).
This would help in bringing down the time taken for building the
libraries and the initialization time of the application.
Additional Reference
--------------------
- http://www.cisco.com/c/en/us/products/servers-unified-computing
Contact Information
-------------------
Any questions or bugs should be reported to DPDK community and to the ENIC PMD
maintainers:
- John Daley <johndale@cisco.com>
- Nelson Escobar <neescoba@cisco.com>
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