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LiquidIO VF Poll Mode Driver
============================

The LiquidIO VF PMD library (librte_pmd_lio) provides poll mode driver support for
Cavium LiquidIO® II server adapter VFs. PF management and VF creation can be
done using kernel driver.

More information can be found at `Cavium Official Website
<http://cavium.com/LiquidIO_Adapters.html>`_.

Supported LiquidIO Adapters
-----------------------------

- LiquidIO II CN2350 210SV/225SV
- LiquidIO II CN2350 210SVPT
- LiquidIO II CN2360 210SV/225SV
- LiquidIO II CN2360 210SVPT


Pre-Installation Configuration
------------------------------

The following options can be modified in the ``config`` file.
Please note that enabling debugging options may affect system performance.

- ``CONFIG_RTE_LIBRTE_LIO_PMD`` (default ``y``)

  Toggle compilation of LiquidIO PMD.

- ``CONFIG_RTE_LIBRTE_LIO_DEBUG_DRIVER`` (default ``n``)

  Toggle display of generic debugging messages.

- ``CONFIG_RTE_LIBRTE_LIO_DEBUG_INIT`` (default ``n``)

  Toggle display of initialization related messages.

- ``CONFIG_RTE_LIBRTE_LIO_DEBUG_RX`` (default ``n``)

  Toggle display of receive fast path run-time messages.

- ``CONFIG_RTE_LIBRTE_LIO_DEBUG_TX`` (default ``n``)

  Toggle display of transmit fast path run-time messages.

- ``CONFIG_RTE_LIBRTE_LIO_DEBUG_MBOX`` (default ``n``)

  Toggle display of mailbox messages.

- ``CONFIG_RTE_LIBRTE_LIO_DEBUG_REGS`` (default ``n``)

  Toggle display of register reads and writes.


SR-IOV: Prerequisites and Sample Application Notes
--------------------------------------------------

This section provides instructions to configure SR-IOV with Linux OS.

#. Verify SR-IOV and ARI capabilities are enabled on the adapter using ``lspci``:

   .. code-block:: console

      lspci -s <slot> -vvv

   Example output:

   .. code-block:: console

      [...]
      Capabilities: [148 v1] Alternative Routing-ID Interpretation (ARI)
      [...]
      Capabilities: [178 v1] Single Root I/O Virtualization (SR-IOV)
      [...]
      Kernel driver in use: LiquidIO

#. Load the kernel module:

   .. code-block:: console

      modprobe liquidio

#. Bring up the PF ports:

   .. code-block:: console

      ifconfig p4p1 up
      ifconfig p4p2 up

#. Change PF MTU if required:

   .. code-block:: console

      ifconfig p4p1 mtu 9000
      ifconfig p4p2 mtu 9000

#. Create VF device(s):

   Echo number of VFs to be created into ``"sriov_numvfs"`` sysfs entry
   of the parent PF.

   .. code-block:: console

      echo 1 > /sys/bus/pci/devices/0000:03:00.0/sriov_numvfs
      echo 1 > /sys/bus/pci/devices/0000:03:00.1/sriov_numvfs

#. Assign VF MAC address:

   Assign MAC address to the VF using iproute2 utility. The syntax is::

      ip link set <PF iface> vf <VF id> mac <macaddr>

   Example output:

   .. code-block:: console

      ip link set p4p1 vf 0 mac F2:A8:1B:5E:B4:66

#. Assign VF(s) to VM.

   The VF devices may be passed through to the guest VM using qemu or
   virt-manager or virsh etc.

   Example qemu guest launch command:

   .. code-block:: console

      ./qemu-system-x86_64 -name lio-vm -machine accel=kvm \
      -cpu host -m 4096 -smp 4 \
      -drive file=<disk_file>,if=none,id=disk1,format=<type> \
      -device virtio-blk-pci,scsi=off,drive=disk1,id=virtio-disk1,bootindex=1 \
      -device vfio-pci,host=03:00.3 -device vfio-pci,host=03:08.3

#. Running testpmd

   Refer to the document
   :ref:`compiling and testing a PMD for a NIC <pmd_build_and_test>` to run
   ``testpmd`` application.

   .. note::

      Use ``igb_uio`` instead of ``vfio-pci`` in VM.

   Example output:

   .. code-block:: console

      [...]
      EAL: PCI device 0000:03:00.3 on NUMA socket 0
      EAL:   probe driver: 177d:9712 net_liovf
      EAL:   using IOMMU type 1 (Type 1)
      PMD: net_liovf[03:00.3]INFO: DEVICE : CN23XX VF
      EAL: PCI device 0000:03:08.3 on NUMA socket 0
      EAL:   probe driver: 177d:9712 net_liovf
      PMD: net_liovf[03:08.3]INFO: DEVICE : CN23XX VF
      Interactive-mode selected
      USER1: create a new mbuf pool <mbuf_pool_socket_0>: n=171456, size=2176, socket=0
      Configuring Port 0 (socket 0)
      PMD: net_liovf[03:00.3]INFO: Starting port 0
      Port 0: F2:A8:1B:5E:B4:66
      Configuring Port 1 (socket 0)
      PMD: net_liovf[03:08.3]INFO: Starting port 1
      Port 1: 32:76:CC:EE:56:D7
      Checking link statuses...
      Port 0 Link Up - speed 10000 Mbps - full-duplex
      Port 1 Link Up - speed 10000 Mbps - full-duplex
      Done
      testpmd>

#. Enabling VF promiscuous mode

   One VF per PF can be marked as trusted for promiscuous mode.

   .. code-block:: console

      ip link set dev <PF iface> vf <VF id> trust on


Limitations
-----------

VF MTU
~~~~~~

VF MTU is limited by PF MTU. Raise PF value before configuring VF for larger packet size.

VLAN offload
~~~~~~~~~~~~

Tx VLAN insertion is not supported and consequently VLAN offload feature is
marked partial.

Ring size
~~~~~~~~~

Number of descriptors for Rx/Tx ring should be in the range 128 to 512.

CRC striping
~~~~~~~~~~~~

LiquidIO adapters strip ethernet FCS of every packet coming to the host
interface. So, CRC will be stripped even when the ``rxmode.hw_strip_crc``
member is set to 0 in ``struct rte_eth_conf``.
