docs/doc/source/node_management/openstack/pci-sr-iov-ethernet-interface-devices.rst
Rafael Jardim d6fb867888 Upstreaming WRO
Removed duplicate abbrev definitions

Signed-off-by: Rafael Jardim <rafaeljordao.jardim@windriver.com>
Change-Id: I7910d9f54e158250004abd7e17a4e119f8064252
Signed-off-by: Ron Stone <ronald.stone@windriver.com>
2021-03-31 08:57:23 -04:00

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.. vic1596720744539
.. _pci-sr-iov-ethernet-interface-devices:
=====================================
PCI SR-IOV Ethernet Interface Devices
=====================================
A |SRIOV| ethernet interface is a physical |PCI| ethernet |NIC| that implements
hardware-based virtualization mechanisms to expose multiple virtual network
interfaces that can be used by one or more virtual machines simultaneously.
The |PCI|-SIG Single Root I/O Virtualization and Sharing \(|SRIOV|\) specification
defines a standardized mechanism to create individual virtual ethernet devices
from a single physical ethernet interface. For each exposed virtual ethernet
device, formally referred to as a Virtual Function \(VF\), the |SRIOV| interface
provides separate management memory space, work queues, interrupts resources,
and |DMA| streams, while utilizing common resources behind the host interface.
Each VF therefore has direct access to the hardware and can be considered to be
an independent ethernet interface.
When compared with a |PCI| Passthrough ethernet interface, a |SRIOV| ethernet
interface:
.. _pci-sr-iov-ethernet-interface-devices-ul-tyq-ymg-rr:
- Provides benefits similar to those of a |PCI| Passthrough ethernet interface,
including lower latency packet processing.
- Scales up more easily in a virtualized environment by providing multiple
VFs that can be attached to multiple virtual machine interfaces.
- Shares the same limitations, including the lack of support for |LAG|, |QoS|,
|ACL|, and live migration.
- Has the same requirements regarding the |VLAN| configuration of the access
switches.
- Provides a similar configuration workflow when used on |prod-os|.
The configuration of a |PCI| |SRIOV| ethernet interface is identical to
:ref:`Configure PCI Passthrough ethernet Interfaces
<configure-pci-passthrough-ethernet-interfaces>` except that
.. _pci-sr-iov-ethernet-interface-devices-ul-ikt-nvz-qmb:
- you use **pci-sriov** instead of **pci-passthrough** when defining the
network type of an interface
- the segmentation ID of the project network\(s\) used is more significant
here since this identifies the particular |VF| of the |SRIOV| interface
- when creating the neutron port, you must use ``--vnic-typedirect``
- when creating a neutron port backed by an |SRIOV| |VF|, you must use
``--vnic-type direct``