Intel Ethernet Cloud White Paper

VM x

Hardware

Virtual

Server

Adapters

Software

Virtual Software Switch

Hypervisor

Intel® Ethernet Controller

High-Trafﬁc VM

Virtual Ethernet Bridge - Layer 2 Sorter and Classiﬁer

Intel® VT-d

Rx Tx

VM y

Direct Assignment

VM n

VM 2VM 1

Low-Trafﬁc VMs

Queue 1

(VM 1 and VM 2)

Queue 2

Unassigned

Queue x

(VM 3)

VF nVF y

VF Driver VF Driver

VMDq SR-IOV

. Intel® VT-c supports I/O virtualization with both VMDq and SR-IOV, both of which enhance network

performance dramatically for cloud environments.



Intel® Virtualization Technology for Connectivity (Intel® VT-c) supports both approaches to I/O virtualization that are used

by leading hypervisors, as shown in Figure B:

•  works in

conjunction with the hypervisor to take advantage of the

on-controller sorting and traffic steering of the Receive and

Transmit queues to provide balanced bandwidth allocation,

increased I/O performance, and support for differential

traffic loads among VMs.

•  is a PCI-SIG

standard that virtualizes physical I/O ports of a network

controller into multiple virtual functions (VFs), which it maps

to individual VMs, enabling them to achieve near-native

network I/O performance by making use of direct access.

