Intel Ethernet and Configuring SR-IOV on Windows Server* 2012

Intel
®
Ethernet and Configuring SR-IOV on Windows* Server 2012 5
1 Introduction
The Intel
®
Ethernet Converged Network Adapter and Intel
®
Ethernet Server Adapter family
of adapters introduced numerous industry-leading features that are helping data center
administrators implement innovative solutions for difficult and challenging connectivity
problems. I/O Virtualization is one of the fastest growing usage models within the data
center.
1.1 Deploying IO Virtualization in Microsoft
Windows Server 2012 Hyper-V
Many of the 10Gb Converged Network Adapters and 1Gb Server Adapters that are based on Intel®
Ethernet Controllers include Intel® Virtualization Technology for Connectivity (Intel® VT-c) which is a
collection of I/O virtualization technologies that enables lower CPU utilization, reduced system latency,
and improved networking throughput. Intel® VT-c is one of the key component technologies of Intel®
Virtualization Technology that have been included as part of the Microsoft Windows Server 2012 Hyper-V.
Virtual Machine Device Queues (VMDq) provides hardware assists to the hypervisor that improves
traffic management within the server by offloading traffic sorting and routing from the hypervisor’s virtual
switch to the Intel® Ethernet Controller. Working in conjunction with Microsoft Virtual Machine Queues*,
VMDq enables traffic steering and balanced bandwidth allocation across the Intel Ethernet Controller’s
multiple hardware queues.
PCI-SIG Single Root I/O Virtualization and Sharing (SR-IOV) support allows multiple virtual
machines to bypass the hypervisor networking stack and talk directly to unique resources on Intel®
Ethernet Converged Network Adapters. The PCI-SIG SR-IOV standard offers an advanced, nonproprietary
approach to providing I/O resources directly to virtual machines that helps significantly reduce latency,
reduce CPU utilization and increase throughput.
1.1.1 SR-IOV Overview in Microsoft Windows
Server 2012 Hyper-V
The single root I/O virtualization (SR-IOV) interface is an extension to the PCI Express (PCIe)
specification. SR-IOV allows a network adapter to separate access to its resources among various PCIe
hardware functions. These functions consist of the following types:
• A PCIe Physical Function (PF). This function is the primary function of the device and
advertises the device's SR-IOV capabilities. The PF is associated with the Hyper-V parent
partition in a virtualized environment.
• One or more PCIe Virtual Functions (VFs). A VF is a lightweight PCIe function on a network
adapter that supports the SR-IOV interface. The VF is associated with the PCIe Physical
Function (PF) on the network adapter, and represents a virtualized instance of the network
adapter. Each VF has its own PCI Configuration space. Each VF also shares one or more
physical resources on the network adapter, such as an external network port, with the PF
and other VFs. Each VF is associated with a Hyper-V child partition in a virtualized
environment.