Installation guide

USB p asst h ro u g h

The KVM hypervisor supports attaching USB devices on the host system to virtual

machines. USB device assignment allows guests to have exclusive access to USB devices

for a range of tasks. It allows USB devices to appear and behave as if they were physically

attached to the virtual machine.

Note

For more information on USB passthrough, refer to the Red Hat Enterprise Linux 6

Virtualization Administration Guide.

SR- IO V

SR-IOV (Single Root I/O Virtualization) is a PCI Express standard that extends a single

physical PCI function to share its PCI resources as separate, virtual functions (VFs). Each

function is capable of being used by a different virtual machine via PCI device assignment.

An SR-IOV capable PCI-e device, provides a Single Root Function (for example, a single

Ethernet port) and presents multiple, separate virtual devices as unique PCI device

functions. Each virtual device may have its own unique PCI configuration space, memory-

mapped registers, and individual MSI-based interrupts.

Note

For more information on SR-IOV, refer to the Red Hat Enterprise Linux 6 Virtualization

Host Configuration and Guest Installation Guide.

NPIV

N_Port ID Virtualization (NPIV) is a functionality available with some Fibre Channel

devices. NPIV shares a single physical N_Port as multiple N_Port IDs. NPIV provides

similar functionality for Fibre Channel Host Bus Adapters (HBAs) that SR-IOV provides for

PCIe interfaces. With NPIV, virtual machines can be provided with a virtual Fibre Channel

initiator to Storage Area Networks (SANs).

NPIV can provide high density virtualized environments with enterprise-level storage

solutions.

Note

For more information on NPIV, refer to the Red Hat Enterprise Linux 6 Virtualization

Administration Guide.

4.4. Guest CPU models

CPU models define which host CPU features are exposed to the guest operating system. q emu - kvm

and lib virt contain definitions for several current processor models, allowing users to enable CPU

features that are available only in newer CPU models. The set of CPU features that can be exposed to

guests depends on support in the host CPU, the kernel, and q emu - kvm code.

⁠Chapt er 4 . Int roduct io n t o Red Hat virt ualizat ion product s