Chapter 1. KVM Installation and Requirements

Chapter 1. KVM Installation and Requirements¶

Contents

1.1. Hardware Requirements
1.2. Supported Guest Operating Systems
1.3. The kvm package
1.4. Installing KVM

KVM is a full virtualization solution for x86 processors supporting hardware virtualization (Intel VT or AMD-V). It consists of two main components: A set of Kernel modules (kvm.ko, kvm-intel.ko, and kvm-amd.ko) providing the core virtualization infrastructure and processor specific drivers and a userspace program (qemu-kvm) that provides emulation for virtual devices and control mechanisms to manage VM Guests (virtual machines). The term KVM more properly refers to the Kernel level virtualization functionality, but is in practice more commonly used to reference the userspace component.

VM Guests (virtual machines), virtual storage and networks can be managed with libvirt-based and QEMU tools. libvirt is a library that provides an API to manage VM Guests based on different virtualization solutions, among them KVM and Xen. It offers a graphical user interface as well as a command line program. The QEMU tools are KVM/QEMU specific and are only available for the command line.

1.1. Hardware Requirements¶

Currently, Novell only supports KVM full virtualization on x86_64 hosts. KVM is designed around hardware virtualization features included in AMD (AMD-V) and Intel (VT-x) CPUs. It supports virtualization features of chipsets, and PCI devices, such as an I/O Memory Mapping Unit (IOMMU) and Single Root I/O Virtualization (SR-IOV)).

You can test whether your CPU supports hardware virtualization with the following command:

egrep '(vmx|svm)' /proc/cpuinfo

If this command returns no output, your processor either does not support hardware virtualization, or this feature has been disabled in the BIOS.

The following websites identify processors which support hardware virtualization:

http://wiki.xensource.com/xenwiki/HVM_Compatible_Processors

http://en.wikipedia.org/wiki/X86_virtualization


The KVM Kernel modules will not load if the CPU does not support hardware virtualization or if this feature is not enabled in the BIOS.

The general minimum hardware requirements for the VM Host Server are the same as outlined in . However, additional RAM for each virtualized guest is needed. It should at least be the same amount that is needed for a physical installation. It is also strongly recommended to have at least one processor core or hyper-thread for each running guest.

1.2. Supported Guest Operating Systems¶

The following table lists guest operating systems tested and their support status offered by Novell. All operating systems listed are supported in both 32 and 64-bit x86 versions. Para-virtualized drivers (PV drivers) are listed where available.

Para-virtualized drivers for KVM

virtio-net: Virtual network driver.
virtio-blk: Virtual block device driver for para-virtualized block devices.
virtio-balloon: Memory driver for dynamic memory allocation. Allows to dynamically change the amount of memory allocated to a guest.
kvm-clock: Clock synchronization driver.

Supported KVM Guest Operating Systems on openSUSE

openSUSE 11.4
	Virtualization Type:	Fully virtualized
	PV drivers:	kvm-clock, virtio-net, virtio-blk, virtio-balloon
	Support Status:	Fully Supported
openSUSE 10 SP3
	Virtualization Type:	Fully virtualized
	PV drivers:	kvm-clock, virtio-net, virtio-blk, virtio-balloon
	Support Status:	Fully Supported
openSUSE 9 SP4
	Virtualization Type:	Fully virtualized
	Support Status:	Fully Supported
	Note:	32-bit Kernel: specify `clock=pmtmr` on Linux boot line 64-bit Kernel: specify `ignore_lost_ticks` on Linux boot line
SUSE Linux Enterprise Desktop 11 SP1
	Virtualization Type:	Fully virtualized
	PV drivers:	kvm-clock, virtio-net, virtio-blk, virtio-balloon
	Support Status:	Tech Preview
RedHat Enterprise Linux 4.x / 5.x
	Virtualization Type:	Fully Virtualized
	PV drivers:	See http://www.redhat.com/
	Support Status:	Best Effort
	Note:	Refer to the RHEL Virtualization guide for more information.
Windows XP SP3+ / Windows Server 2003 SP2+ / Windows Server 2008+ / Windows Vista SP1+ / Windows 7
	Virtualization Type:	Best Effort
	PV drivers:	virtio-net, virtio-blk, virtio-balloon
	Support Status:	Best Effort


Guest images created under a previous SUSE Linux Enterprise version are not supported.

1.2.1. Availability of para-virtualized Drivers¶

To improve the performance of the guest operating system, para-virtualized drivers are provided when available. Although they are not required, it is strongly recommended to use them. The para-virtualized drivers are available as follows:

SUSE Linux Enterprise Server 11 SP1: included in Kernel
SUSE Linux Enterprise Server 10 SP3: Available from http://drivers.suse.com/novell/Novell-virtio-drivers-2.6.27/sle10-sp3/install-readme.html. Refer to Section 5.3.1, “Adding para-virtualized Drivers During the Installation” or Section A.1.1, “Installing Para-Virtualized Drivers for SUSE Linux Enterprise Server 10 SP3” for installation instructions.
SUSE Linux Enterprise Server 9 SP4: not available
RedHat: available in RedHat Enterprise Linux 5.4 and newer
Windows: Available from /usr/share/qemu-kvm/win-virtio-drivers.iso. Refer to Section A.1.2, “Installing virtio Drivers for Microsoft Windows*” for installation instructions.

1.3. The `kvm` package¶

The kvm package provides qemu-kvm, the program that performs the actual emulation. In addition to the qemu-kvm program, the kvm package also comes with a monitoring utility (kvm-stat), firmware components, key-mapping files, scripts, and Windows drivers (/usr/share/qemu-kvm/win-virtio-drivers.iso).

Originally, the kvm package also provided the KVM Kernel modules. Now, these modules are included with the Kernel and only userspace components are included in the current kvm package.

Using the libvirt-based tools is the recommended way of managing VM Guests. Interoperability with other virtualization tools has been tested and is an essential part of Novell's support stance. All tools are provided by packages carrying the tool's name.

libvirt: A toolkit that provides management of VM Guests, virtual networks, and storage. libvirt provides an API, a daemon, and a shell (virsh).
Virtual Machine Manager: A graphical management tool for VM Guests.
vm-install: Define a VM Guest and install its operating system.
virt-viewer: An X viewer client for VM Guests which supports TLS/SSL encryption of x509 certificate authentication and SASL authentication.

Support for creating and manipulating file-based virtual disk images is provided by qemu-img. qemu-img is provided by the package virt-utils.

1.4. Installing KVM¶

KVM is not installed by default. To install KVM and all virtualization tools, proceed as follows:

Start YaST and choose Virtualization+Installing Hypervisor and Tools.
Select KVM and confirm with Accept.
Confirm the list of packages that is to be installed with Install.
Agree to set up a network bridge by clicking Yes. It is recommended using a bridge on a VM Host Server (virtual machine host). If you prefer to manually configure a different network setup, you can safely skip this step by clicking No.
After the setup has been finished reboot the machine as YaST suggests. Alternatively load the required kernel modules and start libvirtd to avoid a reboot:
```
modprobe kvm-intel # on Intel machines only
modprobe kvm-amd   # on AMD machines only
rclibvirtd start
```