openSUSE 12.2: Chapitre 1. KVM Installation and Requirements

Chapitre 1. KVM Installation and Requirements¶

Table des matières

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, SUSE 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 Web site identifies processors which support hardware virtualization: http://wiki.xensource.com/xenwiki/HVM_Compatible_Processors


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 for openSUSE. 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 SUSE. All operating systems listed are supported in both 32 and 64-bit x86 versions. A list of other supported operating systems (not tested by SUSE) is available at http://www.linux-kvm.org/page/Guest_Support_Status.

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.

Tableau 1.1. Supported KVM Guest Operating Systems on openSUSE

openSUSE 11.2 or newer
	PV drivers:	kvm-clock, virtio-net, virtio-blk, virtio-balloon
	Support Status:	Fully supported (fully virtualized)
SLES 11 SP2 / SLES 11 SP1 / SLES 10 SP4
	PV drivers:	kvm-clock, virtio-net, virtio-blk, virtio-balloon
	Support Status:	Fully supported (fully virtualized)
SLES 9 SP4
	Support Status:	Fully Supported (fully virtualized)
	Note:	32-bit Kernel: specify `clock=pmtmr` on Linux boot line 64-bit Kernel: specify `ignore_lost_ticks` on Linux boot line
SLED 12.2 / SLED 11 SP1
	PV drivers:	kvm-clock, virtio-net, virtio-blk, virtio-balloon
	Support Status:	Technology Preview (fully virtualized)
OES 2 SP3 / OES 11
	PV drivers:	kvm-clock, virtio-net, virtio-blk, virtio-balloon
	Support Status:	Fully supported (fully virtualized)
RedHat Enterprise Linux 4.8+ / 5.5+ / 6.0+
	PV drivers:	See http://www.redhat.com/
	Support Status:	Best Effort (fully virtualized)
	Note:	Refer to the RHEL Virtualization guide for more information.
Windows 2003 SP2+ / Windows 2008 SP2+ / Windows 2008 R2+
	PV drivers:	virtio-net, virtio-blk, virtio-balloon; drivers from the Virtual Machine Driver Pack (http://www.suse.com/products/vmdriverpack/) are preferred
	Support Status:	Fully supported with Server Virtualization Validation Program (SVVP) certification (fully virtualized)
Windows XP SP3+ / Windows Vista SP2+ / Windows 7 SP1+
	PV drivers:	virtio-net, virtio-blk, virtio-balloon; drivers from the Virtual Machine Driver Pack (http://www.suse.com/products/vmdriverpack/) are preferred
	Support Status:	Best effort (fully virtualized)


Guest images created under SUSE Linux Enterprise Server 11 SP1 are supported, but 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 / SP2: included in Kernel
SUSE Linux Enterprise Server 10 SP4: included in Kernel
SUSE Linux Enterprise Server 9 SP4: not available
RedHat: available in RedHat Enterprise Linux 5.4 and newer
Windows: SUSE has developed virtio based drivers for Windows, which are available in the Virtual Machine Driver Pack (VMDP). These drivers are preferred over the drivers provided in the /usr/share/qemu-kvm/win-virtio-drivers.iso image file (the latter being deprecated and will probably not be provided in future releases). See http://www.suse.com/products/vmdriverpack/ for more information.

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 debug level monitoring utility (kvm-stat), firmware components, key-mapping files, scripts, and deprecated para-virtualized 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 SUSE'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).
virt-manager (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 manually and start libvirtd to avoid a reboot:
```
modprobe kvm-intel # on Intel machines only
modprobe kvm-amd   # on AMD machines only
modprobe vhost-net
rclibvirtd start
```

	The `vhost-net` Kernel Module
The vost-net kernel module allows for a more efficient network transport to the guest. It is automatically used by `libvirt` if loaded, or when using the qemu-kvm commandline, by adding `,vhost=on` to the networking option.