xen  4.15.0
About: The Xen hypervisor is a virtual machine monitor for x86, x86_64, IA64, PowerPC and other CPU architectures that supports execution of multiple guest operating systems in isolated environments.
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xen Documentation

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What is Xen?

Xen is a Virtual Machine Monitor (VMM) originally developed by the Systems Research Group of the University of Cambridge Computer Laboratory, as part of the UK-EPSRC funded XenoServers project. Xen is freely-distributable Open Source software, released under the GNU GPL. Since its initial public release, Xen has grown a large development community, spearheaded by xen.org (https://www.xen.org).

This file contains some quick-start instructions to install Xen on your system. For more information see https://www.xen.org/ and https://wiki.xen.org/

Quick-Start Guide

First, this is just a quick-start guide. For more comprehensive information see the INSTALL file and the Xen wiki at https://wiki.xenproject.org and in particular https://wiki.xenproject.org/wiki/Getting_Started.

Second, there are a number of prerequisites for building a Xen source release. Make sure you have all the following installed, either by visiting the project webpage or installing a pre-built package provided by your OS distributor: * GNU Make v3.80 or later * C compiler and linker: - For x86: - GCC 4.1.2_20070115 or later - GNU Binutils or later or - Clang/LLVM 3.5 or later - For ARM 32-bit: - GCC 4.9 or later - GNU Binutils 2.24 or later - For ARM 64-bit: - GCC 5.1 or later - GNU Binutils 2.24 or later * Development install of zlib (e.g., zlib-dev) * Development install of Python 2.6 or later (e.g., python-dev) * Development install of curses (e.g., libncurses-dev) * Development install of openssl (e.g., openssl-dev) * Development install of x11 (e.g. xorg-x11-dev) * Development install of uuid (e.g. uuid-dev) * Development install of yajl (e.g. libyajl-dev) * Development install of libaio (e.g. libaio-dev) version 0.3.107 or greater. * Development install of GLib v2.0 (e.g. libglib2.0-dev) * Development install of Pixman (e.g. libpixman-1-dev) * pkg-config * bridge-utils package (/sbin/brctl) * iproute package (/sbin/ip) * GNU bison and GNU flex * GNU gettext * ACPI ASL compiler (iasl)

In addition to the above there are a number of optional build prerequisites. Omitting these will cause the related features to be disabled at compile time: * Development install of Ocaml (e.g. ocaml-nox and ocaml-findlib). Required to build ocaml components which includes the alternative ocaml xenstored. * cmake (if building vtpm stub domains) * pandoc, transfig, pod2{man,html,text} for rendering various pieces of documentation into alternative formats * figlet (for generating the traditional Xen start of day banner) * systemd daemon development files * Development install of libnl3 (e.g., libnl-3-200, libnl-3-dev, etc). Required if network buffering is desired when using Remus with libxl. See docs/README.remus for detailed information. * 16-bit x86 assembler, loader and compiler for qemu-traditional / rombios (dev86 rpm or bin86 & bcc debs) * Development install of liblzma for rombios * Development install of libbz2, liblzma, liblzo2, and libzstd for DomU kernel decompression.

Second, you need to acquire a suitable kernel for use in domain 0. If possible you should use a kernel provided by your OS distributor. If no suitable kernel is available from your OS distributor then refer to https://wiki.xen.org/wiki/XenDom0Kernels for suggestions for suitable kernels to use. If you are looking to compile a Dom0 kernel from source, please refer to https://wiki.xen.org/wiki/XenParavirtOps.

[NB. Unless noted otherwise, all the following steps should be performed with root privileges.]

  1. Download and untar the source tarball file. This will be a file named xen-unstable-src.tgz, or xen-$version-src.tgz. You can also pull the current version from the git or mercurial repositories at https://xenbits.xen.org/

    tar xzf xen-unstable-src.tgz

    Assuming you are using the unstable tree, this will untar into xen-unstable. The rest of the instructions use the unstable tree as an example, substitute the version for unstable.

  2. cd to xen-unstable (or whatever you sensibly rename it to).

  3. For the very first build, or if you want to destroy build trees, perform the following steps:


    make world

    make install

    See the documentation in the INSTALL file for more info.

    This will create and install onto the local machine. It will build the xen binary (xen.gz), the tools and the documentation.

    You can override the destination for make install by setting DESTDIR to some value.

  4. To rebuild an existing tree without modifying the config:

    make dist

    This will build and install xen, tools, and docs into the local dist/ directory.

    You can override the destination for make install by setting DISTDIR to some value.

    make install and make dist differ in that make install does the right things for your local machine (installing the appropriate version of udev scripts, for example), but make dist includes all versions of those scripts, so that you can copy the dist directory to another machine and install from that distribution.

xenstore: xenstored and oxenstored

Xen uses a configuration database called xenstore [0] to maintain configuration and status information shared between domains. A daemon is implemented as part of xenstore to act as an interface for access to the database for dom0 and guests. Two xenstored daemons are supported, one written in C which we refer to as the xenstored (sometimes referred to as cxenstored), and another written in Ocaml called oxenstored. Details for xenstore and the different implementations can be found on the wiki's xenstore reference guide [1] and the xenstored [2] page. You can choose which xenstore you want to enable as default on a system through configure:

    ./configure --with-xenstored=xenstored
    ./configure --with-xenstored=oxenstored

By default oxenstored will be used if the ocaml development tools are found. If you enable oxenstored the xenstored will still be built and installed, the xenstored used can be changed through the configuration file:

/etc/sysconfig/xencommons or /etc/default/xencommons

You can change the preferred xenstored you want to use in the configuration but since we cannot stop the daemon a reboot will be required to make the change take effect.

[0] https://wiki.xen.org/wiki/XenStore [1] https://wiki.xen.org/wiki/XenStoreReference [2] https://wiki.xen.org/wiki/Xenstored

Python Runtime Libraries

Various tools, such as pygrub, have the following runtime dependencies:

* Python 2.6 or later.
      URL:    http://www.python.org/
      Debian: python

Note that the build system expects python to be available. If your system only has python2 or python3 but not python (as in Linux From Scratch), you will need to create a symlink for it, or specify PYTHON= when invoking make, like (note the position of PYTHON= matters):

# make PYTHON=/usr/bin/python3

Intel(R) Trusted Execution Technology Support

Intel's technology for safer computing, Intel(R) Trusted Execution Technology (Intel(R) TXT), defines platform-level enhancements that provide the building blocks for creating trusted platforms. For more information, see http://www.intel.com/technology/security/.

Intel(R) TXT support is provided by the Trusted Boot (tboot) module in conjunction with minimal logic in the Xen hypervisor.

Tboot is an open source, pre- kernel/VMM module that uses Intel(R) TXT to perform a measured and verified launch of an OS kernel/VMM.

The Trusted Boot module is available from http://sourceforge.net/projects/tboot. This project hosts the code in a mercurial repo at http://tboot.sourceforge.net/hg/tboot.hg and contains tarballs of the source. Instructions in the tboot README describe how to modify grub.conf to use tboot to launch Xen.