Difference between revisions of "Compiling Xen From Source"

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{{TODO|This page needs to be changed to reflect the [http://blog.xen.org/index.php/2013/02/25/xen-is-now-officially-in-git/ Xen Project's move to Git].}}
 
 
==Introduction==
 
==Introduction==
  
The purpose of this document is to guide users through the process of installing Xen from source (either from the tarball releases or from a source code repository).
+
The purpose of this document is to guide users through the process of installing Xen Project software from source (either from the tarball releases or from a source code repository).
  
This document was written targeting the Xen 4.2 release, but an attempt will be made to point out differences from previous releases where relevant.
+
This document was written targeting the Xen Project 4.2 release, but an attempt will be made to point out differences from previous releases where relevant.
  
 
An assumption is made of some familiarity with the general concept of building software and with using your distributions package manager to install relevant build tools etc.
 
An assumption is made of some familiarity with the general concept of building software and with using your distributions package manager to install relevant build tools etc.
Line 10: Line 9:
 
==Why Build From Source?==
 
==Why Build From Source?==
  
Before embarking on the process of building Xen yourself it is worth considering whether this is even necessary. There are many distributions around these days which have excellent support for Xen available right from the package manager, a partial list is available at [[Dom0 Kernels for Xen]]. Where possible it is highly recommended that users consume Xen via their chosen distribution wherever possible. Using the distribution packaging will give you a much more integrated solution and allow you to take advantage of all the resources provided by your distribution (e.g. documentation, support etc). You can find articles on how to install Xen on various distributions in [[:Category:Host Install]].
+
Before embarking on the process of building Xen Project software yourself it is worth considering whether this is even necessary. There are many distributions around these days which have excellent support for Xen available right from the package manager, a partial list is available at [[Dom0 Kernels for Xen]]. Where possible it is highly recommended that users consume Xen Project via their chosen distribution wherever possible. Using the distribution packaging will give you a much more integrated solution and allow you to take advantage of all the resources provided by your distribution (e.g. documentation, support etc). You can find articles on how to install Xen Project on various distributions in [[:Category:Host Install]].
  
 
The remainder of this document assumes that you have considered this and really do want to build from source.
 
The remainder of this document assumes that you have considered this and really do want to build from source.
Line 16: Line 15:
 
==Host (Domain 0) OS Installation==
 
==Host (Domain 0) OS Installation==
  
Before installing Xen you will first need to install your domain 0 OS, unless you have already done so. [[Host OS Install Considerations]] contains some things which you might want to consider while doing this.
+
Before installing Xen Project you will first need to install your domain 0 OS, unless you have already done so. [[Host OS Install Considerations]] contains some things which you might want to consider while doing this.
  
==Obtaining the Xen Source Code==
+
==Obtaining the Xen Project Source Code==
  
The primary ways to obtain the Xen source code for a stable release are via the release tarballs or by cloning from the appropriate Mercurial source repository. For the development version of Xen (''xen-unstable'') Git is the primary source and Mercurial is the secondary source.
+
The primary ways to obtain the Xen Project source code for a stable release are via the release tarballs or by cloning from the appropriate Mercurial source repository. For the development version of Xen Project (''xen-unstable'') Git is the primary source and Mercurial is the secondary source.
  
 
===Release Tarballs===
 
===Release Tarballs===
  
The latest Xen releases are linked to from [http://www.xen.org/products/downloads.html The Xen.org download page]
+
The latest Xen Project releases are linked to from [http://www.xen.org/products/downloads.html The Xen.org download page]
  
 
===Git===
 
===Git===
  
Xen's source code repositories are hosted using the Git version control system on [http://xenbits.xen.org/ xenbits].
+
The source code repositories are hosted using the Git version control system on [http://xenbits.xen.org/ xenbits].
  
 
Each stable release has its own branch ''stable-X.Y'' (e.g. stable-4.2 on [http://xenbits.xen.org/gitweb/?p=xen.git;a=summary Xen.git summary page]). The code intended for the next stable point release is added to the branch ''staging-X.Y'' (e.g. staging-4.2 on [http://xenbits.xen.org/gitweb/?p=xen.git;a=summary Xen.git summary page]), and after they pass automated tests they will be pushed to ''stable-X.Y'' for the next release. The point releases are tagged in the main tree with ''RELEASE-X.Y.Z'' (e.g. RELEASE-4.2.2 on [http://xenbits.xen.org/gitweb/?p=xen.git;a=summary Xen.git summary page]). The result of automated tests are available on [http://lists.xen.org/mailman/listinfo/xen-devel xen-devel] mailing list.
 
Each stable release has its own branch ''stable-X.Y'' (e.g. stable-4.2 on [http://xenbits.xen.org/gitweb/?p=xen.git;a=summary Xen.git summary page]). The code intended for the next stable point release is added to the branch ''staging-X.Y'' (e.g. staging-4.2 on [http://xenbits.xen.org/gitweb/?p=xen.git;a=summary Xen.git summary page]), and after they pass automated tests they will be pushed to ''stable-X.Y'' for the next release. The point releases are tagged in the main tree with ''RELEASE-X.Y.Z'' (e.g. RELEASE-4.2.2 on [http://xenbits.xen.org/gitweb/?p=xen.git;a=summary Xen.git summary page]). The result of automated tests are available on [http://lists.xen.org/mailman/listinfo/xen-devel xen-devel] mailing list.
  
[[Xen Repositories]] contains information on the various repositories for the stable and development branches.
+
[[Xen Repositories|Xen Project Repositories]] contains information on the various repositories for the stable and development branches.
  
 
To clone the source first install ''Git'' using your distro's package manager. Then execute the following command:
 
To clone the source first install ''Git'' using your distro's package manager. Then execute the following command:
Line 40: Line 39:
 
As the default HEAD in xen.git is ''master'', your local repository will also have a branch called ''master'' pointing to the upstream branch.
 
As the default HEAD in xen.git is ''master'', your local repository will also have a branch called ''master'' pointing to the upstream branch.
 
If you wish to use different HEAD (say, ''staging''), you can:
 
If you wish to use different HEAD (say, ''staging''), you can:
  $ cd xen; git checkout -b staging staging
+
  $ cd xen; git checkout -b staging origin/staging
 
You can also checkout any tags, branches as you wish.
 
You can also checkout any tags, branches as you wish.
  
 
===Mercurial===
 
===Mercurial===
  
<strong>Please note that Xen.org has moved to using Git. The following section is deprecated. We do maintain Mercurial repositories mirroring Git ones, so we retain following section for reference.</strong>
+
<strong>Please note that XenProject.org has moved to using Git. The following section is deprecated. We do maintain Mercurial repositories mirroring Git ones, so we retain following section for reference.</strong>
  
Xen's source code repositories are hosted using the [http://mercurial.selenic.com/ Mercurial] version control system on [http://xenbits.xen.org/ xenbits].
+
Xen Project's source code repositories are hosted using the [http://mercurial.selenic.com/ Mercurial] version control system on [http://xenbits.xen.org/ xenbits].
  
Each stable release has it's own branch ''xen-X.Y-testing.hg'' (e.g. [http://xenbits.xen.org/hg/xen-4.2-testing.hg xen-4.2-testing.hg]) where code intended for the next stable point release is added. The Xen development branch is known as ''xen-unstable'' and has its own repository [http://xenbits.xen.org/hg/xen-unstable.hg xen-unstable.hg].
+
Each stable release has it's own branch ''xen-X.Y-testing.hg'' (e.g. [http://xenbits.xen.org/hg/xen-4.2-testing.hg xen-4.2-testing.hg]) where code intended for the next stable point release is added. The Xen Project development branch is known as ''xen-unstable'' and has its own repository [http://xenbits.xen.org/hg/xen-unstable.hg xen-unstable.hg].
  
Each Xen stable and development branch is available in two forms either tested (the main branch) or untested (the ''staging'' branch). When commits are made to a Xen tree they are first added to the ''staging'' branch and only propagated to the main branch after automated testing has passed. For example all commits to the Xen development branch will initially appear in [http://xenbits.xen.org/hg/staging/xen-unstable.hg staging/xen-unstable.hg] and then propagate to [http://xenbits.xen.org/hg/xen-unstable.hg xen-unstable.hg] after automated testing has completed. The automated test results are posted to the [http://lists.xen.org/mailman/listinfo/xen-devel xen-devel] mailing list.
+
Each stable and development branch is available in two forms either tested (the main branch) or untested (the ''staging'' branch). When commits are made to a Xen Project tree they are first added to the ''staging'' branch and only propagated to the main branch after automated testing has passed. For example all commits to the Xen Project development branch will initially appear in [http://xenbits.xen.org/hg/staging/xen-unstable.hg staging/xen-unstable.hg] and then propagate to [http://xenbits.xen.org/hg/xen-unstable.hg xen-unstable.hg] after automated testing has completed. The automated test results are posted to the [http://lists.xen.org/mailman/listinfo/xen-devel xen-devel] mailing list.
  
[[Xen Repositories]] contains information on the various repositories for the stable and development branches.
+
[[Xen Repositories|Xen Project Repositories]] contains information on the various repositories for the stable and development branches.
  
 
To clone the source first install the ''mercurial'' tool using your distributions package manager. Then execute the following command:
 
To clone the source first install the ''mercurial'' tool using your distributions package manager. Then execute the following command:
Line 66: Line 65:
 
==Quick-Start==
 
==Quick-Start==
  
The ''README'' at the top level of the Xen source code tree contains a quick-start guide to building Xen. This provides a quick overview of the process and requirements for building Xen and will generally contain the most up to date information specific to the particular Xen tree you are looking at. After obtaining the Xen source this is the first document you should read.
+
The ''README'' at the top level of the Xen Project source code tree contains a quick-start guide to building the software. This provides a quick overview of the process and requirements for building Xen Project software and will generally contain the most up to date information specific to the particular source tree you are looking at. After obtaining the Xen Project source this is the first document you should read.
  
 
==Building from Source==
 
==Building from Source==
  
=== Linux distro specific help ===  
+
This section documents all known requirements to build from source.
* Check [[Xen_4.2_Build_From_Source_On_RHEL_CentOS_Fedora]] wiki page for info about compiling Xen from source on rpm-based distributions.
+
 
 +
===Updated /sbin/installkernel on Linux ===
 +
 
 +
Linux distributions shipping with grub2 will need to ensure that their /sbin/installkernel script, which has to be provided by each Linux distribution, copies the the kernel configuration upon a custom kernel install time. The requirement for the config file comes from [http://git.savannah.gnu.org/cgit/grub.git/tree/util/grub.d/20_linux_xen.in upstream grub2 /etc/grub.d/20_linux_xen] which       
 +
will only add xen as an instance to your grub.cfg if and only if it finds in your config file either of:
 +
 
 +
    CONFIG_XEN_DOM0=y
 +
    CONFIG_XEN_PRIVILEGED_GUEST=y
 +
 
 +
Without this a user compiling and installing their own kernel with proper support for xen and with the xen hypervisor present will not get their respective grub2 update script to pick up the xen hypervisor. Debian testing has proper support for this, OpenSUSE required [https://github.com/openSUSE/mkinitrd/commit/56f8a20e1bf3efa9c822a724cb33f5683818b7ec this change upstream on mkinitrd], so OpenSUSE folks will want to get the latest /sbin/installkernel hosted on the [https://github.com/openSUSE/mkinitrd OpenSUSE mkinitrd repository on github].
 +
 
 +
    # If on OpenSUSE update your /sbin/installkernel
 +
    git clone https://github.com/openSUSE/mkinitrd.git
 +
    cd mkinitrd
 +
    sudo cp sbin/installkernel /sbin/installkernel
 +
 
 +
Fedora might need a similar update. Please edit this wiki once you confirm.
  
 
===Build Dependencies===
 
===Build Dependencies===
  
Xen uses several external libraries and tools. The primary list of these prerequisites is the list present in the ''README'' file.
+
Xen Project uses several external libraries and tools. The primary list of these prerequisites is the list present in the ''README'' file.
  
 
Even this list assumes some sort of basic development environment. A good starting point for this is to use your distributions ''development install'' package option.
 
Even this list assumes some sort of basic development environment. A good starting point for this is to use your distributions ''development install'' package option.
  
e.g. under Debian / Ubuntu (and derived distributions) install the ''build-essential'' package:
+
==== Build Dependencies - Debian / Ubuntu ====
 +
 
 +
Under Debian / Ubuntu (and derived distributions) install the ''build-essential'' package:
 
  # apt-get install build-essential
 
  # apt-get install build-essential
  
Line 87: Line 104:
 
  # apt-get install make gcc libc6-dev zlib1g-dev python python-dev python-twisted libncurses5-dev patch libvncserver-dev libsdl-dev libjpeg62-dev
 
  # apt-get install make gcc libc6-dev zlib1g-dev python python-dev python-twisted libncurses5-dev patch libvncserver-dev libsdl-dev libjpeg62-dev
 
  # apt-get install iasl libbz2-dev e2fslibs-dev git-core uuid-dev ocaml ocaml-findlib libx11-dev bison flex xz-utils libyajl-dev
 
  # apt-get install iasl libbz2-dev e2fslibs-dev git-core uuid-dev ocaml ocaml-findlib libx11-dev bison flex xz-utils libyajl-dev
  # apt-get install gettext
+
  # apt-get install gettext libpixman-1-dev libaio-dev markdown pandoc
  
whereas under RHEL, CentOS, Fedora (and similar rpm based) distributions the ''Development Libraries'' and ''Development Tools'' package groups:
+
And if you're building on Wheezy onward:
  # yum groupinstall "Development Libraries" "Development Tools"
+
# apt-get install libc6-dev-i386
 +
 
 +
One useful shortcut can be to use your distributions package manager to install all the prerequisite packages is to install those packages which are noted as being required to build the distribution's own Xen packages. e.g. under Debian or a Debian derived distribution:
 +
# apt-get build-dep xen
 +
 
 +
However you need to be mindful of new prerequisites added between whatever version of Xen Project software is in your distribution and the version you are building when using this trick.
 +
 
 +
==== Build Dependencies - OpenSUSE ====
 +
 
 +
If you're now on the latest OpenSUSE you'll note its now a
 +
rolling distribution base. The default instructions do not actually encourage you to
 +
install the source repositories, and even if you did
 +
install them the instructions disable them by default, so
 +
be sure to install them and enable them otherwise
 +
the command zypper source-install -d won't work.
 +
To enable the required repository if you already had it
 +
installed:
 +
 
 +
# zypper mr -e repo-src-oss
 +
 
 +
Now get the build dependencies for Xen
 +
 
 +
# zypper source-install -d xen
 +
 
 +
Here's a list of things not currentloy picked up by the build dependencies which have been found to be needed:
 +
 
 +
  # zypper install systemd-devel gettext-tools\
 +
    ocaml ocaml-compiler-libs ocaml-runtime \
 +
    ocaml-ocamldoc ocaml-findlib glibc-devel-32bit make patch
 +
 
 +
While at it also get the build dependencies for Linux:
 +
 
 +
# zypper source-install -d kernel-desktop
 +
 
 +
==== Build Dependencies - Fedora ====
 +
 
 +
These instructions are kept separate from RHEL / Centos as Fedora is updated more frequently, so you are expected to do less work to build the latest and greatest Xen.
 +
 
 +
Install known build dependencies:
 +
 
 +
# yum-builddep xen
 +
 
 +
Install things not picked up by the current build dependencies:
 +
 
 +
# yum install glibc-devel.x86_64 systemd-devel.x86_64
 +
 
 +
Get build dependencies for Linux, the kernel, while at it:
 +
 
 +
# yum-builddep kernel
 +
 
 +
==== Build Dependencies - RHEL / Centos ====
 +
 
 +
Under RHEL, CentOS, Fedora based distributions you want to install the ''Development Tools'' package groups:
 +
  # yum groupinstall "Development Tools"
 +
 
 +
(On old CentOS and Fedora, a group called ''Development Libraries'' should, if available, installed too. That is not present in recent releases of the distributions any longer, though).
 +
 
 +
Then install known build dependencies (confirmation needed if this works on RHEL / Centos):
 +
 
 +
# yum-builddep xen
 +
 
 +
You also need to install these additional rpms:
  
you also need to install these additional rpms:
 
 
  # yum install transfig wget tar less texi2html libaio-devel dev86 glibc-devel e2fsprogs-devel gitk mkinitrd iasl xz-devel bzip2-devel
 
  # yum install transfig wget tar less texi2html libaio-devel dev86 glibc-devel e2fsprogs-devel gitk mkinitrd iasl xz-devel bzip2-devel
 
  # yum install pciutils-libs pciutils-devel SDL-devel libX11-devel gtk2-devel bridge-utils PyXML qemu-common qemu-img mercurial texinfo
 
  # yum install pciutils-libs pciutils-devel SDL-devel libX11-devel gtk2-devel bridge-utils PyXML qemu-common qemu-img mercurial texinfo
 
  # yum install libidn-devel yajl yajl-devel ocaml ocaml-findlib ocaml-findlib-devel python-devel uuid-devel libuuid-devel openssl-devel
 
  # yum install libidn-devel yajl yajl-devel ocaml ocaml-findlib ocaml-findlib-devel python-devel uuid-devel libuuid-devel openssl-devel
  # yum install glibc-devel.i686
+
  # yum install python-markdown pandoc systemd-devel glibc-devel.i686
 +
 
 +
If on CentOS, for some of this packages (e.g., '''dev86''' and '''pandoc'''), enabling the [http://fedoraproject.org/wiki/EPEL EPEL] [http://fedoraproject.org/wiki/EPEL additional repository] is necessary.
  
Having installed this you should then install each of the prerequisites listed in the ''README'' using your distribution's package management tool. In general Xen tries to only depend upon external tools and libraries which are commonly available in distributions therefore obtaining the prerequisites other than from your distribution's package management system is out of scope for this document. If you have trouble locating a particular prerequisite then please contact the [http://lists.xen.org/mailman/listinfo/xen-users xen-users] mailing list.
+
==== Additional notes ====
  
One useful shortcut can be to use your distributions package manager to install all the prerequisite packages is to install those packages which are noted as being required to build the distribution's own Xen packages. e.g. under Debian or a Debian derived distribution:
+
Having installed this you should then install each of the prerequisites listed in the ''README'' using your distribution's package management tool. In general the Xen Project code tries to only depend upon external tools and libraries which are commonly available in distributions therefore obtaining the prerequisites other than from your distribution's package management system is out of scope for this document. If you have trouble locating a particular prerequisite then please contact the [http://lists.xenproject.org/mailman/listinfo/xen-users xen-users] mailing list.
# apt-get build-dep xen
 
('''TBD''' ''equivalent for RPM/yum/etc type distributions''). However you need to be mindful of new prerequisites added between whatever version of Xen is in your distribution and the version you are building when using this trick.
 
  
 
===Configure===
 
===Configure===
  
From Xen 4.2 onwards Xen uses the commonly used ''autoconf'' tool to provide compile time configurability of the toolstack. This allows some control of what features are built into Xen, as well as compile time sanity checking. To configure Xen simply run the provided ''configure'' script:
+
From Xen Project 4.2 onwards, the software uses the commonly used ''autoconf'' tool to provide compile time configurability of the toolstack. This allows some control of what features are built into Xen Project, as well as compile time sanity checking. To configure Xen Project, simply run the provided ''configure'' script:
 
  $ ./configure
 
  $ ./configure
  
Line 119: Line 196:
 
                             DISABLED)
 
                             DISABLED)
  
This step is only required from Xen 4.2 onwards. Prior to Xen 4.2 these options could be configured by passing a variable on the ''make'' command line during build & install or by writing the variable to a file named ''.config'' at the top level of the source tree.
+
This step is only required from Xen Project 4.2 onwards. Prior to Xen Project 4.2 these options could be configured by passing a variable on the ''make'' command line during build & install or by writing the variable to a file named ''.config'' at the top level of the source tree.
  
 
====Use ''http://'' Rather Than ''git://'' to Clone Additional Repositories====
 
====Use ''http://'' Rather Than ''git://'' to Clone Additional Repositories====
  
When building Xen from Mercurial the build system will automatically clone several additional repositories from the network. Some of these repositories use the version control system which uses its own protocol on a specific port. Sometimes this causes issues due to firewalls etc blocking the git port. This can be worked around by instructing the Xen build system to clone such repositories using a less efficient HTTP based protocol:
+
When building the software from Mercurial, the build system will automatically clone several additional repositories from the network. Some of these repositories use the version control system which uses its own protocol on a specific port. Sometimes this causes issues due to firewalls etc blocking the git port. This can be worked around by instructing the Xen build system to clone such repositories using a less efficient HTTP based protocol:
 
  $ ./configure --enable-githttp
 
  $ ./configure --enable-githttp
  
Prior to Xen 4.2 this could be achieved by writing ''GIT_HTTP=y'' to your ''.config'':
+
Prior to Xen Project 4.2 this could be achieved by writing ''GIT_HTTP=y'' to your ''.config'':
 
  $ cat .config
 
  $ cat .config
 
  GIT_HTTP = y
 
  GIT_HTTP = y
Line 132: Line 209:
 
====Library Installation Directory====
 
====Library Installation Directory====
  
Xen 4.2 onwards defaults to installing libraries into /usr/lib by default. Users on systems which use /usr/lib64 for 64-bit libraries should use the --libdir option. e.g:
+
Xen Project 4.2 onwards defaults to installing libraries into /usr/lib by default and from 4.3 onwards defaults to installing to /usr/local/lib by default.
  
  $ ./configure --libdir=/usr/lib64
+
Users on systems which use /usr/local/lib64 for 64-bit libraries should use the --libdir option. e.g:
 +
 
 +
  $ ./configure --libdir=/usr/local/lib64
  
 
Failure to do this usually results in errors about libraries not found or using older versions of the libraries which will likely not work.
 
Failure to do this usually results in errors about libraries not found or using older versions of the libraries which will likely not work.
 +
 +
_NB_: If you are using `--prefix=/usr` you should use `--libdir=/usr/lib64` too.
 +
 +
====Systemd====
 +
 +
If the target system uses [http://www.freedesktop.org/wiki/Software/systemd/ systemd], do not forget to enable it:
 +
 +
$ ./configure --enable-systemd
  
 
====Python Prefix and Module Layout====
 
====Python Prefix and Module Layout====
  
On some distros (e.g. Debian and Ubuntu) Xen may install the python parts of Xen into the wrong place (See [http://bugs.debian.org/693721 Debian bug #693721]). Therefore it is necessary to set ''PYTHON_PREFIX_ARG=--install-layout=deb'':
+
On some distros (e.g. Debian and Ubuntu) Xen Project may install the python parts of the code into the wrong place (See [http://bugs.debian.org/693721 Debian bug #693721]). Therefore it is necessary to set ''PYTHON_PREFIX_ARG=--install-layout=deb'':
 
  $ cat .config
 
  $ cat .config
 
  PYTHON_PREFIX_ARG=--install-layout=deb
 
  PYTHON_PREFIX_ARG=--install-layout=deb
Line 159: Line 246:
 
===Build & Install===
 
===Build & Install===
  
{{Warning|Building Xen downloads various components at build time. This means that building Xen currently requires an active connection to the Internet}}
+
{{Warning|Xen Project downloads various components at build time. This means that building Xen Project currently requires an active connection to the Internet}}
  
 
To build all components (hypervisor, tools, docs, stubdomains, etc) you can use the ''dist'' target.
 
To build all components (hypervisor, tools, docs, stubdomains, etc) you can use the ''dist'' target.
Line 186: Line 273:
 
If you want to install onto a remote machine then you can simply copy the ''dist'' directory over and '''TBD'''
 
If you want to install onto a remote machine then you can simply copy the ''dist'' directory over and '''TBD'''
  
After installing you rebuild your dynamic linker cache by running:
+
A better option is to make a "package-ball" -- a package which is the equivalent of a tarball with no dependency checking or set-up.  There are target for either deb-based systems:
 +
# make debball
 +
or rpm-based systems:
 +
# make rpmball
 +
 
 +
Packages are placed in the ''dist/'' directory.
 +
 
 +
Installing the resulting package is functionally equivalent to the ''make install'' target above, but because the files are tracked by the package manager, it is easier to remove or update.
 +
 
 +
After installing (either via ''make install'' or a packageballl) you rebuild your dynamic linker cache by running:
 
  # /sbin/ldconfig
 
  # /sbin/ldconfig
  
 
To get more information on the available targets use the ''help'' target:
 
To get more information on the available targets use the ''help'' target:
 
  $ make help
 
  $ make help
 +
 +
=== Linux grub2 update ===
 +
 +
When on Linux and using grub2 after installing Xen you will also need to make sure grub2 will pick up your new shiny Xen hypervisor. Distributions differ on how to do this. This section documents how to do this for known distributions.
 +
 +
==== update grub2 config on OpenSUSE ====
 +
 +
# update-bootloader --refresh
 +
 +
==== update grub2 config on Debian ====
 +
 +
# update-grub
 +
 +
==== update grub2 config on Fedora ====
 +
 +
TBD
 +
 +
==== update grub2 config on RHEL / Centos ====
 +
 +
TBD
  
 
===Troubleshooting===
 
===Troubleshooting===
Line 200: Line 316:
 
===Kernels===
 
===Kernels===
  
Xen no longer ships with its own Linux kernel for either dom0 or domU use. This is because now that Xen is supported by the upstream Linux kernel tree there is no need for a separate kernel port. There is no requirement for a domain 0 (or guest) kernel to match your hypervisor so you are free to pick the kernel which best suits your needs (e.g. many distributions supply a kernel which is compatible with Xen, which is a quick and easy path). [[Dom0 Kernels for Xen]] contains some guidance on this issue.
+
The Linux kernel now supports different hypervisors with one kernel. There is also no requirement for a domain 0 (or guest) kernel to match your hypervisor so you are free to pick the kernel which best suits your needs (e.g. many distributions supply a kernel which is compatible with Xen Project, which is a quick and easy path). [[Dom0 Kernels for Xen]] contains some guidance on this issue.
 +
 
 +
==== Compiling latest Linux kernel support ====
 +
 
 +
If compiling Linux from source for either dom0 or a guest you can now enable Xen support for both through one simple kernel configuration helper, this was added as of v4.2:
 +
 
 +
    make xenconfig
 +
 
 +
This lets you build a kernel which can support xen dom0 or xen guests on i386, x86-64 and arm64.
 +
 
 +
===Post-Installation===
 +
 
 +
A few system services should be manually enabled after the installation:
 +
 
 +
====SystemV====
 +
 
 +
Required:
 +
 
 +
update-rc.d xencommons defaults 19 18
 +
 
 +
Optional:
 +
 
 +
update-rc.d xendomains defaults 21 20
 +
update-rc.d xen-watchdog defaults 22 23
 +
 
 +
 
 +
====systemd====
 +
 
 +
Required:
 +
 
 +
systemctl enable xen-qemu-dom0-disk-backend.service
 +
systemctl enable xen-init-dom0.service
 +
systemctl enable xenconsoled.service
 +
 
 +
Optional:
 +
 
 +
systemctl enable xendomains.service
 +
systemctl enable xen-watchdog.service
 +
systemctl enable xendriverdomain.service
 +
 
 +
After making those changes reboot the system.
  
 
==Host Configuration==
 
==Host Configuration==
  
Once Xen is installed there is still some host level setup required. [[:Category:Host Configuration]] covers this.
+
Once the Xen Project code is installed there is still some host level setup required. [[:Category:Host Configuration]] covers this.
  
[[Category:Users]] [[Category:Host Install]]
+
[[Category:Users]] [[Category:Host Install]] [[Category:Developers]] [[Category:Fundamentals]]

Latest revision as of 15:23, 13 March 2019

Introduction

The purpose of this document is to guide users through the process of installing Xen Project software from source (either from the tarball releases or from a source code repository).

This document was written targeting the Xen Project 4.2 release, but an attempt will be made to point out differences from previous releases where relevant.

An assumption is made of some familiarity with the general concept of building software and with using your distributions package manager to install relevant build tools etc.

Why Build From Source?

Before embarking on the process of building Xen Project software yourself it is worth considering whether this is even necessary. There are many distributions around these days which have excellent support for Xen available right from the package manager, a partial list is available at Dom0 Kernels for Xen. Where possible it is highly recommended that users consume Xen Project via their chosen distribution wherever possible. Using the distribution packaging will give you a much more integrated solution and allow you to take advantage of all the resources provided by your distribution (e.g. documentation, support etc). You can find articles on how to install Xen Project on various distributions in Category:Host Install.

The remainder of this document assumes that you have considered this and really do want to build from source.

Host (Domain 0) OS Installation

Before installing Xen Project you will first need to install your domain 0 OS, unless you have already done so. Host OS Install Considerations contains some things which you might want to consider while doing this.

Obtaining the Xen Project Source Code

The primary ways to obtain the Xen Project source code for a stable release are via the release tarballs or by cloning from the appropriate Mercurial source repository. For the development version of Xen Project (xen-unstable) Git is the primary source and Mercurial is the secondary source.

Release Tarballs

The latest Xen Project releases are linked to from The Xen.org download page

Git

The source code repositories are hosted using the Git version control system on xenbits.

Each stable release has its own branch stable-X.Y (e.g. stable-4.2 on Xen.git summary page). The code intended for the next stable point release is added to the branch staging-X.Y (e.g. staging-4.2 on Xen.git summary page), and after they pass automated tests they will be pushed to stable-X.Y for the next release. The point releases are tagged in the main tree with RELEASE-X.Y.Z (e.g. RELEASE-4.2.2 on Xen.git summary page). The result of automated tests are available on xen-devel mailing list.

Xen Project Repositories contains information on the various repositories for the stable and development branches.

To clone the source first install Git using your distro's package manager. Then execute the following command:

$ git clone URL

Where URL is the URL of the repository you wish to clone. In our case we should use:

$ git clone git://xenbits.xen.org/xen.git

As the default HEAD in xen.git is master, your local repository will also have a branch called master pointing to the upstream branch. If you wish to use different HEAD (say, staging), you can:

$ cd xen; git checkout -b staging origin/staging

You can also checkout any tags, branches as you wish.

Mercurial

Please note that XenProject.org has moved to using Git. The following section is deprecated. We do maintain Mercurial repositories mirroring Git ones, so we retain following section for reference.

Xen Project's source code repositories are hosted using the Mercurial version control system on xenbits.

Each stable release has it's own branch xen-X.Y-testing.hg (e.g. xen-4.2-testing.hg) where code intended for the next stable point release is added. The Xen Project development branch is known as xen-unstable and has its own repository xen-unstable.hg.

Each stable and development branch is available in two forms either tested (the main branch) or untested (the staging branch). When commits are made to a Xen Project tree they are first added to the staging branch and only propagated to the main branch after automated testing has passed. For example all commits to the Xen Project development branch will initially appear in staging/xen-unstable.hg and then propagate to xen-unstable.hg after automated testing has completed. The automated test results are posted to the xen-devel mailing list.

Xen Project Repositories contains information on the various repositories for the stable and development branches.

To clone the source first install the mercurial tool using your distributions package manager. Then execute the following command:

$ hg clone URL

Where URL is the URL of the repository you wish to clone. e.g. to clone the latest tested xen-unstable tree:

$ hg clone http://xenbits.xen.org/hg/xen-unstable.hg

Or to clone the staging (e.g. not yet tested) xen-unstable tree:

$ hg clone http://xenbits.xen.org/hg/staging/xen-unstable.hg

You may want to get a specific changeset (revision), for example when trying to replicate someone else's build, or when dealing with other patches you have to apply afterwards. You can do this with the -r option. For example, to get changeset 25364:

$ hg clone -r 25364 http://xenbits.xen.org/hg/xen-unstable.hg

Quick-Start

The README at the top level of the Xen Project source code tree contains a quick-start guide to building the software. This provides a quick overview of the process and requirements for building Xen Project software and will generally contain the most up to date information specific to the particular source tree you are looking at. After obtaining the Xen Project source this is the first document you should read.

Building from Source

This section documents all known requirements to build from source.

Updated /sbin/installkernel on Linux

Linux distributions shipping with grub2 will need to ensure that their /sbin/installkernel script, which has to be provided by each Linux distribution, copies the the kernel configuration upon a custom kernel install time. The requirement for the config file comes from upstream grub2 /etc/grub.d/20_linux_xen which will only add xen as an instance to your grub.cfg if and only if it finds in your config file either of:

   CONFIG_XEN_DOM0=y
   CONFIG_XEN_PRIVILEGED_GUEST=y

Without this a user compiling and installing their own kernel with proper support for xen and with the xen hypervisor present will not get their respective grub2 update script to pick up the xen hypervisor. Debian testing has proper support for this, OpenSUSE required this change upstream on mkinitrd, so OpenSUSE folks will want to get the latest /sbin/installkernel hosted on the OpenSUSE mkinitrd repository on github.

   # If on OpenSUSE update your /sbin/installkernel
   git clone https://github.com/openSUSE/mkinitrd.git
   cd mkinitrd
   sudo cp sbin/installkernel /sbin/installkernel 

Fedora might need a similar update. Please edit this wiki once you confirm.

Build Dependencies

Xen Project uses several external libraries and tools. The primary list of these prerequisites is the list present in the README file.

Even this list assumes some sort of basic development environment. A good starting point for this is to use your distributions development install package option.

Build Dependencies - Debian / Ubuntu

Under Debian / Ubuntu (and derived distributions) install the build-essential package:

# apt-get install build-essential

you also need to install these additional debs:

# apt-get install bcc bin86 gawk bridge-utils iproute libcurl3 libcurl4-openssl-dev bzip2 module-init-tools transfig tgif 
# apt-get install texinfo texlive-latex-base texlive-latex-recommended texlive-fonts-extra texlive-fonts-recommended pciutils-dev mercurial
# apt-get install make gcc libc6-dev zlib1g-dev python python-dev python-twisted libncurses5-dev patch libvncserver-dev libsdl-dev libjpeg62-dev
# apt-get install iasl libbz2-dev e2fslibs-dev git-core uuid-dev ocaml ocaml-findlib libx11-dev bison flex xz-utils libyajl-dev
# apt-get install gettext libpixman-1-dev libaio-dev markdown pandoc

And if you're building on Wheezy onward:

# apt-get install libc6-dev-i386

One useful shortcut can be to use your distributions package manager to install all the prerequisite packages is to install those packages which are noted as being required to build the distribution's own Xen packages. e.g. under Debian or a Debian derived distribution:

# apt-get build-dep xen

However you need to be mindful of new prerequisites added between whatever version of Xen Project software is in your distribution and the version you are building when using this trick.

Build Dependencies - OpenSUSE

If you're now on the latest OpenSUSE you'll note its now a rolling distribution base. The default instructions do not actually encourage you to install the source repositories, and even if you did install them the instructions disable them by default, so be sure to install them and enable them otherwise the command zypper source-install -d won't work. To enable the required repository if you already had it installed:

# zypper mr -e repo-src-oss 

Now get the build dependencies for Xen

# zypper source-install -d xen

Here's a list of things not currentloy picked up by the build dependencies which have been found to be needed:

 # zypper install systemd-devel gettext-tools\
   ocaml ocaml-compiler-libs ocaml-runtime \
   ocaml-ocamldoc ocaml-findlib glibc-devel-32bit make patch

While at it also get the build dependencies for Linux:

# zypper source-install -d kernel-desktop

Build Dependencies - Fedora

These instructions are kept separate from RHEL / Centos as Fedora is updated more frequently, so you are expected to do less work to build the latest and greatest Xen.

Install known build dependencies:

# yum-builddep xen

Install things not picked up by the current build dependencies:

# yum install glibc-devel.x86_64 systemd-devel.x86_64

Get build dependencies for Linux, the kernel, while at it:

# yum-builddep kernel 

Build Dependencies - RHEL / Centos

Under RHEL, CentOS, Fedora based distributions you want to install the Development Tools package groups:

# yum groupinstall "Development Tools"

(On old CentOS and Fedora, a group called Development Libraries should, if available, installed too. That is not present in recent releases of the distributions any longer, though).

Then install known build dependencies (confirmation needed if this works on RHEL / Centos):

# yum-builddep xen

You also need to install these additional rpms:

# yum install transfig wget tar less texi2html libaio-devel dev86 glibc-devel e2fsprogs-devel gitk mkinitrd iasl xz-devel bzip2-devel
# yum install pciutils-libs pciutils-devel SDL-devel libX11-devel gtk2-devel bridge-utils PyXML qemu-common qemu-img mercurial texinfo
# yum install libidn-devel yajl yajl-devel ocaml ocaml-findlib ocaml-findlib-devel python-devel uuid-devel libuuid-devel openssl-devel
# yum install python-markdown pandoc systemd-devel glibc-devel.i686

If on CentOS, for some of this packages (e.g., dev86 and pandoc), enabling the EPEL additional repository is necessary.

Additional notes

Having installed this you should then install each of the prerequisites listed in the README using your distribution's package management tool. In general the Xen Project code tries to only depend upon external tools and libraries which are commonly available in distributions therefore obtaining the prerequisites other than from your distribution's package management system is out of scope for this document. If you have trouble locating a particular prerequisite then please contact the xen-users mailing list.

Configure

From Xen Project 4.2 onwards, the software uses the commonly used autoconf tool to provide compile time configurability of the toolstack. This allows some control of what features are built into Xen Project, as well as compile time sanity checking. To configure Xen Project, simply run the provided configure script:

$ ./configure

To see the various options run the configure script with --help e.g.:

$ ./configure --help
[...]
 Optional Features:
   --disable-option-checking  ignore unrecognized --enable/--with options
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
   --enable-githttp        Download GIT repositories via HTTP (default is
                           DISABLED)

This step is only required from Xen Project 4.2 onwards. Prior to Xen Project 4.2 these options could be configured by passing a variable on the make command line during build & install or by writing the variable to a file named .config at the top level of the source tree.

Use http:// Rather Than git:// to Clone Additional Repositories

When building the software from Mercurial, the build system will automatically clone several additional repositories from the network. Some of these repositories use the version control system which uses its own protocol on a specific port. Sometimes this causes issues due to firewalls etc blocking the git port. This can be worked around by instructing the Xen build system to clone such repositories using a less efficient HTTP based protocol:

$ ./configure --enable-githttp

Prior to Xen Project 4.2 this could be achieved by writing GIT_HTTP=y to your .config:

$ cat .config
GIT_HTTP = y

Library Installation Directory

Xen Project 4.2 onwards defaults to installing libraries into /usr/lib by default and from 4.3 onwards defaults to installing to /usr/local/lib by default.

Users on systems which use /usr/local/lib64 for 64-bit libraries should use the --libdir option. e.g:

$ ./configure --libdir=/usr/local/lib64

Failure to do this usually results in errors about libraries not found or using older versions of the libraries which will likely not work.

_NB_: If you are using `--prefix=/usr` you should use `--libdir=/usr/lib64` too.

Systemd

If the target system uses systemd, do not forget to enable it:

$ ./configure --enable-systemd

Python Prefix and Module Layout

On some distros (e.g. Debian and Ubuntu) Xen Project may install the python parts of the code into the wrong place (See Debian bug #693721). Therefore it is necessary to set PYTHON_PREFIX_ARG=--install-layout=deb:

$ cat .config
PYTHON_PREFIX_ARG=--install-layout=deb

Some versions of Ubuntu have a bug which requires instead that PYTHON_PREFIX_ARG is to set the empty string:

$ cat .config
PYTHON_PREFIX_ARG=

As of 4.2 this option is not yet supported by the configure script and therefore should still be set via .config or on the make command line.

The most common symptom of this issue is pygrub failing to work, with output similar to:

Traceback (most recent call last):
   File "/usr/lib/xen/bin/pygrub", line 20, in <module>
     import xen.lowlevel.xc
ImportError: No module named xen.lowlevel.xc

Build & Install

Icon Ambox.png Xen Project downloads various components at build time. This means that building Xen Project currently requires an active connection to the Internet


To build all components (hypervisor, tools, docs, stubdomains, etc) you can use the dist target.

$ make dist

If you wish to just (re)build a single component you can use the appropriate dist-COMPONENT target:

$ make dist-xen
$ make dist-tools
$ make dist-docs
$ ... etc ...

If you want to rebuild a tree as if from a fresh check then you can use the world target. This is effectively the same as clean and the dist

$ make world

All of the above targets will build and install the appropriate component into the dist subdirectory but not actually install onto the system.

To install onto the local machine simply call the install target (as root):

# make install

As with dist you can also install individual components using the appropriate install-COMPONENT target:

# make install-xen
# make install-tools
# make install-docs
# ... etc ...

If you want to install onto a remote machine then you can simply copy the dist directory over and TBD

A better option is to make a "package-ball" -- a package which is the equivalent of a tarball with no dependency checking or set-up. There are target for either deb-based systems:

# make debball

or rpm-based systems:

# make rpmball

Packages are placed in the dist/ directory.

Installing the resulting package is functionally equivalent to the make install target above, but because the files are tracked by the package manager, it is easier to remove or update.

After installing (either via make install or a packageballl) you rebuild your dynamic linker cache by running:

# /sbin/ldconfig

To get more information on the available targets use the help target:

$ make help

Linux grub2 update

When on Linux and using grub2 after installing Xen you will also need to make sure grub2 will pick up your new shiny Xen hypervisor. Distributions differ on how to do this. This section documents how to do this for known distributions.

update grub2 config on OpenSUSE

# update-bootloader --refresh

update grub2 config on Debian

# update-grub

update grub2 config on Fedora

TBD

update grub2 config on RHEL / Centos

TBD

Troubleshooting

  • If SeaBIOS fails to compile when building Xen 4.2 on a system with a non-English locale, try setting LC_ALL to en_US.UTF-8 before calling make:
# export LC_ALL=en_US.UTF-8
# make world

Kernels

The Linux kernel now supports different hypervisors with one kernel. There is also no requirement for a domain 0 (or guest) kernel to match your hypervisor so you are free to pick the kernel which best suits your needs (e.g. many distributions supply a kernel which is compatible with Xen Project, which is a quick and easy path). Dom0 Kernels for Xen contains some guidance on this issue.

Compiling latest Linux kernel support

If compiling Linux from source for either dom0 or a guest you can now enable Xen support for both through one simple kernel configuration helper, this was added as of v4.2:

   make xenconfig

This lets you build a kernel which can support xen dom0 or xen guests on i386, x86-64 and arm64.

Post-Installation

A few system services should be manually enabled after the installation:

SystemV

Required:

update-rc.d xencommons defaults 19 18

Optional:

update-rc.d xendomains defaults 21 20
update-rc.d xen-watchdog defaults 22 23


systemd

Required:

systemctl enable xen-qemu-dom0-disk-backend.service
systemctl enable xen-init-dom0.service
systemctl enable xenconsoled.service

Optional:

systemctl enable xendomains.service
systemctl enable xen-watchdog.service
systemctl enable xendriverdomain.service

After making those changes reboot the system.

Host Configuration

Once the Xen Project code is installed there is still some host level setup required. Category:Host Configuration covers this.