Compiling Xen from source * Overview * Options recognized by configure * Variables recognized by make * Systemd support * History of options * Examples Overview ======== The xen source contains four subsystems: xen, tools, stubdom and docs. All but xen have to be prepared for build with a configure script in the toplevel directory. configure recognizes certain arguments and environment variables which are used to adjust various aspects of the following compile process. Once configure is done, make(1) has to be called. Also make(1) recognizes certain arguments. The following sections will give an overview. Options recognized by configure =============================== The configure script in the toplevel directory will recognize these options. It will pass them to the configure scripts in the tools, stubdom, and docs directory. Individual subsystems can be selected by one of the following options. Please note that stubdom requires tools. --disable-xen --disable-tools --enable-stubdom --disable-docs The well known GNU configure options to specify the target directories. Some components of these paths will be compiled into the binaries. Note: prefix defaults to /usr/local, sysconfdir defaults to /etc, localstatedir defaults to /var. --prefix=DIR --libdir=DIR --libexecdir=BASEDIR --bindir=DIR --sbindir=DIR --sysconfdir=DIR --sharedstatedir=DIR --localstatedir=DIR --includedir=DIR --datarootdir=DIR --datadir=DIR --mandir=DIR --docdir=DIR To automatically run the toolstack in dom0 during system startup some sysv runlevel scripts are installed. This option allows to set the path for a given system. Possible values are /etc/init.d, /etc/rc.d/init.d or /etc/rc.d. If not specified configure tries to guess the path. --with-initddir=DIR The runlevel scripts load certain configuration files. They are typically located in a subdirectory of /etc. Possible values are this subdirectory are "sysconfig" or "default". If not specified configure tries to guess the subdir. --with-sysconfig-leaf-dir=SUBDIR If the tools are configured with a non-standard --prefix the runtime linker will either not find the required libraries or it will load them from a wrong location. Compiling the tools with rpath will force the linker to look in the correct location. --enable-rpath During build in a git checkout the buildsystem needs to download additional tools such as qemu. This is done with either the native git protocol, or via http if this option is enabled. --enable-githttp Disable xenstat and xentop monitoring tools. --disable-monitors Disable build of certain ocaml libraries and tools. To actually build them ocaml development packages must be installed. If they are missing configure will automatically disable this option. --disable-ocamltools Disable XSM policy compilation. --disable-xsmpolicy Attempt to build of an OVMF firmware binary. This requires special versions of development tools. Use at your own risk. --enable-ovmf Use the given OVMF binary instead of compiling a private copy. --with-system-ovmf=PATH Build a private copy of SeaBIOS. --disable-seabios Use the given SeaBIOS binary instead of compiling a private copy. --with-system-seabios=PATH Build the old qemu used by xm/xend. This is required if existing domUs should be migrated to this host, or if existing domU snapshots should be started with this version of the tools. Only if all domUs used the new upstream qemu during initial start it is safe to disable this option. The old qemu requires rombios, which can be disable along with qemu-traditional. --enable-qemu-traditional --enable-rombios The libxl toolstack uses the upstream qemu per default. A private copy will be built. If desired this private copy can be configured with additional options passed to its configure script. --with-extra-qemuu-configure-args="arg1 arg2" Use the given qemu binary instead of compiling a private copy. --with-system-qemu=PATH A dom0 requires a set of backend drivers. The configure script already supplies a list of known drivers which are automatically loaded in dom0. This internal list can be changed with this option. --with-linux-backend-modules="kmod1 kmod2" Two variants of a xenstored exist: the original xenstored written in C (xenstored) or the newer and robust one written in Ocaml (oxenstored). The oxenstored daemon is the default but can only be used if the required ocaml packages are installed. In case they are missing the original xenstored will be used. Valid names are xenstored and oxenstored. --with-xenstored=name The path where to store core dumps for domUs which are configured with coredump-destroy or coredump-restart can be specified with this option. --with-xen-dumpdir=DIR Instead of starting the tools in dom0 with sysv runlevel scripts they can also be started by systemd. If this option is enabled xenstored will receive the communication socked directly from systemd. So starting it manually will not work anymore. The paths to systemd internals can also be changed in case the default paths do not fit anymore. NOTE: if systemd development packages are installed the systemd support will be the enabled per default. Using --disable-systemd will override this detection and the sysv runlevel scripts have to be used. --enable-systemd --with-systemd=DIR --with-systemd-modules-load=DIR The old backend drivers are disabled because qdisk is now the default. This option can be used to build them anyway. --enable-blktap2 Build various stubom components, some are only example code. Its usually enough to specify just --enable-stubdom and leave these options alone. --enable-ioemu-stubdom --enable-c-stubdom --enable-caml-stubdom --disable-pv-grub --disable-xenstore-stubdom --enable-vtpm-stubdom --enable-vtpmmgr-stubdom --disable-extfiles Per default some parts of the tools code will print additional runtime debug. This option can be used to disable such code paths. --disable-debug The configure script recognizes also many environment variables. Calling the individual configure scripts in the subdirectories with the "--help" option will list these environment variables. Variables recognized by make ========================== The following variables are recognized by the build system. They have to be passed as make options, like 'make variable=value'. Having these variables in the environment, like 'env variable=value make', will not work for most of them. In addition to pass variables as make options it is also supported to create a ".config" file in the toplevel directory. The file will be sourced by make(1). The well known variable to specify an offset during make install, useful for packaging. DESTDIR= Per default some parts of the tools code will print additional runtime debug. This option can be used to disable such code paths. debug=y debug_symbols=y If --prefix= was used during configure the and ocaml was enabled the resulting libraries will not be installed in the specified path. Instead the path provided by ocamlfind(1) will be used. This variable can be used to override this path. Using the environment variable OCAMLFIND_DESTDIR= and OCAMLFIND_METADIR= will have the same effect. OCAMLDESTDIR= The xen subsystem will install the hypervisor into fixed locations. BOOT_DIR defaults to /boot, DEBUG_DIR defaults to /usr/lib/debug and EFI_DIR to /usr/lib64/efi. BOOT_DIR= DEBUG_DIR= EFI_DIR= The make target 'rpmball' will build a xen.rpm. This variable can be used to append a custom string to the name. In addition a string can be appended to the rpm Release: tag. PKG_SUFFIX= PKG_RELEASE= The hypervisor will report a certain version string. This variable can be used to append a custom string to the version. XEN_VENDORVERSION= During boot xen will report a certain user@host string, which can be changed with these variables. XEN_WHOAMI= XEN_DOMAIN= Some components of xen and tools will include an unpredictable timestamp into the binaries. To allow reproducible builds the following variables can be used to provide fixed timestamps in the expected format. XEN_BUILD_DATE= XEN_BUILD_TIME=hh:mm:ss SMBIOS_REL_DATE=mm/dd/yyyy VGABIOS_REL_DATE="dd Mon yyyy" During tools build external repos will be cloned into the source tree. This variable can be used to point to a different git binary to be used. GIT= During tools build external repos will be cloned into the source tree. During stubdom build external packages will be downloaded into the source tree. These variables can be used to point to a different locations. XEN_EXTFILES_URL= OVMF_UPSTREAM_URL= QEMU_UPSTREAM_URL= QEMU_TRADITIONAL_URL= SEABIOS_UPSTREAM_URL= MINIOS_UPSTREAM_URL= Using additional CFLAGS to build tools which will run in dom0 is required when building distro packages. These variables can be used to pass RPM_OPT_FLAGS. EXTRA_CFLAGS_XEN_TOOLS= EXTRA_CFLAGS_QEMU_TRADITIONAL= EXTRA_CFLAGS_QEMU_XEN= This variable can be used to use DIR/include and DIR/lib during build. This is the same as PREPEND_LIB and PREPEND_INCLUDES. APPEND_LIB and APPEND_INCLUDES= will be appended to the CFLAGS/LDFLAGS variable. EXTRA_PREFIX=DIR PREPEND_LIB=DIR PREPEND_INCLUDES=DIR APPEND_LIB=DIR APPEND_INCLUDES=DIR While the tools build will set the path to the python binary with the configure script, the hypervisor build has to use this variable to use a different python binary. PYTHON= Building the python tools may fail unless certain options are passed to setup.py. Config.mk contains additional info how to use this variable. PYTHON_PREFIX_ARG= The hypervisor may be built with XSM/Flask support, which can be changed by running: make -C xen menuconfig and enabling XSM/Flask in the 'Common Features' menu. A security policy is required to use XSM/Flask; if the SELinux policy compiler is available, the policy from tools can be included in the hypervisor. This option is enabled by default if XSM is enabled and the compiler (checkpolicy) is found. The location of this executable can be set using the environment variable. CHECKPOLICY= Use clang instead of GCC. clang=y Systemd support =============== If the systemd development packages are available then the support for systemd will be enabled per default. It is required to manually enable the installed systemd service files. Systemd has dependency tracking, which means all dependencies will be started automatically: systemctl enable xen-qemu-dom0-disk-backend.service systemctl enable xen-init-dom0.service systemctl enable xenconsoled.service Other optional services are: systemctl enable xendomains.service systemctl enable xen-watchdog.service QEMU Deprivilege ================ It is recommended to run QEMU as non-root. See docs/misc/qemu-deprivilege.txt for an explanation on what you need to do at installation time to run QEMU as a dedicated user. History of options ================== Prior to xen-4.5 configure recognized essentially only the --prefix= and --libdir= option to specify target directories. Starting with xen-4.5 all paths can be adjusted once with configure. Examples ======== * To build a private copy of tools and xen: configure --prefix=/odd/path --sysconfdir=/odd/path/etc --enable-rpath make sudo make install BOOT_DIR=/ood/path/boot EFI_DIR=/odd/path/efi * Use configure and make to build a distro rpm package (it is required to unset variables set by the rpm configure macro): %build export WGET=$(type -P false) export GIT=$(type -P false) export EXTRA_CFLAGS_XEN_TOOLS="$RPM_OPT_FLAGS" export EXTRA_CFLAGS_QEMU_TRADITIONAL="$RPM_OPT_FLAGS" export EXTRA_CFLAGS_QEMU_XEN="$RPM_OPT_FLAGS" %configure \ --with-initddir=%{_initddir} unset CFLAGS CXXFLAGS FFLAGS LDFLAGS make %install make install \ SYSCONFIG_DIR=/var/adm/fillup-templates \ DESTDIR=$RPM_BUILD_ROOT * To build xen and tools using a cross compiler: ./configure --build=x86_64-unknown-linux-gnu --host=aarch64-linux-gnu make XEN_TARGET_ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- make XEN_TARGET_ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \ DESTDIR=/some/path install TODO ==== - DESTDIR should be empty, not "/" - add make uninstall targets - replace private path variables as needed (SBINDIR/sbindir) - ... # vim: tw=72 et