QEMU Upstream

How to build QEMU (upstream version) with Xen

Get the source

• Get Xen source (version 4.2 aka xen-unstable development version)
• Get QEMU upstream source from:
  • Recommended: xen-stable-0.15 qemu branch
    • git://xenbits.xen.org/people/sstabellini/qemu-dm.git xen-stable-0.15
    • Announcement of the "xen-stable-0.15" qemu branch and more info here: http://lists.xensource.com/archives/html/xen-devel/2011-07/msg01359.html
• Other option: Anthony's git tree used for development
  • git://xenbits.xen.org/people/aperard/qemu-dm.git
• Example for "xen-stable-0.15" branch
  • git clone git://xenbits.xen.org/people/sstabellini/qemu-dm.git qemu-dm.git
  • cd qemu-dm.git
  • git checkout -b xen-stable-0.15 origin/xen-stable-0.15

Build it!

• Build Xen
  • make xen tools, if it fail see bellow.
• Build QEMU upstream with Xen
  • For xen-unstable.hg versions between 23412:996c7726a376 and 23632:33717472f37e you will need to copy path_to_xen/tools/libxc/xc_e820.h to $path_to_xen_source/dist/install/usr/include" for configuration script to work. After 23632:33717472f37e xc_e820.h was squashed into xenctrl.h
  • ./configure --enable-xen --target-list=i386-softmmu --extra-cflags="-I$path_to_xen_source/tools/include -I$path_to_xen_source/tools/libxc -I$path_to_xen_source/tools/xenstore" --extra-ldflags="-L$path_to_xen_source/tools/libxc -L$path_to_xen_source/tools/xenstore"
  • make

Troubleshooting compilation errors: If you get an error from configure like "ERROR: User requested feature xen ERROR: configure was not able to find it" then see this: http://xen.1045712.n5.nabble.com/Upstream-Qemu-With-Xen-configuration-problem-td4561779.html , ie. you need to point the paths for "configure" to xen source directory, not to xen dist directory.

Run it!

Either:

• Add "device_model = path/to/new/qemu" in your VM configuration files.
  • This have been change in the latest xen-unstable tree: now use:
    • device_model_override = '/root/work/qemu/_build/i386-softmmu/qemu'
    • device_model_version = 'qemu-xen'
• Replace /usr/lib/xen/bin/qemu-dm by the qemu present in i386-softmmu/qemu of the build of QEMU.

 with the last xen-unstable, device_model_version = 'qemu-xen' is needed in the guest configuration file.

Now xl will always try run qemu upstream with seabios, so build xen with seabios.

• For troubleshooting device_model related errors (Xen specific options -domain-name, -vcpus, etc) see: http://xen.1045712.n5.nabble.com/Upstream-QEMU-not-working-with-Xen-unstable-lacks-option-definitions-td4372252.html

Use with SeaBIOS

• Get SeaBIOS from git://git.seabios.org/seabios.git
  • As of commit ee2bc468cbc7 in that tree no patches to SeaBIOS are required.
  • You can take the .config file here to put in the root of your source tree
  • and build SeaBIOS (make).
• In xen-unstable source tree, add the file .config with SEABIOS_DIR = /path/to/seabios. If this does not work a temporary hack is to modify the SEABIOS_ROM path in tools/firmware/hvmloader/Makefile to point to path_to_seabios/out/bios.bin
• Build Xen, at least make tools to update the "xen-bios"
  • tips: make -C tools/firmware clean before make tools to take into account the new SEABIOS_DIR parameter.
• Run it!