Windows in QEMU on KVM-L4

Rolf Sommerhalder rolf.sommerhalder at
Wed Apr 18 11:44:30 CEST 2012


In their paper [1], the authors mention that they were able to run
32-bit versions of Windows XP and 7, among other guest OSes, in KVM-L4
on AMD x86 processors with AMD-V extensions.

Does anyone from the list happen to have an .iso around which boots on
such an AMD machine and demonstrates the performance of Windows (any
version will do) running in KVM-L4?
Alternatively, I would be grateful for any recipe how to adapt a demo CD
or Fisco.OC/L4Re build environment so that it allows to start a Windows
image in QEMU/KVM on L4.

So far, I have managed to install and to run Windows 7 Pro in a QEMU/KVM
image on my Linux host. As this image is over 4 GByte by itself, plus
QEMU with its dependencies, there is no way of just extending the
ramdisk image in order to load and run it in L4Linux.

After searching this list, I so far found two possible ways to proceed:

a) Extended the ramdisk so that it mounts a disk partition /dev/hdaX,
and then chroot to that mounted partition. Then try to launch the QEMU
image from that new root.
However, a previous poster here ran into a problem while trying this,
and it is unclear to me if was able to overcome it [2].

b) Abandon the ramdisk and have L4Linux mount a disk partition as its
root file system directly upon boot.
This was tried in 2006 and it is unclear if it finally worked [3].

In both cases, I presume that the binaries in that partition (QEMU and
its dependencies) must match the version of the L4Linux kernel (which is
3.0). My Linux build environment uses Ubuntu 10.04 LTS (which uses
kernel 2.6.x).

My only interest at this early stage of a quick Proof of Concept is just
to get a feeling if a faithfully virtualised Windows run on top of
KVM-L4 still performs reasonably well on a recent (Business-) PC, so
that it is still acceptable to the average user.

Previous results published suggested that real-world Linux applications
incur (only) a 4..5% overhead when run on top of L4Linux, compared to
running them natively on (bare metal) Linux. Now I would like to know if
this surprisingly low overhead also continues throughout KVM-L4 with
Windows as one of its "applications".

Thanks in advance for any hints,

[1] Virtual Machines Jailed - Virtualization in Systems with Small
Trusted Computing Bases
Michael Peter, Henning Schild, Adam Lackorzynski, Alexander Warg
VTDS'09: Workshop on Virtualization Technology for Dependable Systems
(Eurosys 2009 affiliated workshop) , March 2009

[2] Using hard disk as root filesystem

[3] Booting L4Linux/Fiasco with root=/dev/hda

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