To do some of my testing on Debian Lenny, I back-ported a more recent version of kvm and qemu. This involves getting the newer source packages and re-building them on Debian Lenny. It is also possible, in some cases to simply install newer versions of the binary packages, however, you will often encounter dependancy problems.
Package
openbios-ppc
openbios-sparc
Version
1.0-3
1.0-1
ref: http://www.debian.org/doc/maint-guide/ch-build.en.html
I create a separate userid just for building (extra). Note that some of these instructions assume you have added the testing/unstable/experimental repos available in your /etc/apt/sources.list.d/
as root:
Building qemu
Building kvm
Building vgabios
Building bochsbios
I needed to hack the debian/rules a bit to make this go. Mostly problems around the doc building.
... as root
cd /usr/src
rm -rf modules
apt-get install kvm-source/experimental
m-a ... this uses the module assistant to rebuild the kernel modules
dpkg -i ...the new kvm-modules-2.6.26-2-amd64....deb you just created