I started playing with kvm 28-4~bpo.1 on my etch.
I installed Fedora Core 9, but during boot I had a lot of messages like

ata2.00: status: { DRDY ERR }

and

HSM violation

So I backported kvm 72+dfsg-4 from lenny and got rid of this error.

Download : kvm_72+dfsg-4_amd64.deb