You are right. I was implying that libvirt in 10.10 would create proper configuration files and not have this bug, but I didn't verify that. The only thing that I could verify is that some images (32-bit guests) that used to work with /usr/bin/kvm in 10.04 stopped working in 10.10. In my case, replacing /usr/bin/kvm (which points to /usr/bin/qemu-system-x86_64) by /usr/bin/qemu fixed the problem.
You are right. I was implying that libvirt in 10.10 would create proper configuration files and not have this bug, but I didn't verify that. The only thing that I could verify is that some images (32-bit guests) that used to work with /usr/bin/kvm in 10.04 stopped working in 10.10. In my case, replacing /usr/bin/kvm (which points to /usr/bin/ qemu-system- x86_64) by /usr/bin/qemu fixed the problem.