Description:
A few days ago I started qemu-kvm to boot from a physical partition on a second HDD (which is unrelated to my Arch installation) using `qemu-kvm /dev/sdc' which resulted immediately into a black screen. The computer halted. After a hard reset, Arch couldn't boot anymore. The partitions seemed to be fine (I was able to mount and browse them) but for some reason, the device couldn't be found anymore:

Booting the kernel.
mount: only root can do that (effective uid 1000)
mount: only root can do that (effective uid 1000)
mount: only root can do that (effective uid 1000)
mount: only root can do that (effective uid 1000)
ERROR: device '' not found. Skipping fsck.
ERROR: Unable to find root device ''. You are being dropped to a recovery shell.

The permissions for init were correct and I regenerated the kernel image inside a chroot, but that all didn't help. A reinstallation of the base system was done to get the system back up.

A few minutes ago I was trying to start a CentOS VM with virt-manager (which uses qemu-kvm in the back). Black screen, just the same I had a few days ago. Fortunately the system booted after a hard reset. No entries in the log files what actually happened. Once the system was back up, I've tried to boot the VM again using virt-manager and it succeeded instantly. As this seems to repeat from time to time, I'd like to get this fixed as this may cause serious data loss.

Additional info:
* qemu-kvm Version 1.0.1-3
* libvirt 0.9.12-3
* using a Intel Core2Quad processor with VT enabled

Steps to reproduce:
Start a VM either using virt-manager or manually by using qemu-kvm inside a console. Sadly this happens only from time to time so with a little "luck" the system will crash.