I just wasted a fair amount of time on a RedHat 6.1 box being setup to be a hypervisor with KVM, trying to figure how why when I ran
virsh version it was telling me among other things
internal error Cannot find suitable emulator for x86_64
All the appropriate packages such as qemu-kvm were installed, but it just didn't seem to want to work. Finally as I was about to try reinstalling RHEL, I remoted into the actual console and saw:
kvm: disabled by bios
Doh!, and looking back in
/var/log/messages the same thing was buried deep within all the boot noise. While trying to figure this out I managed to just be looking for
qemu in the logs and somehow didn't search for
kvm. Enabled virtualization in the BIOS and everything's gravy now.
So there you go, if you're Googling that first error message and get lots of other nonsense, look for the message about the BIOS.