Comment 44 for bug 1057024

Bernd Rothert (bro) wrote :

Failure to start kvm can also be caused by VirtualBox running on the host - watch out for dmesg like:

kvm: enabling virtualization on CPU3 failed
kvm: enabling virtualization on CPU0 failed
kvm: enabling virtualization on CPU2 failed
kvm: enabling virtualization on CPU1 failed

to fix it:
# /etc/init.d/virtualbox stop
# rmmod rmmod vboxnetflt

and the KVM VMs should start from virt-manager like a charm

n.b.
# grep libvirt /etc/group
kvm:x:127:libvirt-qemu
libvirtd:x:130:<yourusername>