Comment 4 for bug 2018999

I tried the solution that ykarel (thanks!) proposed and it worked.

1) Changing the /etc/nova/nova-cpu.conf
[libvirt]
live_migration_uri = qemu+ssh://stack@%s/system
cpu_model = Nehalem
cpu_mode = custom
virt_type = qemu # kvm -> qemu

[workarounds]
ibvirt_disable_apic = True

2) Restarting n-cpu
sudo systemctl restart devstack@n-cpu