If you're trying to start a cloud-init based Ubuntu VM with KVM you will suffer long boot times and confusing output on the terminal. If you want to get rid of it you need to remove cloud-init.
echo 'datasource_list: [ None ]' | sudo -s tee /etc/cloud/cloud.cfg.d/90_dpkg.cfg
sudo apt-get purge cloud-init
sudo rm -rf /etc/cloud/; sudo rm -rf /var/lib/cloud/
Touch the file
/etc/cloud/cloud-init.disabled or use the kernel parameter
cloud-init=disabled to disable cloud-init without completely removing it.