This error was received on CentOS 7, at the beginning of the install command:

ERROR    internal error: process exited while connecting to monitor: qemu-kvm: -chardev pty,id=charserial0: Failed to create chardev

The fix is to edit /etc/fstab find the devpts line and change it to:

devpts /dev/pts devpts gid=5,mode=620 0 0

Run remount command

mount -o remount /dev/pts

And it should be enough