Sets the number of vCPUs this QEMU VM.

        :param cpus: number of vCPUs.

def cpus(self, cpus):
        """
        Sets the number of vCPUs this QEMU VM.

        :param cpus: number of vCPUs.
        """

        log.info('QEMU VM "{name}" [{id}] has set the number of vCPUs to {cpus}'.format(name=self._name, id=self._id, cpus=cpus))
        self._cpus = cpus