Comment 2 for bug 1876258

virtio devices have serials, but not by default in qemu/kvm. As a workaround, you can add a serial to your virtio disk, using qemu command line:

 -drive if=none,id=bootdrive,file=$BOOT,format=qcow2
 -device virtio-blk-pci,drive=bootdrive,serial="myserial"

Or if you use libvirt, in the guest xml:

    <disk type='file' device='disk'>
      <source file='/media/lacie-500-disk-2/virtual-machines/scratch5.img'/>
      <target dev='vda' bus='virtio'/>
      <serial>dan123virtio</serial>
    </disk>