virsh attach-disk testbed /dev/sr0 hdc --type cdrom

virsh attach-disk testbed ~/virtio-win-0.1-22.iso hdc --type cdrom

<disk type='block' device='cdrom'>
  <driver name='qemu' type='raw'/>
  <source dev='/dev/sr0'/>
  <target dev='hdc' bus='ide'/>
  <readonly/>
</disk>

virsh update-device testbed ~/cdrom-real.xml

virsh # qemu-monitor-command mirage --hmp --cmd "info block"
drive-virtio-disk0: type=hd removable=0 file=/home/daoist/mirage/mirage.qcow2 ro=0 drv=raw encrypted=0
drive-ide0-0-0: type=cdrom removable=1 locked=0 file=/home/daoist/iso/en_windows_7_ultimate_with_sp1_x64_dvd_u_677332.iso ro=1 drv=raw encrypted=0

virsh # qemu-monitor-command mirage --hmp --cmd "eject drive-ide0-0-0"
virsh # qemu-monitor-command mirage --hmp --cmd "change drive-ide0-0-0 /path/to/new.iso"
virsh #

virsh qemu-monitor-command <domain> --hmp --cmd "info block"

virsh qemu-monitor-command windows44407 --hmp --cmd "info block"

lsscsi

[root@kvmatrix ~]# lsscsi
[#:0:0:0]    cd/dvd  HL-DT-ST BD-RE  WH14NS40  1.03  /dev/sr0

<controller type='scsi' index='0' model='virtio-scsi'/>
    <hostdev mode='subsystem' type='scsi'>
      <source>
        <adapter name='scsi_host#'/>
        <address type='scsi' bus='0' target='0' unit='0'/>
      </source>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </hostdev>