QEMU : change cdrom

http://en.wikibooks.org/wiki/QEMU/Monitor#change

(qemu) info block
ide0-hd0: type=hd removable=0 file=/path/to/winxp.img
ide0-hd1: type=hd removable=0 file=/path/to/pagefile.raw
ide1-hd1: type=hd removable=0 file=/path/to/testing_data.img
ide1-cd0: type=cdrom removable=1 locked=0 file=/dev/sr0 ro=1 drv=host_device
floppy0: type=floppy removable=1 locked=0 [not inserted]
sd0: type=floppy removable=1 locked=0 [not inserted]
(qemu) change ide1-cd0 /path/to/my.iso
(qemu) change ide1-cd0 /dev/sr0 host_device