Qemu upstream bugs with xen

[Fabio Fantoni <fabio.fantoni@heliman.it>]

1) Both linux and windows domU with qemu upstream have an additional 
empty floppy and cdrom.
Is there a way to remove these additionals block devices?

2) xl cd-eject and cd-insert are not working:

xl -vvv cd-eject W7 hdb
libxl: debug: libxl.c:2389:libxl_cdrom_insert: ao 0x1b95990: create: 
how=(nil) callback=(nil) poller=0x1b95930
libxl: debug: libxl_device.c:229:libxl__device_disk_set_backend: Disk 
vdev=hdb spec.backend=phy
libxl: debug: libxl_device.c:175:disk_try_backend: Disk vdev=hdb, 
backend phy unsuitable as phys path not a block device
libxl: error: libxl_device.c:269:libxl__device_disk_set_backend: no 
suitable backend for disk hdb
libxl: debug: libxl_event.c:1482:libxl__ao_abort: ao 0x1b95990: abort
libxl: debug: libxl_event.c:1472:libxl__ao__destroy: ao 0x1b95990: destroy
xc: debug: hypercall buffer: total allocations:4 total releases:4
xc: debug: hypercall buffer: current allocations:0 maximum allocations:2
xc: debug: hypercall buffer: cache current size:2
xc: debug: hypercall buffer: cache hits:1 misses:2 toobig:1

xl -vvv cd-insert W7 hdb raw:/mnt/vm/iso/QUANTAL.iso
libxl: debug: libxl.c:2389:libxl_cdrom_insert: ao 0x1d07990: create: 
how=(nil) callback=(nil) poller=0x1d079f0
libxl: debug: libxl_device.c:229:libxl__device_disk_set_backend: Disk 
vdev=hdb spec.backend=phy
libxl: error: libxl_device.c:243:libxl__device_disk_set_backend: Disk 
vdev=hdb failed to stat: raw:/mnt/vm/iso/QUANTAL.iso: No such file or 
directory
libxl: debug: libxl_event.c:1482:libxl__ao_abort: ao 0x1d07990: abort
libxl: debug: libxl_event.c:1472:libxl__ao__destroy: ao 0x1d07990: destroy
xc: debug: hypercall buffer: total allocations:4 total releases:4
xc: debug: hypercall buffer: current allocations:0 maximum allocations:2
xc: debug: hypercall buffer: cache current size:2
xc: debug: hypercall buffer: cache hits:1 misses:2 toobig:1

Seem there is parsing error about backend and device/iso path, for now I 
not found solution for fix it on code.

3) There is still big problem of network not working after restore on 
windows domU, but for now I not found exactly cause.