On 12/05/2013 11:29 PM, Markus Armbruster wrote: > Markus Armbruster <arm...@redhat.com> writes: > >> Paolo Bonzini <pbonz...@redhat.com> writes: >> >>> Il 04/12/2013 05:55, Alexey Kardashevskiy ha scritto: >>>> Normally the user is expected to eject DVD if it is not locked by >>>> the guest. eject_device() makes few checks and calls bdrv_close() >>>> if DVD is not in use. >>>> >>>> However it is still possible to eject DVD even if it is in use. >>>> For that, QEMU sets "eject requested" flag, the guest reads it, issues >>>> ALLOW_MEDIUM_REMOVAL(enable=1) and START_STOP(start=0). But in this case, >>>> bdrv_close() is not called anywhere so it remains "inserted" in QEMU's >>>> terms. >>> >>> This is expected behavior, and matches what IDE does. >>> >>> Markus, can you confirm? >> >> Confirmed. See commit 4be9762. >> >> Alexey, monitor commands eject does two things: it first opens the tray, >> and if that works, it removes the medium. >> >> If the tray is locked closed, it tells the device model that eject was >> requested. Works just like the physical eject button. >> >> With -f, it then rips out the medium. This is similar to opening the >> tray with a unbent paperclip. Let's ignore this case. >> >> The scsi-cd device model tells the guest about the eject request. A >> well-behaved guest will then command the device to unlock and open the >> tray. >> >> The guest uses the same commands on behalf of its applications, >> e.g. /usr/bin/eject. >> >> Your patch changes behavior of "eject /dev/sr0 && eject -t /dev/sr0": >> you no longer get the same medium back. You normally do with real >> hardware. > > Alexey asked me for details on IRC. > > $ qemu -nodefaults -monitor stdio -S -machine accel=kvm -m 512 -display > vnc=:0 -device cirrus-vga -drive if=none,id=disk,file=test.qcow2 -device > ide-hd,drive=disk,bus=ide.0 -drive if=none,id=cd,file=f16.iso -device > ide-cd,drive=cd,bus=ide.1 > QEMU 1.7.50 monitor - type 'help' for more information > (qemu) info block cd > > cd: f16.iso (raw) > Removable device: not locked, tray closed > > Boot the guest (Fedora 16, no X) > > (qemu) c > > The guest locked the tray: > > (qemu) info block cd > > cd: f16.iso (raw) > Removable device: locked, tray closed > > In the guest, log in as root on the console, and run > > # eject /dev/sr0 > > Makes the guest open the tray: > > (qemu) info block cd > > cd: f16.iso (raw) > Removable device: locked, tray open > > In the guest, run > > # eject -t /dev/sr0 > > Makes the guest close the tray: > > (qemu) info block cd > > cd: f16.iso (raw) > Removable device: locked, tray closed > > Verify the guest can access the medium: > > # mount -r /dev/sr0 /mnt > >> The somewhat unfortunate consequence is that monitor command eject can >> only remove the medium when the tray is not locked.
Thanks! Just out of curiosity. A lot (in fact, all around me) dvd drives do not support trayclose as they are in laptops or servers (which use the same laptop models). I cannot even verify how this "eject -t" exactly works - no hardware around me. And even if I could find it, I could easily take the disc off the tray in that short period of time between tray is open and tray is closed but we still absolutely want "eject" + "eject -t" to work as you described. Why exactly? :) Only because change of behavior is bad? Just asking. Thanks. -- Alexey
