Re: [Qemu-devel] [PATCH] qmp: report TRAY_STATE_CHANGED events

[Luiz Capitulino <lcapitulino@redhat.com>]

On Fri, 04 Nov 2011 11:53:53 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:

> On 11/01/2011 06:03 AM, ShaoHe Feng wrote:
> > after the guest startups, then I right click mouse in the UI of the
> > guest,  and select the Eject from the menu.
> > there comes an event in the qmp-monitor.
> > {"timestamp": {"seconds": 1320118137, "microseconds": 420150}, "event":
> > "TRAY_STATE_CHANGED", "data": {"device": "ide0-cd1", "state": "open"}}
> >
> > however, if I change the cdrom by this command:
> > { "execute": "change","arguments": { "device": "ide0-cd1", "target":
> > "/home/fsh/image/OCDC-natty-Test-Drive-20110823_010339.iso" } }
> > there is no any event.
> > and { "execute": "eject", "arguments": { "device": "ide0-cd1" } },
> > there is also no any event.
> 
> This was by design.  The idea was that management can do the following 
> to change a CD when the guest keeps the medium locked and reacts to 
> eject requests (like very recent Linux does):

Just a note: this didn't make 1.0... I replied to it but didn't get
feedback:

  http://lists.gnu.org/archive/html/qemu-devel/2011-10/msg03096.html

> 
> Scenario 1: non-forced media change
> 
>       1. start looking at TRAY_STATE_CHANGED events
>       2. execute "eject" command
>       3. execute "query-block"
>       4. if disk is still shown as closed, check for guest reactions:
>          4.1. if no TRAY_STATE_CHANGED event has been reported since
>               step 1, wait until a TRAY_STATE_CHANGED event has arrived
>          4.2. if the TRAY_STATE_CHANGED event had state == closed, fail
>       5. execute "change" command
> 
> Scenario 2: forced media change
> 
>       1. execute "eject -f" command (with the posted patches that
>          always unlock the tray upon "eject -f")
>       2. execute "change" command
>       3. if it fails, restart
> 
> Paolo
>