[libvirt] [PATCH 4/9] qemu: Do not start with source for removable disks if tray is open

[Paolo Bonzini]

Il 13/03/2012 20:15, Eric Blake ha scritto:
> > If the disk type is "block", and the source drive is a CD-ROM, the
> > virtual tray state should be tied to the physical tray, even though this
> > isn't always the case due to QEMU bugs.
> 
> Are we trying to map the tray='open' to what the guest sees (in which
> case, we should reject it for non-cdrom guest views), what the host sees
> (even if the guest is viewing the storage as a non-cdrom IDE disk, but
> the host storage backing that disk is a cdrom), or both?
> 
> I would argue that <target tray='open'/> should describe _only_ the
> guest's view, regardless of host state (if host is even tying a physical
> cdrom to the guest), and that if we _need_ the host state, that it
> should be an optional element in <source>.

I'm only concerned of the passthrough case, in which:

1) the host tray state and guest tray state are the same (or should be);

2) the guest tray state is not controlled by an empty source;

3) the host tray state cannot really be controlled by either libvirt or
QEMU.  Think of laptops whose tray can only open, not close.

Paolo