Re: [Qemu-devel] [PATCH 3/4] SCSI-Hotdel: Implement drive_hot_del

[Gerd Hoffmann]

On 09/30/09 17:45, Wolfgang Mauerer wrote:
> Gerd Hoffmann wrote:
> >     Hi,
> >
> > > +     dinfo = drive_get(type, bus, unit);
> > > +     if (!dinfo) {
> > > +         monitor_printf(mon, "Trying to remove non-existent device\n");
> > > +        return;
> > > +     }
> >
> > No.  Just don't do this silly if/bus/unit parsing.  At very minimum use
> > drive_get_by_id() here, then have something like 'drive_del $id'.
> >
> > IMHO much better would be to go qdev instead though.  We should have
> > generic device_add + device_del monitor commands which work for any
> > device, pretty much like the -device command line switch.
>
> That makes sense, but I'd nevertheless prefer to stick with the
> more traditional approach right now, replacing the
> bus/unit parsing with an ID-based variant.

Have a look at the "qdev: bus management updates." patch series posted a 
few days ago.  It adds device_add+device_del.

> However, is there any
> standard way to get from an instance of DriveInfo to
> the corresponding instance of SCSIDevice respectively
> SCSIDeviceInfo?

No.  It is linked the other way around: The device has a reference to 
the DriveInfo.  Which is one of the reasons why I think drive_del isn't 
that a great idea.

cheers,
  Gerd