Re: [Qemu-devel] [PATCH v2 1/7] bootindex: add modify_boot_device_path function

[Gerd Hoffmann <kraxel@redhat.com>]

  Hi,

> > > > I think it is ok to allow only *changing* the bootindex.
> > > >
> > > Yes, that's no problem.
> > 
> > But then yoy always  will have a old entry where you can take the suffix
> > from, and you don't need the suffix as parameter for the monitor
> > command.
> > 
> No, optional. 

> Because the bootindex property is not a necessary property for devices.
> If a device, such as IDE cdrom haven't attach the bootindex in qemu booting 
> command line, the global fw_boot_order will not have its entry.

I'd suggest to simply not support this and throw an error then.

> So, we should
> save the suffix as parameter.

I think it is a bad idea to have the suffix as monitor command
parameter.  It is a implementation detail which the monitor users should
not have to worry about.

Easiest way to do this is to allow *changing* an existing bootindex
entry only, and not support *adding* new boot entries.  The user has to
set a bootindex for any device it might want to boot from in the future
then.  I think this is acceptable.

If you want support adding bootentries at runtime (and it probably makes
sense to support removing entries too in that case) the suffix handling
should be reworked.  The suffix could be stored in DeviceState instead
of being passed to the add_bootentry function, so you can add boot
entries later on without expecting the user to know what the correct
suffix is.

cheers,
  Gerd