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

[Gonglei (Arei)]

> -----Original Message-----
> From: Gerd Hoffmann [mailto:address@hidden
> Sent: Monday, July 28, 2014 6:02 PM
> Subject: Re: [PATCH v2 1/7] bootindex: add modify_boot_device_path function
> 
>   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.
> 
Ok.

> > 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.
> 
Yes. Actually I also have this misgivings.

> 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.
> 
Hmm..

> 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.
> 
That's a good idea! I think this is a good improvement. 

Any other comments? Thanks!

Best regards,
-Gonglei