Re: Proper support for PCI-based option rom loading (was Re: [Qemu-devel] Re: qdev property bug?)

[Michael S. Tsirkin]

On Wed, Dec 16, 2009 at 02:42:51PM +0100, Gerd Hoffmann wrote:
>   Hi,
>
>> What will happen when we find a bug in one of ROMs
>> I wonder? I think we will need to keep the old ROM
>> around, and put it in as part of compat machine type?
>
> What do you want?
> Old way to load the rom?
> Old rom binaries (i.e. etherboot)?
> Both?
>
> The new way to load the roms is a guest-visible change (devices get a  
> rom bar they had not before), so we might want to have a backward  
> compatibility property for that.  Not sure whenever this is a problem.
>
> Allowing old ROMs isn't easy as they don't support BEV.
>
> cheers,
>   Gerd


I am mostly concerned with migrating between qemu versions with
different roms, while guest was in the middle of running ROM.
This might be solved if we migrated ROM content together with
the device and put some padding in ROM content so that
size can be kept constant.

-- 
MST