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

[Gerd Hoffmann <kraxel@redhat.com>]

On 12/15/09 03:37, Anthony Liguori wrote:
> Okay, I think I've figured out how this is supposed to work. With these
> two patches to SeaBIOS and the patch to qemu, I can run:
>
> qemu -net nic,model=rtl8139 -net nic,model=virtio -net nic,model=e1000
> -boot menu=on
>
> And all three option roms load. I can also select which NIC I want to
> boot from using the F12 menu. This works by not actually loading the
> option roms in the 1M space, but instead making them mappable through
> the PCI devices. With PMM and DDIM, the result is that we only have to
> copy in 2K for each option rom which means we can support up to 48
> unique option roms. That should be plenty for now.
>
> These patches are very rough but I'll clean them up tomorrow. I'm not
> sure the best way to integrate with the rom infrastructure since we no
> longer have a physical address to map to. Any suggestions Gerd?

Is this needed in the first place?  Integration into pci like your patch 
does looks sensible to me.  That wouldn't get us re-loading on reset, 
but as the guest shouldn't be able to modify the roms I don't think we 
need this ...

We could also add a "romfile" property to the pci bus and do everything 
(except setting the default filename) in generic pci code.

I'm more worried about the CONFIG_OPTIONROMS_DEPLOYED patches for 
seabios, although I don't fully understand what they are doing.  There 
are non-pci option roms (linuxboot, multiboot, extboot) which qemu will 
continue to deploy the way roms are deployed today.

cheers,
   Gerd