Re: [Qemu-devel] [SeaBIOS] [RFC PATCH v2] fw/pci: Add support for mapping Intel IGD OpRegion via QEMU

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 2016-02-03 at 10:04 +0100, Gerd Hoffmann wrote:
>   Hi,
> 
> > +static void intel_igd_opregion_setup(struct pci_device *dev, void *arg)
> > +{
> > +    struct romfile_s *file = romfile_find("etc/igd-opregion");
> 
> Is it possible to have multiple igd devices in a single machine?
> So, should we include the pci address in the file name?
> 
> Guess not needed, it's chipset graphics after all ...

Hmm, I think that's probably a pretty good observation, we don't want to
revisit this if vGPUs need/want an OpRegion or if Intel decides to start
allowing more than one per system.  Either could pretty easily introduce
multiple into a VM.

> > +    pci_config_writel(bdf, 0xFC, cpu_to_le32((u32)opregion));
> 
> Looks a bit funny in code which is never ever going to run on big endian
> machines ;)

Clearly I stole it from code that wasn't assuming little endian and
figured "why not", it's a nop anyway and one less thing to care about
when IBM licenses Intel graphics for POWER systems... ;)

> Patch looks good to me.

Thanks!

Alex