Re: [Qemu-devel] [PATCH] ppc/spapr: Allow VIRTIO_VGA

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2015-09-15 at 11:19 +0200, Gerd Hoffmann wrote:
> On Di, 2015-09-15 at 15:51 +1000, Benjamin Herrenschmidt wrote:
> > It works fine with the Linux driver out of the box
> 
> Do you actually want the vga compatibility bits on pseries?

Yes, our firmware SLOF uses them (via MMIO BARs) for the early boot
stuff (well, it will use them when the patches I sent are merged).

> There also is virtio-gpu-pci (same thing as virtio-vga but without 
> vga compatibility), which should already be enabled on ppc64.
> 
> Thel inux kvm driver certainly doesn't need vga compatibility.
> 
> For slof support it might be useful though, the vga compatibility
> bits
> in virtio-vga are fully compatible to stdvga, so slof support should
> be
> as simple as adding a PCI ID ...

Right. Well, I first had to update SLOF to use the MMIO BARs rather
than the legacy IO crap, but yes, that's pretty much what I did.

> cheers,
>   Gerd
>