Re: [Qemu-devel] [v5][PATCH 0/5] xen: add Intel IGD passthrough support

[Chen, Tiejun]

On 2014/6/25 17:59, Paolo Bonzini wrote:
> Il 25/06/2014 11:55, Michael S. Tsirkin ha scritto:
> > > You're saying we will reserve a free BAR to address those
> > information to
> > > expose to guest, but which device does this free BAR belong to? The
> > video
> > > device? Or PCH/MCH?
> >
> > If you just want to pass a couple of IDs, then don't, it's a waste.
> > But I still don't know what problem you are trying to solve,
> > looking at guest driver did not help.
>
> It's not just a couple of IDs, it's also random fields of the MCH
> configuration space.  Grep drivers/gpu/drm/i915 for bridge_dev.

Paolo,

No, we're not pointing the bridge_dev here, which is a host bridge at 
00:00.0.

Here it should be a ISA bridge at 00:1f.0. Please see intel_detect_pch() 
to know why we need this.

Thanks
Tiejun