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

[Michael S. Tsirkin]

On Wed, Jun 25, 2014 at 09:44:14AM +0200, Paolo Bonzini wrote:
> Il 25/06/2014 09:35, Chen, Tiejun ha scritto:
> >>How are you going to make this work for Q35 or another PCIe machine that
> >>already has an ISA bridge at 00:1f.0?
> >>
> >
> >Could we simply pass the vendor/device ids of the host ISA bridge here?
> 
> No, because the firmware then would not recognize the host ISA bridge and
> would fail to initialize the ACPI PMBASE, the PCI interrupt routing, etc.
> 
> Paolo

It might be possible to move the Q35 bridge elsewhere.
seabios doesn't care where the host bridge is.
ACPI tables in QEMU can be adjusted.