[SeaBIOS] Fwd: [RFC 0/2] (Ongoing)Support multiple pci domains in pci_device

[Zihan Yang]

[forgot to cc to the mail list]

Kevin O'Connor <kevin at koconnor.net> 于2018年8月8日周三 下午10:14写道：
>
> On Thu, Aug 02, 2018 at 10:39:13AM +0800, Zihan Yang wrote:
> > NOTE: This patch set is still ongoing and does not fully function
> > as its goal. But it involves some API changes, therefore I post them for
> > comments before moving on to make sure I'm on the right path.
> >
> > The corresponding qemu part can be found at
> > https://gitlab.com/WhoisZihan/qemu-pci-domain/tree/master/qemu
> > I will submit it to qemu list later.
> >
> > Currently seabios assumes there is only one pci domain(0), and almost
> > everything operates on pci domain 0 by default. This patch aims to add
> > multiple pci domain support for pci_device, while reserve the original
> > API for compatibility.
>
> Thanks.  I understand the desire to support multiple PCI domains in
> QEMU and the guest OS.  However, what is the high level reason for
> wanting the BIOS to be able to interact with the secondary PCI
> domains?

The pxb-pcie host bus is put into a separated domain, so are the devices
under the pxb host bus. I think we should also initialize busses in other
domains and probe those devices during bios initialization. But currently
qemu only binds port 0xcf8 and 0xcfc to q35 host's conf_mem and data_mem,
if we want to read the config space of pxb host, we should use another port.
I use port range 0x1000 and 0x1004 for a temporary workaround because they
seem to be 'free' now.

Please correct me if I misunderstand it.

P.S. Maybe you would want to ignore this patch set as there are a few bugs
that I fix later, and I will soon send a v2 patch (v2 is not working
either, but I
think I find where the current problem is), soon after I fix my
network proxy issue...

Thanks
Zihan