Re: [Qemu-devel] [PATCH RFC V2 14/17] hw/pci: piix - suport multiple host bridges

[Alexander Graf <agraf@suse.de>]

On 16.02.15 14:29, Marcel Apfelbaum wrote:
> On 02/16/2015 03:00 PM, Alexander Graf wrote:
>>
>>
>> On 16.02.15 10:54, Marcel Apfelbaum wrote:
>>> From: Marcel Apfelbaum <marcel.a@redhat.com>
>>>
>>> Instead of assuming it has only one bus, it
>>> enumerates all the host bridges until it finds
>>> the one with bus number corresponding with the
>>> config register.
>>>
>>> Signed-off-by: Marcel Apfelbaum <marcel@redhat.com>
>>
> Hi Alexander,
> Thank you for the review.
> 
> 
>> How 440 specific is this? Wouldn't we need similar code for q35 and gpxe?
> For gpxe: I have no idea.
> For Q35: PCI Express have native support for extra root bridges by
> having multiple Root Complexes(RC), but in this case each RC
> handles its separate configuration space.
> 
> It may be possible to use the same hack as in PC to expose a
> PCIe Root Port as a different host bridge and a primary bus behind
> it, but it is out of this series scope.
> 
> The series aims to address the limitation that PC machines support
> NUMA nodes for CPU/memory but not PCI.
> 
> Anyway, we can move the code when neeeded, but since it will
> take some and the implementation is not certain, for the moment
> is 440 specific.

Sorry, I didn't realize that this was legacy PCI specific :).


Alex