Re: [Qemu-devel] [PATCH 0/3] pci: allow PCI bus slots to be marked as reserved

[Mark Cave-Ayland]

On 11/07/17 18:59, Mark Cave-Ayland wrote:

> On 11/07/17 16:57, Michael S. Tsirkin wrote:
> 
>> On Tue, Jul 11, 2017 at 06:51:50PM +0300, Marcel Apfelbaum wrote:
>>> On 11/07/2017 18:31, Michael S. Tsirkin wrote:
>>>> On Fri, Jul 07, 2017 at 08:43:59AM +0100, Mark Cave-Ayland wrote:
>>>>> For some machines it is impossible to plug devices into a particular PCI 
>>>>> bus
>>>>> slot, e.g. for a real Ultra 5 there are 2 PCI bridges attached to the root
>>>>> bus behind which all devices must be plugged. Ignoring this rule will 
>>>>> cause
>>>>> problems with interrupt routing since the interrupt numbers are calculated
>>>>> based upon PCI bridge id and secondary PCI bus slot id.
>>>>>
>>>>> This patchset adds a new dev_reserved_mask property to PCIBus which is a
>>>>> bitmask used to indicate whether PCI bus slots are reserved, i.e. they 
>>>>> cannot
>>>>> be used for hot or cold plugging on a particular PCI bus.
>>>>>
>>>>> Signed-off-by: Mark Cave-Ayland <address@hidden>
>>>>
>>>
>>> Hi Michael,
>>>
>>>> Could you please point me at series making use of this
>>>> functionality?
>>>
>>> There is a discussion upstream, I am not aware of patches yet.
>>>
>>> https://lists.gnu.org/archive/html/qemu-devel/2017-07/msg00771.html
>>>
>>> Thanks,
>>> Marcel
>>
>> It is probably a good idea to defer merging this patchset
>> until there's an agreement on how it will be used.
> 
> I have a local patchset that uses it, but it has been held up by the
> on-going issues with the fw_cfg patchset upon which it is also dependent.
> 
> I will try and find some time this evening to rebase the patchset and
> send it out as I am aware that freeze is coming up soon.

You can see the use of this feature in patch 8 of my sun4u patchset
here:
https://lists.nongnu.org/archive/html/qemu-devel/2017-07/msg03041.html.


ATB,

Mark.