Re: [Qemu-devel] [PATCH V4] hw/pxb: add chassis_nr property

[Marcel Apfelbaum <marcel.apfelbaum@gmail.com>]

On 03/17/2016 12:02 PM, Cao jin wrote:
> hi
>
> On 03/15/2016 07:44 PM, Marcel Apfelbaum wrote:
>> On 03/15/2016 10:00 AM, Cao jin wrote:
>
>>>
>>> And I have another personal question: In qemu design, it seems every
>>> pci bridge reside in a separate chassis, what`s benefit?  why don`t
>>> put them all in the main chassis?
>>
>> Please have a look on pci-to-pci bridge specification, chapter 13, slot
>> numbering.
>>
>
> thanks for the hint.
> I still have a question: in docs/pci_expander_bridge.txt, it says: create a TYPE_PCI_BRIDGE_DEV to enable hotplug support.
> But I didn`t see it can hotplug as following step:
>
> 1: ./qemu-system-x86_64 -device pxb,id=br,bus=pci.0,bus_nr=2 -hda linux.img -smp 2 --enable-kvm -m 1024 -monitor stdio
>
> 2: in monitor, type: device_add e1000,bus=br
> result: no message output to monitor, and don`t see e1000 nic in guest
>
> Is is a bug or I test it in a wrong way?

Hi,

You used hot-plug correctly, it doesn't work yet since I am still working on this feature.
The bridge gives us the basics environment for hot-plug, what is missing is ACPI "bsel" mechanism.

Thanks,
Marcel

>