[libvirt] [PATCH v3 2/2] Add USB option capability

[Li Zhang]

On 2013年04月04日 00:20, Daniel P. Berrange wrote:
> On Wed, Apr 03, 2013 at 10:14:15AM +0800, Li Zhang wrote:
>> On 2013年04月02日 18:06, Daniel P. Berrange wrote:
>>> On Fri, Mar 29, 2013 at 01:22:47PM +0800, Li Zhang wrote:
>>>> From: Li Zhang <zhlcindy at linux.vnet.ibm.com>
>>>>
>>>> To avoid the collision for creating USB controllers in machine->init()
>>>> and -device xx command line, it needs to set usb=off to avoid one USB
>>>> controller created in machine->init(). So that libvirt can use -device
>>>> or -usb to create USB controller sucessfully.
>>>> So QEMU_CAPS_MACHINE_USB_OPT capability is added, and it is for QEMU
>>>> v1.3.0 onwards which supports USB option.
>>>>
>>>> Signed-off-by: Li Zhang <zhlcindy at linux.vnet.ibm.com>
>>> I'm not seeing why this is needed - we pass -nodefconfig and -nodefaults
>>> which ought to disable any default built-in USB controller already
>>> surely ?
>> With -nodefconfig and -nodefaults, QEMU doesn't disable USB controller.
>>
>> In QEMU, USB controller will be created according to usb_enabled(default).
>> This the default value can be set according to different platforms.
>> For example, in pSeries guest,
>> Because there are no ps2 devices, so it needs USB keyboard and mouse
>> with VGA.
>> So, USB controller will be created with graphic enabled in machine->init().
>>
>> if (usb_enabled(spapr->has_graphics)) {
>>      pci_create_simple(phb->bus, -1, "pci-ohci");
>>      if (spapr->has_graphics) {
>>         usbdevice_create("keyboard");
>>         usbdevice_create("mouse");
>>      }
>> }
>>
>> Libvirt can't know this controller which is created by QEMU.
>> So it will report error. :)
> Ok, I see what's going on now. This is horrible QEMU behaviour, but we
> have to live with it.
>
> So I'm ok with your proposed patch. Before we can commit it though, either
> you need to update some existing test case, or add a new test case that
> covers this CLI option.
OK, I will add one test case for it.

Thanks. :)
> Regards,
> Daniel