Re: Usb passthrough with upstream qemu question

[Fabio Fantoni <fabio.fantoni@m2r.biz>]

Il 04/10/2013 16:25, George Dunlap ha scritto:
> On 04/10/13 15:00, Fabio Fantoni wrote:
>> Il 04/10/2013 15:30, George Dunlap ha scritto:
>>> On 04/10/13 14:16, Fabio Fantoni wrote:
>>>> Il 04/10/2013 11:59, George Dunlap ha scritto:
>>>>> On 25/09/13 15:11, Pasi Kärkkäinen wrote:
>>>>>> On Tue, Sep 24, 2013 at 10:59:18AM +0100, George Dunlap wrote:
>>>>>>> On 09/23/2013 03:46 PM, Fabio Fantoni wrote:
>>>>>>>> I tested my latest patches about usb controllers (1-2-3) and usb
>>>>>>>> redirection (from Spice client) support for upstream qemu and 
>>>>>>>> are working.
>>>>>>>> I also tested usb passthrough (from dom0) but seems that with 
>>>>>>>> older
>>>>>>>> -usbdevice paraters is not working.
>>>>>>>> I see the qemu docs/qdev-device-use.txt and based on this I 
>>>>>>>> tried the
>>>>>>>> new parameters, for example:
>>>>>>>> device_model_args=["-device","usb-host,vendorid=0x058f,productid=0x6387"] 
>>>>>>>>
>>>>>>>> With new parameters usb passthrough is working, also with new usb
>>>>>>>> controller and also with usb redirection enabled.
>>>>>>>> I did all tests using latest xen and qemu version (1.6).
>>>>>>>> I think should be good to change upstream qemu parameters for usb
>>>>>>>> passthrough on libxl with the new ones.
>>>>>>> Yes, I think it would be better.  The main difficulty is that the
>>>>>>> libxl parameter is basically the old-style usbdevice parameter
>>>>>>> passed straight through.  To support the current libxl parameter
>>>>>>> with the new qemu would mean interpreting the usbdevice parameter
>>>>>>> and translating it into the new-style parameter.
>>>>>>>
>>>>>>> My USB hot-plug series begins to introduce a more reasonable
>>>>>>> interface for USB devices. Once that's in, we can think about
>>>>>>> introducing a similar new interface for creating domains, that
>>>>>>> should match the new way of specifying devices better. Then we
>>>>>>> could just say, "If you're using spice, you have to use the new
>>>>>>> interface."
>>>>>>>
>>>>>>> Unfortunately, it's looking like the USB hot-plug series may not
>>>>>>> make it into 4.4 unless someone else can pick it up (or unless we
>>>>>>> slip the feature freeze).
>>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> Is the latest version of the usb hotplug series posted to xen-devel,
>>>>>> or are these not-yet-posted changes in your (private) tree?
>>>>>>
>>>>>> Just wondering if someone else wants to take a look at that.
>>>>>
>>>>> The latest patches I posted were version 6; the 1/2 can be found 
>>>>> here:
>>>>>
>>>>> http://marc.info/?l=xen-devel&m=136638728928743
>>>>>
>>>>> I can't remember if I went through and made any changes as a 
>>>>> result of comments or not; My latest local version can be found here:
>>>>>
>>>>> git://xenbits.xen.org/people/gdunlap/xen.git 
>>>>> out/hvm-usb-hotplug.v6-plus
>>>>>
>>>>>  -George
>>>>
>>>> Thanks for reply, I see your patches but I didn't found changes on 
>>>> "xl create" parts.
>>>> Please could you keep an eye on my yesterday's mail about "xl 
>>>> create" part changes?
>>>> http://lists.xen.org/archives/html/xen-devel/2013-10/msg00157.html
>>>> For now I'm trying to do patch for basic spice support to pv.
>>>> After that I'll try to do a patch for changes usb qemu parameters 
>>>> to make usb passthrough full working also with usb2,usb3 and usb 
>>>> redirection enabled ifno one else can do.
>>>
>>> So at the moment, USB devices specified in the config file are added 
>>> to the guest on the qemu command line.  However, most devices aren't 
>>> like that: if you specify a PCI pass-through device, it will create 
>>> the guest, and then the domain creation will call the pci add 
>>> functions, just as it would if you were hot-plugging the device 
>>> afterwards.
>>>
>>> So the idea would be that once the new USB hotplug interface was 
>>> fully functional, then you'd do the same thing: just specify the USB 
>>> controller on the qemu command line, and add in the other USB 
>>> devices afterwards (i.e., after qemu had come up but before actually 
>>> unpausing the guest).
>>>
>>>  -George
>>
>> If I'm not wrong on what you mean, usb controller definition should 
>> be right with my patch "usbversion" while actual usbpassthrough part 
>> should be
>> replaced/remade in order to have devices passed by usbdevice and 
>> usbdevice_list added after qemu launch with hotplug function you had 
>> already did with your patches.
>> Did you mean something else?
>
> I thought the "usbpassthrough" stuff had to do with spice.
>
> In any case, what you describe it sounds pretty close, with one 
> caveat: Because usbdevice and usbdevice_list are basically just 
> passing through strings that qemu understands on its command line, I 
> don't think we can re-use them: I think we'd have to introduce another 
> config option that would have a new interface which matches the new 
> libxl interface better.  We'd have to keep the old ones around for 
> backwards compatibility, but we can deprecate them.
>
>  -George

So to be sure, you mean to keep the old parameters usbdevice and 
usbdevice_list with only usb1 (making them deprecated), and introduce a 
new parameter storing the devices usbpassthrough list (from dom0) which 
will use the new usb1-2-3 controller (with usbversion) and your 
usbhotplug functions?
Is it right?