Re: [Qemu-devel] [Xen-devel] [PATCH v2] libxl: usb2 and usb3 controller support for upstream qemu

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

Il 11/07/2013 17:56, Dario Faggioli ha scritto:
> On gio, 2013-07-11 at 12:33 +0200, Fabio Fantoni wrote:
>> Usage: usbversion=1|2|3 (default=2)
>> Specifies the type of an emulated USB bus in the guest. 1 for usb1,
>> 2 for usb2 and 3 for usb3, it is available only with upstream qemu.
>> Default is 2.
>>
>> Signed-off-by: Fabio Fantoni <fabio.fantoni@m2r.biz>
>>
>> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
>> index d218a2d..b4c6921 100644
>> --- a/tools/libxl/libxl_types.idl
>> +++ b/tools/libxl/libxl_types.idl
>> @@ -325,6 +325,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
>>                                          ("serial",           string),
>>                                          ("boot",             string),
>>                                          ("usb",              libxl_defbool),
>> +                                       ("usbversion",              integer),
>>                                          # usbdevice:
>>                                          # - "tablet" for absolute mouse,
>>                                          # - "mouse" for PS/2 protocol relative mouse
>>
> I believe this calls for a `#define LIBXL_HAVE_USBVERSION' (or something
> like that) in libxl.h, doesn't it?
>
> See the comment about "libxl API compatibility" in libxl.h itself for
> more details.
>
> Regards,
> Dario
>
Is it necessary even if I just want to apply it to xen 4.4 (as a new 
features) and not backport it to older versions?
Or probably I don't understand exactly what is the function of LIBXL_HAVE_*.
I tried to grep all code for LIBXL_HAVE_* to see an example of use but I 
found only one an I don't understand.