Re: [Qemu-devel] [PATCH v3] libxl: usb2 and usb3 controller support for upstream qemu

[George Dunlap <george.dunlap@eu.citrix.com>]

On 18/07/13 12:09, Ian Jackson wrote:
> Fabio Fantoni writes ("Re: [PATCH v3] libxl: usb2 and usb3 controller support for upstream qemu"):
>> Il 12/07/2013 17:33, George Dunlap ha scritto:
>>> On 12/07/13 13:36, Fabio Fantoni wrote:
> [someone wrote:]
>>>>> I'm just curious, why is this so complicated?  Is this likely to be
>>>>> fragile and break in the future?
> ...
>>>> I tried already but there are problems with retrocompatibility:
>>>> http://lists.xen.org/archives/html/xen-devel/2013-07/msg00491.html
>>>> I was also asking if it is possible to remove some hardcoded options
>>>> without breaking something but I had no reply.
>>> So this seems to be a response to the first paragraph ("why is this so
>>> complicated, is it fragile").
> I'm afraid that I don't think it's really a sufficient response to
> "why is this so complicated, is it fragile?".  "I don't know" is not
> very convincing :-).
>
> My worry would be that these options would change their meaning in the
> future, or indeed that the whole edifice which requires callers to
> specify things at this excruciating level of detail might (sensibly!)
> be abolished.

So far qemu has been pretty good about supporting deprecated 
command-line arguments; e.g., libxl still passes outdated usb parameters 
to qemu-xen.

  -George