Re: [Qemu-devel] [PATCH v2] usb: Remove legacy -usbdevice option

[Thomas Huth]

On 04.01.2018 16:47, Paolo Bonzini wrote:
> On 04/01/2018 16:35, Thomas Huth wrote:
>>> Well, why not, it just doesn't seem to me much simpler than
>>> "-serial braille" and "-device usb-braille" :)
>>
>> FWIW, I think I'd also rather prefer to add some little bit of "magic"
>> to "-device usb-braille" instead of introducing yet another command line
>> parameter. QEMU's command line interface is already way too much
>> overcrowded, so IMHO we should try to avoid new parameters if possible.
> 
> The point of deprecation is not to make the interface simpler, it is to
> avoid cases where one option is doing too much and/or crossing
> abstraction boundaries, for example -net creating both a device and a
> hub port.
> 
> "-serial" is okay because it only creates the front-end, it's the board
> that decides how to attach it to the back-end.
> 
> -usbdevice creating both a front-end and a back-end is not a problem per
> se.  The issue with -usbdevice is just that it's too much code.
> 
> However, adding magic to "-device usb-braille" that creates both a
> front-end and a back-end is completely the opposite of sane...

Ok, makes sense.

But instead of introducing a new "-braille" parameter, maybe we should
rather keep some of the convenience "-usbdevice" possibilities around?
E.g. keep "-usbdevice braille", "-usbdevice mouse", etc. but remove
things like "-usbdevice serial" and "-usbdevice host" where the code is
rather ugly and the user do not gain much in comparison to "-device" ?

 Thomas