[Qemu-devel] deprecating/removing bluetooth (was: Re: List of files containing devices which have not been QOMified)

[Gerd Hoffmann <kraxel@redhat.com>]

On Fri, Nov 09, 2018 at 02:16:53PM +0100, Paolo Bonzini wrote:
> On 09/11/2018 13:39, Thomas Huth wrote:
> > On 2018-11-09 12:29, Gerd Hoffmann wrote:
> >>
> >> Tried this after studying docs:
> >>
> >>   qemu -usb -device usb-bt-dongle -bt hci,vlan=0 -bt device:keyboard
> >>
> >> Segfaults right anway on first keypress.
> >> I guess that qualifies as "broken and obviously unused".
> > 
> > Thanks for checking! I guess that means we could even get rid of it
> > without deprecating it first if it is broken already for more than two
> > releases...?
> 
> I think what others were using bluetooth passthrough.  But it's
> certainly possible that it's broken.

That code is in bt-*.c (toplevel dir).  Likewise no actual code changes
since ages.  Comes in two variants, host + vhci.  vhci commit says:

    commit ab2b6f507ded382df734fe6a237ec56e2f421de4
    Author: balrog <balrog@c046a42c-6fe2-441c-8c8c-71466251a162>
    Date:   Mon Sep 29 00:31:41 2008 +0000

        Use VHCI to allow the host os to participate in a qemu bluetooth "vlan".
    
        This does the reverse of bt-host.c, proxying from guest to host.
        Appears to be more reliable.

Hmm.  Not much of a clue.  Also ten years old.

There is also a null hci, not connecting to anything.  Probably useful as
dummy when your board has bluetooth (see arm/nseries) but you don't want
hook up any bluetooth devices.

Anyone has used bluetooth passthrough and can report what the state is?

I guess the keyboard can be dropped right away no matter what.

cheers,
  Gerd