Re: [PATCH for-5.0 3/4] Remove the core bluetooth code

[Thomas Huth <thuth@redhat.com>]

On 01/02/2020 19.53, Philippe Mathieu-Daudé wrote:
> On Sat, Feb 1, 2020 at 7:51 PM Thomas Huth <thuth@redhat.com> wrote:
>> On 01/02/2020 17.09, Philippe Mathieu-Daudé wrote:
>>> On 11/20/19 10:10 AM, Thomas Huth wrote:
>>>> It's been deprecated since QEMU v3.1. We've explicitly asked in the
>>>> deprecation message that people should speak up on qemu-devel in case
>>>> they are still actively using the bluetooth part of QEMU, but nobody
>>>> ever replied that they are really still using it.
>>>>
>>>> I've tried it on my own to use this bluetooth subsystem for one of my
>>>> guests, but I was also not able to get it running anymore: When I was
>>>> trying to pass-through a real bluetooth device, either the guest did
>>>> not see the device at all, or the guest crashed.
>>>>
>>>> Even worse for the emulated device: When running
>>>>
>>>>  qemu-system-x86_64 -bt device:keyboard
>>>>
>>>> QEMU crashes once you hit a key.
>>>>
>>>> So it seems like the bluetooth stack is not only neglected, it is
>>>> completely bitrotten, as far as I can tell. The only attention that
>>>> this code got during the past years were some CVEs that have been
>>>> spotted there. So this code is a burden for the developers, without
>>>> any real benefit anymore. Time to remove it.
>>>>
>>>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>>>> ---
>>>>  Makefile.objs        |    2 -
>>>>  bt-host.c            |  198 ----
>>>>  bt-vhci.c            |  167 ----
>>>>  configure            |   31 -
>>>>  hw/Kconfig           |    1 -
>>>>  hw/Makefile.objs     |    1 -
>>>>  hw/bt/Kconfig        |    2 -
>>>>  hw/bt/Makefile.objs  |    3 -
>>>>  hw/bt/core.c         |  143 ---
>>>>  hw/bt/hci-csr.c      |  512 ----------
>>>>  hw/bt/hci.c          | 2263 ------------------------------------------
>>>>  hw/bt/hid.c          |  553 -----------
>>>>  hw/bt/l2cap.c        | 1367 -------------------------
>>>>  hw/bt/sdp.c          |  989 ------------------
>>>>  include/hw/bt.h      | 2177 ----------------------------------------
>>>>  include/sysemu/bt.h  |   20 -
>>>>  qemu-deprecated.texi |    7 -
>>>>  qemu-options.hx      |   79 --
>>>>  vl.c                 |  136 ---
>>>>  19 files changed, 8651 deletions(-)
>>>>  delete mode 100644 bt-host.c
>>>>  delete mode 100644 bt-vhci.c
>>>>  delete mode 100644 hw/bt/Kconfig
>>>>  delete mode 100644 hw/bt/Makefile.objs
>>>>  delete mode 100644 hw/bt/core.c
>>>>  delete mode 100644 hw/bt/hci-csr.c
>>>>  delete mode 100644 hw/bt/hci.c
>>>>  delete mode 100644 hw/bt/hid.c
>>>>  delete mode 100644 hw/bt/l2cap.c
>>>>  delete mode 100644 hw/bt/sdp.c
>>>>  delete mode 100644 include/hw/bt.h
>>>>  delete mode 100644 include/sysemu/bt.h
>>>>
>>> [...]> diff --git a/configure b/configure
>>>> index 6099be1d84..ecce4ada2d 100755
>>>> --- a/configure
>>>> +++ b/configure
>>>> @@ -349,7 +349,6 @@ unset target_list_exclude
>>>>  # Distributions want to ensure that several features are compiled in, and it
>>>>  # is impossible without a --enable-foo that exits if a feature is not found.
>>>>
>>>> -bluez=""
>>>>  brlapi=""
>>>>  curl=""
>>>>  curses=""
>>>> @@ -1151,10 +1150,6 @@ for opt do
>>>>    ;;
>>>>    --enable-brlapi) brlapi="yes"
>>>>    ;;
>>>> -  --disable-bluez) bluez="no"
>>>> -  ;;
>>>> -  --enable-bluez) bluez="yes"
>>>> -  ;;
>>>
>>> Now than I'm bisecting over this commit, I realize removing this
>>> option was not a good idea, we should have done like commit
>>> cb6414dfec8 or 315d3184525:
>>>
>>>   @@ -886,10 +885,6 @@ for opt do
>>>   -  --disable-uuid) uuid="no"
>>>   -  ;;
>>>   -  --enable-uuid) uuid="yes"
>>>   -  ;;
>>>   ...
>>>   +  --enable-uuid|--disable-uuid)
>>>   +      echo "$0: $opt is obsolete, UUID support is always built" >&2
>>>   +  ;;
>>
>> Looks trivial ... so if it bugs you, just send a patch?
> 
> I thought about it but this won't fix much, it is too late now.
> 
> I simply wanted to share this bugged me so we try to avoid doing the
> same mistake again.

Makes sense. I'll try to remember it for the future.

 Thomas