Re: [PATCH] multiprocess: move feature to meson_options.txt

[Philippe Mathieu-Daudé]

On 2/25/21 6:50 PM, Jag Raman wrote:
> 
> 
>> On Feb 25, 2021, at 11:35 AM, Stefan Hajnoczi <stefanha@redhat.com> wrote:
>>
>> On Thu, Feb 25, 2021 at 01:15:53PM +0100, Paolo Bonzini wrote:
>>> On 25/02/21 11:38, Philippe Mathieu-Daudé wrote:
>>>> On 2/24/21 1:23 PM, Paolo Bonzini wrote:
>>>>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>>>>> ---
>>>>>  configure         | 12 ++++--------
>>>>>  meson.build       |  9 +++++++--
>>>>>  meson_options.txt |  2 ++
>>>>>  3 files changed, 13 insertions(+), 10 deletions(-)
>>>> ...
>>>>
>>>>> @@ -2535,6 +2540,7 @@ endif
>>>>>  summary_info += {'target list':       ' '.join(target_dirs)}
>>>>>  if have_system
>>>>>    summary_info += {'default devices':   get_option('default_devices')}
>>>>> +  summary_info += {'Multiprocess QEMU': multiprocess_allowed}
>>>>
>>>> Since you are changing this, it is a good opportunity to find a
>>>> better description to this feature (similarly how we recently clarified
>>>> the TCI description).
>>>>
>>>> The current description is confusing with multiprocessing (which is
>>>> by default on QEMU and every developer want to exploit that).
>>>>
>>>> So the main multiprocess code resides in hw/remote/mpqemu*.
>>>>
>>>> I have the impression "monolithic application" is common in
>>>> software engineering. What about "polylithic QEMU"?
>>>>
>>>> Stefan once described it as "out of (main) process device emulation".
>>>
>>> Out of process emulation?
>>
>> When Multiprocess QEMU switches to the vfio-user protocol the feature
>> could be renamed to "vfio-user device backends".
> 
> I personally don’t have any preference for the name.

Great.

So with the summary/description updated as:

summary_info += {'Multiprocess QEMU (vfio-user device backends)':
multiprocess_allowed}

option('multiprocess', type: 'feature', value: 'auto',
       description: 'Multiprocess QEMU (vfio-user device backends) support')

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> 
> Like Stefan pointed out, this would be merged with the
> vfio-user model for emulating devices in a separate
> process. We could probably rename this during that change.
> 
> Thank you very much!
> —
> Jag
> 
>>
>> Stefan
>