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

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

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".

Relevant links:
https://english.stackexchange.com/questions/112633/whats-an-antonym-of-monolithic-as-in-monolithic-architecture/119212#119212
https://infovis-wiki.net/wiki/Polylithic_design

...
>  if not supported_cpus.contains(cpu)
> diff --git a/meson_options.txt b/meson_options.txt
> index 675a9c500a..bf11de7bb2 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -45,6 +45,8 @@ option('cfi', type: 'boolean', value: 'false',
>         description: 'Control-Flow Integrity (CFI)')
>  option('cfi_debug', type: 'boolean', value: 'false',
>         description: 'Verbose errors in case of CFI violation')
> +option('multiprocess', type: 'feature', value: 'auto',
> +       description: 'Multiprocess QEMU support')