Re: [PATCH] configure: add option for virtiofsd

[Paolo Bonzini]

On 08/10/20 11:17, misono.tomohiro@fujitsu.com wrote:
> Hi Paolo
> 
> Thanks a lot for the clear explanation. I will update the patch to follow the 
> meson style.
> I realized virtiofsd actually needs tools (i.e. "--disable-tools 
> --enable-virtiofsd"
> does not work with above meson.build) since virtiofsd requires libvhost_user 
> which will
> be built ony when tools are built. So, I will keep the current dependency 
> check (except 'have_system').

I'm thinking the behavior for --disable-tools --enable-virtiofsd would
be confusing.  Therefore, another possibility is not introducing
--enable-virtiofsd.  Instead, you can reuse --enable-vhost-user-fs:

- --enable-vhost-user-fs will fail if tools are enabled and cap-ng or
seccomp are unavailable

- --enable-vhost-user-fs --disable-tools will not look for cap-ng or
seccomp, because then the flag only controls inclusion of vhost-user-fs
in the emulators

- if "--enable-vhost-user-fs" is not specified and tools are enabled,
vhost-user-fs will only be included in the emulators if cap-ng and
seccomp are available

- if "--enable-vhost-user-fs" is not specified, tools are enabled and
cap-ng/seccomp are unavilable, vhost-user-fs will not be included in the
emulators either

- if "--enable-vhost-user-fs" is not specified but tools are not
enabled, configure will not check if cap-ng or seccomp.

In this case reusing most of your previous patch, and not moving
everything to meson, is totally okay.  I don't want you to impose more
transition work.

Paolo