Re: [Qemu-devel] RFC: DSO (dynamic shared objects) support

[Paolo Bonzini]

Il 18/06/2013 14:42, Anthony Liguori ha scritto:
>> > Next, and this is the most complex part.  The build system for
>> > modules, and configuring it.   I heard there were plans to use
>> > something like kbuild system for that, has anything been done
>> > in this context?
> GSoC just kicked off yesterday.  Paolo can perhaps shed some light on
> what the plans are.

The plans is just to add kconfig, not kbuild, similar to
seabios/busybox/etc.

It would provide configurability by target and board, and in addition
make it obvious which bits of default-configs/ (such as PCI, USB, HPET,
etc.) are actually configurable.

I outlined a possible implementation at the end of
http://wiki.qemu.org/Features/Modules, though something nicer may be
possible (possibly taking inspiration from Kconfig).

>> > With current config/build system, the following changes are
>> > needed:
>> >
>> >  o split individual libs from libs_softmmu into their own
>> >    variables.

Ack.  This could be doable already and independent from everything else.

>> >  o allow obj-m (and similar) in addition to obj-y, with build
>> >    flags and rules to produce an .so.
> We also need a way to define the module targets.  My Makefile-fu is
> not all that great but I suspect we can do something like:
> 
> libqemu-%.ko: $(eval $(obj-%-m))
> 
> I don't think that works but that's the rough idea.  We would then
> need to define each module target by hand but that's probably
> reasonable in the short term until we have kconfig.

You can limit that to multiple-source modules, which is the common case.
 Single-source modules are easily handled.

Paolo