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Date: Tue, 18 Jun 2013 16:19:08 +0400
From: Michael Tokarev <mjt@tls.msk.ru>
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Subject: Re: [Qemu-devel] RFC: DSO (dynamic shared objects) support
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To: Laszlo Ersek <lersek@redhat.com>
Cc: qemu-devel <qemu-devel@nongnu.org>

18.06.2013 16:17, Laszlo Ersek wrote:
> On 06/18/13 13:37, Michael Tokarev wrote:
> 
>> 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?
> 
> Sorry for responding separately... Some module/symbol versioning will be
> necessary, as the binding will be delayed until runtime, and users
> *will* mix and match qemu and modules, and get random crashes. AFAIK
> versioning is a good way to avoid that (you would get an error in
> dlopen(), and dlerror() would pinpoint problem).
> 
> No idea how to implement this though, except I expect there's no chance
> to do it halfway portably without libtool.

Well, I think this is trivial really.

Duding build, we re-#define register_module_init() to have a version
number (or even a build id), for example register_module_init_1_6_0().
This is a function which each plugin will call inside its constructor.
Being unable to find this symbol in calling qemu it will fail to load.

Thanks,

/mjt