Re: [Qemu-devel] An opinion on copyright-notice-less qemu files

[Anthony Liguori <anthony@codemonkey.ws>]

Hi Richard,

Thanks for posting this!

On 10/26/2011 05:43 PM, Richard Fontana wrote:
> Hi qemu developers,
>
> WARNING: (1) I am not your lawyer; (2) this is not legal advice; (3)
> this is a long post which you will probably find extremely boring
> unless you happen to be a licensing geek, which I suspect is not true
> of most if not all of you.
>
> My colleague Paolo Bonzini was discussing with me the subject of what
> the qemu project should do (if anything) about files in qemu that have
> no copyright/license notice, in connection with the recent qemu-devel
> subthread on "GPLv3 troubles". In a sense the underlying issue is what
> the legal status of such files is.
>
> Paolo correctly identified four possibilities (I am here paraphrasing
> how Paolo put them):
>
> 1) Assume nothing about the file - therefore, to deal with the GPLv3
> compatibility issue, ask all authors for permission to treat as GPLv2+
> (GPLv2 or later).
>
> 2) Because qemu has a LICENSE file (which, importantly, I am assuming
> has been in place more or less from the get-go)

This is only sort of correct.  QEMU has been around since about 2003.  There has 
been a LICENSE file for all of it's significant history.

But for a long time period, QEMU contained no GPL code out side linux-user and 
LGPL code in libcpu.  The device model was strictly X11 licensed.  The old 
LICENSE file stated:

+The following points clarify the QEMU licenses:
+
+1) The QEMU virtual CPU core library (libqemu.a) and the QEMU PC
+   system emulator are released under the GNU Lesser General Public
+   License.
+
+2) The Linux user mode QEMU emulator is released under the GNU General
+   Public License.
+
+3) The QEMU Accelerator Module is a proprietary product. It is
+   available without charge. Commercial use of the QEMU Accelerator
+   Module is allowed.
+
+   Redistribution of the QEMU Accelerator Module: any person or
+   organisation wishing to distribute it, for example on a CD or as a
+   binary or source package, must have an explicit authorization from
+   the author.
+
+   The QEMU Accelerator Module is available without any express or
+   implied warranty. In no event will the author be held liable for
+   any damages arising from the use of this software.
+
+4) QEMU is a trademark of Fabrice Bellard.

Around 2007, a decision was made to allow GPL code in the system emulator.  At 
that point in time, the LICENSE text was clarified to it's current content (more 
or less).

A number of the pre-2007 files lack copyrights and where created before the 
"QEMU is overall licensed as GPL" text was added.

I don't think this necessarily changes your interpretation significantly but I 
thought its important to make this clarification at least.

Regards,

Anthony Liguori