Re: [Qemu-devel] [PATCH 0/8] tcg/interpreter: Add TCG + interpreter for bytecode (virtual machine)

[Blue Swirl]

On Sun, Sep 25, 2011 at 8:37 PM, Stefan Weil <address@hidden> wrote:
> Am 18.09.2011 15:00, schrieb Blue Swirl:
>
> On Sun, Sep 18, 2011 at 12:46 PM, malc <address@hidden> wrote:
>
> On Sun, 18 Sep 2011, Blue Swirl wrote:
>
> On Sun, Sep 18, 2011 at 10:49 AM, malc <address@hidden> wrote:
>
> On Sun, 18 Sep 2011, Blue Swirl wrote:
>
> On Sat, Sep 17, 2011 at 7:59 PM, Stefan Weil <address@hidden> wrote:
>
> Hello,
>
> these patches add a new code generator (TCG target) to qemu.
>
> Unlike other tcg target code generators, this one does not generate
> machine code for some cpu. It generates machine independent bytecode
> which is interpreted later. That's why I called it TCI (tiny code
> interpreter).
>
> I wrote most of the code two years ago and included feedback and
> contributions from several QEMU developers, notably TeleMan,
> Stuart Brady, Blue Swirl and Malc. See the history here:
> http://lists.nongnu.org/archive/html/qemu-devel/2009-09/msg01710.html
>
> Since that time, I used TCI regularly, added small fixes and improvements
> and rebased it to latest QEMU. Some versions were tested using
> ARM (emulated and real), PowerPC (emulated) and MIPS (emulated) hosts,
> but normally I run it on i386 and x86_64 hosts.
>
> I'd appreciate to see TCI in QEMU 1.0.
>
> Regards,
> Stefan Weil
>
> The patches 2 and 4 are optional, patch 8 is only needed for running
> TCI on a PowerPC host.
>
> I think patches 1 to 4 and 8 could be applied soon as they are now,
> they should benefit plain TCG too. I had some comments to other
> patches, but otherwise everything looks great.
>
> Hold the horses until Stefan settles the licensing issues.
>
> Which issues? For which patches?
>
>
> Read tcg/LICENSE.
>
> "All the files in this directory and subdirectories are released under
> a BSD like license (see header in each file). No other license is
> accepted."
>
> The wording of the file should be changed to list the files for which
> the BSD like license applies (and for which no other license is
> accepted), the file can't stop us adding new files with different
> licenses.
>
> Thanks for all feedback given.
>
> These license issues delayed my further working on tci.
> In the meantime, I asked Fabrice Bellard. Here is his answer:
>
> "Sorry but I no longer care about the license of this code.
> But if I was still in charge of the project,
> I would clearly refuse any non BSD code in TCG. "
>
> Although I agree with Blue's opinion given above, I also
> want to respect Fabrice.
>
> Therefore I suggest these changes:
>
> * tcg/bytecode is moved to tcg/tci, and I change the license to BSD.
>
> * The interpreter is moved from tcg/tci.c to tci.c and remains GPL.
>   It is no longer in TCG, so there is no conflict with tcg/LICENSE.
>
> This might seem to be a trick, but in some way it is similar to the
> other tcg target implementations: the code generator is always BSD,
> and the generated code is run on a system with a different license.
>
> Comments welcome. As soon as there is a consensus on the way how tci
> can be integrated I'll continue with patch series v2.
>
> Patches 1 to 4 could be applied immediately (that would reduce the
> size of the new series).

I applied 1 to 4, thanks.