Re: [Qemu-devel] [PATCH] hax-interface: Add BSD license

[Yu Ning]

On 11/17/2017 2:00, Eduardo Habkost wrote:
> On Thu, Nov 16, 2017 at 07:47:44AM +0100, Stefan Weil wrote:
> > Am 16.11.2017 um 07:50 schrieb address@hidden:
> > > From: Yu Ning <address@hidden>
> > >
> > > hax-interface.h defines the interface between the HAXM kernel
> > > module and the HAXM QEMU accelerator. The same code can be found in
> > > the following files of the HAXM kernel module:
> > >
> > >   include/hax_interface.h
> > >   include/vcpu_state.h
> > >   core/include/vm.h
> > >
> > > These files are now open source under the 3-clause BSD license,
> > > whereas hax-interface.h in QEMU uses GPLv2.
> Why is this a problem?

I know very little about licenses.  If this is not a problem, I'm happy 
to just abandon this patch.
> > > Address this inconsistency by adding the BSD license to the QEMU
> > > file, per Stefan Weil's comment on this HAXM pull request:
> > >
> > >   https://github.com/intel/haxm/pull/2
> The existing code on qemu.git don't match the code on the GitHub
> repository above exactly, and its copyright history looks hard to
> track[1].

Right. I don't know when the QEMU header (hax-interface.h) first 
appeared, but I think it's probably a derivative of the HAXM ones, which 
date back to no later than June 2011.

> If we really care about consistency between the two
> projects, shouldn't we just delete the existing file and copy the
> headers from github.com/intel/haxm directly?

That's a good solution, but not feasible at the moment, because in the 
HAXM kernel module, a small piece of the interface code currently 
resides in an internal header (core/include/vm.h). Probably we should 
clean up the interface headers on the HAXM side, and then push the 
change to QEMU.

> Also, does it even make sense to keep the two licenses in the
> file?

I don't know the answer.  If it doesn't make sense, I can either remove 
the original GPLv2 license, or abandon this patch and later come back 
with another one implementing the above solution.