Re: [Xen-devel] [PATCH 1/9] drm/xen-front: Introduce Xen para-virtualized frontend driver

[Oleksandr Andrushchenko]

On 02/21/2018 11:17 AM, Roger Pau Monnà wrote:
> On Wed, Feb 21, 2018 at 10:03:34AM +0200, Oleksandr Andrushchenko wrote:
> > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> >
> > Introduce skeleton of the para-virtualized Xen display
> > frontend driver. This patch only adds required
> > essential stubs.
> >
> > Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> > ---
> >   drivers/gpu/drm/Kconfig             |  2 +
> >   drivers/gpu/drm/Makefile            |  1 +
> >   drivers/gpu/drm/xen/Kconfig         | 17 ++++++++
> >   drivers/gpu/drm/xen/Makefile        |  5 +++
> >   drivers/gpu/drm/xen/xen_drm_front.c | 83 +++++++++++++++++++++++++++++++++++++
> >   5 files changed, 108 insertions(+)
> >   create mode 100644 drivers/gpu/drm/xen/Kconfig
> >   create mode 100644 drivers/gpu/drm/xen/Makefile
> >   create mode 100644 drivers/gpu/drm/xen/xen_drm_front.c
> >
> > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> > index deeefa7a1773..757825ac60df 100644
> > --- a/drivers/gpu/drm/Kconfig
> > +++ b/drivers/gpu/drm/Kconfig
> > @@ -289,6 +289,8 @@ source "drivers/gpu/drm/pl111/Kconfig"
> >   
> >   source "drivers/gpu/drm/tve200/Kconfig"
> >   
> > +source "drivers/gpu/drm/xen/Kconfig"
> > +
> >   # Keep legacy drivers last
> >   
> >   menuconfig DRM_LEGACY
> > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> > index 50093ff4479b..9d66657ea117 100644
> > --- a/drivers/gpu/drm/Makefile
> > +++ b/drivers/gpu/drm/Makefile
> > @@ -103,3 +103,4 @@ obj-$(CONFIG_DRM_MXSFB)	+= mxsfb/
> >   obj-$(CONFIG_DRM_TINYDRM) += tinydrm/
> >   obj-$(CONFIG_DRM_PL111) += pl111/
> >   obj-$(CONFIG_DRM_TVE200) += tve200/
> > +obj-$(CONFIG_DRM_XEN) += xen/
> > diff --git a/drivers/gpu/drm/xen/Kconfig b/drivers/gpu/drm/xen/Kconfig
> > new file mode 100644
> > index 000000000000..4cca160782ab
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xen/Kconfig
> > @@ -0,0 +1,17 @@
> > +config DRM_XEN
> > +	bool "DRM Support for Xen guest OS"
> > +	depends on XEN
> > +	help
> > +	  Choose this option if you want to enable DRM support
> > +	  for Xen.
> > +
> > +config DRM_XEN_FRONTEND
> > +	tristate "Para-virtualized frontend driver for Xen guest OS"
> > +	depends on DRM_XEN
> > +	depends on DRM
> > +	select DRM_KMS_HELPER
> > +	select VIDEOMODE_HELPERS
> > +	select XEN_XENBUS_FRONTEND
> > +	help
> > +	  Choose this option if you want to enable a para-virtualized
> > +	  frontend DRM/KMS driver for Xen guest OSes.
> > diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile
> > new file mode 100644
> > index 000000000000..967074d348f6
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xen/Makefile
> > @@ -0,0 +1,5 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +
> > +drm_xen_front-objs := xen_drm_front.o
> > +
> > +obj-$(CONFIG_DRM_XEN_FRONTEND) += drm_xen_front.o
> > diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
> > new file mode 100644
> > index 000000000000..fd372fb464a1
> > --- /dev/null
> > +++ b/drivers/gpu/drm/xen/xen_drm_front.c
> > @@ -0,0 +1,83 @@
> > +/*
> > + *  Xen para-virtual DRM device
> > + *
> > + *   This program is free software; you can redistribute it and/or modify
> > + *   it under the terms of the GNU General Public License as published by
> > + *   the Free Software Foundation; either version 2 of the License, or
> > + *   (at your option) any later version.
> > + *
> > + *   This program is distributed in the hope that it will be useful,
> > + *   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + *   GNU General Public License for more details.
> Most Xen drivers in Linux use a dual GPL/BSD license, so that they can
> be imported into other non GPL OSes:
>
> This program is free software; you can redistribute it and/or
> modify it under the terms of the GNU General Public License version 2
> as published by the Free Software Foundation; or, when distributed
> separately from the Linux kernel or incorporated into other
> software packages, subject to the following license:
>
> Permission is hereby granted, free of charge, to any person obtaining a copy
> of this source file (the "Software"), to deal in the Software without
> restriction, including without limitation the rights to use, copy, modify,
> merge, publish, distribute, sublicense, and/or sell copies of the Software,
> and to permit persons to whom the Software is furnished to do so, subject to
> the following conditions:
>
> The above copyright notice and this permission notice shall be included in
> all copies or substantial portions of the Software.
>
> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
> IN THE SOFTWARE.
>
> IMO it would be good to release this driver under the same license, so
> it can be incorporated into other OSes.
I am in any way expert in licensing, but the above seems to be
/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
At least this is what I see at [1] for MIT.
Could you please tell which license(s) as listed at [1]
would be appropriate for Xen drivers in terms of how it is
expected to appear in the kernel code, e.g. expected
SPDX-License-Identifier?
> Thanks, Roger.
Thank you,
Oleksandr

[1] https://spdx.org/licenses/