Re: [PATCH RFC 1/4] drm/i915: add create_context2 ioctl

Jesse Barnes
2016-08-15T16:32:42Z

On Mon, 2016-08-15 at 13:56 +0100, Chris Wilson wrote:
> On Mon, Aug 15, 2016 at 03:25:43PM +0300, Mika Kuoppala wrote:
> >
> > Chris Wilson <chris@chris-wilson.co.uk> writes:
> >
> > >
> > > On Mon, Aug 15, 2016 at 02:48:04PM +0300, Mika Kuoppala wrote:
> > > >
> > > > From: Jesse Barnes <jbarnes@virtuousgeek.org>
> > > >
> > > > Add i915_gem_context_create2_ioctl for passing flags
> > > > (e.g. SVM) when creating a context.
> > > >
> > > > v2: check the pad on create_context
> > > > v3: rebase
> > > > v4: i915_dma is no more. create_gvt needs flags
> > > >
> > > > Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> > > > Cc: Chris Wilson <chris@chris-wilson.co.uk>
> > > > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> > > > Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> (v1)
> > > > Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
> > >
> > > Considering we can use deferred ppgtt creation and have setparam
> > > do we
> > > need a new create ioctl just to set a flag?
> >
> > So like this:
> >
> > - create ctx with the default create ioctl
> > - set cxt param it for svm capable.
> > - first submit deferred creates
> >
> > And we use the setparam point for returning
> > error if svm context are not there.
>
> (and a call to set svm on a context after first use is illegal)
>
> That's the outline I had in my head. I am not sure if the result is
> cleaner - I just hope it is ;)
>

I opted against that initially because creating the tables and setup
after the fact for the process actually seemed messier.  Plus I thought
we'd want more flags at context create later anyway...

Not that my opinion matters anymore. :)

Jesse