Re: [igt-dev] [PATCH i-g-t 3/4] lib/igt_gt: Add compute engine

["Dixit, Ashutosh" <ashutosh.dixit@intel.com>]

On Thu, 21 Oct 2021 17:12:26 -0700, Dixit, Ashutosh wrote:
>
> On Thu, 21 Oct 2021 00:33:21 -0700, Zbigniew Kempczyński wrote:
> >
> > On Thu, Oct 21, 2021 at 10:05:07AM +0530, priyanka.dandamudi@intel.com wrote:
> > > From: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> > >
> > > Add compute (CCS) engine. Add this to the IGT
> > > structure to allow gem tests to execute.
> > >
> > > Signed-off-by: Stuart Summers <stuart.summers@intel.com>
> > > Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> > > Signed-off-by: Priyanka Dandamudi <priyanka.dandamudi@intel.com>
> > > Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
> > > Cc: Arjun Melkaveri <arjun.melkaveri@intel.com>
> > > ---
> > >  lib/igt_gt.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > >
> > > diff --git a/lib/igt_gt.c b/lib/igt_gt.c
> > > index a0ba04cc..80fb65ca 100644
> > > --- a/lib/igt_gt.c
> > > +++ b/lib/igt_gt.c
> > > @@ -604,6 +604,10 @@ const struct intel_execution_engine2 intel_execution_engines2[] = {
> > >	{ "vcs1", I915_ENGINE_CLASS_VIDEO, 1, I915_EXEC_BSD | I915_EXEC_BSD_RING2 },
> > >	{ "vcs2", I915_ENGINE_CLASS_VIDEO, 2, -1 },
> > >	{ "vecs0", I915_ENGINE_CLASS_VIDEO_ENHANCE, 0, I915_EXEC_VEBOX },
> > > +	{ "ccs0", I915_ENGINE_CLASS_COMPUTE, 0 , -1},
> > > +	{ "ccs1", I915_ENGINE_CLASS_COMPUTE, 1 , -1},
> > > +	{ "ccs2", I915_ENGINE_CLASS_COMPUTE, 2 , -1},
> > > +	{ "ccs3", I915_ENGINE_CLASS_COMPUTE, 3 , -1},
>
> Is this correct? Isn't intel_execution_engines2 a list of just the legacy
> engines? I don't think compute engines (which may vary in number) can be
> added to the list of legacy engines. Isn't it true that compute engines can
> only be accessed by querying the present engines dynamically (using
> something like intel_ctx_create_all_physical())?

I've copied Tvrtko (the boss :), but I am pretty sure what I said is
correct. Legacy engines are what context 0 is created with (without adding
any more engines onto context 0). So unless we can confirm that these
engines are present for context 0 in the kernel we can't add them in IGT.