[Intel-gfx] [PATCH] drm/i915: relax debug BUG_ON() for closed context in hw_id pin

[Chris Wilson]

Quoting Zhenyu Wang (2019-03-09 03:39:36)
> On 2019.03.08 08:31:51 +0000, Chris Wilson wrote:
> > Quoting Zhenyu Wang (2019-03-08 07:52:37)
> > > Current GVT created context is marked closed as not to be used for
> > > host user. But its hw_id should still be used. So this is to relax
> > > debug BUG_ON() in __i915_gem_context_pin_hw_id() for GVT contexts
> > > which can use force single submission flag to identify.
> > 
> > The alternative strategy would be to always pin the id for GVT. How many
> > gvt contexts? One per host or one per client? Or we don't mark them as
> > closed (not so keen on that as it does provide some protection).
> >
> 
> Currently one per VM guest, always pin the id would also be good.
> 
> > I think I'd rather delete the GEM_BUG_ON() if it's not invariant -- we
> > only escape it firing for kernel contexts because they pin their id.
> 
> I think anyway we'd better pin id for gvt context, as it's good to keep
> it for one VM cycle.

Pin away, I have a plan to remove the hw-id limit...
-Chris