[Intel-gfx] [PATCH 4/4] drm/i915/gen12: Invalidate aux table entries forcibly

[Chris Wilson]

Quoting Mika Kuoppala (2020-05-06 16:20:22)
> Chris Wilson <chris at chris-wilson.co.uk> writes:
> 
> > Quoting Mika Kuoppala (2020-05-06 15:47:34)
> >> Aux table invalidation can fail on update. So
> >> next access may cause memory access to be into stale entry.
> >> 
> >> Proposed workaround is to invalidate entries between
> >> all batchbuffers.
> >
> > This sounds like it should have a sunset clause. Do we anticipate being
> > able to drop this w/a in future?
> 
> Rafael kindly pointed out that Mesa already does this:
> https://gitlab.freedesktop.org/mesa/mesa/-/blob/master/src/gallium/drivers/iris/iris_state.c#L5131
> So I would say we can drop this patch.

Is the false hit self-contained? Is it caused by PTE update of the
address or by a 3D state change i.e. is it a potential isolation issue?
-Chris