[PATCH v2] drm/i915/gvt: Fix crash after request->hw_context change

[Chris Wilson]

Quoting Chris Wilson (2018-05-21 10:54:57)
> Quoting Zhenyu Wang (2018-05-21 09:17:52)
> > When we do shadowing, workload's request might not be allocated yet,
> > so we still require shadow context's object. And when complete workload,
> > delay to zero workload's request pointer after used for update guest context.
> > 
> > v2: Move request alloc earlier as already try to track shadow status
> > depending on request state, which also facilitate to use request->hw_context
> > for target engine context reference.
> > 
> > Fixes: 1fc44d9b1afb ("drm/i915: Store a pointer to intel_context in i915_request")
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> > Cc: Zhi Wang <zhi.a.wang at intel.com>
> > Cc: Weinan Li <weinan.z.li at intel.com>
> > Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
> 
> Looks like it's applying the principles we discussed to avoid
> chasing gem_context to get at the pinned intel_context,
> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> 
> Thanks for the fixup!

And pushed, many thanks again.
-Chris