[Intel-gfx] [PATCH] drm/i915/guc: Reserve the upper end of the Global GTT for the GuC

[Chris Wilson]

On Thu, Dec 22, 2016 at 03:53:15PM +0100, Arkadiusz Hiler wrote:
> On Wed, Dec 21, 2016 at 07:35:04PM +0100, Srivatsa, Anusha wrote:
> > With enable_guc_loading=2 and enable_guc_submission=0 I get HuC
> > authentication failure and with enable_guc_loading and
> > enable_guc_submisssion both set to 2 the device does not show any
> > display.
> 
> Sadly "the fix" fixes the issues we had with the loading - we can load
> GuC but...
> 
> GuC Actions (INTEL_GUC_ACTION*, and intel_guc_send()) seem to care about
> kernel context pinned location as well (not directly though). And it's
> much more restritive.
> 
> Experimentally I was able to determine that if we have ctx pinned above
> 0x10000000 (2 GB) mark, GuC Actions just fail.

Are we certain this only applies to the kernel/golden context? No other
objects accessed by the GuC are affected?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre