[Intel-gfx] [PATCH v2] drm/i915: Seal busy-ioctl uABI and prevent leaking of internal ids

[Chris Wilson]

On Fri, Jan 15, 2016 at 04:51:46PM +0000, Chris Wilson wrote:
> Tvrtko was looking through the execbuffer-ioctl and noticed that the
> uABI was tightly coupled to our internal engine identifiers. Close
> inspection also revealed that we leak those internal engine identifiers
> through the busy-ioctl, and those internal identifiers already do not
> match the user identifiers. Fortuitiously, there is only one user of the
> set of busy rings from the busy-ioctl, and they only wish to choose
> between the RENDER and the BLT engines.
> 
> Let's fix the userspace ABI while we still can.
> 
> v2: Update the uAPI documentation to explain the identifiers.

Testcase: igt/gem_busy
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre