[Intel-gfx] [PATCH] drm/i915: Remove secure batch buffer flag SNB+

[Ben Widawsky]

On Wed, 05 Oct 2011 22:26:54 +0100
Chris Wilson <chris at chris-wilson.co.uk> wrote:

> On Wed,  5 Oct 2011 13:01:56 -0700, Ben Widawsky <ben at bwidawsk.net> wrote:
> > Docs say that the secure batchbuffer field for > SNB B0 (products that
> > actually shipped) should be 0 when not using PPGTT. I'd guess this has
> > no positive or negative effect, but is just here to jive with the docs.
> 
> How explicit is the warning? Enough to allow arbitrary writes into the
> MMIO space?
> -Chris
> 

The docs really suck, and I am honestly quite confused.

It simply says (for both blitter and render):
"This field must be '0' unless the Per-Process GTT Enable is '1'"

:/

I'm sure we already have a test for it, but I can write one if not.

Ben