[Intel-gfx] [RFC 00/22] Gen7 batch buffer command parser

[Daniel Vetter]

On Thu, Dec 5, 2013 at 9:47 PM, Volkin, Bradley D
<bradley.d.volkin at intel.com> wrote:
> On Tue, Nov 26, 2013 at 12:24:14PM -0800, Volkin, Bradley D wrote:
>> On Tue, Nov 26, 2013 at 11:35:38AM -0800, Daniel Vetter wrote:
>> > I think long-term we should even scan secure batches. We'd need to allow
>> > some registers which only the drm master (i.e. owner of the display
>> > hardware) is allowed to do, e.g. for scanline waits. But once we have that
>> > we should be able to port all current users of secure batches over to
>> > scanned batches and so enforce this everywhere by default.
>> >
>> > The other issue is that igt tests assume to be able to run some evil
>> > tests, so maybe we don't actually want this.
>>
>> Agreed. I thought we could handle this as a follow-up task once the basic stuff is
>> in place, particularly given that we'd want to modify at least some users to test.
>> I also wasn't sure if we would want the check to be root && master, as in the current
>> secure flag, or just master.
>
> So my plan to initially not parse secure batches might be shot. During further testing,
> I found that it looks like Ubuntu 13.10 ships with fdo bug 71328 out of the box (sna
> doesn't set the EXEC_SECURE flag when doing scanline waits). Sooo...
>
> If we parse all batches and allow extra commands/registers from the drm master, should
> that list just be the commands/registers used for scanline waits? Are there others you
> can think of?

No, I think the additional stuff the drm master is allowed to do is
just the scanline waits. Everything else that the ddx might or might
not be doing should also be possible as a normal process (e.g. the
BTILE register to switch the blitter into y-tiled mode). But Chris
should know if there's anything else really.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch