[Intel-gfx] [PATCH 7/8] drm/i915: Asynchronous cmdparser

[Chris Wilson]

Quoting Chris Wilson (2019-12-07 17:01:09)
> Execute the cmdparser asynchronously as part of the submission pipeline.
> Using our dma-fences, we can schedule execution after an asynchronous
> piece of work, so we move the cmdparser out from under the struct_mutex
> inside execbuf as run it as part of the submission pipeline. The same
> security rules apply, we copy the user batch before validation and
> userspace cannot touch the validation shadow. The only caveat is that we
> will do request construction before we complete cmdparsing and so we
> cannot know the outcome of the validation step until later -- so the
> execbuf ioctl does not report -EINVAL directly, but we must cancel
> execution of the request and flag the error on the out-fence.
 
Closes: https://gitlab.freedesktop.org/drm/intel/issues/611
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris