Take and hold a reference to each of the vma (and their objects) as we process them with the cmdparser. This stops them being freed during the work if the GEM execbuf is interrupted and the request we expected to keep the objects alive is incomplete. Fixes: 686c7c35abc2 ("drm/i915/gem: Asynchronous cmdparser") Closes: https://gitlab.freedesktop.org/drm/intel/issues/970 Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200113154555.1909639-1-chris@chris-wilson.co.uk