From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH] drm/i915: Avoid reading through unaccessible PTEs during an error event Date: Tue, 29 Nov 2011 12:05:27 +0100 Message-ID: <20111129110526.GA3989@phenom.ffwll.local> References: <1322559310-13158-1-git-send-email-chris@chris-wilson.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-fx0-f49.google.com (mail-fx0-f49.google.com [209.85.161.49]) by gabe.freedesktop.org (Postfix) with ESMTP id D78309EDA2 for ; Tue, 29 Nov 2011 03:04:09 -0800 (PST) Received: by faan17 with SMTP id n17so899983faa.36 for ; Tue, 29 Nov 2011 03:04:08 -0800 (PST) Content-Disposition: inline In-Reply-To: <1322559310-13158-1-git-send-email-chris@chris-wilson.co.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Chris Wilson Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Tue, Nov 29, 2011 at 09:35:10AM +0000, Chris Wilson wrote: > We need to sanity check that the buffer is actually bound into the > mappable range of the GTT prior to reading it back through the GTT with > the CPU. Fortuitously, the only buffers we have been interested in so > far are constrained to be in the mappable region in order to handle > potential relocations. However, this can be relaxed in future and given > that the purpose is to read back following an error we should be extra > careful and not assume everything is safe. > > Signed-off-by: Chris Wilson Reviewed-by: Daniel Vetter For the lazy-gtt binding we need to also check whether the ptes are correct (they should because we pin buffers with relocations as mappable). I'll add that additional paranoia to my series. -- Daniel Vetter Mail: daniel@ffwll.ch Mobile: +41 (0)79 365 57 48