From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8EB6AC4338F for ; Mon, 9 Aug 2021 19:37:44 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 56A0E60C51 for ; Mon, 9 Aug 2021 19:37:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 56A0E60C51 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BFF8689D5C; Mon, 9 Aug 2021 19:37:43 +0000 (UTC) Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 59B3589C6E; Mon, 9 Aug 2021 19:37:42 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10070"; a="275799585" X-IronPort-AV: E=Sophos;i="5.84,308,1620716400"; d="scan'208";a="275799585" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2021 12:37:41 -0700 X-IronPort-AV: E=Sophos;i="5.84,308,1620716400"; d="scan'208";a="671034983" Received: from dut151-iclu.fm.intel.com ([10.105.23.43]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2021 12:37:41 -0700 Date: Mon, 9 Aug 2021 19:37:39 +0000 From: Matthew Brost To: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Message-ID: <20210809193739.GA124301@DUT151-ICLU.fm.intel.com> References: <20210808180757.81440-1-matthew.brost@intel.com> <20210808180757.81440-3-matthew.brost@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Intel-gfx] [PATCH 2/3] drm/i915/selftests: Fix memory corruption in live_lrc_isolation X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Mon, Aug 09, 2021 at 03:38:38PM +0200, Daniel Vetter wrote: > On Sun, Aug 08, 2021 at 11:07:56AM -0700, Matthew Brost wrote: > > GuC submission has exposed an existing memory corruption in > > live_lrc_isolation. We believe that some writes to the watchdog offsets > > in the LRC (0x178 & 0x17c) can result in trashing of portions of the > > address space. With GuC submission there are additional objects which > > can move the context redzone into the space that is trashed. To > > workaround this avoid poisoning the watchdog. > > A Bspec reference here would be good (we can quote anything that's marked > for public release, so doesn't have one of the IP markers). > Let me see what I dig up in the bspec. BTW - Hopefully we can root cause this soon with a proper fix. > Also I think the above should be replicated in condensed form instead of > the XXX comment. > Sure. Matt > With those: Acked-by: Daniel Vetter since I > definitely have enough clue here for a detailed review. > -Daniel > > > > > Signed-off-by: Matthew Brost > > --- > > drivers/gpu/drm/i915/gt/selftest_lrc.c | 29 +++++++++++++++++++++++++- > > 1 file changed, 28 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c > > index b0977a3b699b..6500e9fce8a0 100644 > > --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c > > +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c > > @@ -1074,6 +1074,32 @@ record_registers(struct intel_context *ce, > > goto err_after; > > } > > > > +static u32 safe_offset(u32 offset, u32 reg) > > +{ > > + /* XXX skip testing of watchdog */ > > + if (offset == 0x178 || offset == 0x17c) > > + reg = 0; > > + > > + return reg; > > +} > > + > > +static int get_offset_mask(struct intel_engine_cs *engine) > > +{ > > + if (GRAPHICS_VER(engine->i915) < 12) > > + return 0xfff; > > + > > + switch (engine->class) { > > + default: > > + case RENDER_CLASS: > > + return 0x07ff; > > + case COPY_ENGINE_CLASS: > > + return 0x0fff; > > + case VIDEO_DECODE_CLASS: > > + case VIDEO_ENHANCEMENT_CLASS: > > + return 0x3fff; > > + } > > +} > > + > > static struct i915_vma *load_context(struct intel_context *ce, u32 poison) > > { > > struct i915_vma *batch; > > @@ -1117,7 +1143,8 @@ static struct i915_vma *load_context(struct intel_context *ce, u32 poison) > > len = (len + 1) / 2; > > *cs++ = MI_LOAD_REGISTER_IMM(len); > > while (len--) { > > - *cs++ = hw[dw]; > > + *cs++ = safe_offset(hw[dw] & get_offset_mask(ce->engine), > > + hw[dw]); > > *cs++ = poison; > > dw += 2; > > } > > -- > > 2.28.0 > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch