lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <cover.1656921701.git.mchehab@kernel.org>
Date:   Mon,  4 Jul 2022 16:20:02 +0100
From:   Mauro Carvalho Chehab <mchehab@...nel.org>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Thomas Hellström 
        <thomas.hellstrom@...ux.intel.com>,
        Chris Wilson <chris@...is-wilson.co.uk>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Mika Kuoppala <mika.kuoppala@...ux.intel.com>,
        Thomas Hellstrom <thomas.hellstrom@...el.com>,
        Chris Wilson <chris.p.wilson@...el.com>,
        Tvrtko Ursulin <tvrtko.ursulin@...ux.intel.com>,
        Andi Shyti <andi.shyti@...ux.intel.com>,
        Daniel Vetter <daniel@...ll.ch>,
        David Airlie <airlied@...ux.ie>,
        dri-devel@...ts.freedesktop.org, intel-gfx@...ts.freedesktop.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v3 0/2] Fix TLB invalidate issues with Broadwell

i915 selftest hangcheck is causing the i915 driver timeouts, as reported
by Intel CI bot:

http://gfx-ci.fi.intel.com/cibuglog-ng/issuefilterassoc/24297?query_key=42a999f48fa6ecce068bc8126c069be7c31153b4

When such test runs, the only output is:

	[   68.811639] i915: Performing live selftests with st_random_seed=0xe138eac7 st_timeout=500
	[   68.811792] i915: Running hangcheck
	[   68.811859] i915: Running intel_hangcheck_live_selftests/igt_hang_sanitycheck
	[   68.816910] i915 0000:00:02.0: [drm] Cannot find any crtc or sizes
	[   68.841597] i915: Running intel_hangcheck_live_selftests/igt_reset_nop
	[   69.346347] igt_reset_nop: 80 resets
	[   69.362695] i915: Running intel_hangcheck_live_selftests/igt_reset_nop_engine
	[   69.863559] igt_reset_nop_engine(rcs0): 709 resets
	[   70.364924] igt_reset_nop_engine(bcs0): 903 resets
	[   70.866005] igt_reset_nop_engine(vcs0): 659 resets
	[   71.367934] igt_reset_nop_engine(vcs1): 549 resets
	[   71.869259] igt_reset_nop_engine(vecs0): 553 resets
	[   71.882592] i915: Running intel_hangcheck_live_selftests/igt_reset_idle_engine
	[   72.383554] rcs0: Completed 16605 idle resets
	[   72.884599] bcs0: Completed 18641 idle resets
	[   73.385592] vcs0: Completed 17517 idle resets
	[   73.886658] vcs1: Completed 15474 idle resets
	[   74.387600] vecs0: Completed 17983 idle resets
	[   74.387667] i915: Running intel_hangcheck_live_selftests/igt_reset_active_engine
	[   74.889017] rcs0: Completed 747 active resets
	[   75.174240] intel_engine_reset(bcs0) failed, err:-110
	[   75.174301] bcs0: Completed 525 active resets

After that, the machine just silently hangs.

Bisecting the issue, the patch that introduced the regression is:

    7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")

Reverting it fix the issues, but introduce other problems, as TLB
won't be invalidated anymore. So, instead, let's fix the root cause.

It turns that the TLB flush logic ends conflicting with i915 reset,
which is called during selftest hangcheck. So, the TLB cache should
be serialized together with i915 reset.

Tested on an Intel NUC5i7RYB with an i7-5557U Broadwell CPU.

v3:
- Removed the logic that would check if the engine is awake before doing
  TLB flush invalidation as backporting PM logic up to Kernel 4.x could be
  too painful. After getting this one merged, I'll submit a separate patch
  with the PM awake logic.

v2:

- Reduced to bare minimum fixes, as this shoud be backported deeply
  into stable.


Chris Wilson (2):
  drm/i915/gt: Serialize GRDOM access between multiple engine resets
  drm/i915/gt: Serialize TLB invalidates with GT resets

 drivers/gpu/drm/i915/gt/intel_gt.c    | 15 ++++++++++-
 drivers/gpu/drm/i915/gt/intel_reset.c | 37 ++++++++++++++++++++-------
 2 files changed, 42 insertions(+), 10 deletions(-)

-- 
2.36.1


Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ