From patchwork Tue Jan 21 13:04:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11343795 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 989721398 for ; Tue, 21 Jan 2020 13:04:23 +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 80C7A217F4 for ; Tue, 21 Jan 2020 13:04:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80C7A217F4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 099856ECE3; Tue, 21 Jan 2020 13:04:23 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 76FA46ECE3 for ; Tue, 21 Jan 2020 13:04:21 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 19958227-1500050 for multiple; Tue, 21 Jan 2020 13:04:12 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Tue, 21 Jan 2020 13:04:11 +0000 Message-Id: <20200121130411.267092-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200121100927.114886-1-chris@chris-wilson.co.uk> References: <20200121100927.114886-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v3] drm/i915/execlists: Reclaim the hanging virtual request 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" If we encounter a hang on a virtual engine, as we process the hang the request may already have been moved back to the virtual engine (we are processing the hang on the physical engine). We need to reclaim the request from the virtual engine so that the locking is consistent and local to the real engine on which we will hold the request for error state capturing. v2: Pull the reclamation into execlists_hold() and assert that cannot be called from outside of the reset (i.e. with the tasklet disabled). v3: Added selftest Fixes: 748317386afb ("drm/i915/execlists: Offline error capture") Testcase: igt/gem_exec_balancer/hang Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/gt/intel_lrc.c | 29 +++++ drivers/gpu/drm/i915/gt/selftest_lrc.c | 158 ++++++++++++++++++++++++- 2 files changed, 186 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 3a30767ff0c4..11dfee4fe9ea 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -2396,6 +2396,35 @@ static void __execlists_hold(struct i915_request *rq) static void execlists_hold(struct intel_engine_cs *engine, struct i915_request *rq) { + if (rq->engine != engine) { /* preempted virtual engine */ + struct virtual_engine *ve = to_virtual_engine(rq->engine); + unsigned long flags; + + /* + * intel_context_inflight() is only protected by virtue + * of process_csb() being called only by the tasklet (or + * directly from inside reset while the tasklet is suspended). + * Assert that neither of those are allowed to run while we + * poke at the request queues. + */ + GEM_BUG_ON(!reset_in_progress(&engine->execlists)); + + /* + * An unsubmitted request along a virtual engine will + * remain on the active (this) engine until we are able + * to process the context switch away (and so mark the + * context as no longer in flight). That cannot have happened + * yet, otherwise we would not be hanging! + */ + spin_lock_irqsave(&ve->base.active.lock, flags); + GEM_BUG_ON(intel_context_inflight(rq->context) != engine); + GEM_BUG_ON(ve->request != rq); + ve->request = NULL; + spin_unlock_irqrestore(&ve->base.active.lock, flags); + + rq->engine = engine; + } + spin_lock_irq(&engine->active.lock); /* diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c index b208c2176bbd..1beb47c3ba9e 100644 --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c @@ -335,7 +335,6 @@ static int live_hold_reset(void *arg) if (test_and_set_bit(I915_RESET_ENGINE + id, >->reset.flags)) { - spin_unlock_irq(&engine->active.lock); intel_gt_set_wedged(gt); err = -EBUSY; goto out; @@ -3411,6 +3410,162 @@ static int live_virtual_bond(void *arg) return 0; } +static int reset_virtual_engine(struct intel_gt *gt, + struct intel_engine_cs **siblings, + unsigned int nsibling) +{ + struct intel_engine_cs *engine; + struct intel_context *ve; + unsigned long *heartbeat; + struct igt_spinner spin; + struct i915_request *rq; + unsigned int n; + int err = 0; + + /* + * In order to support offline error capture for fast preempt reset, + * we need to decouple the guilty request and ensure that it and its + * descendents are not executed while the capture is in progress. + */ + + if (!intel_has_reset_engine(gt)) + return 0; + + heartbeat = kmalloc_array(nsibling, sizeof(*heartbeat), GFP_KERNEL); + if (!heartbeat) + return -ENOMEM; + + if (igt_spinner_init(&spin, gt)) { + err = -ENOMEM; + goto out_heartbeat; + } + + ve = intel_execlists_create_virtual(siblings, nsibling); + if (IS_ERR(ve)) { + err = PTR_ERR(ve); + goto out_spin; + } + + for (n = 0; n < nsibling; n++) + engine_heartbeat_disable(siblings[n], &heartbeat[n]); + + rq = igt_spinner_create_request(&spin, ve, MI_ARB_CHECK); + if (IS_ERR(rq)) { + err = PTR_ERR(rq); + goto out; + } + i915_request_add(rq); + + if (!igt_wait_for_spinner(&spin, rq)) { + intel_gt_set_wedged(gt); + err = -ETIME; + goto out; + } + + engine = rq->engine; + GEM_BUG_ON(engine == ve->engine); + + /* Take ownership of the reset and tasklet */ + if (test_and_set_bit(I915_RESET_ENGINE + engine->id, + >->reset.flags)) { + intel_gt_set_wedged(gt); + err = -EBUSY; + goto out; + } + tasklet_disable(&engine->execlists.tasklet); + + engine->execlists.tasklet.func(engine->execlists.tasklet.data); + GEM_BUG_ON(execlists_active(&engine->execlists) != rq); + + /* Fake a preemption event; failed of course */ + spin_lock_irq(&engine->active.lock); + __unwind_incomplete_requests(engine); + spin_unlock_irq(&engine->active.lock); + + /* Reset the engine while keeping our active request on hold */ + execlists_hold(engine, rq); + GEM_BUG_ON(!i915_request_on_hold(rq)); + + intel_engine_reset(engine, NULL); + GEM_BUG_ON(rq->fence.error != -EIO); + + /* Release our grasp on the engine, letting CS flow again */ + tasklet_enable(&engine->execlists.tasklet); + clear_and_wake_up_bit(I915_RESET_ENGINE + engine->id, >->reset.flags); + + /* Check that we do not resubmit the held request */ + i915_request_get(rq); + if (!i915_request_wait(rq, 0, HZ / 5)) { + pr_err("%s: on hold request completed!\n", + engine->name); + i915_request_put(rq); + err = -EIO; + goto out; + } + GEM_BUG_ON(!i915_request_on_hold(rq)); + + /* But is resubmitted on release */ + execlists_unhold(engine, rq); + if (i915_request_wait(rq, 0, HZ / 5) < 0) { + pr_err("%s: held request did not complete!\n", + engine->name); + intel_gt_set_wedged(gt); + err = -ETIME; + } + i915_request_put(rq); + +out: + for (n = 0; n < nsibling; n++) + engine_heartbeat_enable(siblings[n], heartbeat[n]); + + intel_context_put(ve); +out_spin: + igt_spinner_fini(&spin); +out_heartbeat: + kfree(heartbeat); + return err; +} + +static int live_virtual_reset(void *arg) +{ + struct intel_gt *gt = arg; + struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1]; + unsigned int class, inst; + + /* + * Check that the context image retains non-privileged (user) registers + * from one engine to the next. For this we check that the CS_GPR + * are preserved. + */ + + if (USES_GUC_SUBMISSION(gt->i915)) + return 0; + + /* As we use CS_GPR we cannot run before they existed on all engines. */ + if (INTEL_GEN(gt->i915) < 9) + return 0; + + for (class = 0; class <= MAX_ENGINE_CLASS; class++) { + int nsibling, err; + + nsibling = 0; + for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) { + if (!gt->engine_class[class][inst]) + continue; + + siblings[nsibling++] = gt->engine_class[class][inst]; + } + if (nsibling < 2) + continue; + + err = reset_virtual_engine(gt, siblings, nsibling); + if (err) + return err; + } + + return 0; +} + int intel_execlists_live_selftests(struct drm_i915_private *i915) { static const struct i915_subtest tests[] = { @@ -3436,6 +3591,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) SUBTEST(live_virtual_mask), SUBTEST(live_virtual_preserved), SUBTEST(live_virtual_bond), + SUBTEST(live_virtual_reset), }; if (!HAS_EXECLISTS(i915))