While debugging an issue with full GT resets I went down a rabbit hole thinking the scrubbing of lost G2H wasn't working correctly. This proved to be incorrect as this was working just fine but this chase inspired me to write a selftest to prove that this works. This simple selftest injects errors dropping various G2H and then issues a full GT reset proving that the scrubbing of these G2H doesn't blow up.
v2: (Daniel Vetter) - Use ifdef instead of macros for selftests v3: (Checkpatch) - A space after 'switch' statement v4: (Daniele) - A comment saying GT won't idle if G2H are lost
Reviewed-by: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com Signed-off-by: Matthew Brost matthew.brost@intel.com --- drivers/gpu/drm/i915/gt/intel_context_types.h | 18 +++ .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 25 ++++ drivers/gpu/drm/i915/gt/uc/selftest_guc.c | 127 ++++++++++++++++++ .../drm/i915/selftests/i915_live_selftests.h | 1 + .../i915/selftests/intel_scheduler_helpers.c | 12 ++ .../i915/selftests/intel_scheduler_helpers.h | 2 + 6 files changed, 185 insertions(+) create mode 100644 drivers/gpu/drm/i915/gt/uc/selftest_guc.c
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h index e54351a170e2..3a73f3117873 100644 --- a/drivers/gpu/drm/i915/gt/intel_context_types.h +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h @@ -198,6 +198,24 @@ struct intel_context { */ u8 guc_prio; u32 guc_prio_count[GUC_CLIENT_PRIORITY_NUM]; + +#ifdef CONFIG_DRM_I915_SELFTEST + /** + * @drop_schedule_enable: Force drop of schedule enable G2H for selftest + */ + bool drop_schedule_enable; + + /** + * @drop_schedule_disable: Force drop of schedule disable G2H for + * selftest + */ + bool drop_schedule_disable; + + /** + * @drop_deregister: Force drop of deregister G2H for selftest + */ + bool drop_deregister; +#endif };
#endif /* __INTEL_CONTEXT_TYPES__ */ diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index 56f11accd6cc..5844bb954922 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -2645,6 +2645,13 @@ int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
trace_intel_context_deregister_done(ce);
+#ifdef CONFIG_DRM_I915_SELFTEST + if (unlikely(ce->drop_deregister)) { + ce->drop_deregister = false; + return 0; + } +#endif + if (context_wait_for_deregister_to_register(ce)) { struct intel_runtime_pm *runtime_pm = &ce->engine->gt->i915->runtime_pm; @@ -2699,10 +2706,24 @@ int intel_guc_sched_done_process_msg(struct intel_guc *guc, trace_intel_context_sched_done(ce);
if (context_pending_enable(ce)) { +#ifdef CONFIG_DRM_I915_SELFTEST + if (unlikely(ce->drop_schedule_enable)) { + ce->drop_schedule_enable = false; + return 0; + } +#endif + clr_context_pending_enable(ce); } else if (context_pending_disable(ce)) { bool banned;
+#ifdef CONFIG_DRM_I915_SELFTEST + if (unlikely(ce->drop_schedule_disable)) { + ce->drop_schedule_disable = false; + return 0; + } +#endif + /* * Unpin must be done before __guc_signal_context_fence, * otherwise a race exists between the requests getting @@ -3079,3 +3100,7 @@ bool intel_guc_virtual_engine_has_heartbeat(const struct intel_engine_cs *ve)
return false; } + +#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) +#include "selftest_guc.c" +#endif diff --git a/drivers/gpu/drm/i915/gt/uc/selftest_guc.c b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c new file mode 100644 index 000000000000..fb0e4a7bd8ca --- /dev/null +++ b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright �� 2021 Intel Corporation + */ + +#include "selftests/intel_scheduler_helpers.h" + +static struct i915_request *nop_user_request(struct intel_context *ce, + struct i915_request *from) +{ + struct i915_request *rq; + int ret; + + rq = intel_context_create_request(ce); + if (IS_ERR(rq)) + return rq; + + if (from) { + ret = i915_sw_fence_await_dma_fence(&rq->submit, + &from->fence, 0, + I915_FENCE_GFP); + if (ret < 0) { + i915_request_put(rq); + return ERR_PTR(ret); + } + } + + i915_request_get(rq); + i915_request_add(rq); + + return rq; +} + +static int intel_guc_scrub_ctbs(void *arg) +{ + struct intel_gt *gt = arg; + int ret = 0; + int i; + struct i915_request *last[3] = {NULL, NULL, NULL}, *rq; + intel_wakeref_t wakeref; + struct intel_engine_cs *engine; + struct intel_context *ce; + + wakeref = intel_runtime_pm_get(gt->uncore->rpm); + engine = intel_selftest_find_any_engine(gt); + + /* Submit requests and inject errors forcing G2H to be dropped */ + for (i = 0; i < 3; ++i) { + ce = intel_context_create(engine); + if (IS_ERR(ce)) { + ret = PTR_ERR(ce); + pr_err("Failed to create context, %d: %d\n", i, ret); + goto err; + } + + switch (i) { + case 0: + ce->drop_schedule_enable = true; + break; + case 1: + ce->drop_schedule_disable = true; + break; + case 2: + ce->drop_deregister = true; + break; + } + + rq = nop_user_request(ce, NULL); + intel_context_put(ce); + + if (IS_ERR(rq)) { + ret = PTR_ERR(rq); + pr_err("Failed to create request, %d: %d\n", i, ret); + goto err; + } + + last[i] = rq; + } + + for (i = 0; i < 3; ++i) { + ret = i915_request_wait(last[i], 0, HZ); + if (ret < 0) { + pr_err("Last request failed to complete: %d\n", ret); + goto err; + } + i915_request_put(last[i]); + last[i] = NULL; + } + + /* Force all H2G / G2H to be submitted / processed */ + intel_gt_retire_requests(gt); + msleep(500); + + /* Scrub missing G2H */ + intel_gt_handle_error(engine->gt, -1, 0, "selftest reset"); + + /* GT will not idle if G2H are lost */ + ret = intel_gt_wait_for_idle(gt, HZ); + if (ret < 0) { + pr_err("GT failed to idle: %d\n", ret); + goto err; + } + +err: + for (i = 0; i < 3; ++i) + if (last[i]) + i915_request_put(last[i]); + intel_runtime_pm_put(gt->uncore->rpm, wakeref); + + return ret; +} + +int intel_guc_live_selftests(struct drm_i915_private *i915) +{ + static const struct i915_subtest tests[] = { + SUBTEST(intel_guc_scrub_ctbs), + }; + struct intel_gt *gt = &i915->gt; + + if (intel_gt_is_wedged(gt)) + return 0; + + if (!intel_uc_uses_guc_submission(>->uc)) + return 0; + + return intel_gt_live_subtests(tests, gt); +} diff --git a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h index cfa5c4165a4f..3cf6758931f9 100644 --- a/drivers/gpu/drm/i915/selftests/i915_live_selftests.h +++ b/drivers/gpu/drm/i915/selftests/i915_live_selftests.h @@ -47,5 +47,6 @@ selftest(execlists, intel_execlists_live_selftests) selftest(ring_submission, intel_ring_submission_live_selftests) selftest(perf, i915_perf_live_selftests) selftest(slpc, intel_slpc_live_selftests) +selftest(guc, intel_guc_live_selftests) /* Here be dragons: keep last to run last! */ selftest(late_gt_pm, intel_gt_pm_late_selftests) diff --git a/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c index 4b328346b48a..310fb83c527e 100644 --- a/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c +++ b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.c @@ -14,6 +14,18 @@ #define REDUCED_PREEMPT 10 #define WAIT_FOR_RESET_TIME 10000
+struct intel_engine_cs *intel_selftest_find_any_engine(struct intel_gt *gt) +{ + struct intel_engine_cs *engine; + enum intel_engine_id id; + + for_each_engine(engine, gt, id) + return engine; + + pr_err("No valid engine found!\n"); + return NULL; +} + int intel_selftest_modify_policy(struct intel_engine_cs *engine, struct intel_selftest_saved_policy *saved, u32 modify_type) diff --git a/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h index 35c098601ac0..ae60bb507f45 100644 --- a/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h +++ b/drivers/gpu/drm/i915/selftests/intel_scheduler_helpers.h @@ -10,6 +10,7 @@
struct i915_request; struct intel_engine_cs; +struct intel_gt;
struct intel_selftest_saved_policy { u32 flags; @@ -23,6 +24,7 @@ enum selftest_scheduler_modify { SELFTEST_SCHEDULER_MODIFY_FAST_RESET, };
+struct intel_engine_cs *intel_selftest_find_any_engine(struct intel_gt *gt); int intel_selftest_modify_policy(struct intel_engine_cs *engine, struct intel_selftest_saved_policy *saved, enum selftest_scheduler_modify modify_type);