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@xxxxxxxxx>
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
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 f5bee833ee7d..5970c54a2e72 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -2639,6 +2639,13 @@ 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;
@@ -2693,10 +2700,24 @@ 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
@@ -3073,3 +3094,7 @@ 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);
--
2.32.0
