[PATCH 2/8] drm/i915/selftests: Add tests for timeslicing virtual engines

[Chris Wilson]

Make sure that we can execute a virtual request on an already busy
engine, and conversely that we can execute a normal request if the
engines are already fully occupied by virtual requests.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/selftest_lrc.c | 179 +++++++++++++++++++++++++
 1 file changed, 179 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 824f99c4cc7c..1fc54359bd53 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -3766,6 +3766,184 @@ static int live_virtual_mask(void *arg)
 	return 0;
 }
 
+static int slicein_virtual_engine(struct intel_gt *gt,
+				  struct intel_engine_cs **siblings,
+				  unsigned int nsibling)
+{
+	struct intel_context *ce;
+	struct i915_request *rq;
+	struct igt_spinner spin;
+	unsigned int n;
+	int err = 0;
+
+	/*
+	 * Virtual requests must take part in timeslicing on the target engines.
+	 */
+
+	if (igt_spinner_init(&spin, gt))
+		return -ENOMEM;
+
+	for (n = 0; n < nsibling; n++) {
+		ce = intel_context_create(siblings[n]);
+		if (IS_ERR(ce)) {
+			err = PTR_ERR(ce);
+			goto out;
+		}
+
+		rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+		intel_context_put(ce);
+
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			goto out;
+		}
+
+		i915_request_add(rq);
+	}
+
+	ce = intel_execlists_create_virtual(siblings, nsibling);
+	if (IS_ERR(ce)) {
+		err = PTR_ERR(ce);
+		goto out;
+	}
+
+	rq = intel_context_create_request(ce);
+	intel_context_put(ce);
+	if (IS_ERR(rq)) {
+		err = PTR_ERR(rq);
+		goto out;
+	}
+
+	i915_request_get(rq);
+	i915_request_add(rq);
+	if (i915_request_wait(rq, 0, HZ / 10) < 0) {
+		GEM_TRACE_ERR("%s(%s) failed to slice in virtual request\n",
+			      __func__, rq->engine->name);
+		GEM_TRACE_DUMP();
+		intel_gt_set_wedged(gt);
+		err = -EIO;
+	}
+	i915_request_put(rq);
+
+out:
+	igt_spinner_end(&spin);
+	if (igt_flush_test(gt->i915))
+		err = -EIO;
+	igt_spinner_fini(&spin);
+	return err;
+}
+
+static int sliceout_virtual_engine(struct intel_gt *gt,
+				   struct intel_engine_cs **siblings,
+				   unsigned int nsibling)
+{
+	struct intel_context *ce;
+	struct i915_request *rq;
+	struct igt_spinner spin;
+	unsigned int n;
+	int err = 0;
+
+	/*
+	 * Virtual requests must allow others a fair timeslice.
+	 */
+
+	if (igt_spinner_init(&spin, gt))
+		return -ENOMEM;
+
+	for (n = 0; n <= nsibling; n++) { /* oversubscribed */
+		ce = intel_execlists_create_virtual(siblings, nsibling);
+		if (IS_ERR(ce)) {
+			err = PTR_ERR(ce);
+			goto out;
+		}
+
+		rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK);
+		intel_context_put(ce);
+
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			goto out;
+		}
+
+		i915_request_add(rq);
+	}
+
+	for (n = 0; !err && n < nsibling; n++) {
+		ce = intel_context_create(siblings[n]);
+		if (IS_ERR(ce)) {
+			err = PTR_ERR(ce);
+			goto out;
+		}
+
+		rq = intel_context_create_request(ce);
+		intel_context_put(ce);
+
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			goto out;
+		}
+
+		i915_request_get(rq);
+		i915_request_add(rq);
+		if (i915_request_wait(rq, 0, HZ / 10) < 0) {
+			GEM_TRACE_ERR("%s(%s) failed to slice out virtual request\n",
+				      __func__, siblings[n]->name);
+			GEM_TRACE_DUMP();
+			intel_gt_set_wedged(gt);
+			err = -EIO;
+		}
+		i915_request_put(rq);
+	}
+
+out:
+	igt_spinner_end(&spin);
+	if (igt_flush_test(gt->i915))
+		err = -EIO;
+	igt_spinner_fini(&spin);
+	return err;
+}
+
+static int live_virtual_slice(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1];
+	unsigned int class, inst;
+	int err;
+
+	if (intel_uc_uses_guc_submission(&gt->uc))
+		return 0;
+
+	for (class = 0; class <= MAX_ENGINE_CLASS; class++) {
+		unsigned int nsibling;
+
+		nsibling = 0;
+		for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
+			struct intel_engine_cs *engine;
+
+			engine = gt->engine_class[class][inst];
+			if (!engine)
+				break;
+
+			if (!intel_engine_has_timeslices(engine))
+				continue;
+
+			siblings[nsibling++] = engine;
+		}
+		if (nsibling < 2)
+			continue;
+
+		err = slicein_virtual_engine(gt, siblings, nsibling);
+		if (err)
+			return err;
+
+		err = sliceout_virtual_engine(gt, siblings, nsibling);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 static int preserved_virtual_engine(struct intel_gt *gt,
 				    struct intel_engine_cs **siblings,
 				    unsigned int nsibling)
@@ -4329,6 +4507,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(live_virtual_engine),
 		SUBTEST(live_virtual_mask),
 		SUBTEST(live_virtual_preserved),
+		SUBTEST(live_virtual_slice),
 		SUBTEST(live_virtual_bond),
 		SUBTEST(live_virtual_reset),
 	};
-- 
2.20.1