drm/i915/guc: GuC virtual engines

Implement GuC virtual engines. Rather simple implementation, basically
just allocate an engine, setup context enter / exit function to virtual
engine specific functions, set all other variables / functions to guc
versions, and set the engine mask to that of all the siblings.

v2: Update to work with proto-ctx
v3:
 (Daniele)
  - Drop include, add comment to intel_virtual_engine_has_heartbeat

Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727002348.97202-2-matthew.brost@intel.com

drivers/gpu/drm/i915/gem/i915_gem_context.c

@@ -74,7 +74,6 @@
 #include "gt/intel_context_param.h"
 #include "gt/intel_engine_heartbeat.h"
 #include "gt/intel_engine_user.h"
-#include "gt/intel_execlists_submission.h" /* virtual_engine */
 #include "gt/intel_gpu_commands.h"
 #include "gt/intel_ring.h"
 
@@ -363,9 +362,6 @@ set_proto_ctx_engines_balance(struct i915_user_extension __user *base,
 	if (!HAS_EXECLISTS(i915))
 		return -ENODEV;
 
-	if (intel_uc_uses_guc_submission(&i915->gt.uc))
-		return -ENODEV; /* not implement yet */
-
 	if (get_user(idx, &ext->engine_index))
 		return -EFAULT;
 
@@ -950,8 +946,8 @@ static struct i915_gem_engines *user_engines(struct i915_gem_context *ctx,
 			break;
 
 		case I915_GEM_ENGINE_TYPE_BALANCED:
-			ce = intel_execlists_create_virtual(pe[n].siblings,
-							    pe[n].num_siblings);
+			ce = intel_engine_create_virtual(pe[n].siblings,
+							 pe[n].num_siblings);
 			break;
 
 		case I915_GEM_ENGINE_TYPE_INVALID:

drivers/gpu/drm/i915/gt/intel_context_types.h

@@ -47,6 +47,12 @@ struct intel_context_ops {
 
 	void (*reset)(struct intel_context *ce);
 	void (*destroy)(struct kref *kref);
+
+	/* virtual engine/context interface */
+	struct intel_context *(*create_virtual)(struct intel_engine_cs **engine,
+						unsigned int count);
+	struct intel_engine_cs *(*get_sibling)(struct intel_engine_cs *engine,
+					       unsigned int sibling);
 };
 
 struct intel_context {

drivers/gpu/drm/i915/gt/intel_engine.h

@@ -273,13 +273,41 @@ intel_engine_has_preempt_reset(const struct intel_engine_cs *engine)
 	return intel_engine_has_preemption(engine);
 }
 
+struct intel_context *
+intel_engine_create_virtual(struct intel_engine_cs **siblings,
+			    unsigned int count);
+
+static inline bool
+intel_virtual_engine_has_heartbeat(const struct intel_engine_cs *engine)
+{
+	/*
+	 * For non-GuC submission we expect the back-end to look at the
+	 * heartbeat status of the actual physical engine that the work
+	 * has been (or is being) scheduled on, so we should only reach
+	 * here with GuC submission enabled.
+	 */
+	GEM_BUG_ON(!intel_engine_uses_guc(engine));
+
+	return intel_guc_virtual_engine_has_heartbeat(engine);
+}
+
 static inline bool
 intel_engine_has_heartbeat(const struct intel_engine_cs *engine)
 {
 	if (!IS_ACTIVE(CONFIG_DRM_I915_HEARTBEAT_INTERVAL))
 		return false;
 
-	return READ_ONCE(engine->props.heartbeat_interval_ms);
+	if (intel_engine_is_virtual(engine))
+		return intel_virtual_engine_has_heartbeat(engine);
+	else
+		return READ_ONCE(engine->props.heartbeat_interval_ms);
+}
+
+static inline struct intel_engine_cs *
+intel_engine_get_sibling(struct intel_engine_cs *engine, unsigned int sibling)
+{
+	GEM_BUG_ON(!intel_engine_is_virtual(engine));
+	return engine->cops->get_sibling(engine, sibling);
 }
 
 #endif /* _INTEL_RINGBUFFER_H_ */

drivers/gpu/drm/i915/gt/intel_engine_cs.c

@@ -1796,6 +1796,20 @@ ktime_t intel_engine_get_busy_time(struct intel_engine_cs *engine, ktime_t *now)
 	return total;
 }
 
+struct intel_context *
+intel_engine_create_virtual(struct intel_engine_cs **siblings,
+			    unsigned int count)
+{
+	if (count == 0)
+		return ERR_PTR(-EINVAL);
+
+	if (count == 1)
+		return intel_context_create(siblings[0]);
+
+	GEM_BUG_ON(!siblings[0]->cops->create_virtual);
+	return siblings[0]->cops->create_virtual(siblings, count);
+}
+
 static bool match_ring(struct i915_request *rq)
 {
 	u32 ring = ENGINE_READ(rq->engine, RING_START);

drivers/gpu/drm/i915/gt/intel_execlists_submission.c

@@ -199,6 +199,9 @@ static struct virtual_engine *to_virtual_engine(struct intel_engine_cs *engine)
 	return container_of(engine, struct virtual_engine, base);
 }
 
+static struct intel_context *
+execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count);
+
 static struct i915_request *
 __active_request(const struct intel_timeline * const tl,
 		 struct i915_request *rq,
@@ -2599,6 +2602,8 @@ static const struct intel_context_ops execlists_context_ops = {
 
 	.reset = lrc_reset,
 	.destroy = lrc_destroy,
+
+	.create_virtual = execlists_create_virtual,
 };
 
 static int emit_pdps(struct i915_request *rq)
@@ -3549,6 +3554,17 @@ static void virtual_context_exit(struct intel_context *ce)
 		intel_engine_pm_put(ve->siblings[n]);
 }
 
+static struct intel_engine_cs *
+virtual_get_sibling(struct intel_engine_cs *engine, unsigned int sibling)
+{
+	struct virtual_engine *ve = to_virtual_engine(engine);
+
+	if (sibling >= ve->num_siblings)
+		return NULL;
+
+	return ve->siblings[sibling];
+}
+
 static const struct intel_context_ops virtual_context_ops = {
 	.flags = COPS_HAS_INFLIGHT,
 
@@ -3563,6 +3579,8 @@ static const struct intel_context_ops virtual_context_ops = {
 	.exit = virtual_context_exit,
 
 	.destroy = virtual_context_destroy,
+
+	.get_sibling = virtual_get_sibling,
 };
 
 static intel_engine_mask_t virtual_submission_mask(struct virtual_engine *ve)
@@ -3711,20 +3729,13 @@ static void virtual_submit_request(struct i915_request *rq)
 	spin_unlock_irqrestore(&ve->base.sched_engine->lock, flags);
 }
 
-struct intel_context *
-intel_execlists_create_virtual(struct intel_engine_cs **siblings,
-			       unsigned int count)
+static struct intel_context *
+execlists_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
 {
 	struct virtual_engine *ve;
 	unsigned int n;
 	int err;
 
-	if (count == 0)
-		return ERR_PTR(-EINVAL);
-
-	if (count == 1)
-		return intel_context_create(siblings[0]);
-
 	ve = kzalloc(struct_size(ve, siblings, count), GFP_KERNEL);
 	if (!ve)
 		return ERR_PTR(-ENOMEM);

drivers/gpu/drm/i915/gt/intel_execlists_submission.h

@@ -32,10 +32,6 @@ void intel_execlists_show_requests(struct intel_engine_cs *engine,
 							int indent),
 				   unsigned int max);
 
-struct intel_context *
-intel_execlists_create_virtual(struct intel_engine_cs **siblings,
-			       unsigned int count);
-
 bool
 intel_engine_in_execlists_submission_mode(const struct intel_engine_cs *engine);
 

drivers/gpu/drm/i915/gt/selftest_execlists.c

@@ -3733,7 +3733,7 @@ static int nop_virtual_engine(struct intel_gt *gt,
 	GEM_BUG_ON(!nctx || nctx > ARRAY_SIZE(ve));
 
 	for (n = 0; n < nctx; n++) {
-		ve[n] = intel_execlists_create_virtual(siblings, nsibling);
+		ve[n] = intel_engine_create_virtual(siblings, nsibling);
 		if (IS_ERR(ve[n])) {
 			err = PTR_ERR(ve[n]);
 			nctx = n;
@@ -3929,7 +3929,7 @@ static int mask_virtual_engine(struct intel_gt *gt,
 	 * restrict it to our desired engine within the virtual engine.
 	 */
 
-	ve = intel_execlists_create_virtual(siblings, nsibling);
+	ve = intel_engine_create_virtual(siblings, nsibling);
 	if (IS_ERR(ve)) {
 		err = PTR_ERR(ve);
 		goto out_close;
@@ -4060,7 +4060,7 @@ static int slicein_virtual_engine(struct intel_gt *gt,
 		i915_request_add(rq);
 	}
 
-	ce = intel_execlists_create_virtual(siblings, nsibling);
+	ce = intel_engine_create_virtual(siblings, nsibling);
 	if (IS_ERR(ce)) {
 		err = PTR_ERR(ce);
 		goto out;
@@ -4112,7 +4112,7 @@ static int sliceout_virtual_engine(struct intel_gt *gt,
 
 	/* XXX We do not handle oversubscription and fairness with normal rq */
 	for (n = 0; n < nsibling; n++) {
-		ce = intel_execlists_create_virtual(siblings, nsibling);
+		ce = intel_engine_create_virtual(siblings, nsibling);
 		if (IS_ERR(ce)) {
 			err = PTR_ERR(ce);
 			goto out;
@@ -4214,7 +4214,7 @@ static int preserved_virtual_engine(struct intel_gt *gt,
 	if (err)
 		goto out_scratch;
 
-	ve = intel_execlists_create_virtual(siblings, nsibling);
+	ve = intel_engine_create_virtual(siblings, nsibling);
 	if (IS_ERR(ve)) {
 		err = PTR_ERR(ve);
 		goto out_scratch;
@@ -4354,7 +4354,7 @@ static int reset_virtual_engine(struct intel_gt *gt,
 	if (igt_spinner_init(&spin, gt))
 		return -ENOMEM;
 
-	ve = intel_execlists_create_virtual(siblings, nsibling);
+	ve = intel_engine_create_virtual(siblings, nsibling);
 	if (IS_ERR(ve)) {
 		err = PTR_ERR(ve);
 		goto out_spin;

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

@@ -60,6 +60,15 @@
  *
  */
 
+/* GuC Virtual Engine */
+struct guc_virtual_engine {
+	struct intel_engine_cs base;
+	struct intel_context context;
+};
+
+static struct intel_context *
+guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count);
+
 #define GUC_REQUEST_SIZE 64 /* bytes */
 
 /*
@@ -931,14 +940,17 @@ static int guc_lrc_desc_pin(struct intel_context *ce)
 	return ret;
 }
 
-static int guc_context_pre_pin(struct intel_context *ce,
-			       struct i915_gem_ww_ctx *ww,
-			       void **vaddr)
+static int __guc_context_pre_pin(struct intel_context *ce,
+				 struct intel_engine_cs *engine,
+				 struct i915_gem_ww_ctx *ww,
+				 void **vaddr)
 {
-	return lrc_pre_pin(ce, ce->engine, ww, vaddr);
+	return lrc_pre_pin(ce, engine, ww, vaddr);
 }
 
-static int guc_context_pin(struct intel_context *ce, void *vaddr)
+static int __guc_context_pin(struct intel_context *ce,
+			     struct intel_engine_cs *engine,
+			     void *vaddr)
 {
 	if (i915_ggtt_offset(ce->state) !=
 	    (ce->lrc.lrca & CTX_GTT_ADDRESS_MASK))
@@ -949,7 +961,19 @@ static int guc_context_pin(struct intel_context *ce, void *vaddr)
 	 * explaination of why.
 	 */
 
-	return lrc_pin(ce, ce->engine, vaddr);
+	return lrc_pin(ce, engine, vaddr);
+}
+
+static int guc_context_pre_pin(struct intel_context *ce,
+			       struct i915_gem_ww_ctx *ww,
+			       void **vaddr)
+{
+	return __guc_context_pre_pin(ce, ce->engine, ww, vaddr);
+}
+
+static int guc_context_pin(struct intel_context *ce, void *vaddr)
+{
+	return __guc_context_pin(ce, ce->engine, vaddr);
 }
 
 static void guc_context_unpin(struct intel_context *ce)
@@ -1054,6 +1078,21 @@ static inline void guc_lrc_desc_unpin(struct intel_context *ce)
 	deregister_context(ce, ce->guc_id);
 }
 
+static void __guc_context_destroy(struct intel_context *ce)
+{
+	lrc_fini(ce);
+	intel_context_fini(ce);
+
+	if (intel_engine_is_virtual(ce->engine)) {
+		struct guc_virtual_engine *ve =
+			container_of(ce, typeof(*ve), context);
+
+		kfree(ve);
+	} else {
+		intel_context_free(ce);
+	}
+}
+
 static void guc_context_destroy(struct kref *kref)
 {
 	struct intel_context *ce = container_of(kref, typeof(*ce), ref);
@@ -1068,11 +1107,11 @@ static void guc_context_destroy(struct kref *kref)
 	 * registered with the GuC.
 	 */
 	if (context_guc_id_invalid(ce)) {
-		lrc_destroy(kref);
+		__guc_context_destroy(ce);
 		return;
 	} else if (!lrc_desc_registered(guc, ce->guc_id)) {
 		release_guc_id(guc, ce);
-		lrc_destroy(kref);
+		__guc_context_destroy(ce);
 		return;
 	}
 
@@ -1087,7 +1126,7 @@ static void guc_context_destroy(struct kref *kref)
 	spin_lock_irqsave(&guc->contexts_lock, flags);
 	if (context_guc_id_invalid(ce)) {
 		spin_unlock_irqrestore(&guc->contexts_lock, flags);
-		lrc_destroy(kref);
+		__guc_context_destroy(ce);
 		return;
 	}
 
@@ -1132,6 +1171,8 @@ static const struct intel_context_ops guc_context_ops = {
 
 	.reset = lrc_reset,
 	.destroy = guc_context_destroy,
+
+	.create_virtual = guc_create_virtual,
 };
 
 static void __guc_signal_context_fence(struct intel_context *ce)
@@ -1260,6 +1301,83 @@ static int guc_request_alloc(struct i915_request *rq)
 	return 0;
 }
 
+static struct intel_engine_cs *
+guc_virtual_get_sibling(struct intel_engine_cs *ve, unsigned int sibling)
+{
+	struct intel_engine_cs *engine;
+	intel_engine_mask_t tmp, mask = ve->mask;
+	unsigned int num_siblings = 0;
+
+	for_each_engine_masked(engine, ve->gt, mask, tmp)
+		if (num_siblings++ == sibling)
+			return engine;
+
+	return NULL;
+}
+
+static int guc_virtual_context_pre_pin(struct intel_context *ce,
+				       struct i915_gem_ww_ctx *ww,
+				       void **vaddr)
+{
+	struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
+
+	return __guc_context_pre_pin(ce, engine, ww, vaddr);
+}
+
+static int guc_virtual_context_pin(struct intel_context *ce, void *vaddr)
+{
+	struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
+
+	return __guc_context_pin(ce, engine, vaddr);
+}
+
+static void guc_virtual_context_enter(struct intel_context *ce)
+{
+	intel_engine_mask_t tmp, mask = ce->engine->mask;
+	struct intel_engine_cs *engine;
+
+	for_each_engine_masked(engine, ce->engine->gt, mask, tmp)
+		intel_engine_pm_get(engine);
+
+	intel_timeline_enter(ce->timeline);
+}
+
+static void guc_virtual_context_exit(struct intel_context *ce)
+{
+	intel_engine_mask_t tmp, mask = ce->engine->mask;
+	struct intel_engine_cs *engine;
+
+	for_each_engine_masked(engine, ce->engine->gt, mask, tmp)
+		intel_engine_pm_put(engine);
+
+	intel_timeline_exit(ce->timeline);
+}
+
+static int guc_virtual_context_alloc(struct intel_context *ce)
+{
+	struct intel_engine_cs *engine = guc_virtual_get_sibling(ce->engine, 0);
+
+	return lrc_alloc(ce, engine);
+}
+
+static const struct intel_context_ops virtual_guc_context_ops = {
+	.alloc = guc_virtual_context_alloc,
+
+	.pre_pin = guc_virtual_context_pre_pin,
+	.pin = guc_virtual_context_pin,
+	.unpin = guc_context_unpin,
+	.post_unpin = guc_context_post_unpin,
+
+	.enter = guc_virtual_context_enter,
+	.exit = guc_virtual_context_exit,
+
+	.sched_disable = guc_context_sched_disable,
+
+	.destroy = guc_context_destroy,
+
+	.get_sibling = guc_virtual_get_sibling,
+};
+
 static void sanitize_hwsp(struct intel_engine_cs *engine)
 {
 	struct intel_timeline *tl;
@@ -1566,7 +1684,7 @@ int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
 	} else if (context_destroyed(ce)) {
 		/* Context has been destroyed */
 		release_guc_id(guc, ce);
-		lrc_destroy(&ce->ref);
+		__guc_context_destroy(ce);
 	}
 
 	decr_outstanding_submission_g2h(guc);
@@ -1681,3 +1799,107 @@ void intel_guc_submission_print_context_info(struct intel_guc *guc,
 			   atomic_read(&ce->guc_sched_state_no_lock));
 	}
 }
+
+static struct intel_context *
+guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count)
+{
+	struct guc_virtual_engine *ve;
+	struct intel_guc *guc;
+	unsigned int n;
+	int err;
+
+	ve = kzalloc(sizeof(*ve), GFP_KERNEL);
+	if (!ve)
+		return ERR_PTR(-ENOMEM);
+
+	guc = &siblings[0]->gt->uc.guc;
+
+	ve->base.i915 = siblings[0]->i915;
+	ve->base.gt = siblings[0]->gt;
+	ve->base.uncore = siblings[0]->uncore;
+	ve->base.id = -1;
+
+	ve->base.uabi_class = I915_ENGINE_CLASS_INVALID;
+	ve->base.instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
+	ve->base.uabi_instance = I915_ENGINE_CLASS_INVALID_VIRTUAL;
+	ve->base.saturated = ALL_ENGINES;
+	ve->base.breadcrumbs = intel_breadcrumbs_create(&ve->base);
+	if (!ve->base.breadcrumbs) {
+		kfree(ve);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	snprintf(ve->base.name, sizeof(ve->base.name), "virtual");
+
+	ve->base.sched_engine = i915_sched_engine_get(guc->sched_engine);
+
+	ve->base.cops = &virtual_guc_context_ops;
+	ve->base.request_alloc = guc_request_alloc;
+
+	ve->base.submit_request = guc_submit_request;
+
+	ve->base.flags = I915_ENGINE_IS_VIRTUAL;
+
+	intel_context_init(&ve->context, &ve->base);
+
+	for (n = 0; n < count; n++) {
+		struct intel_engine_cs *sibling = siblings[n];
+
+		GEM_BUG_ON(!is_power_of_2(sibling->mask));
+		if (sibling->mask & ve->base.mask) {
+			DRM_DEBUG("duplicate %s entry in load balancer\n",
+				  sibling->name);
+			err = -EINVAL;
+			goto err_put;
+		}
+
+		ve->base.mask |= sibling->mask;
+
+		if (n != 0 && ve->base.class != sibling->class) {
+			DRM_DEBUG("invalid mixing of engine class, sibling %d, already %d\n",
+				  sibling->class, ve->base.class);
+			err = -EINVAL;
+			goto err_put;
+		} else if (n == 0) {
+			ve->base.class = sibling->class;
+			ve->base.uabi_class = sibling->uabi_class;
+			snprintf(ve->base.name, sizeof(ve->base.name),
+				 "v%dx%d", ve->base.class, count);
+			ve->base.context_size = sibling->context_size;
+
+			ve->base.emit_bb_start = sibling->emit_bb_start;
+			ve->base.emit_flush = sibling->emit_flush;
+			ve->base.emit_init_breadcrumb =
+				sibling->emit_init_breadcrumb;
+			ve->base.emit_fini_breadcrumb =
+				sibling->emit_fini_breadcrumb;
+			ve->base.emit_fini_breadcrumb_dw =
+				sibling->emit_fini_breadcrumb_dw;
+
+			ve->base.flags |= sibling->flags;
+
+			ve->base.props.timeslice_duration_ms =
+				sibling->props.timeslice_duration_ms;
+			ve->base.props.preempt_timeout_ms =
+				sibling->props.preempt_timeout_ms;
+		}
+	}
+
+	return &ve->context;
+
+err_put:
+	intel_context_put(&ve->context);
+	return ERR_PTR(err);
+}
+
+bool intel_guc_virtual_engine_has_heartbeat(const struct intel_engine_cs *ve)
+{
+	struct intel_engine_cs *engine;
+	intel_engine_mask_t tmp, mask = ve->mask;
+
+	for_each_engine_masked(engine, ve->gt, mask, tmp)
+		if (READ_ONCE(engine->props.heartbeat_interval_ms))
+			return true;
+
+	return false;
+}

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.h

@@ -26,6 +26,8 @@ void intel_guc_submission_print_info(struct intel_guc *guc,
 void intel_guc_submission_print_context_info(struct intel_guc *guc,
 					     struct drm_printer *p);
 
+bool intel_guc_virtual_engine_has_heartbeat(const struct intel_engine_cs *ve);
+
 static inline bool intel_guc_submission_is_supported(struct intel_guc *guc)
 {
 	/* XXX: GuC submission is unavailable for now */