drm/i915/gvt: vGPU schedule policy framework

This patch introduces a vGPU schedule policy framework, with a timer based
schedule policy module for now

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/Makefile

@@ -1,7 +1,7 @@
 GVT_DIR := gvt
 GVT_SOURCE := gvt.o aperture_gm.o handlers.o vgpu.o trace_points.o firmware.o \
 	interrupt.o gtt.o cfg_space.o opregion.o mmio.o display.o edid.o \
-	execlist.o scheduler.o
+	execlist.o scheduler.o sched_policy.o
 
 ccflags-y                      += -I$(src) -I$(src)/$(GVT_DIR) -Wall
 i915-y			       += $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))

drivers/gpu/drm/i915/gvt/gvt.c

@@ -177,6 +177,7 @@ void intel_gvt_clean_device(struct drm_i915_private *dev_priv)
 		return;
 
 	clean_service_thread(gvt);
+	intel_gvt_clean_sched_policy(gvt);
 	intel_gvt_clean_workload_scheduler(gvt);
 	intel_gvt_clean_opregion(gvt);
 	intel_gvt_clean_gtt(gvt);
@@ -244,14 +245,20 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv)
 	if (ret)
 		goto out_clean_opregion;
 
-	ret = init_service_thread(gvt);
+	ret = intel_gvt_init_sched_policy(gvt);
 	if (ret)
 		goto out_clean_workload_scheduler;
 
+	ret = init_service_thread(gvt);
+	if (ret)
+		goto out_clean_sched_policy;
+
 	gvt_dbg_core("gvt device creation is done\n");
 	gvt->initialized = true;
 	return 0;
 
+out_clean_sched_policy:
+	intel_gvt_clean_sched_policy(gvt);
 out_clean_workload_scheduler:
 	intel_gvt_clean_workload_scheduler(gvt);
 out_clean_opregion:

drivers/gpu/drm/i915/gvt/gvt.h

@@ -43,6 +43,7 @@
 #include "edid.h"
 #include "execlist.h"
 #include "scheduler.h"
+#include "sched_policy.h"
 
 #define GVT_MAX_VGPU 8
 
@@ -139,6 +140,7 @@ struct intel_vgpu {
 	unsigned long handle; /* vGPU handle used by hypervisor MPT modules */
 	bool active;
 	bool resetting;
+	void *sched_data;
 
 	struct intel_vgpu_fence fence;
 	struct intel_vgpu_gm gm;

drivers/gpu/drm/i915/gvt/handlers.c

@@ -235,6 +235,7 @@ static int handle_device_reset(struct intel_vgpu *vgpu, unsigned int offset,
 
 	vgpu->resetting = true;
 
+	intel_vgpu_stop_schedule(vgpu);
 	if (scheduler->current_vgpu == vgpu) {
 		mutex_unlock(&vgpu->gvt->lock);
 		intel_gvt_wait_vgpu_idle(vgpu);
@@ -1317,6 +1318,28 @@ static int elsp_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
 	return 0;
 }
 
+static int ring_mode_mmio_write(struct intel_vgpu *vgpu, unsigned int offset,
+		void *p_data, unsigned int bytes)
+{
+	u32 data = *(u32 *)p_data;
+	int ring_id = render_mmio_to_ring_id(vgpu->gvt, offset);
+	bool enable_execlist;
+
+	write_vreg(vgpu, offset, p_data, bytes);
+	if ((data & _MASKED_BIT_ENABLE(GFX_RUN_LIST_ENABLE))
+			|| (data & _MASKED_BIT_DISABLE(GFX_RUN_LIST_ENABLE))) {
+		enable_execlist = !!(data & GFX_RUN_LIST_ENABLE);
+
+		gvt_dbg_core("EXECLIST %s on ring %d\n",
+				(enable_execlist ? "enabling" : "disabling"),
+				ring_id);
+
+		if (enable_execlist)
+			intel_vgpu_start_schedule(vgpu);
+	}
+	return 0;
+}
+
 #define MMIO_F(reg, s, f, am, rm, d, r, w) do { \
 	ret = new_mmio_info(gvt, INTEL_GVT_MMIO_OFFSET(reg), \
 		f, s, am, rm, d, r, w); \
@@ -1398,7 +1421,7 @@ static int init_generic_mmio_info(struct intel_gvt *gvt)
 
 	/* RING MODE */
 #define RING_REG(base) (base + 0x29c)
-	MMIO_RING_DFH(RING_REG, D_ALL, F_MODE_MASK, NULL, NULL);
+	MMIO_RING_DFH(RING_REG, D_ALL, F_MODE_MASK, NULL, ring_mode_mmio_write);
 #undef RING_REG
 
 	MMIO_RING_DFH(RING_MI_MODE, D_ALL, F_MODE_MASK, NULL, NULL);
@@ -2213,7 +2236,7 @@ static int init_broadwell_mmio_info(struct intel_gvt *gvt)
 	MMIO_D(RING_CTL(GEN8_BSD2_RING_BASE), D_BDW_PLUS);
 	MMIO_D(RING_ACTHD(GEN8_BSD2_RING_BASE), D_BDW_PLUS);
 	MMIO_D(RING_ACTHD_UDW(GEN8_BSD2_RING_BASE), D_BDW_PLUS);
-	MMIO_DFH(0x1c29c, D_BDW_PLUS, F_MODE_MASK, NULL, NULL);
+	MMIO_DFH(0x1c29c, D_BDW_PLUS, F_MODE_MASK, NULL, ring_mode_mmio_write);
 	MMIO_DFH(RING_MI_MODE(GEN8_BSD2_RING_BASE), D_BDW_PLUS, F_MODE_MASK,
 			NULL, NULL);
 	MMIO_DFH(RING_INSTPM(GEN8_BSD2_RING_BASE), D_BDW_PLUS, F_MODE_MASK,

drivers/gpu/drm/i915/gvt/sched_policy.c

@@ -0,0 +1,291 @@
+/*
+ * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Anhua Xu
+ *    Kevin Tian <kevin.tian@intel.com>
+ *
+ * Contributors:
+ *    Min He <min.he@intel.com>
+ *    Bing Niu <bing.niu@intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ */
+
+#include "i915_drv.h"
+
+static bool vgpu_has_pending_workload(struct intel_vgpu *vgpu)
+{
+	struct intel_vgpu_execlist *execlist;
+	int i;
+
+	for (i = 0; i < I915_NUM_ENGINES; i++) {
+		execlist = &vgpu->execlist[i];
+		if (!list_empty(workload_q_head(vgpu, i)))
+			return true;
+	}
+
+	return false;
+}
+
+static void try_to_schedule_next_vgpu(struct intel_gvt *gvt)
+{
+	struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
+	int i;
+
+	/* no target to schedule */
+	if (!scheduler->next_vgpu)
+		return;
+
+	gvt_dbg_sched("try to schedule next vgpu %d\n",
+			scheduler->next_vgpu->id);
+
+	/*
+	 * after the flag is set, workload dispatch thread will
+	 * stop dispatching workload for current vgpu
+	 */
+	scheduler->need_reschedule = true;
+
+	/* still have uncompleted workload? */
+	for (i = 0; i < I915_NUM_ENGINES; i++) {
+		if (scheduler->current_workload[i]) {
+			gvt_dbg_sched("still have running workload\n");
+			return;
+		}
+	}
+
+	gvt_dbg_sched("switch to next vgpu %d\n",
+			scheduler->next_vgpu->id);
+
+	/* switch current vgpu */
+	scheduler->current_vgpu = scheduler->next_vgpu;
+	scheduler->next_vgpu = NULL;
+
+	scheduler->need_reschedule = false;
+
+	/* wake up workload dispatch thread */
+	for (i = 0; i < I915_NUM_ENGINES; i++)
+		wake_up(&scheduler->waitq[i]);
+}
+
+struct tbs_vgpu_data {
+	struct list_head list;
+	struct intel_vgpu *vgpu;
+	/* put some per-vgpu sched stats here */
+};
+
+struct tbs_sched_data {
+	struct intel_gvt *gvt;
+	struct delayed_work work;
+	unsigned long period;
+	struct list_head runq_head;
+};
+
+#define GVT_DEFAULT_TIME_SLICE (1 * HZ / 1000)
+
+static void tbs_sched_func(struct work_struct *work)
+{
+	struct tbs_sched_data *sched_data = container_of(work,
+			struct tbs_sched_data, work.work);
+	struct tbs_vgpu_data *vgpu_data;
+
+	struct intel_gvt *gvt = sched_data->gvt;
+	struct intel_gvt_workload_scheduler *scheduler = &gvt->scheduler;
+
+	struct intel_vgpu *vgpu = NULL;
+	struct list_head *pos, *head;
+
+	mutex_lock(&gvt->lock);
+
+	/* no vgpu or has already had a target */
+	if (list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
+		goto out;
+
+	if (scheduler->current_vgpu) {
+		vgpu_data = scheduler->current_vgpu->sched_data;
+		head = &vgpu_data->list;
+	} else {
+		gvt_dbg_sched("no current vgpu search from q head\n");
+		head = &sched_data->runq_head;
+	}
+
+	/* search a vgpu with pending workload */
+	list_for_each(pos, head) {
+		if (pos == &sched_data->runq_head)
+			continue;
+
+		vgpu_data = container_of(pos, struct tbs_vgpu_data, list);
+		if (!vgpu_has_pending_workload(vgpu_data->vgpu))
+			continue;
+
+		vgpu = vgpu_data->vgpu;
+		break;
+	}
+
+	if (vgpu) {
+		scheduler->next_vgpu = vgpu;
+		gvt_dbg_sched("pick next vgpu %d\n", vgpu->id);
+	}
+out:
+	if (scheduler->next_vgpu) {
+		gvt_dbg_sched("try to schedule next vgpu %d\n",
+				scheduler->next_vgpu->id);
+		try_to_schedule_next_vgpu(gvt);
+	}
+
+	/*
+	 * still have vgpu on runq
+	 * or last schedule haven't finished due to running workload
+	 */
+	if (!list_empty(&sched_data->runq_head) || scheduler->next_vgpu)
+		schedule_delayed_work(&sched_data->work, sched_data->period);
+
+	mutex_unlock(&gvt->lock);
+}
+
+static int tbs_sched_init(struct intel_gvt *gvt)
+{
+	struct intel_gvt_workload_scheduler *scheduler =
+		&gvt->scheduler;
+
+	struct tbs_sched_data *data;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&data->runq_head);
+	INIT_DELAYED_WORK(&data->work, tbs_sched_func);
+	data->period = GVT_DEFAULT_TIME_SLICE;
+	data->gvt = gvt;
+
+	scheduler->sched_data = data;
+	return 0;
+}
+
+static void tbs_sched_clean(struct intel_gvt *gvt)
+{
+	struct intel_gvt_workload_scheduler *scheduler =
+		&gvt->scheduler;
+	struct tbs_sched_data *data = scheduler->sched_data;
+
+	cancel_delayed_work(&data->work);
+	kfree(data);
+	scheduler->sched_data = NULL;
+}
+
+static int tbs_sched_init_vgpu(struct intel_vgpu *vgpu)
+{
+	struct tbs_vgpu_data *data;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->vgpu = vgpu;
+	INIT_LIST_HEAD(&data->list);
+
+	vgpu->sched_data = data;
+	return 0;
+}
+
+static void tbs_sched_clean_vgpu(struct intel_vgpu *vgpu)
+{
+	kfree(vgpu->sched_data);
+	vgpu->sched_data = NULL;
+}
+
+static void tbs_sched_start_schedule(struct intel_vgpu *vgpu)
+{
+	struct tbs_sched_data *sched_data = vgpu->gvt->scheduler.sched_data;
+	struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
+
+	if (!list_empty(&vgpu_data->list))
+		return;
+
+	list_add_tail(&vgpu_data->list, &sched_data->runq_head);
+	schedule_delayed_work(&sched_data->work, sched_data->period);
+}
+
+static void tbs_sched_stop_schedule(struct intel_vgpu *vgpu)
+{
+	struct tbs_vgpu_data *vgpu_data = vgpu->sched_data;
+
+	list_del_init(&vgpu_data->list);
+}
+
+struct intel_gvt_sched_policy_ops tbs_schedule_ops = {
+	.init = tbs_sched_init,
+	.clean = tbs_sched_clean,
+	.init_vgpu = tbs_sched_init_vgpu,
+	.clean_vgpu = tbs_sched_clean_vgpu,
+	.start_schedule = tbs_sched_start_schedule,
+	.stop_schedule = tbs_sched_stop_schedule,
+};
+
+int intel_gvt_init_sched_policy(struct intel_gvt *gvt)
+{
+	gvt->scheduler.sched_ops = &tbs_schedule_ops;
+
+	return gvt->scheduler.sched_ops->init(gvt);
+}
+
+void intel_gvt_clean_sched_policy(struct intel_gvt *gvt)
+{
+	gvt->scheduler.sched_ops->clean(gvt);
+}
+
+int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu)
+{
+	return vgpu->gvt->scheduler.sched_ops->init_vgpu(vgpu);
+}
+
+void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu)
+{
+	vgpu->gvt->scheduler.sched_ops->clean_vgpu(vgpu);
+}
+
+void intel_vgpu_start_schedule(struct intel_vgpu *vgpu)
+{
+	gvt_dbg_core("vgpu%d: start schedule\n", vgpu->id);
+
+	vgpu->gvt->scheduler.sched_ops->start_schedule(vgpu);
+}
+
+void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu)
+{
+	struct intel_gvt_workload_scheduler *scheduler =
+		&vgpu->gvt->scheduler;
+
+	gvt_dbg_core("vgpu%d: stop schedule\n", vgpu->id);
+
+	scheduler->sched_ops->stop_schedule(vgpu);
+
+	if (scheduler->next_vgpu == vgpu)
+		scheduler->next_vgpu = NULL;
+
+	if (scheduler->current_vgpu == vgpu) {
+		/* stop workload dispatching */
+		scheduler->need_reschedule = true;
+		scheduler->current_vgpu = NULL;
+	}
+}

drivers/gpu/drm/i915/gvt/sched_policy.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Authors:
+ *    Anhua Xu
+ *    Kevin Tian <kevin.tian@intel.com>
+ *
+ * Contributors:
+ *    Min He <min.he@intel.com>
+ *    Bing Niu <bing.niu@intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ */
+
+#ifndef __GVT_SCHED_POLICY__
+#define __GVT_SCHED_POLICY__
+
+struct intel_gvt_sched_policy_ops {
+	int (*init)(struct intel_gvt *gvt);
+	void (*clean)(struct intel_gvt *gvt);
+	int (*init_vgpu)(struct intel_vgpu *vgpu);
+	void (*clean_vgpu)(struct intel_vgpu *vgpu);
+	void (*start_schedule)(struct intel_vgpu *vgpu);
+	void (*stop_schedule)(struct intel_vgpu *vgpu);
+};
+
+int intel_gvt_init_sched_policy(struct intel_gvt *gvt);
+
+void intel_gvt_clean_sched_policy(struct intel_gvt *gvt);
+
+int intel_vgpu_init_sched_policy(struct intel_vgpu *vgpu);
+
+void intel_vgpu_clean_sched_policy(struct intel_vgpu *vgpu);
+
+void intel_vgpu_start_schedule(struct intel_vgpu *vgpu);
+
+void intel_vgpu_stop_schedule(struct intel_vgpu *vgpu);
+
+#endif

drivers/gpu/drm/i915/gvt/scheduler.h

@@ -45,6 +45,9 @@ struct intel_gvt_workload_scheduler {
 	wait_queue_head_t workload_complete_wq;
 	struct task_struct *thread[I915_NUM_ENGINES];
 	wait_queue_head_t waitq[I915_NUM_ENGINES];
+
+	void *sched_data;
+	struct intel_gvt_sched_policy_ops *sched_ops;
 };
 
 struct intel_vgpu_workload {

drivers/gpu/drm/i915/gvt/vgpu.c

@@ -146,6 +146,14 @@ void intel_gvt_destroy_vgpu(struct intel_vgpu *vgpu)
 	vgpu->active = false;
 	idr_remove(&gvt->vgpu_idr, vgpu->id);
 
+	if (atomic_read(&vgpu->running_workload_num)) {
+		mutex_unlock(&gvt->lock);
+		intel_gvt_wait_vgpu_idle(vgpu);
+		mutex_lock(&gvt->lock);
+	}
+
+	intel_vgpu_stop_schedule(vgpu);
+	intel_vgpu_clean_sched_policy(vgpu);
 	intel_vgpu_clean_gvt_context(vgpu);
 	intel_vgpu_clean_execlist(vgpu);
 	intel_vgpu_clean_display(vgpu);
@@ -231,11 +239,17 @@ struct intel_vgpu *intel_gvt_create_vgpu(struct intel_gvt *gvt,
 	if (ret)
 		goto out_clean_execlist;
 
+	ret = intel_vgpu_init_sched_policy(vgpu);
+	if (ret)
+		goto out_clean_shadow_ctx;
+
 	vgpu->active = true;
 	mutex_unlock(&gvt->lock);
 
 	return vgpu;
 
+out_clean_shadow_ctx:
+	intel_vgpu_clean_gvt_context(vgpu);
 out_clean_execlist:
 	intel_vgpu_clean_execlist(vgpu);
 out_clean_display: