From a38f2cc91837f6c938bd3bf8420dc263a13f07ac Mon Sep 17 00:00:00 2001
From: Conghui Chen <conghui.chen@intel.com>
Date: Mon, 10 Feb 2020 13:55:35 +0000
Subject: [PATCH] hv: sched_bvt: add wakeup and sleep handler

In the wakeup handler, the vcpu_thread object will be inserted into the
runqueue, and in the sleep handler, it will be removed from the queue.
vcpu_thread object is ordered by EVT (effective virtual time).

Tracked-On: #4410

Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
---
 hypervisor/common/sched_bvt.c | 100 +++++++++++++++++++++++++++++++++-
 1 file changed, 98 insertions(+), 2 deletions(-)

diff --git a/hypervisor/common/sched_bvt.c b/hypervisor/common/sched_bvt.c
index 2746ddcfc..330ca07b3 100644
--- a/hypervisor/common/sched_bvt.c
+++ b/hypervisor/common/sched_bvt.c
@@ -30,6 +30,88 @@ struct sched_bvt_data {
 	uint64_t start_tsc;
 };
 
+/*
+ * @pre obj != NULL
+ * @pre obj->data != NULL
+ */
+static bool is_inqueue(struct thread_object *obj)
+{
+	struct sched_bvt_data *data = (struct sched_bvt_data *)obj->data;
+	return !list_empty(&data->list);
+}
+
+/*
+ * @pre obj != NULL
+ * @pre obj->data != NULL
+ * @pre obj->sched_ctl != NULL
+ * @pre obj->sched_ctl->priv != NULL
+ */
+static void runqueue_add(struct thread_object *obj)
+{
+	struct sched_bvt_control *bvt_ctl =
+		(struct sched_bvt_control *)obj->sched_ctl->priv;
+	struct sched_bvt_data *data = (struct sched_bvt_data *)obj->data;
+	struct list_head *pos;
+	struct thread_object *iter_obj;
+	struct sched_bvt_data *iter_data;
+
+	/*
+	 * the earliest evt has highest priority,
+	 * the runqueue is ordered by priority.
+	 */
+
+	if (list_empty(&bvt_ctl->runqueue)) {
+		list_add(&data->list, &bvt_ctl->runqueue);
+	} else {
+		list_for_each(pos, &bvt_ctl->runqueue) {
+			iter_obj = list_entry(pos, struct thread_object, data);
+			iter_data = (struct sched_bvt_data *)iter_obj->data;
+			if (iter_data->evt > data->evt) {
+				list_add_node(&data->list, pos->prev, pos);
+				break;
+			}
+		}
+		if (!is_inqueue(obj)) {
+			list_add_tail(&data->list, &bvt_ctl->runqueue);
+		}
+	}
+}
+
+/*
+ * @pre obj != NULL
+ * @pre obj->data != NULL
+ */
+static void runqueue_remove(struct thread_object *obj)
+{
+	struct sched_bvt_data *data = (struct sched_bvt_data *)obj->data;
+
+	list_del_init(&data->list);
+}
+
+/*
+ * @brief Get the SVT (scheduler virtual time) which indicates the
+ * minimum AVT of any runnable threads.
+ * @pre obj != NULL
+ * @pre obj->data != NULL
+ * @pre obj->sched_ctl != NULL
+ * @pre obj->sched_ctl->priv != NULL
+ */
+
+static int64_t get_svt(struct thread_object *obj)
+{
+	struct sched_bvt_control *bvt_ctl = (struct sched_bvt_control *)obj->sched_ctl->priv;
+	struct sched_bvt_data *obj_data;
+	struct thread_object *tmp_obj;
+	int64_t svt = 0;
+
+	if (!list_empty(&bvt_ctl->runqueue)) {
+		tmp_obj = get_first_item(&bvt_ctl->runqueue, struct thread_object, data);
+		obj_data = (struct sched_bvt_data *)tmp_obj->data;
+		svt = obj_data->avt;
+	}
+	return svt;
+}
+
 static void sched_tick_handler(__unused void *param)
 {
 }
@@ -83,12 +165,26 @@ static struct thread_object *sched_bvt_pick_next(__unused struct sched_control *
 	return NULL;
 }
 
-static void sched_bvt_sleep(__unused struct thread_object *obj)
+static void sched_bvt_sleep(struct thread_object *obj)
 {
+	runqueue_remove(obj);
 }
 
-static void sched_bvt_wake(__unused struct thread_object *obj)
+static void sched_bvt_wake(struct thread_object *obj)
 {
+	struct sched_bvt_data *data;
+	int64_t svt, threshold;
+
+	data = (struct sched_bvt_data *)obj->data;
+	svt = get_svt(obj);
+	threshold = svt - BVT_CSA_MCU;
+	/* adjusting AVT for a thread after a long sleep */
+	data->avt = (data->avt > threshold) ? data->avt : svt;
+	/* TODO: evt = avt - (warp ? warpback : 0U) */
+	data->evt = data->avt;
+	/* add to runqueue in order */
+	runqueue_add(obj);
+
 }
 
 struct acrn_scheduler sched_bvt = {