hv: sched: decouple idle stuff from schedule module

Let init thread end with run_idle_thread(), then idle thread take over and
start to do scheduling.
Change enter_guest_mode() to init_guest_mode() as run_idle_thread() is removed
out of it. Also add run_thread() in schedule module to run
thread_object's thread loop directly.

rename: switch_to_idle -> run_idle_thread

Tracked-On: #3813
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>

Author: Shuo A Liu

hypervisor/arch/x86/guest/vcpu.c

@@ -611,7 +611,7 @@ static uint64_t build_stack_frame(struct acrn_vcpu *vcpu)
 	frame -= 1;
 
 	frame->magic = SP_BOTTOM_MAGIC;
-	frame->rip = (uint64_t)run_sched_thread; /*return address*/
+	frame->rip = (uint64_t)vcpu->thread_obj.thread_entry; /*return address*/
 	frame->rflag = 0UL;
 	frame->rbx = 0UL;
 	frame->rbp = 0UL;

hypervisor/arch/x86/init.c

@@ -49,16 +49,11 @@ static void init_debug_post(uint16_t pcpu_id)
 }
 
 /*TODO: move into guest-vcpu module */
-static void enter_guest_mode(uint16_t pcpu_id)
+static void init_guest_mode(uint16_t pcpu_id)
 {
 	vmx_on();
 
 	launch_vms(pcpu_id);
-
-	switch_to_idle(default_idle);
-
-	/* Control should not come here */
-	cpu_dead();
 }
 
 static void init_primary_pcpu_post(void)
@@ -71,7 +66,9 @@ static void init_primary_pcpu_post(void)
 
 	init_debug_post(BOOT_CPU_ID);
 
-	enter_guest_mode(BOOT_CPU_ID);
+	init_guest_mode(BOOT_CPU_ID);
+
+	run_idle_thread();
 }
 
 /* NOTE: this function is using temp stack, and after SWITCH_TO(runtime_sp, to)
@@ -101,5 +98,7 @@ void init_secondary_pcpu(void)
 
 	init_debug_post(pcpu_id);
 
-	enter_guest_mode(pcpu_id);
+	init_guest_mode(pcpu_id);
+
+	run_idle_thread();
 }

hypervisor/common/hv_main.c

@@ -11,6 +11,7 @@
 #include <irq.h>
 #include <schedule.h>
 #include <profiling.h>
+#include <sprintf.h>
 #include <trace.h>
 #include <logmsg.h>
 
@@ -90,3 +91,22 @@ void default_idle(__unused struct thread_object *obj)
 		}
 	}
 }
+
+void run_idle_thread(void)
+{
+	uint16_t pcpu_id = get_pcpu_id();
+	struct thread_object *idle = &per_cpu(idle, pcpu_id);
+	char idle_name[16];
+
+	snprintf(idle_name, 16U, "idle%hu", pcpu_id);
+	(void)strncpy_s(idle->name, 16U, idle_name, 16U);
+	idle->pcpu_id = pcpu_id;
+	idle->thread_entry = default_idle;
+	idle->switch_out = NULL;
+	idle->switch_in = NULL;
+
+	run_thread(idle);
+
+	/* Control should not come here */
+	cpu_dead();
+}

hypervisor/common/schedule.c

@@ -194,29 +194,14 @@ void wake_thread(struct thread_object *obj)
 	release_schedule_lock(pcpu_id);
 }
 
-void run_sched_thread(struct thread_object *obj)
+void run_thread(struct thread_object *obj)
 {
+	get_schedule_lock(obj->pcpu_id);
+	get_cpu_var(sched_ctl).curr_obj = obj;
+	set_thread_status(obj, THREAD_STS_RUNNING);
+	release_schedule_lock(obj->pcpu_id);
+
 	if (obj->thread_entry != NULL) {
 		obj->thread_entry(obj);
 	}
-
-	ASSERT(false, "Shouldn't go here, invalid thread entry!");
-}
-
-void switch_to_idle(thread_entry_t idle_thread)
-{
-	uint16_t pcpu_id = get_pcpu_id();
-	struct thread_object *idle = &per_cpu(idle, pcpu_id);
-	char idle_name[16];
-
-	snprintf(idle_name, 16U, "idle%hu", pcpu_id);
-	(void)strncpy_s(idle->name, 16U, idle_name, 16U);
-	idle->pcpu_id = pcpu_id;
-	idle->thread_entry = idle_thread;
-	idle->switch_out = NULL;
-	idle->switch_in = NULL;
-	get_cpu_var(sched_ctl).curr_obj = idle;
-	set_thread_status(idle, THREAD_STS_RUNNING);
-
-	run_sched_thread(idle);
 }

hypervisor/include/common/schedule.h

@@ -53,7 +53,6 @@ uint16_t sched_get_pcpuid(const struct thread_object *obj);
 struct thread_object *sched_get_current(uint16_t pcpu_id);
 
 void init_sched(uint16_t pcpu_id);
-void switch_to_idle(thread_entry_t idle_thread);
 void get_schedule_lock(uint16_t pcpu_id);
 void release_schedule_lock(uint16_t pcpu_id);
 
@@ -63,11 +62,12 @@ void remove_thread_obj(struct thread_object *obj, uint16_t pcpu_id);
 void make_reschedule_request(uint16_t pcpu_id, uint16_t delmode);
 bool need_reschedule(uint16_t pcpu_id);
 
+void run_thread(struct thread_object *obj);
 void sleep_thread(struct thread_object *obj);
 void wake_thread(struct thread_object *obj);
 void schedule(void);
-void run_sched_thread(struct thread_object *obj);
 
 void arch_switch_to(void *prev_sp, void *next_sp);
+void run_idle_thread(void);
 #endif /* SCHEDULE_H */