From 5f8e7a6cb7e1d55c7c169804be7c7d292fd1fb9c Mon Sep 17 00:00:00 2001
From: Shuo A Liu <shuo.a.liu@intel.com>
Date: Tue, 18 Jun 2019 17:49:56 +0800
Subject: [PATCH] hv: sched: add kick_thread to support notification

kick means to notify one thread_object. If the target thread object is
running, send a IPI to notify it; if the target thread object is
runnable, make reschedule on it.

Also add kick_vcpu API in vcpu layer to notify vcpu.

Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
---
 hypervisor/arch/x86/guest/vcpu.c         |  5 +++++
 hypervisor/arch/x86/guest/virq.c         | 15 +--------------
 hypervisor/common/schedule.c             | 18 ++++++++++++++++++
 hypervisor/include/arch/x86/guest/vcpu.h | 11 +++++++++++
 hypervisor/include/common/schedule.h     |  1 +
 5 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/hypervisor/arch/x86/guest/vcpu.c b/hypervisor/arch/x86/guest/vcpu.c
index 9980cd907..b86f53347 100644
--- a/hypervisor/arch/x86/guest/vcpu.c
+++ b/hypervisor/arch/x86/guest/vcpu.c
@@ -598,6 +598,11 @@ void offline_vcpu(struct acrn_vcpu *vcpu)
 	vcpu->state = VCPU_OFFLINE;
 }
 
+void kick_vcpu(const struct acrn_vcpu *vcpu)
+{
+	kick_thread(&vcpu->thread_obj);
+}
+
 /*
 * @pre (&vcpu->stack[CONFIG_STACK_SIZE] & (CPU_STACK_ALIGN - 1UL)) == 0
 */
diff --git a/hypervisor/arch/x86/guest/virq.c b/hypervisor/arch/x86/guest/virq.c
index ee119c609..603585345 100644
--- a/hypervisor/arch/x86/guest/virq.c
+++ b/hypervisor/arch/x86/guest/virq.c
@@ -106,21 +106,8 @@ static bool is_guest_irq_enabled(struct acrn_vcpu *vcpu)
 
 void vcpu_make_request(struct acrn_vcpu *vcpu, uint16_t eventid)
 {
-	uint16_t pcpu_id = pcpuid_from_vcpu(vcpu);
-
 	bitmap_set_lock(eventid, &vcpu->arch.pending_req);
-	/*
-	 * if current hostcpu is not the target vcpu's hostcpu, we need
-	 * to invoke IPI to wake up target vcpu
-	 *
-	 * TODO: Here we just compare with cpuid, since cpuid currently is
-	 *  global under pCPU / vCPU 1:1 mapping. If later we enabled vcpu
-	 *  scheduling, we need change here to determine it target vcpu is
-	 *  VMX non-root or root mode
-	 */
-	if (get_pcpu_id() != pcpu_id) {
-		send_single_ipi(pcpu_id, VECTOR_NOTIFY_VCPU);
-	}
+	kick_vcpu(vcpu);
 }
 
 /*
diff --git a/hypervisor/common/schedule.c b/hypervisor/common/schedule.c
index e3addc3b0..847bafd03 100644
--- a/hypervisor/common/schedule.c
+++ b/hypervisor/common/schedule.c
@@ -222,6 +222,24 @@ void wake_thread(struct thread_object *obj)
 	release_schedule_lock(pcpu_id, rflag);
 }
 
+void kick_thread(const struct thread_object *obj)
+{
+	uint16_t pcpu_id = obj->pcpu_id;
+	uint64_t rflag;
+
+	obtain_schedule_lock(pcpu_id, &rflag);
+	if (is_running(obj)) {
+		if (get_pcpu_id() != pcpu_id) {
+			send_single_ipi(pcpu_id, VECTOR_NOTIFY_VCPU);
+		}
+	} else if (is_runnable(obj)) {
+		make_reschedule_request(pcpu_id, DEL_MODE_IPI);
+	} else {
+		/* do nothing */
+	}
+	release_schedule_lock(pcpu_id, rflag);
+}
+
 void run_thread(struct thread_object *obj)
 {
 	uint64_t rflag;
diff --git a/hypervisor/include/arch/x86/guest/vcpu.h b/hypervisor/include/arch/x86/guest/vcpu.h
index cee27e0b7..3d5578f81 100644
--- a/hypervisor/include/arch/x86/guest/vcpu.h
+++ b/hypervisor/include/arch/x86/guest/vcpu.h
@@ -636,6 +636,17 @@ void resume_vcpu(struct acrn_vcpu *vcpu);
  */
 void launch_vcpu(struct acrn_vcpu *vcpu);
 
+/**
+ * @brief kick the vcpu and let it handle pending events
+ *
+ * Kick a vCPU to handle the pending events.
+ *
+ * @param[in] vcpu pointer to vcpu data structure
+ *
+ * @return None
+ */
+void kick_vcpu(const struct acrn_vcpu *vcpu);
+
 /**
  * @brief create a vcpu for the vm and mapped to the pcpu.
  *
diff --git a/hypervisor/include/common/schedule.h b/hypervisor/include/common/schedule.h
index 4a3b39f4d..808beacca 100644
--- a/hypervisor/include/common/schedule.h
+++ b/hypervisor/include/common/schedule.h
@@ -100,6 +100,7 @@ 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 kick_thread(const struct thread_object *obj);
 void schedule(void);
 
 void arch_switch_to(void *prev_sp, void *next_sp);