dm: vm_event: create vm_event thread

This patch creates a thread for vm_event delivery. The thread uses epoll
to poll event notifications, then read out the msg data queued in sbuf.
An event handler is called upon success receiving. Both HV and DM event
sources share the same process.

Also vm_event tx API for DM event source is added in this patch.

Tracked-On: #8547
Signed-off-by: Wu Zhou <wu.zhou@intel.com>
Reviewed-by: Jian Jun Chen <jian.jun.chen@intel.com>

devicemodel/core/vm_event.c

@@ -34,6 +34,9 @@ static int epoll_fd;
 static bool started = false;
 static char hv_vm_event_page[4096] __aligned(4096);
 static char dm_vm_event_page[4096] __aligned(4096);
+static pthread_t vm_event_tid;
+
+static void general_event_handler(struct vmctx *ctx, struct vm_event *event);
 
 enum event_source_type {
 	EVENT_SOURCE_TYPE_HV,
@@ -49,6 +52,78 @@ struct vm_event_tunnel {
 	bool enabled;
 };
 
+struct vm_event_proc {
+	vm_event_handler ve_handler;
+};
+
+static struct vm_event_proc ve_proc[VM_EVENT_COUNT] = {
+	[VM_EVENT_RTC_CHG] = {
+		.ve_handler = general_event_handler,
+	},
+	[VM_EVENT_POWEROFF] = {
+		.ve_handler = general_event_handler,
+	},
+	[VM_EVENT_TRIPLE_FAULT] = {
+		.ve_handler = general_event_handler,
+	},
+};
+
+static inline struct vm_event_proc *get_vm_event_proc(struct vm_event *event)
+{
+	struct vm_event_proc *proc = NULL;
+	if (event->type < VM_EVENT_COUNT) {
+		proc = &ve_proc[event->type];
+	}
+	return proc;
+}
+
+static void general_event_handler(struct vmctx *ctx, struct vm_event *event)
+{
+	return;
+}
+
+static void *vm_event_thread(void *param)
+{
+	int n, i;
+	struct vm_event ve;
+	eventfd_t val;
+	struct vm_event_tunnel *tunnel;
+	struct vmctx *ctx = param;
+
+	struct epoll_event eventlist[MAX_EPOLL_EVENTS];
+
+	while (started) {
+		n = epoll_wait(epoll_fd, eventlist, MAX_EPOLL_EVENTS, -1);
+		if (n < 0) {
+			if (errno != EINTR) {
+				pr_err("%s: epoll failed %d\n", __func__, errno);
+			}
+			continue;
+		}
+		for (i = 0; i < n; i++) {
+			if (i < MAX_EPOLL_EVENTS) {
+				tunnel = eventlist[i].data.ptr;
+				eventfd_read(tunnel->kick_fd, &val);
+				if (tunnel && tunnel->enabled) {
+					while (!sbuf_is_empty(tunnel->sbuf)) {
+						struct vm_event_proc *proc;
+						sbuf_get(tunnel->sbuf, (uint8_t*)&ve);
+						pr_dbg("%ld vm event from%d %d\n", val, tunnel->type, ve.type);
+						proc = get_vm_event_proc(&ve);
+						if (proc && proc->ve_handler) {
+							(proc->ve_handler)(ctx, &ve);
+						} else {
+							pr_warn("%s: unhandled vm event type %d\n", __func__, ve.type);
+						}
+
+					}
+				}
+			}
+		}
+	}
+	return NULL;
+}
+
 static struct vm_event_tunnel ve_tunnel[MAX_VM_EVENT_TUNNELS] = {
 	{
 		.type = EVENT_SOURCE_TYPE_HV,
@@ -146,6 +221,12 @@ int vm_event_init(struct vmctx *ctx)
 		goto out;
 	}
 
+	error = pthread_create(&vm_event_tid, NULL, vm_event_thread, ctx);
+	if (error) {
+		pr_err("%s: vm_event create failed %d\n", __func__, errno);
+		goto out;
+	}
+
 	started = true;
 	return 0;
 
@@ -160,11 +241,44 @@ out:
 
 int vm_event_deinit(void)
 {
+	void *jval;
+
 	if (started) {
+		started = false;
+		pthread_kill(vm_event_tid, SIGCONT);
+		pthread_join(vm_event_tid, &jval);
 		close(epoll_fd);
 		destory_event_tunnel(&ve_tunnel[HV_VM_EVENT_TUNNEL]);
 		destory_event_tunnel(&ve_tunnel[DM_VM_EVENT_TUNNEL]);
-		started = false;
 	}
 	return 0;
 }
+
+/* Send a dm generated vm_event by putting it to sbuf.
+ * A thread will receive and process those events.
+ * Events will be dropped if sbuf is full.
+ * They also maight be dropped due to event throttle control in receive thread.
+ */
+int dm_send_vm_event(struct vm_event *event)
+{
+	struct vm_event_tunnel *tunnel = &ve_tunnel[DM_VM_EVENT_TUNNEL];
+	struct shared_buf *sbuf;
+	int32_t ret = -1;
+	uint32_t size_sent;
+
+	if (!tunnel->enabled) {
+		return -1;
+	}
+	sbuf = tunnel->sbuf;
+
+	if (sbuf != NULL) {
+		pthread_mutex_lock(&tunnel->mtx);
+		size_sent = sbuf_put(sbuf, (uint8_t *)event, sizeof(*event));
+		pthread_mutex_unlock(&tunnel->mtx);
+		if (size_sent == VM_EVENT_ELE_SIZE) {
+			eventfd_write(tunnel->kick_fd, 1UL);
+			ret = 0;
+		}
+	}
+	return ret;
+}

devicemodel/include/vm_event.h

@@ -12,5 +12,6 @@
 
 int vm_event_init(struct vmctx *ctx);
 int vm_event_deinit(void);
+int dm_send_vm_event(struct vm_event *event);
 
 #endif /* VM_EVENT_H */

hypervisor/include/public/acrn_common.h

@@ -833,6 +833,8 @@ struct shared_buf {
 #define VM_EVENT_POWEROFF	1U
 #define VM_EVENT_TRIPLE_FAULT	2U
 
+#define VM_EVENT_COUNT		3U
+
 #define VM_EVENT_DATA_LEN	28U
 
 struct vm_event {