[dpdk-dev,V12,3/3] app/testpmd: use uevent to monitor hotplug

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 9414d0e..87e3753 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -373,6 +373,8 @@  uint8_t bitrate_enabled;
 struct gro_status gro_ports[RTE_MAX_ETHPORTS];
 uint8_t gro_flush_cycles = GRO_DEFAULT_FLUSH_CYCLES;
 
+static struct hotplug_request_list hp_list;
+
 /* Forward function declarations */
 static void map_port_queue_stats_mapping_registers(portid_t pi,
 						   struct rte_port *port);
@@ -380,6 +382,13 @@  static void check_all_ports_link_status(uint32_t port_mask);
 static int eth_event_callback(portid_t port_id,
 			      enum rte_eth_event_type type,
 			      void *param, void *ret_param);
+static int eth_uevent_callback(char *device_name, enum rte_dev_event_type type,
+			      void *param);
+static int eth_uevent_callback_register(portid_t port_id);
+static int in_hotplug_list(const char *dev_name);
+
+static int hotplug_list_add(const char *dev_name,
+			    enum rte_dev_event_type event);
 
 /*
  * Check if all the ports are started.
@@ -1729,6 +1738,27 @@  reset_port(portid_t pid)
 	printf("Done\n");
 }
 
+static int
+eth_uevent_callback_register(portid_t port_id)
+{
+	int diag;
+	char device_name[128];
+
+	snprintf(device_name, sizeof(device_name),
+		"%s", rte_eth_devices[port_id].device->name);
+
+	/* register the uevent callback */
+
+	diag = rte_dev_callback_register(device_name,
+		eth_uevent_callback, (void *)(intptr_t)port_id);
+	if (diag) {
+		printf("Failed to setup uevent callback\n");
+		return -1;
+	}
+
+	return 0;
+}
+
 void
 attach_port(char *identifier)
 {
@@ -1745,6 +1775,8 @@  attach_port(char *identifier)
 	if (rte_eth_dev_attach(identifier, &pi))
 		return;
 
+	eth_uevent_callback_register(pi);
+
 	socket_id = (unsigned)rte_eth_dev_socket_id(pi);
 	/* if socket_id is invalid, set to 0 */
 	if (check_socket_id(socket_id) < 0)
@@ -1756,6 +1788,8 @@  attach_port(char *identifier)
 
 	ports[pi].port_status = RTE_PORT_STOPPED;
 
+	hotplug_list_add(identifier, RTE_DEV_EVENT_REMOVE);
+
 	printf("Port %d is attached. Now total ports is %d\n", pi, nb_ports);
 	printf("Done\n");
 }
@@ -1782,6 +1816,9 @@  detach_port(portid_t port_id)
 
 	nb_ports = rte_eth_dev_count();
 
+	hotplug_list_add(rte_eth_devices[port_id].device->name,
+			 RTE_DEV_EVENT_ADD);
+
 	printf("Port '%s' is detached. Now total ports is %d\n",
 			name, nb_ports);
 	printf("Done\n");
@@ -1805,6 +1842,9 @@  pmd_test_exit(void)
 			close_port(pt_id);
 		}
 	}
+
+	rte_dev_event_monitor_stop();
+
 	printf("\nBye...\n");
 }
 
@@ -1889,6 +1929,49 @@  rmv_event_callback(void *arg)
 			dev->device->name);
 }
 
+static void
+rmv_uevent_callback(void *arg)
+{
+	char name[RTE_ETH_NAME_MAX_LEN];
+	uint8_t port_id = (intptr_t)arg;
+
+	rte_eal_alarm_cancel(rmv_uevent_callback, arg);
+
+	RTE_ETH_VALID_PORTID_OR_RET(port_id);
+	printf("removing port id:%u\n", port_id);
+
+	if (!in_hotplug_list(rte_eth_devices[port_id].device->name))
+		return;
+
+	stop_packet_forwarding();
+
+	stop_port(port_id);
+	close_port(port_id);
+	if (rte_eth_dev_detach(port_id, name)) {
+		RTE_LOG(ERR, USER1, "Failed to detach port '%s'\n", name);
+		return;
+	}
+
+	nb_ports = rte_eth_dev_count();
+
+	printf("Port '%s' is detached. Now total ports is %d\n",
+			name, nb_ports);
+}
+
+static void
+add_uevent_callback(void *arg)
+{
+	char *dev_name = (char *)arg;
+
+	rte_eal_alarm_cancel(add_uevent_callback, arg);
+
+	if (!in_hotplug_list(dev_name))
+		return;
+
+	RTE_LOG(ERR, EAL, "add device: %s\n", dev_name);
+	attach_port(dev_name);
+}
+
 /* This function is used by the interrupt thread */
 static int
 eth_event_callback(portid_t port_id, enum rte_eth_event_type type, void *param,
@@ -1931,6 +2014,82 @@  eth_event_callback(portid_t port_id, enum rte_eth_event_type type, void *param,
 }
 
 static int
+in_hotplug_list(const char *dev_name)
+{
+	struct hotplug_request *hp_request = NULL;
+
+	TAILQ_FOREACH(hp_request, &hp_list, next) {
+		if (!strcmp(hp_request->dev_name, dev_name))
+			break;
+	}
+
+	if (hp_request)
+		return 1;
+
+	return 0;
+}
+
+static int
+hotplug_list_add(const char *dev_name, enum rte_dev_event_type event)
+{
+	struct hotplug_request *hp_request;
+
+	hp_request = rte_zmalloc("hoplug request",
+			sizeof(*hp_request), 0);
+	if (hp_request == NULL) {
+		fprintf(stderr, "%s can not alloc memory\n",
+			__func__);
+		return -ENOMEM;
+	}
+
+	hp_request->dev_name = dev_name;
+	hp_request->event = event;
+
+	TAILQ_INSERT_TAIL(&hp_list, hp_request, next);
+
+	return 0;
+}
+
+/* This function is used by the interrupt thread */
+static int
+eth_uevent_callback(char *device_name, enum rte_dev_event_type type, void *arg)
+{
+	static const char * const event_desc[] = {
+		[RTE_DEV_EVENT_UNKNOWN] = "Unknown",
+		[RTE_DEV_EVENT_ADD] = "add",
+		[RTE_DEV_EVENT_REMOVE] = "remove",
+	};
+
+	if (type >= RTE_DEV_EVENT_MAX) {
+		fprintf(stderr, "%s called upon invalid event %d\n",
+			__func__, type);
+		fflush(stderr);
+	} else if (event_print_mask & (UINT32_C(1) << type)) {
+		printf("%s event\n",
+			event_desc[type]);
+		fflush(stdout);
+	}
+
+	switch (type) {
+	case RTE_DEV_EVENT_REMOVE:
+		if (rte_eal_alarm_set(100000,
+			rmv_uevent_callback, arg))
+			fprintf(stderr, "Could not set up deferred "
+				"device removal\n");
+		break;
+	case RTE_DEV_EVENT_ADD:
+		if (rte_eal_alarm_set(500000,
+			add_uevent_callback, (void *)device_name))
+			fprintf(stderr, "Could not set up deferred "
+				"device add\n");
+		break;
+	default:
+		break;
+	}
+	return 0;
+}
+
+static int
 set_tx_queue_stats_mapping_registers(portid_t port_id, struct rte_port *port)
 {
 	uint16_t i;
@@ -2415,6 +2574,15 @@  main(int argc, char** argv)
 		       nb_rxq, nb_txq);
 
 	init_config();
+
+	/* enable hot plug monitoring */
+	TAILQ_INIT(&hp_list);
+	rte_dev_event_monitor_start();
+	RTE_ETH_FOREACH_DEV(port_id) {
+		hotplug_list_add(rte_eth_devices[port_id].device->name,
+			 RTE_DEV_EVENT_REMOVE);
+		eth_uevent_callback_register(port_id);
+	}
 	if (start_port(RTE_PORT_ALL) != 0)
 		rte_exit(EXIT_FAILURE, "Start ports failed\n");
 
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index 2a266fd..64254e6 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -63,6 +63,15 @@  typedef uint16_t streamid_t;
 #define TM_MODE			0
 #endif
 
+struct hotplug_request {
+	TAILQ_ENTRY(hotplug_request) next; /**< Callbacks list */
+	const char *dev_name;                /* request device name */
+	enum rte_dev_event_type event;      /**< device event type */
+};
+
+/** @internal Structure to keep track of registered callbacks */
+TAILQ_HEAD(hotplug_request_list, hotplug_request);
+
 enum {
 	PORT_TOPOLOGY_PAIRED,
 	PORT_TOPOLOGY_CHAINED,