[dpdk-dev,V15,3/5] app/testpmd: use uevent to monitor hotplug

Message ID 1521610066-12966-3-git-send-email-jia.guo@intel.com (mailing list archive)
State Superseded, archived
Headers

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/Intel-compilation fail Compilation issues

Commit Message

Guo, Jia March 21, 2018, 5:27 a.m. UTC
use testpmd for example, to show app how to request and use
uevent monitoring to handle the hot removal event and the
hot insertion event.

Signed-off-by: Jeff Guo <jia.guo@intel.com>
---
v15->v14:
add "--hot-plug" configure parameter in testpmd to switch the hotplug feature
---
 app/test-pmd/parameters.c |   5 +-
 app/test-pmd/testpmd.c    | 194 +++++++++++++++++++++++++++++++++++++++++++++-
 app/test-pmd/testpmd.h    |  11 +++
 3 files changed, 208 insertions(+), 2 deletions(-)
  

Comments

Guo, Jia March 26, 2018, 10:55 a.m. UTC | #1
About hot plug in dpdk, We already have proactive way to add/remove devices
through APIs (rte_eal_hotplug_add/remove), and also have fail-safe driver to
offload the fail-safe work from the app user. But there are still lack of a
general mechanism to monitor hotplug event for all driver, now the hotplug
interrupt event is diversity between each device and driver, such as mlx4,
pci driver and others.

Use the hot removal event for example, pci drivers not all exposure the
remove interrupt, so in order to make user to easy use the hot plug feature
for pci driver, something must be done to detect the remove event at the
kernel level and offer a new line of interrupt to the user land.

Base on the uevent of kobject mechanism in kernel, we could use it to
benefit for monitoring the hot plug status of the device which not only
uio/vfio of pci bus devices, but also other, such as cpu/usb/pci-express
bus devices.

The idea is comming as bellow.

a.The uevent message form FD monitoring which will be useful.
remove@/devices/pci0000:80/0000:80:02.2/0000:82:00.0/0000:83:03.0/0000:84:00.2/uio/uio2
ACTION=remove
DEVPATH=/devices/pci0000:80/0000:80:02.2/0000:82:00.0/0000:83:03.0/0000:84:00.2/uio/uio2
SUBSYSTEM=uio
MAJOR=243
MINOR=2
DEVNAME=uio2
SEQNUM=11366

b.add uevent monitoring machanism:
add several general api to enable uevent monitoring.

c.add common uevent handler and uevent failure handler
uevent of device should be handler at bus or device layer, and the memory read
and write failure when hot removal should be handle correctly before detach behaviors.

d.show example how to use uevent monitor
enable uevent monitoring in testpmd or fail-safe to show usage.

patchset history:
v16->v15:
1.remove some linux related code out of eal common layer
2.fix some uneasy readble issue.

v15->v14:
1.use exist eal interrupt epoll to replace of rte service usage for monitor thread,
2.add new device event handle type in eal interrupt.
3.remove the uevent type check and any policy from eal,
let it check and management in user's callback.
4.add "--hot-plug" configure parameter in testpmd to switch the hotplug feature.

v14->v13:
1.add __rte_experimental on function defind and fix bsd build issue

v13->v12:
1.fix some logic issue and null check issue
2.fix monitor stop func issue

v12->v11:
1.identify null param in callback for monitor all devices uevent

v11->v10:
1:modify some typo and add experimental tag in new file.
2:modify callback register calling.

v10->v9:
1.fix prefix issue.
2.use a common callback lists for all device and all type to replace
add callback parameter into device struct.
3.delete some unuse part.

v9->v8:
split the patch set into small and explicit patch

v8->v7:
1.use rte_service to replace pthread management.
2.fix defind issue and copyright issue
3.fix some lock issue

v7->v6:
1.modify vdev part according to the vdev rework
2.re-define and split the func into common and bus specific code
3.fix some incorrect issue.
4.fix the system hung after send packcet issue.

v6->v5:
1.add hot plug policy, in eal, default handle to prepare hot plug work for
all pci device, then let app to manage to deside which device need to
hot plug.
2.modify to manage event callback in each device.
3.fix some system hung issue when igb_uio release.
4.modify the pci part to the bus-pci base on the bus rework.
5.add hot plug policy in app, show example to use hotplug list to manage
to deside which device need to hot plug.

v5->v4:
1.Move uevent monitor epolling from eal interrupt to eal device layer.
2.Redefine the eal device API for common, and distinguish between linux and bsd
3.Add failure handler helper api in bus layer.Add function of find device by name.
4.Replace of individual fd bind with single device, use a common fd to polling all device.
5.Add to register hot insertion monitoring and process, add function to auto bind driver befor user add device
6.Refine some coding style and typos issue
7.add new callback to process hot insertion

v4->v3:
1.move uevent monitor api from eal interrupt to eal device layer.
2.create uevent type and struct in eal device.
3.move uevent handler for each driver to eal layer.
4.add uevent failure handler to process signal fault issue.
5.add example for request and use uevent monitoring in testpmd.

v3->v2:
1.refine some return error
2.refine the string searching logic to avoid memory issue

v2->v1:
1.remove global variables of hotplug_fd, add uevent_fd
in rte_intr_handle to let each pci device self maintain it fd,
to fix dual device fd issue.
2.refine some typo error.


Jeff Guo (3):
  eal: add device event handle in interrupt thread
  eal: add device event monitor framework
  app/testpmd: enable device hotplug monitoring

 app/test-pmd/parameters.c                          |   5 +-
 app/test-pmd/testpmd.c                             | 195 ++++++++++++++++++++-
 app/test-pmd/testpmd.h                             |  11 ++
 lib/librte_eal/bsdapp/eal/Makefile                 |   1 +
 lib/librte_eal/bsdapp/eal/eal_dev.c                |  19 ++
 lib/librte_eal/common/eal_common_dev.c             | 145 +++++++++++++++
 lib/librte_eal/common/eal_private.h                |  24 +++
 lib/librte_eal/common/include/rte_dev.h            |  92 ++++++++++
 lib/librte_eal/common/include/rte_eal_interrupts.h |   1 +
 lib/librte_eal/linuxapp/eal/Makefile               |   1 +
 lib/librte_eal/linuxapp/eal/eal_dev.c              |  20 +++
 lib/librte_eal/linuxapp/eal/eal_interrupts.c       |   5 +-
 12 files changed, 516 insertions(+), 3 deletions(-)
 create mode 100644 lib/librte_eal/bsdapp/eal/eal_dev.c
 create mode 100644 lib/librte_eal/linuxapp/eal/eal_dev.c
  
Guo, Jia March 26, 2018, 11:20 a.m. UTC | #2
About hot plug in dpdk, We already have proactive way to add/remove devices
through APIs (rte_eal_hotplug_add/remove), and also have fail-safe driver
to offload the fail-safe work from the app user. But there are still lack
of a general mechanism to monitor hotplug event for all driver, now the
hotplug interrupt event is diversity between each device and driver, such
as mlx4, pci driver and others.

Use the hot removal event for example, pci drivers not all exposure the
remove interrupt, so in order to make user to easy use the hot plug
feature for pci driver, something must be done to detect the remove event
at the kernel level and offer a new line of interrupt to the user land.

Base on the uevent of kobject mechanism in kernel, we could use it to
benefit for monitoring the hot plug status of the device which not only
uio/vfio of pci bus devices, but also other, such as cpu/usb/pci-express bus devices.

The idea is comming as bellow.

a.The uevent message form FD monitoring which will be useful.
remove@/devices/pci0000:80/0000:80:02.2/0000:82:00.0/0000:83:03.0/0000:84:00.2/uio/uio2
ACTION=remove
DEVPATH=/devices/pci0000:80/0000:80:02.2/0000:82:00.0/0000:83:03.0/0000:84:00.2/uio/uio2
SUBSYSTEM=uio
MAJOR=243
MINOR=2
DEVNAME=uio2
SEQNUM=11366

b.add uevent monitoring machanism:
add several general api to enable uevent monitoring.

c.add common uevent handler and uevent failure handler
uevent of device should be handler at bus or device layer, and the memory read
and write failure when hot removal should be handle correctly before detach behaviors.

d.show example how to use uevent monitor
enable uevent monitoring in testpmd or fail-safe to show usage.

patchset history:
v16->v15:
1.remove some linux related code out of eal common layer
2.fix some uneasy readble issue.

v15->v14:
1.use exist eal interrupt epoll to replace of rte service usage for monitor thread,
2.add new device event handle type in eal interrupt.
3.remove the uevent type check and any policy from eal,
let it check and management in user's callback.
4.add "--hot-plug" configure parameter in testpmd to switch the hotplug feature.

v14->v13:
1.add __rte_experimental on function defind and fix bsd build issue

v13->v12:
1.fix some logic issue and null check issue
2.fix monitor stop func issue

v12->v11:
1.identify null param in callback for monitor all devices uevent

v11->v10:
1:modify some typo and add experimental tag in new file.
2:modify callback register calling.

v10->v9:
1.fix prefix issue.
2.use a common callback lists for all device and all type to replace
add callback parameter into device struct.
3.delete some unuse part.

v9->v8:
split the patch set into small and explicit patch

v8->v7:
1.use rte_service to replace pthread management.
2.fix defind issue and copyright issue
3.fix some lock issue

v7->v6:
1.modify vdev part according to the vdev rework
2.re-define and split the func into common and bus specific code
3.fix some incorrect issue.
4.fix the system hung after send packcet issue.

v6->v5:
1.add hot plug policy, in eal, default handle to prepare hot plug work for
all pci device, then let app to manage to deside which device need to
hot plug.
2.modify to manage event callback in each device.
3.fix some system hung issue when igb_uioome typo error.release.
4.modify the pci part to the bus-pci base on the bus rework.
5.add hot plug policy in app, show example to use hotplug list to manage
to deside which device need to hot plug.

v5->v4:
1.Move uevent monitor epolling from eal interrupt to eal device layer.
2.Redefine the eal device API for common, and distinguish between linux and bsd
3.Add failure handler helper api in bus layer.Add function of find device by name.
4.Replace of individual fd bind with single device, use a common fd to polling all device.
5.Add to register hot insertion monitoring and process, add function to auto bind driver befor user add device
6.Refine some coding style and typos issue
7.add new callback to process hot insertion

v4->v3:
1.move uevent monitor api from eal interrupt to eal device layer.
2.create uevent type and struct in eal device.
3.move uevent handler for each driver to eal layer.
4.add uevent failure handler to process signal fault issue.
5.add example for request and use uevent monitoring in testpmd.

v3->v2:
1.refine some return error
2.refine the string searching logic to avoid memory issue

v2->v1:
1.remove global variables of hotplug_fd, add uevent_fd
in rte_intr_handle to let each pci device self maintain it fd,
to fix dual device fd issue.
2.refine some typo error.

Jeff Guo (4):
  eal: add device event handle in interrupt thread
  eal: add device event monitor framework
  eal/linux: uevent parse and process
  app/testpmd: enable device hotplug monitoring

 app/test-pmd/parameters.c                          |   5 +-
 app/test-pmd/testpmd.c                             | 195 +++++++++++++++++-
 app/test-pmd/testpmd.h                             |  11 +
 lib/librte_eal/bsdapp/eal/Makefile                 |   1 +
 lib/librte_eal/bsdapp/eal/eal_dev.c                |  19 ++
 lib/librte_eal/common/eal_common_dev.c             | 145 +++++++++++++
 lib/librte_eal/common/eal_private.h                |  24 +++
 lib/librte_eal/common/include/rte_dev.h            |  92 +++++++++
 lib/librte_eal/common/include/rte_eal_interrupts.h |   1 +
 lib/librte_eal/linuxapp/eal/Makefile               |   1 +
 lib/librte_eal/linuxapp/eal/eal_dev.c              | 228 +++++++++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_interrupts.c       |   5 +-
 12 files changed, 724 insertions(+), 3 deletions(-)
 create mode 100644 lib/librte_eal/bsdapp/eal/eal_dev.c
 create mode 100644 lib/librte_eal/linuxapp/eal/eal_dev.c
  

Patch

diff --git a/app/test-pmd/parameters.c b/app/test-pmd/parameters.c
index 97d22b8..825d602 100644
--- a/app/test-pmd/parameters.c
+++ b/app/test-pmd/parameters.c
@@ -186,6 +186,7 @@  usage(char* progname)
 	printf("  --flow-isolate-all: "
 	       "requests flow API isolated mode on all ports at initialization time.\n");
 	printf("  --tx-offloads=0xXXXXXXXX: hexadecimal bitmask of TX queue offloads\n");
+	printf("  --hot-plug: enalbe hot plug for device.\n");
 }
 
 #ifdef RTE_LIBRTE_CMDLINE
@@ -621,6 +622,7 @@  launch_args_parse(int argc, char** argv)
 		{ "print-event",		1, 0, 0 },
 		{ "mask-event",			1, 0, 0 },
 		{ "tx-offloads",		1, 0, 0 },
+		{ "hot-plug",			0, 0, 0 },
 		{ 0, 0, 0, 0 },
 	};
 
@@ -1102,7 +1104,8 @@  launch_args_parse(int argc, char** argv)
 					rte_exit(EXIT_FAILURE,
 						 "invalid mask-event argument\n");
 				}
-
+			if (!strcmp(lgopts[opt_idx].name, "hot-plug"))
+				hot_plug = 1;
 			break;
 		case 'h':
 			usage(argv[0]);
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 4c0e258..915532e 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -12,6 +12,7 @@ 
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <errno.h>
+#include <stdbool.h>
 
 #include <sys/queue.h>
 #include <sys/stat.h>
@@ -284,6 +285,9 @@  uint8_t lsc_interrupt = 1; /* enabled by default */
  */
 uint8_t rmv_interrupt = 1; /* enabled by default */
 
+
+uint8_t hot_plug = 0; /**< hotplug disabled by default. */
+
 /*
  * Display or mask ether events
  * Default to all events except VF_MBOX
@@ -384,6 +388,8 @@  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);
@@ -391,6 +397,14 @@  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 bool in_hotplug_list(const char *dev_name);
+
+static int hotplug_list_add(struct rte_device *device,
+				enum rte_kernel_driver device_kdrv);
 
 /*
  * Check if all the ports are started.
@@ -1853,6 +1867,27 @@  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)
 {
@@ -1869,6 +1904,8 @@  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)
@@ -1880,6 +1917,12 @@  attach_port(char *identifier)
 
 	ports[pi].port_status = RTE_PORT_STOPPED;
 
+	if (hot_plug) {
+		hotplug_list_add(rte_eth_devices[pi].device,
+				 rte_eth_devices[pi].data->kdrv);
+		eth_uevent_callback_register(pi);
+	}
+
 	printf("Port %d is attached. Now total ports is %d\n", pi, nb_ports);
 	printf("Done\n");
 }
@@ -1906,6 +1949,12 @@  detach_port(portid_t port_id)
 
 	nb_ports = rte_eth_dev_count();
 
+	if (hot_plug) {
+		hotplug_list_add(rte_eth_devices[port_id].device,
+				 rte_eth_devices[port_id].data->kdrv);
+		eth_uevent_callback_register(port_id);
+	}
+
 	printf("Port '%s' is detached. Now total ports is %d\n",
 			name, nb_ports);
 	printf("Done\n");
@@ -1929,6 +1978,9 @@  pmd_test_exit(void)
 			close_port(pt_id);
 		}
 	}
+
+	rte_dev_event_monitor_stop();
+
 	printf("\nBye...\n");
 }
 
@@ -2013,6 +2065,49 @@  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,
@@ -2059,6 +2154,85 @@  eth_event_callback(portid_t port_id, enum rte_eth_event_type type, void *param,
 	return 0;
 }
 
+static bool
+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 true;
+
+	return false;
+}
+
+static int
+hotplug_list_add(struct rte_device *device, enum rte_kernel_driver device_kdrv)
+{
+	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 = device->name;
+	hp_request->dev_kdrv = device_kdrv;
+
+	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",
+	};
+	char *dev_name = malloc(strlen(device_name) + 1);
+
+	strcpy(dev_name, device_name);
+
+	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(100000,
+			add_uevent_callback, dev_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)
 {
@@ -2474,8 +2648,9 @@  signal_handler(int signum)
 int
 main(int argc, char** argv)
 {
-	int  diag;
+	int diag;
 	portid_t port_id;
+	int ret;
 
 	signal(SIGINT, signal_handler);
 	signal(SIGTERM, signal_handler);
@@ -2543,6 +2718,23 @@  main(int argc, char** argv)
 		       nb_rxq, nb_txq);
 
 	init_config();
+
+	if (hot_plug) {
+		/* enable hot plug monitoring */
+		ret = rte_dev_event_monitor_start();
+		if (ret) {
+			rte_errno = EINVAL;
+			return -1;
+		}
+		if (TAILQ_EMPTY(&hp_list))
+			TAILQ_INIT(&hp_list);
+		RTE_ETH_FOREACH_DEV(port_id) {
+			hotplug_list_add(rte_eth_devices[port_id].device,
+					 rte_eth_devices[port_id].data->kdrv);
+			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 153abea..c619e11 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_kernel_driver dev_kdrv;            /* kernel driver binded */
+};
+
+/** @internal Structure to keep track of registered callbacks */
+TAILQ_HEAD(hotplug_request_list, hotplug_request);
+
 enum {
 	PORT_TOPOLOGY_PAIRED,
 	PORT_TOPOLOGY_CHAINED,
@@ -319,6 +328,8 @@  extern volatile int test_done; /* stop packet forwarding when set to 1. */
 extern uint8_t lsc_interrupt; /**< disabled by "--no-lsc-interrupt" parameter */
 extern uint8_t rmv_interrupt; /**< disabled by "--no-rmv-interrupt" parameter */
 extern uint32_t event_print_mask;
+extern uint8_t hot_plug; /**< enable by "--hot-plug" parameter */
+
 /**< set by "--print-event xxxx" and "--mask-event xxxx parameters */
 
 #ifdef RTE_LIBRTE_IXGBE_BYPASS