The mechanism can initially register the sigbus handler after the device
event monitor is enabled. When a sigbus event is captured, it will check
the failure address and accordingly handle the memory failure of the
corresponding device by invoke the hot-unplug handler. It could prevent
the application from crashing when a device is hot-unplugged.
By this patch, users could call below new added APIs to enable/disable
the device hotplug handle mechanism. Note that it just implement the
hot-unplug handler in these functions, the other handler of hotplug, such
as handler for hotplug binding, could be add in the future if need:
- rte_dev_hotplug_handle_enable
- rte_dev_hotplug_handle_disable
Signed-off-by: Jeff Guo <jia....@intel.com>
Acked-by: Shaopeng He <shaopeng...@intel.com>
---
v11->v10:
change some words and change the invoked func name.
add experimental tag
---
doc/guides/rel_notes/release_18_08.rst | 5 +
lib/librte_eal/bsdapp/eal/eal_dev.c | 14 +++
lib/librte_eal/common/eal_private.h | 26 +++++
lib/librte_eal/common/include/rte_dev.h | 26 +++++
lib/librte_eal/linuxapp/eal/eal_dev.c | 162 +++++++++++++++++++++++++++++++-
lib/librte_eal/rte_eal_version.map | 2 +
6 files changed, 234 insertions(+), 1 deletion(-)
diff --git a/doc/guides/rel_notes/release_18_08.rst
b/doc/guides/rel_notes/release_18_08.rst
index 321fa84..fe0e60f 100644
--- a/doc/guides/rel_notes/release_18_08.rst
+++ b/doc/guides/rel_notes/release_18_08.rst
@@ -117,6 +117,11 @@ New Features
Added support for chained mbufs (input and output).
+* **Added hot-unplug handle mechanism.**
+
+ ``rte_dev_hotplug_handle_enable`` and ``rte_dev_hotplug_handle_disable`` are
+ for enabling or disabling hotplug handle mechanism.
+
API Changes
-----------
diff --git a/lib/librte_eal/bsdapp/eal/eal_dev.c
b/lib/librte_eal/bsdapp/eal/eal_dev.c
index 1c6c51b..255d611 100644
--- a/lib/librte_eal/bsdapp/eal/eal_dev.c
+++ b/lib/librte_eal/bsdapp/eal/eal_dev.c
@@ -19,3 +19,17 @@ rte_dev_event_monitor_stop(void)
RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n");
return -1;
}
+
+int __rte_experimental
+rte_dev_hotplug_handle_enable(void)
+{
+ RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n");
+ return -1;
+}
+
+int __rte_experimental
+rte_dev_hotplug_handle_disable(void)
+{
+ RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n");
+ return -1;
+}
diff --git a/lib/librte_eal/common/eal_private.h
b/lib/librte_eal/common/eal_private.h
index a2d1528..637f20d 100644
--- a/lib/librte_eal/common/eal_private.h
+++ b/lib/librte_eal/common/eal_private.h
@@ -317,4 +317,30 @@ rte_devargs_layers_parse(struct rte_devargs *devargs,
*/
int rte_bus_sigbus_handler(const void *failure_addr);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Register the sigbus handler.
+ *
+ * @return
+ * - On success, zero.
+ * - On failure, a negative value.
+ */
+int
+rte_dev_sigbus_handler_register(void);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Unregister the sigbus handler.
+ *
+ * @return
+ * - On success, zero.
+ * - On failure, a negative value.
+ */
+int
+rte_dev_sigbus_handler_unregister(void);
+
#endif /* _EAL_PRIVATE_H_ */
diff --git a/lib/librte_eal/common/include/rte_dev.h
b/lib/librte_eal/common/include/rte_dev.h
index b80a805..ff580a0 100644
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -460,4 +460,30 @@ rte_dev_event_monitor_start(void);
int __rte_experimental
rte_dev_event_monitor_stop(void);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Enable hotplug handling for devices.
+ *
+ * @return
+ * - On success, zero.
+ * - On failure, a negative value.
+ */
+int __rte_experimental
+rte_dev_hotplug_handle_enable(void);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Disable hotplug handling for devices.
+ *
+ * @return
+ * - On success, zero.
+ * - On failure, a negative value.
+ */
+int __rte_experimental
+rte_dev_hotplug_handle_disable(void);
+
#endif /* _RTE_DEV_H_ */
diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c
b/lib/librte_eal/linuxapp/eal/eal_dev.c
index 1cf6aeb..14b18d8 100644
--- a/lib/librte_eal/linuxapp/eal/eal_dev.c
+++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
@@ -4,6 +4,8 @@
#include <string.h>
#include <unistd.h>
+#include <fcntl.h>
+#include <signal.h>
#include <sys/socket.h>
#include <linux/netlink.h>
@@ -14,15 +16,32 @@
#include <rte_malloc.h>
#include <rte_interrupts.h>
#include <rte_alarm.h>
+#include <rte_bus.h>
+#include <rte_eal.h>
+#include <rte_spinlock.h>
+#include <rte_errno.h>
#include "eal_private.h"
static struct rte_intr_handle intr_handle = {.fd = -1 };
static bool monitor_started;
+static bool hotplug_handle;
#define EAL_UEV_MSG_LEN 4096
#define EAL_UEV_MSG_ELEM_LEN 128
+/*
+ * spinlock for device hot-unplug failure handling. If it try to access bus or
+ * device, such as handle sigbus on bus or handle memory failure for device
+ * just need to use this lock. It could protect the bus and the device to avoid
+ * race condition.
+ */
+static rte_spinlock_t failure_handle_lock = RTE_SPINLOCK_INITIALIZER;
+
+static struct sigaction sigbus_action_old;
+
+static int sigbus_need_recover;
+
static void dev_uev_handler(__rte_unused void *param);
/* identify the system layer which reports this event. */
@@ -33,6 +52,49 @@ enum eal_dev_event_subsystem {
EAL_DEV_EVENT_SUBSYSTEM_MAX
};
+static void
+sigbus_action_recover(void)
+{
+ if (sigbus_need_recover) {
+ sigaction(SIGBUS, &sigbus_action_old, NULL);
+ sigbus_need_recover = 0;
+ }
+}
+
+static void sigbus_handler(int signum, siginfo_t *info,
+ void *ctx __rte_unused)
+{
+ int ret;
+
+ RTE_LOG(INFO, EAL, "Thread[%d] catch SIGBUS, fault address:%p\n",
+ (int)pthread_self(), info->si_addr);
+
+ rte_spinlock_lock(&failure_handle_lock);
+ ret = rte_bus_sigbus_handler(info->si_addr);
+ rte_spinlock_unlock(&failure_handle_lock);
+ if (ret == -1) {
+ rte_exit(EXIT_FAILURE,
+ "Failed to handle SIGBUS for hot-unplug, "
+ "(rte_errno: %s)!", strerror(rte_errno));
+ } else if (ret == 1) {
+ if (sigbus_action_old.sa_handler)
+ (*(sigbus_action_old.sa_handler))(signum);
+ else
+ rte_exit(EXIT_FAILURE,
+ "Failed to handle generic SIGBUS!");
+ }
+
+ RTE_LOG(INFO, EAL, "Success to handle SIGBUS for hot-unplug!\n");
+}
+
+static int cmp_dev_name(const struct rte_device *dev,
+ const void *_name)
+{
+ const char *name = _name;
+
+ return strcmp(dev->name, name);
+}
+
static int
dev_uev_socket_fd_create(void)
{
@@ -147,6 +209,9 @@ dev_uev_handler(__rte_unused void *param)
struct rte_dev_event uevent;
int ret;
char buf[EAL_UEV_MSG_LEN];
+ struct rte_bus *bus;
+ struct rte_device *dev;
+ const char *busname = "";
memset(&uevent, 0, sizeof(struct rte_dev_event));
memset(buf, 0, EAL_UEV_MSG_LEN);
@@ -171,8 +236,43 @@ dev_uev_handler(__rte_unused void *param)
RTE_LOG(DEBUG, EAL, "receive uevent(name:%s, type:%d, subsystem:%d)\n",
uevent.devname, uevent.type, uevent.subsystem);
- if (uevent.devname)
+ switch (uevent.subsystem) {
+ case EAL_DEV_EVENT_SUBSYSTEM_PCI:
+ case EAL_DEV_EVENT_SUBSYSTEM_UIO:
+ busname = "pci";
+ break;
+ default:
+ break;
+ }
+
+ if (uevent.devname) {
+ if (uevent.type == RTE_DEV_EVENT_REMOVE && hotplug_handle) {
+ rte_spinlock_lock(&failure_handle_lock);
+ bus = rte_bus_find_by_name(busname);
+ if (bus == NULL) {
+ RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n",
+ busname);
+ return;
+ }
+
+ dev = bus->find_device(NULL, cmp_dev_name,
+ uevent.devname);
+ if (dev == NULL) {
+ RTE_LOG(ERR, EAL, "Cannot find device (%s) on "
+ "bus (%s)\n", uevent.devname, busname);
+ return;
+ }
+
+ ret = bus->hot_unplug_handler(dev);
+ rte_spinlock_unlock(&failure_handle_lock);
+ if (ret) {
+ RTE_LOG(ERR, EAL, "Can not handle hot-unplug "
+ "for device (%s)\n", dev->name);
+ return;
+ }
+ }
dev_callback_process(uevent.devname, uevent.type);
+ }
}
int __rte_experimental
@@ -220,5 +320,65 @@ rte_dev_event_monitor_stop(void)
close(intr_handle.fd);
intr_handle.fd = -1;
monitor_started = false;
+
return 0;
}
+
+int __rte_experimental
+rte_dev_sigbus_handler_register(void)
+{
+ sigset_t mask;
+ struct sigaction action;
+
+ rte_errno = 0;
+
