Signed-off-by: Jeff Guo <jia....@intel.com>
---
v19->18:
add note for limitation of multiple hotplug
---
doc/guides/rel_notes/release_18_05.rst | 6 ++
kernel/linux/igb_uio/igb_uio.c | 4 +
lib/librte_eal/common/include/rte_dev.h | 19 +++++
lib/librte_eal/linuxapp/eal/eal_dev.c | 140
+++++++++++++++++++++++++++++++-
lib/librte_eal/rte_eal_version.map | 1 +
5 files changed, 169 insertions(+), 1 deletion(-)
diff --git a/doc/guides/rel_notes/release_18_05.rst
b/doc/guides/rel_notes/release_18_05.rst
index cb9e050..2707e73 100644
--- a/doc/guides/rel_notes/release_18_05.rst
+++ b/doc/guides/rel_notes/release_18_05.rst
@@ -70,6 +70,12 @@ New Features
Linux uevent is supported as backend of this device event
notification framework.
+* **Added hot plug failure handler.**
+
+ Added a failure handler machenism to handle hot unplug device.
+
+ * ``rte_dev_handle_hot_unplug`` for handle hot unplug device failure.
+
API Changes
-----------
diff --git a/kernel/linux/igb_uio/igb_uio.c
b/kernel/linux/igb_uio/igb_uio.c index 4cae4dd..293c310 100644
--- a/kernel/linux/igb_uio/igb_uio.c
+++ b/kernel/linux/igb_uio/igb_uio.c
@@ -344,6 +344,10 @@ igbuio_pci_release(struct uio_info *info, struct
inode
*inode)
struct rte_uio_pci_dev *udev = info->priv;
struct pci_dev *dev = udev->pdev;
+ /* check if device has been remove before release */
+ if ((&dev->dev.kobj)->state_remove_uevent_sent == 1)
+ return -1;
+
mutex_lock(&udev->lock);
if (--udev->refcnt > 0) {
mutex_unlock(&udev->lock);
diff --git a/lib/librte_eal/common/include/rte_dev.h
b/lib/librte_eal/common/include/rte_dev.h
index a5203e7..17c446d 100644
--- a/lib/librte_eal/common/include/rte_dev.h
+++ b/lib/librte_eal/common/include/rte_dev.h
@@ -361,4 +361,23 @@ 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
+ *
+ * It can be used to register the device signal bus handler, and save
+the
+ * current environment for each thread, when signal bus error invoke,
+the
+ * handler would restore the environment by long jmp to each working
+ * thread previous locate, then block the thread to waiting until the
+memory
+ * recovery and remapping be finished, that would guaranty the system
+not
+ * crash when the device be hot unplug.
+ *
+ * @param none
+ * @return
+ * - From a successful direct invocation, zero.
+ * - From a call of siglongjmp(), non_zero.
+ */
+int __rte_experimental
+rte_dev_handle_hot_unplug(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 9478a39..84b7efc 100644
--- a/lib/librte_eal/linuxapp/eal/eal_dev.c
+++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
@@ -4,6 +4,9 @@
#include <string.h>
#include <unistd.h>
+#include <signal.h>
+#include <setjmp.h>
+#include <pthread.h>
#include <sys/socket.h>
#include <linux/netlink.h>
@@ -13,12 +16,17 @@
#include <rte_malloc.h>
#include <rte_interrupts.h>
#include <rte_alarm.h>
+#include <rte_bus.h>
+#include <rte_per_lcore.h>
#include "eal_private.h"
static struct rte_intr_handle intr_handle = {.fd = -1 }; static bool
monitor_started;
+pthread_mutex_t failure_recovery_lock; pthread_cond_t
+failure_recovery_cond;
+
#define EAL_UEV_MSG_LEN 4096
#define EAL_UEV_MSG_ELEM_LEN 128
@@ -32,6 +40,22 @@ enum eal_dev_event_subsystem {
EAL_DEV_EVENT_SUBSYSTEM_MAX
};
+static RTE_DEFINE_PER_LCORE(sigjmp_buf, unplug_longjmp_env);
+
+static void sigbus_handler(int signum __rte_unused) {
+ RTE_LOG(DEBUG, EAL, "receive SIGBUS error!\n");
+ siglongjmp(RTE_PER_LCORE(unplug_longjmp_env), 1); }
+
+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)
{
@@ -132,6 +156,31 @@ dev_uev_parse(const char *buf, struct
rte_dev_event *event, int length)
return 0;
}
+static int
+dev_uev_remove_handler(struct rte_device *dev) {
+ struct rte_bus *bus = rte_bus_find_by_device_name(dev->name);
+ int ret;
+
+ if (!dev)
+ return -1;
+
+ if (bus->handle_hot_unplug) {
+ /**
+ * call bus ops to handle hot unplug.
+ */
+ ret = bus->handle_hot_unplug(dev);
+ if (ret) {
+ RTE_LOG(ERR, EAL,
+ "It cannot handle hot unplug for device (%s) "
+ "on the bus.\n ",
+ dev->name);
+ return ret;
+ }
+ }
+ return 0;
+}
+
static void
dev_delayed_unregister(void *param)
{
@@ -146,6 +195,9 @@ 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);
@@ -170,11 +222,87 @@ 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) {
+ bus = rte_bus_find_by_name(busname);
+ if (bus == NULL) {
+ RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n",
+ uevent.devname);
+ return;
+ }
+ dev = bus->find_device(NULL, cmp_dev_name,
+ uevent.devname);
+ if (dev == NULL) {
+ RTE_LOG(ERR, EAL,
+ "Cannot find unplugged device (%s)\n",
+ uevent.devname);
+ return;
+ }
+ ret = dev_uev_remove_handler(dev);
+ if (ret) {
+ RTE_LOG(ERR, EAL, "Driver cannot remap the "
+ "device (%s)\n",
+ dev->name);
+ return;
+ }
+ /* wake up all the threads */
+ pthread_cond_broadcast(&failure_recovery_cond);
+ }
dev_callback_process(uevent.devname, uevent.type);
+ }
}
int __rte_experimental
+rte_dev_handle_hot_unplug(void)
+{
+ struct sigaction act;
+ sigset_t mask;
+ int ret = 0;
+
+ /* set signal handlers */
+ memset(&act, 0x00, sizeof(struct sigaction));
+ act.sa_handler = sigbus_handler;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_RESTART;
+ sigaction(SIGBUS, &act, NULL);
+ sigemptyset(&mask);
+ sigaddset(&mask, SIGBUS);
+ pthread_sigmask(SIG_UNBLOCK, &mask, NULL);
+
+ ret = sigsetjmp(RTE_PER_LCORE(unplug_longjmp_env), 1);
+ if (ret) {
+ /*
+ * Waitting for condition variable before failure recovery
+ * finish. Now the limitation is only handle one device
+ * hot plug, for multiple devices hotplug, need check if
+ * the device belong to this working thread, then directly
+ * call memory remaping, unrelated thread just keep going
+ * their work by no interrupt from hotplug.
+ * TODO: multiple device hotplug
+ */
+ pthread_mutex_lock(&failure_recovery_lock);
+ RTE_LOG(DEBUG, EAL, "begin waiting for the failure handler.\n");
+ pthread_cond_wait(&failure_recovery_cond,
+ &failure_recovery_lock);
+ RTE_LOG(DEBUG, EAL,
+ "come back from waiting for failure handler.\n");
+ pthread_mutex_unlock(&failure_recovery_lock);
