[dpdk-dev] [PATCH V19 2/4] eal: add device event monitor framework
Tan, Jianfeng
jianfeng.tan at intel.com
Thu Apr 5 12:15:53 CEST 2018
On 4/5/2018 4:32 PM, Jeff Guo wrote:
> This patch aims to add a general device event monitor framework at
> EAL device layer, for device hotplug awareness and actions adopted
> accordingly. It could also expand for all other types of device event
> monitor, but not in this scope at the stage.
>
> To get started, users firstly call below new added APIs to enable/disable
> the device event monitor mechanism:
> - rte_dev_event_monitor_start
> - rte_dev_event_monitor_stop
>
> Then users shell register or unregister callbacks through the new added
> APIs. Callbacks can be some device specific, or for all devices.
> -rte_dev_event_callback_register
> -rte_dev_event_callback_unregister
>
> Use hotplug case for example, when device hotplug insertion or hotplug
> removal, we will get notified from kernel, then call user's callbacks
> accordingly to handle it, such as detach or attach the device from the
> bus, and could benefit further fail-safe or live-migration.
>
> Signed-off-by: Jeff Guo <jia.guo at intel.com>
Except some trivial things, I'm ok with this patch, so
Reviewed-by: Jianfeng Tan <jianfeng.tan at intel.com>
> ---
> v19->v18:
> clear the coding style and fix typo
> ---
> doc/guides/rel_notes/release_18_05.rst | 9 ++
> lib/librte_eal/bsdapp/eal/Makefile | 1 +
> lib/librte_eal/bsdapp/eal/eal_dev.c | 21 +++++
> lib/librte_eal/bsdapp/eal/meson.build | 1 +
> lib/librte_eal/common/eal_common_dev.c | 161 ++++++++++++++++++++++++++++++++
> lib/librte_eal/common/eal_private.h | 15 +++
> lib/librte_eal/common/include/rte_dev.h | 94 +++++++++++++++++++
> lib/librte_eal/linuxapp/eal/Makefile | 1 +
> lib/librte_eal/linuxapp/eal/eal_dev.c | 22 +++++
> lib/librte_eal/linuxapp/eal/meson.build | 1 +
> lib/librte_eal/rte_eal_version.map | 10 ++
> 11 files changed, 336 insertions(+)
> create mode 100644 lib/librte_eal/bsdapp/eal/eal_dev.c
> create mode 100644 lib/librte_eal/linuxapp/eal/eal_dev.c
>
> diff --git a/doc/guides/rel_notes/release_18_05.rst b/doc/guides/rel_notes/release_18_05.rst
> index e5fac1c..d3c86bd 100644
> --- a/doc/guides/rel_notes/release_18_05.rst
> +++ b/doc/guides/rel_notes/release_18_05.rst
> @@ -58,6 +58,15 @@ New Features
> * Added support for NVGRE, VXLAN and GENEVE filters in flow API.
> * Added support for DROP action in flow API.
>
> +* **Added device event monitor framework.**
> +
> + Added a general device event monitor framework at EAL, for device dynamic management.
> + Such as device hotplug awareness and actions adopted accordingly. The list of new APIs:
> +
> + * ``rte_dev_event_monitor_start`` and ``rte_dev_event_monitor_stop`` are for
> + the event monitor enable and disable.
> + * ``rte_dev_event_callback_register`` and ``rte_dev_event_callback_unregister``
> + are for the user's callbacks register and unregister.
>
> API Changes
> -----------
> diff --git a/lib/librte_eal/bsdapp/eal/Makefile b/lib/librte_eal/bsdapp/eal/Makefile
> index ed1d17b..90b88eb 100644
> --- a/lib/librte_eal/bsdapp/eal/Makefile
> +++ b/lib/librte_eal/bsdapp/eal/Makefile
> @@ -33,6 +33,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_lcore.c
> SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_timer.c
> SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_interrupts.c
> SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_alarm.c
> +SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_dev.c
>
> # from common dir
> SRCS-$(CONFIG_RTE_EXEC_ENV_BSDAPP) += eal_common_lcore.c
> diff --git a/lib/librte_eal/bsdapp/eal/eal_dev.c b/lib/librte_eal/bsdapp/eal/eal_dev.c
> new file mode 100644
> index 0000000..1c6c51b
> --- /dev/null
> +++ b/lib/librte_eal/bsdapp/eal/eal_dev.c
> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2018 Intel Corporation
> + */
> +
> +#include <rte_log.h>
> +#include <rte_compat.h>
> +#include <rte_dev.h>
> +
> +int __rte_experimental
> +rte_dev_event_monitor_start(void)
> +{
> + RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n");
> + return -1;
> +}
> +
> +int __rte_experimental
> +rte_dev_event_monitor_stop(void)
> +{
> + RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n");
> + return -1;
> +}
> diff --git a/lib/librte_eal/bsdapp/eal/meson.build b/lib/librte_eal/bsdapp/eal/meson.build
> index e83fc91..6dfc533 100644
> --- a/lib/librte_eal/bsdapp/eal/meson.build
> +++ b/lib/librte_eal/bsdapp/eal/meson.build
> @@ -12,4 +12,5 @@ env_sources = files('eal_alarm.c',
> 'eal_timer.c',
> 'eal.c',
> 'eal_memory.c',
> + 'eal_dev.c'
> )
> diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
> index cd07144..e202cf2 100644
> --- a/lib/librte_eal/common/eal_common_dev.c
> +++ b/lib/librte_eal/common/eal_common_dev.c
> @@ -14,9 +14,34 @@
> #include <rte_devargs.h>
> #include <rte_debug.h>
> #include <rte_log.h>
> +#include <rte_spinlock.h>
> +#include <rte_malloc.h>
>
> #include "eal_private.h"
>
> +/**
> + * The device event callback description.
> + *
> + * It contains callback address to be registered by user application,
> + * the pointer to the parameters for callback, and the device name.
> + */
> +struct dev_event_callback {
> + TAILQ_ENTRY(dev_event_callback) next; /**< Callbacks list */
> + rte_dev_event_cb_fn cb_fn; /**< Callback address */
> + void *cb_arg; /**< Callback parameter */
> + char *dev_name; /**< Callback device name, NULL is for all device */
> + uint32_t active; /**< Callback is executing */
> +};
> +
> +/* spinlock for device callbacks */
> +static rte_spinlock_t dev_event_lock = RTE_SPINLOCK_INITIALIZER;
It's still not in the right position; it shall be put after
dev_event_callback list.
> +
> +/* The device event callback list for all registered callbacks. */
> +static struct dev_event_cb_list dev_event_cbs;
> +
> +/** @internal Structure to keep track of registered callbacks */
> +TAILQ_HEAD(dev_event_cb_list, dev_event_callback);
> +
> static int cmp_detached_dev_name(const struct rte_device *dev,
> const void *_name)
> {
> @@ -207,3 +232,139 @@ rte_eal_hotplug_remove(const char *busname, const char *devname)
> rte_eal_devargs_remove(busname, devname);
> return ret;
> }
> +
> +int __rte_experimental
> +rte_dev_event_callback_register(const char *device_name,
> + rte_dev_event_cb_fn cb_fn,
> + void *cb_arg)
> +{
> + struct dev_event_callback *event_cb;
> + int ret;
> +
> + if (!cb_fn)
> + return -EINVAL;
> +
> + rte_spinlock_lock(&dev_event_lock);
> +
> + if (TAILQ_EMPTY(&dev_event_cbs))
> + TAILQ_INIT(&dev_event_cbs);
> +
> + TAILQ_FOREACH(event_cb, &dev_event_cbs, next) {
> + if (event_cb->cb_fn == cb_fn && event_cb->cb_arg == cb_arg) {
> + if (device_name == NULL && event_cb->dev_name == NULL)
> + break;
> + if (device_name == NULL || event_cb->dev_name == NULL)
> + continue;
> + if (!strcmp(event_cb->dev_name, device_name))
> + break;
> + }
> + }
> +
> + /* create a new callback. */
> + if (event_cb == NULL) {
> + event_cb = malloc(sizeof(struct dev_event_callback));
> + if (event_cb != NULL) {
> + event_cb->cb_fn = cb_fn;
> + event_cb->cb_arg = cb_arg;
> + event_cb->active = 0;
> + if (!device_name) {
> + event_cb->dev_name = NULL;
> + } else {
> + event_cb->dev_name = strdup(device_name);
> + if (event_cb->dev_name == NULL) {
> + ret = -ENOMEM;
> + goto error;
> + }
> + }
> + TAILQ_INSERT_TAIL(&dev_event_cbs, event_cb, next);
> + } else {
> + RTE_LOG(ERR, EAL,
> + "Failed to allocate memory for device "
> + "event callback.");
> + ret = -ENOMEM;
> + goto error;
> + }
> + } else {
> + RTE_LOG(ERR, EAL,
> + "The callback is already exist, no need "
> + "to register again.\n");
> + ret = -EEXIST;
> + }
> +
> + rte_spinlock_unlock(&dev_event_lock);
> + return 0;
> +error:
> + free(event_cb);
> + rte_spinlock_unlock(&dev_event_lock);
> + return ret;
> +}
> +
> +int __rte_experimental
> +rte_dev_event_callback_unregister(const char *device_name,
> + rte_dev_event_cb_fn cb_fn,
> + void *cb_arg)
> +{
> + int ret = 0;
> + struct dev_event_callback *event_cb, *next;
> +
> + if (!cb_fn)
> + return -EINVAL;
> +
> + rte_spinlock_lock(&dev_event_lock);
> + /*walk through the callbacks and remove all that match. */
> + for (event_cb = TAILQ_FIRST(&dev_event_cbs); event_cb != NULL;
> + event_cb = next) {
> +
> + next = TAILQ_NEXT(event_cb, next);
> +
> + if (device_name != NULL && event_cb->dev_name != NULL) {
> + if (!strcmp(event_cb->dev_name, device_name)) {
> + if (event_cb->cb_fn != cb_fn ||
> + (cb_arg != (void *)-1 &&
> + event_cb->cb_arg != cb_arg))
> + continue;
> + }
> + } else if (device_name != NULL) {
> + continue;
> + }
> +
> + /*
> + * if this callback is not executing right now,
> + * then remove it.
> + */
> + if (event_cb->active == 0) {
> + TAILQ_REMOVE(&dev_event_cbs, event_cb, next);
> + free(event_cb);
> + ret++;
> + } else {
> + continue;
> + }
> + }
> + rte_spinlock_unlock(&dev_event_lock);
> + return ret;
> +}
> +
> +void
> +dev_callback_process(char *device_name, enum rte_dev_event_type event)
> +{
> + struct dev_event_callback *cb_lst;
> +
> + if (device_name == NULL)
> + return;
> +
> + rte_spinlock_lock(&dev_event_lock);
> +
> + TAILQ_FOREACH(cb_lst, &dev_event_cbs, next) {
> + if (cb_lst->dev_name) {
> + if (strcmp(cb_lst->dev_name, device_name))
> + continue;
> + }
> + cb_lst->active = 1;
> + rte_spinlock_unlock(&dev_event_lock);
> + cb_lst->cb_fn(device_name, event,
> + cb_lst->cb_arg);
> + rte_spinlock_lock(&dev_event_lock);
> + cb_lst->active = 0;
> + }
> + rte_spinlock_unlock(&dev_event_lock);
> +}
> diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
> index 0b28770..88e5a59 100644
> --- a/lib/librte_eal/common/eal_private.h
> +++ b/lib/librte_eal/common/eal_private.h
> @@ -9,6 +9,8 @@
> #include <stdint.h>
> #include <stdio.h>
>
> +#include <rte_dev.h>
> +
> /**
> * Initialize the memzone subsystem (private to eal).
> *
> @@ -205,4 +207,17 @@ struct rte_bus *rte_bus_find_by_device_name(const char *str);
>
> int rte_mp_channel_init(void);
>
> +/**
> + * Internal Executes all the user application registered callbacks for
> + * the specific device. It is for DPDK internal user only. User
> + * application should not call it directly.
> + *
> + * @param device_name
> + * The device name.
> + * @param event
> + * the device event type.
> + *
> + */
> +void
> +dev_callback_process(char *device_name, enum rte_dev_event_type event);
> #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 b688f1e..2ed240e 100644
> --- a/lib/librte_eal/common/include/rte_dev.h
> +++ b/lib/librte_eal/common/include/rte_dev.h
> @@ -24,6 +24,25 @@ extern "C" {
> #include <rte_compat.h>
> #include <rte_log.h>
>
> +/**
> + * The device event type.
> + */
> +enum rte_dev_event_type {
> + RTE_DEV_EVENT_ADD, /**< device being added */
> + RTE_DEV_EVENT_REMOVE, /**< device being removed */
> + RTE_DEV_EVENT_MAX /**< max value of this enum */
> +};
> +
> +struct rte_dev_event {
> + enum rte_dev_event_type type; /**< device event type */
> + int subsystem; /**< subsystem id */
> + char *devname; /**< device name */
> +};
> +
> +typedef void (*rte_dev_event_cb_fn)(char *device_name,
> + enum rte_dev_event_type event,
> + void *cb_arg);
> +
> __attribute__((format(printf, 2, 0)))
> static inline void
> rte_pmd_debug_trace(const char *func_name, const char *fmt, ...)
> @@ -267,4 +286,79 @@ __attribute__((used)) = str
> }
> #endif
>
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice
> + *
> + * It registers the callback for the specific device.
> + * Multiple callbacks cal be registered at the same time.
> + *
> + * @param device_name
> + * The device name, that is the param name of the struct rte_device,
> + * null value means for all devices.
> + * @param cb_fn
> + * callback address.
> + * @param cb_arg
> + * address of parameter for callback.
> + *
> + * @return
> + * - On success, zero.
> + * - On failure, a negative value.
> + */
> +int __rte_experimental
> +rte_dev_event_callback_register(const char *device_name,
> + rte_dev_event_cb_fn cb_fn,
> + void *cb_arg);
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice
> + *
> + * It unregisters the callback according to the specified device.
> + *
> + * @param device_name
> + * The device name, that is the param name of the struct rte_device,
> + * null value means for all devices.
Do you mean all callbacks?
> + * @param cb_fn
> + * callback address.
> + * @param cb_arg
> + * address of parameter for callback, (void *)-1 means to remove all
> + * registered which has the same callback address.
> + *
> + * @return
> + * - On success, return the number of callback entities removed.
> + * - On failure, a negative value.
> + */
> +int __rte_experimental
> +rte_dev_event_callback_unregister(const char *device_name,
> + rte_dev_event_cb_fn cb_fn,
> + void *cb_arg);
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice
> + *
> + * Start the device event monitoring.
> + *
> + * @param none
> + * @return
> + * - On success, zero.
> + * - On failure, a negative value.
> + */
> +int __rte_experimental
> +rte_dev_event_monitor_start(void);
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice
> + *
> + * Stop the device event monitoring .
> + *
> + * @param none
> + * @return
> + * - On success, zero.
> + * - On failure, a negative value.
> + */
> +int __rte_experimental
> +rte_dev_event_monitor_stop(void);
> #endif /* _RTE_DEV_H_ */
> diff --git a/lib/librte_eal/linuxapp/eal/Makefile b/lib/librte_eal/linuxapp/eal/Makefile
> index b9c7727..db67001 100644
> --- a/lib/librte_eal/linuxapp/eal/Makefile
> +++ b/lib/librte_eal/linuxapp/eal/Makefile
> @@ -41,6 +41,7 @@ SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_lcore.c
> SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_timer.c
> SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_interrupts.c
> SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_alarm.c
> +SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_dev.c
>
> # from common dir
> SRCS-$(CONFIG_RTE_EXEC_ENV_LINUXAPP) += eal_common_lcore.c
> diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linuxapp/eal/eal_dev.c
> new file mode 100644
> index 0000000..9c8d1a0
> --- /dev/null
> +++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
> @@ -0,0 +1,22 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2018 Intel Corporation
> + */
> +
> +#include <rte_log.h>
> +#include <rte_compat.h>
> +#include <rte_dev.h>
> +
> +
> +int __rte_experimental
> +rte_dev_event_monitor_start(void)
> +{
> + /* TODO: start uevent monitor for linux */
> + return 0;
> +}
> +
> +int __rte_experimental
> +rte_dev_event_monitor_stop(void)
> +{
> + /* TODO: stop uevent monitor for linux */
> + return 0;
> +}
> diff --git a/lib/librte_eal/linuxapp/eal/meson.build b/lib/librte_eal/linuxapp/eal/meson.build
> index 03974ff..b222571 100644
> --- a/lib/librte_eal/linuxapp/eal/meson.build
> +++ b/lib/librte_eal/linuxapp/eal/meson.build
> @@ -18,6 +18,7 @@ env_sources = files('eal_alarm.c',
> 'eal_vfio_mp_sync.c',
> 'eal.c',
> 'eal_memory.c',
> + 'eal_dev.c',
> )
>
> if has_libnuma == 1
> diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map
> index dd38783..3022df1 100644
> --- a/lib/librte_eal/rte_eal_version.map
> +++ b/lib/librte_eal/rte_eal_version.map
> @@ -260,3 +260,13 @@ EXPERIMENTAL {
> rte_socket_id_by_idx;
>
> } DPDK_18.02;
> +
> +EXPERIMENTAL {
> + global:
> +
> + rte_dev_event_monitor_start;
> + rte_dev_event_monitor_stop;
> + rte_dev_event_callback_register;
> + rte_dev_event_callback_unregister;
Use tab instead of spaces.
> +
> +} DPDK_18.05;
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