Hi Jeff
> -----Original Message-----
> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Jeff Guo
> Sent: Wednesday, April 18, 2018 9:38 PM
> To: step...@networkplumber.org; Richardson, Bruce
> <bruce.richard...@intel.com>; Yigit, Ferruh <ferruh.yi...@intel.com>;
> Ananyev, Konstantin <konstantin.anan...@intel.com>;
> gaetan.ri...@6wind.com; Wu, Jingjing <jingjing...@intel.com>;
> tho...@monjalon.net; mo...@mellanox.com; ma...@mellanox.com; Van
> Haaren, Harry <harry.van.haa...@intel.com>; Tan, Jianfeng
> <jianfeng....@intel.com>
> Cc: jblu...@infradead.org; shreyansh.j...@nxp.com; dev@dpdk.org; Guo,
> Jia <jia....@intel.com>; Zhang, Helin <helin.zh...@intel.com>
> Subject: [dpdk-dev] [PATCH V20 2/4] eal: add failure handler mechanism for
> hot plug
>
> This patch introduces a failure handler mechanism to handle device hot
> unplug event. When device be hot plug out, the device resource become
> invalid, if this resource is still be unexpected read/write, system will
> crash.
> This patch let eal help application to handle this fault, when sigbus error
> occur, check the failure address and accordingly remap the invalid memory
> for the corresponding device, that could guaranty the application not to be
> shut down when hot plug.
>
> Signed-off-by: Jeff Guo <jia....@intel.com>
> ---
> v20->v19:
> refine the logic of remapping for multiple device.
> ---
> doc/guides/rel_notes/release_18_05.rst | 6 ++
> lib/librte_eal/common/include/rte_dev.h | 11 +++
> lib/librte_eal/linuxapp/eal/eal_dev.c | 124
> +++++++++++++++++++++++++++++++-
> lib/librte_eal/rte_eal_version.map | 1 +
> 4 files changed, 141 insertions(+), 1 deletion(-)
>
> diff --git a/doc/guides/rel_notes/release_18_05.rst
> b/doc/guides/rel_notes/release_18_05.rst
> index a018ef5..a4ea9af 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/lib/librte_eal/common/include/rte_dev.h
> b/lib/librte_eal/common/include/rte_dev.h
> index 0955e9a..9933131 100644
> --- a/lib/librte_eal/common/include/rte_dev.h
> +++ b/lib/librte_eal/common/include/rte_dev.h
> @@ -360,4 +360,15 @@ 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 handle the device signal bus error. when signal
> +bus error
> + * occur, the handler would check the failure address to find the
> +corresponding
> + * device and remap the memory resource of the device, that would
> +guaranty
> + * the system not crash when the device be hot unplug.
> + */
> +void __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..33e7026 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>
>
> @@ -13,12 +15,16 @@
> #include <rte_malloc.h>
> #include <rte_interrupts.h>
> #include <rte_alarm.h>
> +#include <rte_bus.h>
> +#include <rte_eal.h>
>
> #include "eal_private.h"
>
> static struct rte_intr_handle intr_handle = {.fd = -1 }; static bool
> monitor_started;
>
> +extern struct rte_bus_list rte_bus_list;
> +
> #define EAL_UEV_MSG_LEN 4096
> #define EAL_UEV_MSG_ELEM_LEN 128
>
> @@ -33,6 +39,68 @@ enum eal_dev_event_subsystem { };
>
> static int
> +dev_uev_failure_process(struct rte_device *dev, void *dev_addr) {
> + struct rte_bus *bus;
> + int ret = 0;
> +
> + if (!dev && !dev_addr) {
> + return -EINVAL;
> + } else if (dev) {
> + bus = rte_bus_find_by_device_name(dev->name);
> + if (bus->handle_hot_unplug) {
> + /**
> + * call bus ops to handle hot unplug.
> + */
> + ret = bus->handle_hot_unplug(dev, dev_addr);
> + if (ret) {
> + RTE_LOG(ERR, EAL,
> + "It cannot handle hot unplug "
> + "for device (%s) "
> + "on the bus.\n ",
> + dev->name);
> + }
> + }
> + } else {
> + TAILQ_FOREACH(bus, &rte_bus_list, next) {
> + if (bus->handle_hot_unplug) {
> + /**
> + * call bus ops to handle hot unplug.
> + */
> + ret = bus->handle_hot_unplug(dev, dev_addr);
> + if (ret) {
> + RTE_LOG(ERR, EAL,
> + "It cannot handle hot unplug "
> + "for the device "
> + "on the bus.\n ");
> + }
> + }
> + }
> + }
> + return ret;
> +}
> +
> +static void sigbus_handler(int signum __rte_unused, siginfo_t *info,
> + void *ctx __rte_unused)
> +{
> + int ret;
> +
> + RTE_LOG(ERR, EAL, "SIGBUS error, fault address:%p\n", info->si_addr);
> + ret = dev_uev_failure_process(NULL, info->si_addr);
> + if (!ret)
> + RTE_LOG(DEBUG, EAL,
> + "SIGBUS error is because of 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)
> {
> struct sockaddr_nl addr;
> @@ -146,6 +214,9 @@ 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);
> @@ -170,8 +241,41 @@ 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_failure_process(dev, NULL);
> + if (ret) {
> + RTE_LOG(ERR, EAL, "Driver cannot remap the "
> + "device (%s)\n",
> + dev->name);
> + return;
> + }
> + }
> dev_callback_process(uevent.devname, uevent.type);
> + }
> }
>
> int __rte_experimental
> @@ -216,8 +320,26 @@ rte_dev_event_monitor_stop(void)
> return ret;
> }
>
> + /* recover sigbus. */
> + sigaction(SIGBUS, NULL, NULL);
> +
> close(intr_handle.fd);
> intr_handle.fd = -1;
> monitor_started = false;
> +
> return 0;
> }
> +
> +void __rte_experimental
> +rte_dev_handle_hot_unplug(void)
> +{
> + struct sigaction act;
> +
> + /* set sigbus handler for hotplug. */
> + memset(&act, 0x00, sizeof(struct sigaction));
> + act.sa_sigaction = sigbus_handler;
> + sigemptyset(&act.sa_mask);
> + sigaddset(&act.sa_mask, SIGBUS);
> + act.sa_flags = SA_SIGINFO;
> + sigaction(SIGBUS, &act, NULL);
> +}
Not sure if it's necessary to expose this API,
it can be invoked in rte_dev_event_monitor_start,
since register a sigbus handler looks like an init step when user device to
enable hotplug
Regards
Qi
> diff --git a/lib/librte_eal/rte_eal_version.map
> b/lib/librte_eal/rte_eal_version.map
> index d02d80b..39a0213 100644
> --- a/lib/librte_eal/rte_eal_version.map
> +++ b/lib/librte_eal/rte_eal_version.map
> @@ -217,6 +217,7 @@ EXPERIMENTAL {
> rte_dev_event_callback_unregister;
> rte_dev_event_monitor_start;
> rte_dev_event_monitor_stop;
> + rte_dev_handle_hot_unplug;
> rte_eal_cleanup;
> rte_eal_devargs_insert;
> rte_eal_devargs_parse;
> --
> 2.7.4
