[dpdk-dev] [PATCH V19 3/4] eal/linux: uevent parse and process
Tan, Jianfeng
jianfeng.tan at intel.com
Thu Apr 5 13:05:21 CEST 2018
On 4/5/2018 5:02 PM, Jeff Guo wrote:
> In order to handle the uevent which has been detected from the kernel
> side, add uevent parse and process function to translate the uevent into
> device event, which user has subscribed to monitor.
>
> Signed-off-by: Jeff Guo <jia.guo at intel.com>
> ---
> v19->18:
> fix some misunderstanding part
> ---
> lib/librte_eal/linuxapp/eal/eal_dev.c | 196 +++++++++++++++++++++++++++++++++-
> 1 file changed, 194 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linuxapp/eal/eal_dev.c
> index 9c8d1a0..4686c41 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_dev.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
> @@ -2,21 +2,213 @@
> * Copyright(c) 2018 Intel Corporation
> */
>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/socket.h>
> +#include <linux/netlink.h>
> +
> #include <rte_log.h>
> #include <rte_compat.h>
> #include <rte_dev.h>
> +#include <rte_malloc.h>
> +#include <rte_interrupts.h>
> +
> +#include "eal_private.h"
> +
> +static struct rte_intr_handle intr_handle = {.fd = -1 };
> +static bool monitor_started;
> +
> +#define EAL_UEV_MSG_LEN 4096
> +#define EAL_UEV_MSG_ELEM_LEN 128
> +
> +/* identify the system layer which reports this event. */
> +enum eal_dev_event_subsystem {
> + EAL_DEV_EVENT_SUBSYSTEM_PCI, /* PCI bus device event */
> + EAL_DEV_EVENT_SUBSYSTEM_UIO, /* UIO driver device event */
> + EAL_DEV_EVENT_SUBSYSTEM_VFIO, /* VFIO driver device event */
> + EAL_DEV_EVENT_SUBSYSTEM_MAX
> +};
> +
> +static int
> +dev_uev_socket_fd_create(void)
> +{
> + struct sockaddr_nl addr;
> + int ret;
> +
> + intr_handle.fd = socket(PF_NETLINK, SOCK_RAW | SOCK_CLOEXEC |
> + SOCK_NONBLOCK,
> + NETLINK_KOBJECT_UEVENT);
> + if (intr_handle.fd < 0) {
> + RTE_LOG(ERR, EAL, "create uevent fd failed.\n");
> + return -1;
> + }
> +
> + memset(&addr, 0, sizeof(addr));
> + addr.nl_family = AF_NETLINK;
> + addr.nl_pid = 0;
> + addr.nl_groups = 0xffffffff;
> +
> + ret = bind(intr_handle.fd, (struct sockaddr *) &addr, sizeof(addr));
> + if (ret < 0) {
> + RTE_LOG(ERR, EAL, "Failed to bind uevent socket.\n");
> + goto err;
> + }
> +
> + return 0;
> +err:
> + close(intr_handle.fd);
> + intr_handle.fd = -1;
> + return ret;
> +}
> +
> +static int
> +dev_uev_parse(const char *buf, struct rte_dev_event *event, int length)
> +{
> + char action[EAL_UEV_MSG_ELEM_LEN];
> + char subsystem[EAL_UEV_MSG_ELEM_LEN];
> + char pci_slot_name[EAL_UEV_MSG_ELEM_LEN];
> + int i = 0, ret = 0;
> +
> + memset(action, 0, EAL_UEV_MSG_ELEM_LEN);
> + memset(subsystem, 0, EAL_UEV_MSG_ELEM_LEN);
> + memset(pci_slot_name, 0, EAL_UEV_MSG_ELEM_LEN);
> +
> + while (i < length) {
> + for (; i < length; i++) {
> + if (*buf)
> + break;
> + buf++;
> + }
> + /**
> + * check device uevent from kernel side, no need to check
> + * uevent from udev.
> + */
> + if (!strncmp(buf, "libudev", 7)) {
> + buf += 7;
> + i += 7;
> + return -1;
> + }
> + if (!strncmp(buf, "ACTION=", 7)) {
> + buf += 7;
> + i += 7;
> + snprintf(action, sizeof(action), "%s", buf);
> + } else if (!strncmp(buf, "SUBSYSTEM=", 10)) {
> + buf += 10;
> + i += 10;
> + snprintf(subsystem, sizeof(subsystem), "%s", buf);
> + } else if (!strncmp(buf, "PCI_SLOT_NAME=", 14)) {
> + buf += 14;
> + i += 14;
> + snprintf(pci_slot_name, sizeof(subsystem), "%s", buf);
> + event->devname = strdup(pci_slot_name);
> + }
> + for (; i < length; i++) {
> + if (*buf == '\0')
> + break;
> + buf++;
> + }
> + }
> +
> + /* parse the subsystem layer */
> + if (!strncmp(subsystem, "uio", 3))
> + event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_UIO;
> + else if (!strncmp(subsystem, "pci", 3))
> + event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_PCI;
> + else if (!strncmp(subsystem, "vfio", 4))
> + event->subsystem = EAL_DEV_EVENT_SUBSYSTEM_VFIO;
> + else
> + ret = -1;
We can just return -1 here.
>
> + /* parse the action type */
> + if (!strncmp(action, "add", 3))
> + event->type = RTE_DEV_EVENT_ADD;
> + else if (!strncmp(action, "remove", 6))
> + event->type = RTE_DEV_EVENT_REMOVE;
> + else
> + ret = -1;
We can just return -1 here.
> + return ret;
return 0 here.
> +}
> +
> +static void
> +dev_uev_handler(__rte_unused void *param)
> +{
> + struct rte_dev_event uevent;
> + int ret;
> + char buf[EAL_UEV_MSG_LEN];
> +
> + memset(&uevent, 0, sizeof(struct rte_dev_event));
> + memset(buf, 0, EAL_UEV_MSG_LEN);
> +
> + ret = recv(intr_handle.fd, buf, EAL_UEV_MSG_LEN, MSG_DONTWAIT);
> + if (ret == 0 || (ret < 0 && errno != EAGAIN)) {
> + /* connection is closed or broken, can not up again. */
> + RTE_LOG(ERR, EAL, "uevent socket connection is broken.\n");
Again, we need an alarm to unregister the callback from intr thread.
> + return;
> + } else if (ret < 0) {
> + RTE_LOG(ERR, EAL,
> + "uevent socket read error(%d): %s.\n",
> + errno, strerror(errno));
> + return;
> + }
I think the above code can be adjusted as:
if (ret == 0 || (ret < 0 && errno == EAGAIN))
return;
else if (ret < 0) {
RTE_LOG(ERR, EAL, "...");
set_alarm_to_unregister();
}
> +
> + ret = dev_uev_parse(buf, &uevent, EAL_UEV_MSG_LEN);
> + if (ret < 0) {
> + RTE_LOG(ERR, EAL, "It is not an valid event "
s/ERR/DEBUG, or there are too many logs.
> + "that need to be handle.\n");
> + return;
> + }
> +
> + RTE_LOG(DEBUG, EAL, "receive uevent(name:%s, type:%d, subsystem:%d)\n",
> + uevent.devname, uevent.type, uevent.subsystem);
> +
> + if (uevent.devname)
> + dev_callback_process(uevent.devname, uevent.type);
> +}
>
> int __rte_experimental
> rte_dev_event_monitor_start(void)
> {
> - /* TODO: start uevent monitor for linux */
> + int ret;
> +
> + if (monitor_started)
> + return 0;
> +
> + ret = dev_uev_socket_fd_create();
> + if (ret) {
> + RTE_LOG(ERR, EAL, "error create device event fd.\n");
> + return -1;
> + }
> +
> + intr_handle.type = RTE_INTR_HANDLE_DEV_EVENT;
> + ret = rte_intr_callback_register(&intr_handle, dev_uev_handler, NULL);
> +
> + if (ret) {
> + RTE_LOG(ERR, EAL, "fail to register uevent callback.\n");
> + return -1;
> + }
> +
> + monitor_started = true;
> +
> return 0;
> }
>
> int __rte_experimental
> rte_dev_event_monitor_stop(void)
> {
> - /* TODO: stop uevent monitor for linux */
> + int ret;
> +
> + if (!monitor_started)
> + return 0;
> +
> + ret = rte_intr_callback_unregister(&intr_handle, dev_uev_handler,
> + (void *)-1);
> + if (ret < 0) {
> + RTE_LOG(ERR, EAL, "fail to unregister uevent callback.\n");
> + return ret;
> + }
> +
> + close(intr_handle.fd);
> + intr_handle.fd = -1;
> + monitor_started = false;
> return 0;
> }
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