This patch adds a callback for cpu hotplug event. The cpu hotplug netlink message is of the following format: {online|offline}@/devices/system/cpu/cpuxx (xx is cpuid) When a cpu online message is received, the callback will get the new added cpuid from the message, and adds it to the cpuset.cpus of a specific cgroup, such as libvirtd, qemu driver, or lxc driver's cpuset cgroup. When a cpu offline message is received, nothing to for now. Signed-off-by: Tang Chen <tangchen(a)cn.fujitsu.com&gt; --- include/libvirt/virterror.h | 2 + src/Makefile.am | 1 + src/libvirt_private.syms | 5 + src/util/cgroup.c | 6 +- src/util/cgroup.h | 4 + src/util/hotplug.c | 221 +++++++++++++++++++++++++++++++++++++++++++ src/util/hotplug.h | 32 +++++++ src/util/virterror.c | 3 +- 8 files changed, 270 insertions(+), 4 deletions(-) create mode 100644 src/util/hotplug.c create mode 100644 src/util/hotplug.h diff --git a/include/libvirt/virterror.h b/include/libvirt/virterror.h index 69c64aa..5e10338 100644 --- a/include/libvirt/virterror.h +++ b/include/libvirt/virterror.h @@ -114,6 +114,8 @@ typedef enum { VIR_FROM_SSH = 50, /* Error from libssh2 connection transport */ + VIR_FROM_HOTPLUG = 51, /* Error from Hotplug driver */ + # ifdef VIR_ENUM_SENTINELS VIR_ERR_DOMAIN_LAST # endif diff --git a/src/Makefile.am b/src/Makefile.am index 95e1bea..c65ee37 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -60,6 +60,7 @@ UTIL_SOURCES = \ util/event.c util/event.h \ util/event_poll.c util/event_poll.h \ util/hooks.c util/hooks.h \ + util/hotplug.c util/hotplug.h \ util/iptables.c util/iptables.h \ util/ebtables.c util/ebtables.h \ util/dnsmasq.c util/dnsmasq.h \ diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 27eb43e..97f9c7b 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -64,6 +64,7 @@ virCgroupAddTaskController; virCgroupAllowDevice; virCgroupAllowDeviceMajor; virCgroupAllowDevicePath; +virCgroupAppRoot; virCgroupControllerTypeFromString; virCgroupControllerTypeToString; virCgroupDenyAllDevices; @@ -643,6 +644,10 @@ virHookInitialize; virHookPresent; +# hotplug.h +virCpuHotplugRegisterCallback; + + # interface_conf.h virInterfaceAssignDef; virInterfaceDefFormat; diff --git a/src/util/cgroup.c b/src/util/cgroup.c index 8541c7f..df5f31a 100644 --- a/src/util/cgroup.c +++ b/src/util/cgroup.c @@ -641,9 +641,9 @@ err: return rc; } -static int virCgroupAppRoot(int privileged, - virCgroupPtr *group, - int create) +int virCgroupAppRoot(int privileged, + virCgroupPtr *group, + int create) { virCgroupPtr rootgrp = NULL; int rc; diff --git a/src/util/cgroup.h b/src/util/cgroup.h index 68ac232..ef9b022 100644 --- a/src/util/cgroup.h +++ b/src/util/cgroup.h @@ -44,6 +44,10 @@ enum { VIR_ENUM_DECL(virCgroupController); +int virCgroupAppRoot(int privileged, + virCgroupPtr *group, + int create); + int virCgroupForDriver(const char *name, virCgroupPtr *group, int privileged, diff --git a/src/util/hotplug.c b/src/util/hotplug.c new file mode 100644 index 0000000..d5ffd67 --- /dev/null +++ b/src/util/hotplug.c @@ -0,0 +1,221 @@ +/* + * Copyright (C) 2012 FUJITSU, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; If not, see + * <http://www.gnu.org/licenses/>;. + * + * Authors: + * Tang Chen <tangchen(a)cn.fujitsu.com&gt; + */ + +#include <sys/types.h> +#include <sys/socket.h> +#include <string.h> +#include <stdlib.h> + +#include "hotplug.h" +#include "cgroup.h" +#include "virterror_internal.h" +#include "virnetlink.h" +#include "logging.h" +#include "memory.h" + +#define VIR_FROM_THIS VIR_FROM_HOTPLUG + +#ifdef __linux__ + +/** + * CPU hotplug message is of the following format: + * {online|offline}@/devices/system/cpu/cpuxx (xx is cpuid) + */ +# define CPU_ONLINE_MSG "online@/devices/system/cpu/cpu" +# define CPU_OFFLINE_MSG "offline@/devices/system/cpu/cpu" + +/** + * getCpuidFromNetlinkMsg: + * + * @msg: The buffer containing the received netlink message + * @cpuid: Contains the cpuid in the message + * + * This function get the cpuid from the following netlink message, + * {online|offline}@/devices/system/cpu/cpuxx (xx is cpuid) + * + * Returns 0 on success, or -1 on error. + */ +static int getCpuidFromNetlinkMsg(unsigned char *msg, + char **cpuid) +{ + char *p = NULL; + size_t len_online = strlen(CPU_ONLINE_MSG); + size_t len_offline = strlen(CPU_OFFLINE_MSG); + + if (VIR_ALLOC_N(*cpuid, 64) < 0) + goto memory_error; + + /** + * For now, we aren't sure if the message is a '/0' ended string. + * So we only test the first len_online or len_offline characters. + */ + if (strncmp((const char *)msg, CPU_ONLINE_MSG, len_online) == 0 || + strncmp((const char *)msg, CPU_OFFLINE_MSG, len_offline) == 0) { + p = strrchr((const char *)msg, '/'); + p = p + 4; + strcpy(*cpuid, p); + return 0; + } else { + VIR_DEBUG("Event is not a cpu hotplug event."); + VIR_FREE(*cpuid); + return -1; + } + +memory_error: + virReportOOMError(); + return -1; +} + +/** + * virCpuHotplugCallback: + * + * @msg: The buffer containing the received netlink message + * @length: The length of the received netlink message + * @peer: The netling sockaddr containing the peer information + * @handled: Contains information if the message has been replied to yet + * @opaque: Contains a cgroup identifier to be modified + * + * Cpu hotplug netlink event handler. It is called when libvirtd + * receives netlink message from kernel, and modifies cpuset.cpus + * of specified cgroup. + */ +static void +virCpuHotplugCallback(unsigned char *msg, + int length, + struct sockaddr_nl *peer, + bool *handled, + void *opaque) +{ + char *cpuid = NULL; + char *cpus = NULL; + virCgroupPtr cgroup = opaque; + + if (!cgroup) + return; + + if (VIR_ALLOC_N(cpus, 1024) < 0) { + virReportOOMError(); + return; + } + + if (getCpuidFromNetlinkMsg(msg, &cpuid) < 0) { + goto error_2; + } + + /** + * If getCpuidFromNetlinkMsg() succeeds, we are sure the + * netlink message is a '/0' ended string. + */ + VIR_DEBUG("netlink (cpu hotplug): %s", msg); + + if (msg == strstr((const char *)msg, "online")) { + VIR_DEBUG("CPU %s online message received.", cpuid); + + if (virCgroupGetCpusetCpus(cgroup, &cpus) < 0) { + virReportSystemError(errno, + "%s", + _("Unable to get cpuset.cpus")); + goto error_1; + } + + if (virAsprintf(&cpus, "%s,%s", cpus, cpuid) < 0) { + virReportOOMError(); + goto error_1; + } + + if (virCgroupSetCpusetCpus(cgroup, cpus) < 0) { + virReportSystemError(errno, + "%s", + _("Unable to set cpuset.cpus")); + goto error_1; + } + + } else if (msg == strstr((const char *)msg, "offline")) { + VIR_DEBUG("CPU %s offline message received.", cpuid); + } + +error_1: + VIR_FREE(cpuid); + +error_2: + VIR_FREE(cpus); + + return; +} + +/** + * virCpuHotplugDestroyCallback: + * + * @watch: watch whose handle to remove + * @macaddr: macaddr whose handle to remove + * @opaque: Contains user data to pass to the callback + * + * This function is called when a netlink message handler is terminated. + * For now, nothing to do. + */ +static void +virCpuHotplugDestroyCallback(int watch ATTRIBUTE_UNUSED, + const virMacAddrPtr macaddr ATTRIBUTE_UNUSED, + void *opaque ATTRIBUTE_UNUSED) +{ + VIR_DEBUG("CPU hotplug netlink handler has been removed."); +} + +/** + * virCpuHotplugRegisterCallback: + * + * @opaque: Contains user data to pass to the callback, which is a + * cgroup identifier to be modified + * + * Register a callback for cpu hotplug event. + * + * Returns -1 if the file handle cannot be registered, number of + * monitor upon success. + */ +int +virCpuHotplugRegisterCallback(void *opaque) +{ + int ret = 0; + virCgroupPtr cgroup = (virCgroupPtr)opaque; + + if (virNetlinkEventServiceIsRunning(NETLINK_KOBJECT_UEVENT)) + ret = virNetlinkEventAddClient(virCpuHotplugCallback, + virCpuHotplugDestroyCallback, + cgroup, NULL, NETLINK_KOBJECT_UEVENT); + + return ret; +} + +#else + +static const char *unsupported = N_("Not a linux system."); + +/** + * virCpuHotplugRegisterCallback: Register a callback for cpu hotplug event. + */ +int +virCpuHotplugRegisterCallback(void *opaque ATTRIBUTE_UNUSED) +{ + VIR_DEBUG("%s", _(unsupported)); + return 0; +} + +#endif /* __linux__ */ diff --git a/src/util/hotplug.h b/src/util/hotplug.h new file mode 100644 index 0000000..8f2cdf3 --- /dev/null +++ b/src/util/hotplug.h @@ -0,0 +1,32 @@ +/* + * Copyright (C) 2012 FUJITSU, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; If not, see + * <http://www.gnu.org/licenses/>;. + * + * Authors: + * Tang Chen <tangchen(a)cn.fujitsu.com&gt; + */ + +#ifndef __HOTPLUG_H_ +# define __HOTPLUG_H_ + +# include "internal.h" + +/** + * virCpuHotplugRegisterCallback: Register a callback for cpu hotplug event. + */ +int virCpuHotplugRegisterCallback(void *opaque); + +#endif diff --git a/src/util/virterror.c b/src/util/virterror.c index 3ee2ae0..1ae26f9 100644 --- a/src/util/virterror.c +++ b/src/util/virterror.c @@ -115,7 +115,8 @@ VIR_ENUM_IMPL(virErrorDomain, VIR_ERR_DOMAIN_LAST, "Parallels Cloud Server", "Device Config", - "SSH transport layer" /* 50 */ + "SSH transport layer", /* 50 */ + "Hotplug driver" /* 51 */ ) -- 1.7.10.1

Signed-off-by: Tang Chen <tangchen(a)cn.fujitsu.com&gt; --- src/qemu/qemu_driver.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 64c407d..509cdd7 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -92,6 +92,7 @@ #include "virnodesuspend.h" #include "virtime.h" #include "virtypedparam.h" +#include "hotplug.h" #define VIR_FROM_THIS VIR_FROM_QEMU @@ -710,6 +711,13 @@ qemudStartup(int privileged) { virStrerror(-rc, ebuf, sizeof(ebuf))); } + /* Register cpu hotplug netlink handler for qemu driver */ + if (virCpuHotplugRegisterCallback(qemu_driver->cgroup) < 0) { + VIR_ERROR(_("Unable to register cpu hotplug netlink handler" + " for qemu driver")); + goto error; + } + if (qemudLoadDriverConfig(qemu_driver, driverConf) < 0) { goto error; } -- 1.7.10.1