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libvirt/src/util/virhostcpu.c
Viktor Mihajlovski 1be35910f7 util: Allow to query the presence of host CPU bitmaps 
The functions to retrieve online and present host CPU information
are only supported on Linux for the time being.

This leads to runtime errors if these function are used on other
platforms. To avoid that, code in higher levels using the functions
must replicate the conditional compilation in higher level which
is error prone (and is plainly spoken ugly).

Adding a function virHostCPUHasBitmap that can be used to check
for host CPU bitmap support.

NB: There are other functions including the host CPU count that
are lacking support on all platforms, but they are too essential
in order to be bypassed.

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
2016-12-13 18:12:09 -05:00

1349 lines
39 KiB
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/*
* virhostcpu.c: helper APIs for host CPU info
*
* Copyright (C) 2006-2016 Red Hat, Inc.
* Copyright (C) 2006 Daniel P. Berrange
*
* 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/>.
*
* Author: Daniel P. Berrange <berrange@redhat.com>
*/
#include <config.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <errno.h>
#include <dirent.h>
#include <sys/utsname.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
#if HAVE_LINUX_KVM_H
# include <linux/kvm.h>
#endif
#if defined(__FreeBSD__) || defined(__APPLE__)
# include <sys/time.h>
# include <sys/types.h>
# include <sys/sysctl.h>
# include <sys/resource.h>
#endif
#include "c-ctype.h"
#include "viralloc.h"
#include "virhostcpupriv.h"
#include "physmem.h"
#include "virerror.h"
#include "count-one-bits.h"
#include "intprops.h"
#include "virarch.h"
#include "virfile.h"
#include "virtypedparam.h"
#include "virstring.h"
#include "virnuma.h"
#include "virlog.h"
#define VIR_FROM_THIS VIR_FROM_NONE
VIR_LOG_INIT("util.hostcpu");
#define KVM_DEVICE "/dev/kvm"
#if defined(__FreeBSD__) || defined(__APPLE__)
static int
virHostCPUGetCountAppleFreeBSD(void)
{
int ncpu_mib[2] = { CTL_HW, HW_NCPU };
unsigned long ncpu;
size_t ncpu_len = sizeof(ncpu);
if (sysctl(ncpu_mib, 2, &ncpu, &ncpu_len, NULL, 0) == -1) {
virReportSystemError(errno, "%s", _("Cannot obtain CPU count"));
return -1;
}
return ncpu;
}
#endif /* defined(__FreeBSD__) || defined(__APPLE__) */
#ifdef __FreeBSD__
# define BSD_CPU_STATS_ALL 4
# define BSD_MEMORY_STATS_ALL 4
# define TICK_TO_NSEC (1000ull * 1000ull * 1000ull / (stathz ? stathz : hz))
static int
virHostCPUGetStatsFreeBSD(int cpuNum,
virNodeCPUStatsPtr params,
int *nparams)
{
const char *sysctl_name;
long *cpu_times;
struct clockinfo clkinfo;
size_t i, j, cpu_times_size, clkinfo_size;
int cpu_times_num, offset, hz, stathz, ret = -1;
struct field_cpu_map {
const char *field;
int idx[CPUSTATES];
} cpu_map[] = {
{VIR_NODE_CPU_STATS_KERNEL, {CP_SYS}},
{VIR_NODE_CPU_STATS_USER, {CP_USER, CP_NICE}},
{VIR_NODE_CPU_STATS_IDLE, {CP_IDLE}},
{VIR_NODE_CPU_STATS_INTR, {CP_INTR}},
{NULL, {0}}
};
if ((*nparams) == 0) {
*nparams = BSD_CPU_STATS_ALL;
return 0;
}
if ((*nparams) != BSD_CPU_STATS_ALL) {
virReportInvalidArg(*nparams,
_("nparams in %s must be equal to %d"),
__FUNCTION__, BSD_CPU_STATS_ALL);
return -1;
}
clkinfo_size = sizeof(clkinfo);
if (sysctlbyname("kern.clockrate", &clkinfo, &clkinfo_size, NULL, 0) < 0) {
virReportSystemError(errno,
_("sysctl failed for '%s'"),
"kern.clockrate");
return -1;
}
stathz = clkinfo.stathz;
hz = clkinfo.hz;
if (cpuNum == VIR_NODE_CPU_STATS_ALL_CPUS) {
sysctl_name = "kern.cp_time";
cpu_times_num = 1;
offset = 0;
} else {
sysctl_name = "kern.cp_times";
cpu_times_num = virHostCPUGetCountAppleFreeBSD();
if (cpuNum >= cpu_times_num) {
virReportInvalidArg(cpuNum,
_("Invalid cpuNum in %s"),
__FUNCTION__);
return -1;
}
offset = cpu_times_num * CPUSTATES;
}
cpu_times_size = sizeof(long) * cpu_times_num * CPUSTATES;
if (VIR_ALLOC_N(cpu_times, cpu_times_num * CPUSTATES) < 0)
goto cleanup;
if (sysctlbyname(sysctl_name, cpu_times, &cpu_times_size, NULL, 0) < 0) {
virReportSystemError(errno,
_("sysctl failed for '%s'"),
sysctl_name);
goto cleanup;
}
for (i = 0; cpu_map[i].field != NULL; i++) {
virNodeCPUStatsPtr param = &params[i];
if (virStrcpyStatic(param->field, cpu_map[i].field) == NULL) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Field '%s' too long for destination"),
cpu_map[i].field);
goto cleanup;
}
param->value = 0;
for (j = 0; j < ARRAY_CARDINALITY(cpu_map[i].idx); j++)
param->value += cpu_times[offset + cpu_map[i].idx[j]] * TICK_TO_NSEC;
}
ret = 0;
cleanup:
VIR_FREE(cpu_times);
return ret;
}
#endif /* __FreeBSD__ */
#ifdef __linux__
# define SYSFS_SYSTEM_PATH "/sys/devices/system"
# define CPUINFO_PATH "/proc/cpuinfo"
# define PROCSTAT_PATH "/proc/stat"
# define SYSFS_THREAD_SIBLINGS_LIST_LENGTH_MAX 8192
# define LINUX_NB_CPU_STATS 4
static const char *sysfs_system_path = SYSFS_SYSTEM_PATH;
void virHostCPUSetSysFSSystemPathLinux(const char *path)
{
if (path)
sysfs_system_path = path;
else
sysfs_system_path = SYSFS_SYSTEM_PATH;
}
/* Return the positive decimal contents of the given
* DIR/cpu%u/FILE, or -1 on error. If DEFAULT_VALUE is non-negative
* and the file could not be found, return that instead of an error;
* this is useful for machines that cannot hot-unplug cpu0, or where
* hot-unplugging is disabled, or where the kernel is too old
* to support NUMA cells, etc. */
static int
virHostCPUGetValue(const char *dir, unsigned int cpu, const char *file,
int default_value)
{
char *path;
FILE *pathfp;
int value = -1;
char value_str[INT_BUFSIZE_BOUND(value)];
char *tmp;
if (virAsprintf(&path, "%s/cpu%u/%s", dir, cpu, file) < 0)
return -1;
pathfp = fopen(path, "r");
if (pathfp == NULL) {
if (default_value >= 0 && errno == ENOENT)
value = default_value;
else
virReportSystemError(errno, _("cannot open %s"), path);
goto cleanup;
}
if (fgets(value_str, sizeof(value_str), pathfp) == NULL) {
virReportSystemError(errno, _("cannot read from %s"), path);
goto cleanup;
}
if (virStrToLong_i(value_str, &tmp, 10, &value) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("could not convert '%s' to an integer"),
value_str);
goto cleanup;
}
cleanup:
VIR_FORCE_FCLOSE(pathfp);
VIR_FREE(path);
return value;
}
static unsigned long
virHostCPUCountThreadSiblings(const char *dir, unsigned int cpu)
{
unsigned long ret = 0;
char *path;
char *str = NULL;
size_t i;
if (virAsprintf(&path, "%s/cpu%u/topology/thread_siblings",
dir, cpu) < 0)
return 0;
if (!virFileExists(path)) {
/* If file doesn't exist, then pretend our only
* sibling is ourself */
ret = 1;
goto cleanup;
}
if (virFileReadAll(path, SYSFS_THREAD_SIBLINGS_LIST_LENGTH_MAX, &str) < 0)
goto cleanup;
for (i = 0; str[i] != '\0'; i++) {
if (c_isxdigit(str[i]))
ret += count_one_bits(virHexToBin(str[i]));
}
cleanup:
VIR_FREE(str);
VIR_FREE(path);
return ret;
}
static int
virHostCPUParseSocket(const char *dir,
virArch arch,
unsigned int cpu)
{
int ret = virHostCPUGetValue(dir, cpu, "topology/physical_package_id", 0);
if (ARCH_IS_ARM(arch) || ARCH_IS_PPC(arch) || ARCH_IS_S390(arch)) {
/* arm, ppc and s390(x) has -1 */
if (ret < 0)
ret = 0;
}
return ret;
}
/* parses a node entry, returning number of processors in the node and
* filling arguments */
static int
ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3)
ATTRIBUTE_NONNULL(4) ATTRIBUTE_NONNULL(6)
ATTRIBUTE_NONNULL(7) ATTRIBUTE_NONNULL(8)
ATTRIBUTE_NONNULL(9)
virHostCPUParseNode(const char *node,
virArch arch,
virBitmapPtr present_cpus_map,
virBitmapPtr online_cpus_map,
int threads_per_subcore,
int *sockets,
int *cores,
int *threads,
int *offline)
{
/* Biggest value we can expect to be used as either socket id
* or core id. Bitmaps will need to be sized accordingly */
const int ID_MAX = 4095;
int ret = -1;
int processors = 0;
DIR *cpudir = NULL;
struct dirent *cpudirent = NULL;
virBitmapPtr node_cpus_map = NULL;
virBitmapPtr sockets_map = NULL;
virBitmapPtr *cores_maps = NULL;
int npresent_cpus = virBitmapSize(present_cpus_map);
int sock_max = 0;
int sock;
int core;
size_t i;
int siblings;
unsigned int cpu;
int direrr;
*threads = 0;
*cores = 0;
*sockets = 0;
if (virDirOpen(&cpudir, node) < 0)
goto cleanup;
/* Keep track of the CPUs that belong to the current node */
if (!(node_cpus_map = virBitmapNew(npresent_cpus)))
goto cleanup;
/* enumerate sockets in the node */
if (!(sockets_map = virBitmapNew(ID_MAX + 1)))
goto cleanup;
while ((direrr = virDirRead(cpudir, &cpudirent, node)) > 0) {
if (sscanf(cpudirent->d_name, "cpu%u", &cpu) != 1)
continue;
if (!virBitmapIsBitSet(present_cpus_map, cpu))
continue;
/* Mark this CPU as part of the current node */
if (virBitmapSetBit(node_cpus_map, cpu) < 0)
goto cleanup;
if (!virBitmapIsBitSet(online_cpus_map, cpu))
continue;
/* Parse socket */
if ((sock = virHostCPUParseSocket(node, arch, cpu)) < 0)
goto cleanup;
if (sock > ID_MAX) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Socket %d can't be handled (max socket is %d)"),
sock, ID_MAX);
goto cleanup;
}
if (virBitmapSetBit(sockets_map, sock) < 0)
goto cleanup;
if (sock > sock_max)
sock_max = sock;
}
if (direrr < 0)
goto cleanup;
sock_max++;
/* allocate cores maps for each socket */
if (VIR_ALLOC_N(cores_maps, sock_max) < 0)
goto cleanup;
for (i = 0; i < sock_max; i++)
if (!(cores_maps[i] = virBitmapNew(ID_MAX + 1)))
goto cleanup;
/* Iterate over all CPUs in the node, in ascending order */
for (cpu = 0; cpu < npresent_cpus; cpu++) {
/* Skip CPUs that are not part of the current node */
if (!virBitmapIsBitSet(node_cpus_map, cpu))
continue;
if (!virBitmapIsBitSet(online_cpus_map, cpu)) {
if (threads_per_subcore > 0 &&
cpu % threads_per_subcore != 0 &&
virBitmapIsBitSet(online_cpus_map,
cpu - (cpu % threads_per_subcore))) {
/* Secondary offline threads are counted as online when
* subcores are in use and the corresponding primary
* thread is online */
processors++;
} else {
/* But they are counted as offline otherwise */
(*offline)++;
}
continue;
}
processors++;
/* Parse socket */
if ((sock = virHostCPUParseSocket(node, arch, cpu)) < 0)
goto cleanup;
if (!virBitmapIsBitSet(sockets_map, sock)) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("CPU socket topology has changed"));
goto cleanup;
}
/* Parse core */
if (ARCH_IS_S390(arch)) {
/* logical cpu is equivalent to a core on s390 */
core = cpu;
} else {
if ((core = virHostCPUGetValue(node, cpu,
"topology/core_id", 0)) < 0)
goto cleanup;
}
if (core > ID_MAX) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("Core %d can't be handled (max core is %d)"),
core, ID_MAX);
goto cleanup;
}
if (virBitmapSetBit(cores_maps[sock], core) < 0)
goto cleanup;
if (!(siblings = virHostCPUCountThreadSiblings(node, cpu)))
goto cleanup;
if (siblings > *threads)
*threads = siblings;
}
/* finalize the returned data */
*sockets = virBitmapCountBits(sockets_map);
for (i = 0; i < sock_max; i++) {
if (!virBitmapIsBitSet(sockets_map, i))
continue;
core = virBitmapCountBits(cores_maps[i]);
if (core > *cores)
*cores = core;
}
if (threads_per_subcore > 0) {
/* The thread count ignores offline threads, which means that only
* only primary threads have been considered so far. If subcores
* are in use, we need to also account for secondary threads */
*threads *= threads_per_subcore;
}
ret = processors;
cleanup:
VIR_DIR_CLOSE(cpudir);
if (cores_maps)
for (i = 0; i < sock_max; i++)
virBitmapFree(cores_maps[i]);
VIR_FREE(cores_maps);
virBitmapFree(sockets_map);
virBitmapFree(node_cpus_map);
return ret;
}
/* Check whether the host subcore configuration is valid.
*
* A valid configuration is one where no secondary thread is online;
* the primary thread in a subcore is always the first one */
static bool
virHostCPUHasValidSubcoreConfiguration(int threads_per_subcore)
{
virBitmapPtr online_cpus = NULL;
int cpu = -1;
bool ret = false;
/* No point in checking if subcores are not in use */
if (threads_per_subcore <= 0)
goto cleanup;
if (!(online_cpus = virHostCPUGetOnlineBitmap()))
goto cleanup;
while ((cpu = virBitmapNextSetBit(online_cpus, cpu)) >= 0) {
/* A single online secondary thread is enough to
* make the configuration invalid */
if (cpu % threads_per_subcore != 0)
goto cleanup;
}
ret = true;
cleanup:
virBitmapFree(online_cpus);
return ret;
}
int
virHostCPUGetInfoPopulateLinux(FILE *cpuinfo,
virArch arch,
unsigned int *cpus,
unsigned int *mhz,
unsigned int *nodes,
unsigned int *sockets,
unsigned int *cores,
unsigned int *threads)
{
virBitmapPtr present_cpus_map = NULL;
virBitmapPtr online_cpus_map = NULL;
char line[1024];
DIR *nodedir = NULL;
struct dirent *nodedirent = NULL;
int nodecpus, nodecores, nodesockets, nodethreads, offline = 0;
int threads_per_subcore = 0;
unsigned int node;
int ret = -1;
char *sysfs_nodedir = NULL;
char *sysfs_cpudir = NULL;
int direrr;
*mhz = 0;
*cpus = *nodes = *sockets = *cores = *threads = 0;
/* Start with parsing CPU clock speed from /proc/cpuinfo */
while (fgets(line, sizeof(line), cpuinfo) != NULL) {
if (ARCH_IS_X86(arch)) {
char *buf = line;
if (STRPREFIX(buf, "cpu MHz")) {
char *p;
unsigned int ui;
buf += 7;
while (*buf && c_isspace(*buf))
buf++;
if (*buf != ':' || !buf[1]) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("parsing cpu MHz from cpuinfo"));
goto cleanup;
}
if (virStrToLong_ui(buf+1, &p, 10, &ui) == 0 &&
/* Accept trailing fractional part. */
(*p == '\0' || *p == '.' || c_isspace(*p)))
*mhz = ui;
}
} else if (ARCH_IS_PPC(arch)) {
char *buf = line;
if (STRPREFIX(buf, "clock")) {
char *p;
unsigned int ui;
buf += 5;
while (*buf && c_isspace(*buf))
buf++;
if (*buf != ':' || !buf[1]) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("parsing cpu MHz from cpuinfo"));
goto cleanup;
}
if (virStrToLong_ui(buf+1, &p, 10, &ui) == 0 &&
/* Accept trailing fractional part. */
(*p == '\0' || *p == '.' || c_isspace(*p)))
*mhz = ui;
/* No other interesting infos are available in /proc/cpuinfo.
* However, there is a line identifying processor's version,
* identification and machine, but we don't want it to be caught
* and parsed in next iteration, because it is not in expected
* format and thus lead to error. */
}
} else if (ARCH_IS_ARM(arch)) {
char *buf = line;
if (STRPREFIX(buf, "BogoMIPS")) {
char *p;
unsigned int ui;
buf += 8;
while (*buf && c_isspace(*buf))
buf++;
if (*buf != ':' || !buf[1]) {
virReportError(VIR_ERR_INTERNAL_ERROR,
"%s", _("parsing cpu MHz from cpuinfo"));
goto cleanup;
}
if (virStrToLong_ui(buf+1, &p, 10, &ui) == 0
/* Accept trailing fractional part. */
&& (*p == '\0' || *p == '.' || c_isspace(*p)))
*mhz = ui;
}
} else if (ARCH_IS_S390(arch)) {
/* s390x has no realistic value for CPU speed,
* assign a value of zero to signify this */
*mhz = 0;
} else {
VIR_WARN("Parser for /proc/cpuinfo needs to be adapted for your architecture");
break;
}
}
/* Get information about what CPUs are present in the host and what
* CPUs are online, so that we don't have to so for each node */
present_cpus_map = virHostCPUGetPresentBitmap();
if (!present_cpus_map)
goto cleanup;
online_cpus_map = virHostCPUGetOnlineBitmap();
if (!online_cpus_map)
goto cleanup;
/* OK, we've parsed clock speed out of /proc/cpuinfo. Get the
* core, node, socket, thread and topology information from /sys
*/
if (virAsprintf(&sysfs_nodedir, "%s/node", sysfs_system_path) < 0)
goto cleanup;
if (virDirOpenQuiet(&nodedir, sysfs_nodedir) < 0) {
/* the host isn't probably running a NUMA architecture */
goto fallback;
}
/* PPC-KVM needs the secondary threads of a core to be offline on the
* host. The kvm scheduler brings the secondary threads online in the
* guest context. Moreover, P8 processor has split-core capability
* where, there can be 1,2 or 4 subcores per core. The primaries of the
* subcores alone will be online on the host for a subcore in the
* host. Even though the actual threads per core for P8 processor is 8,
* depending on the subcores_per_core = 1, 2 or 4, the threads per
* subcore will vary accordingly to 8, 4 and 2 respectively.
* So, On host threads_per_core what is arrived at from sysfs in the
* current logic is actually the subcores_per_core. Threads per subcore
* can only be obtained from the kvm device. For example, on P8 wih 1
* core having 8 threads, sub_cores_percore=4, the threads 0,2,4 & 6
* will be online. The sysfs reflects this and in the current logic
* variable 'threads' will be 4 which is nothing but subcores_per_core.
* If the user tampers the cpu online/offline states using chcpu or other
* means, then it is an unsupported configuration for kvm.
* The code below tries to keep in mind
* - when the libvirtd is run inside a KVM guest or Phyp based guest.
* - Or on the kvm host where user manually tampers the cpu states to
* offline/online randomly.
* On hosts other than POWER this will be 0, in which case a simpler
* thread-counting logic will be used */
if ((threads_per_subcore = virHostCPUGetThreadsPerSubcore(arch)) < 0)
goto cleanup;
/* If the subcore configuration is not valid, just pretend subcores
* are not in use and count threads one by one */
if (!virHostCPUHasValidSubcoreConfiguration(threads_per_subcore))
threads_per_subcore = 0;
while ((direrr = virDirRead(nodedir, &nodedirent, sysfs_nodedir)) > 0) {
if (sscanf(nodedirent->d_name, "node%u", &node) != 1)
continue;
(*nodes)++;
if (virAsprintf(&sysfs_cpudir, "%s/node/%s",
sysfs_system_path, nodedirent->d_name) < 0)
goto cleanup;
if ((nodecpus = virHostCPUParseNode(sysfs_cpudir, arch,
present_cpus_map,
online_cpus_map,
threads_per_subcore,
&nodesockets, &nodecores,
&nodethreads, &offline)) < 0)
goto cleanup;
VIR_FREE(sysfs_cpudir);
*cpus += nodecpus;
if (nodesockets > *sockets)
*sockets = nodesockets;
if (nodecores > *cores)
*cores = nodecores;
if (nodethreads > *threads)
*threads = nodethreads;
}
if (direrr < 0)
goto cleanup;
if (*cpus && *nodes)
goto done;
fallback:
VIR_FREE(sysfs_cpudir);
if (virAsprintf(&sysfs_cpudir, "%s/cpu", sysfs_system_path) < 0)
goto cleanup;
if ((nodecpus = virHostCPUParseNode(sysfs_cpudir, arch,
present_cpus_map,
online_cpus_map,
threads_per_subcore,
&nodesockets, &nodecores,
&nodethreads, &offline)) < 0)
goto cleanup;
*nodes = 1;
*cpus = nodecpus;
*sockets = nodesockets;
*cores = nodecores;
*threads = nodethreads;
done:
/* There should always be at least one cpu, socket, node, and thread. */
if (*cpus == 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("no CPUs found"));
goto cleanup;
}
if (*sockets == 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("no sockets found"));
goto cleanup;
}
if (*threads == 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("no threads found"));
goto cleanup;
}
/* Now check if the topology makes sense. There are machines that don't
* expose their real number of nodes or for example the AMD Bulldozer
* architecture that exposes their Clustered integer core modules as both
* threads and cores. This approach throws off our detection. Unfortunately
* the nodeinfo structure isn't designed to carry the full topology so
* we're going to lie about the detected topology to notify the user
* to check the host capabilities for the actual topology. */
if ((*nodes *
*sockets *
*cores *
*threads) != (*cpus + offline)) {
*nodes = 1;
*sockets = 1;
*cores = *cpus + offline;
*threads = 1;
}
ret = 0;
cleanup:
VIR_DIR_CLOSE(nodedir);
virBitmapFree(present_cpus_map);
virBitmapFree(online_cpus_map);
VIR_FREE(sysfs_nodedir);
VIR_FREE(sysfs_cpudir);
return ret;
}
# define TICK_TO_NSEC (1000ull * 1000ull * 1000ull / sysconf(_SC_CLK_TCK))
int
virHostCPUGetStatsLinux(FILE *procstat,
int cpuNum,
virNodeCPUStatsPtr params,
int *nparams)
{
int ret = -1;
char line[1024];
unsigned long long usr, ni, sys, idle, iowait;
unsigned long long irq, softirq, steal, guest, guest_nice;
char cpu_header[4 + INT_BUFSIZE_BOUND(cpuNum)];
if ((*nparams) == 0) {
/* Current number of cpu stats supported by linux */
*nparams = LINUX_NB_CPU_STATS;
ret = 0;
goto cleanup;
}
if ((*nparams) != LINUX_NB_CPU_STATS) {
virReportInvalidArg(*nparams,
_("nparams in %s must be equal to %d"),
__FUNCTION__, LINUX_NB_CPU_STATS);
goto cleanup;
}
if (cpuNum == VIR_NODE_CPU_STATS_ALL_CPUS) {
strcpy(cpu_header, "cpu ");
} else {
snprintf(cpu_header, sizeof(cpu_header), "cpu%d ", cpuNum);
}
while (fgets(line, sizeof(line), procstat) != NULL) {
char *buf = line;
if (STRPREFIX(buf, cpu_header)) { /* aka logical CPU time */
if (sscanf(buf,
"%*s %llu %llu %llu %llu %llu" // user ~ iowait
"%llu %llu %llu %llu %llu", // irq ~ guest_nice
&usr, &ni, &sys, &idle, &iowait,
&irq, &softirq, &steal, &guest, &guest_nice) < 4) {
continue;
}
if (virHostCPUStatsAssign(&params[0], VIR_NODE_CPU_STATS_KERNEL,
(sys + irq + softirq) * TICK_TO_NSEC) < 0)
goto cleanup;
if (virHostCPUStatsAssign(&params[1], VIR_NODE_CPU_STATS_USER,
(usr + ni) * TICK_TO_NSEC) < 0)
goto cleanup;
if (virHostCPUStatsAssign(&params[2], VIR_NODE_CPU_STATS_IDLE,
idle * TICK_TO_NSEC) < 0)
goto cleanup;
if (virHostCPUStatsAssign(&params[3], VIR_NODE_CPU_STATS_IOWAIT,
iowait * TICK_TO_NSEC) < 0)
goto cleanup;
ret = 0;
goto cleanup;
}
}
virReportInvalidArg(cpuNum,
_("Invalid cpuNum in %s"),
__FUNCTION__);
cleanup:
return ret;
}
static char *
virHostCPUGetGlobalPathLinux(const char *file)
{
char *path = NULL;
if (virAsprintf(&path, "%s/cpu/%s", sysfs_system_path, file) < 0)
return NULL;
return path;
}
static char *
virHostCPUGetPresentPathLinux(void)
{
return virHostCPUGetGlobalPathLinux("present");
}
static char *
virHostCPUGetOnlinePathLinux(void)
{
return virHostCPUGetGlobalPathLinux("online");
}
/* Determine the number of CPUs (maximum CPU id + 1) from a file containing
* a list of CPU ids, like the Linux sysfs cpu/present file */
static int
virHostCPUParseCountLinux(const char *path)
{
char *str = NULL;
char *tmp;
int ret = -1;
if (virFileReadAll(path, 5 * VIR_HOST_CPU_MASK_LEN, &str) < 0)
goto cleanup;
tmp = str;
do {
if (virStrToLong_i(tmp, &tmp, 10, &ret) < 0 ||
!strchr(",-\n", *tmp)) {
virReportError(VIR_ERR_NO_SUPPORT,
_("failed to parse %s"), path);
ret = -1;
goto cleanup;
}
} while (*tmp++ != '\n');
ret++;
cleanup:
VIR_FREE(str);
return ret;
}
/*
* Linux maintains cpu bit map under cpu/online. For example, if
* cpuid=5's flag is not set and max cpu is 7, the map file shows
* 0-4,6-7. This function parses it and returns cpumap.
*/
static virBitmapPtr
virHostCPUParseMapLinux(int max_cpuid, const char *path)
{
virBitmapPtr map = NULL;
char *str = NULL;
if (virFileReadAll(path, 5 * VIR_HOST_CPU_MASK_LEN, &str) < 0)
goto error;
if (virBitmapParse(str, &map, max_cpuid) < 0)
goto error;
VIR_FREE(str);
return map;
error:
VIR_FREE(str);
virBitmapFree(map);
return NULL;
}
#endif
int
virHostCPUStatsAssign(virNodeCPUStatsPtr param,
const char *name,
unsigned long long value)
{
if (virStrcpyStatic(param->field, name) == NULL) {
virReportError(VIR_ERR_INTERNAL_ERROR,
"%s", _("kernel cpu time field is too long"
" for the destination"));
return -1;
}
param->value = value;
return 0;
}
int
virHostCPUGetInfo(virArch hostarch ATTRIBUTE_UNUSED,
unsigned int *cpus ATTRIBUTE_UNUSED,
unsigned int *mhz ATTRIBUTE_UNUSED,
unsigned int *nodes ATTRIBUTE_UNUSED,
unsigned int *sockets ATTRIBUTE_UNUSED,
unsigned int *cores ATTRIBUTE_UNUSED,
unsigned int *threads ATTRIBUTE_UNUSED)
{
#ifdef __linux__
int ret = -1;
FILE *cpuinfo = fopen(CPUINFO_PATH, "r");
if (!cpuinfo) {
virReportSystemError(errno,
_("cannot open %s"), CPUINFO_PATH);
return -1;
}
ret = virHostCPUGetInfoPopulateLinux(cpuinfo, hostarch,
cpus, mhz, nodes,
sockets, cores, threads);
if (ret < 0)
goto cleanup;
cleanup:
VIR_FORCE_FCLOSE(cpuinfo);
return ret;
#elif defined(__FreeBSD__) || defined(__APPLE__)
unsigned long cpu_freq;
size_t cpu_freq_len = sizeof(cpu_freq);
*cpus = virHostCPUGetCountAppleFreeBSD();
if (*cpus == -1)
return -1;
*nodes = 1;
*sockets = 1;
*cores = *cpus;
*threads = 1;
# ifdef __FreeBSD__
/* dev.cpu.%d.freq reports current active CPU frequency. It is provided by
* the cpufreq(4) framework. However, it might be disabled or no driver
* available. In this case fallback to "hw.clockrate" which reports boot time
* CPU frequency. */
if (sysctlbyname("dev.cpu.0.freq", &cpu_freq, &cpu_freq_len, NULL, 0) < 0) {
if (sysctlbyname("hw.clockrate", &cpu_freq, &cpu_freq_len, NULL, 0) < 0) {
virReportSystemError(errno, "%s", _("cannot obtain CPU freq"));
return -1;
}
}
*mhz = cpu_freq;
# else
if (sysctlbyname("hw.cpufrequency", &cpu_freq, &cpu_freq_len, NULL, 0) < 0) {
virReportSystemError(errno, "%s", _("cannot obtain CPU freq"));
return -1;
}
*mhz = cpu_freq / 1000000;
# endif
return 0;
#else
/* XXX Solaris will need an impl later if they port QEMU driver */
virReportError(VIR_ERR_NO_SUPPORT, "%s",
_("node info not implemented on this platform"));
return -1;
#endif
}
int
virHostCPUGetStats(int cpuNum ATTRIBUTE_UNUSED,
virNodeCPUStatsPtr params ATTRIBUTE_UNUSED,
int *nparams ATTRIBUTE_UNUSED,
unsigned int flags)
{
virCheckFlags(0, -1);
#ifdef __linux__
{
int ret;
FILE *procstat = fopen(PROCSTAT_PATH, "r");
if (!procstat) {
virReportSystemError(errno,
_("cannot open %s"), PROCSTAT_PATH);
return -1;
}
ret = virHostCPUGetStatsLinux(procstat, cpuNum, params, nparams);
VIR_FORCE_FCLOSE(procstat);
return ret;
}
#elif defined(__FreeBSD__)
return virHostCPUGetStatsFreeBSD(cpuNum, params, nparams);
#else
virReportError(VIR_ERR_NO_SUPPORT, "%s",
_("node CPU stats not implemented on this platform"));
return -1;
#endif
}
int
virHostCPUGetCount(void)
{
#if defined(__linux__)
/* To support older kernels that lack cpu/present, such as 2.6.18
* in RHEL5, we fall back to count cpu/cpuNN entries; this assumes
* that such kernels also lack hotplug, and therefore cpu/cpuNN
* will be consecutive.
*/
char *present_path = NULL;
char *cpupath = NULL;
int ncpu = -1;
if (!(present_path = virHostCPUGetPresentPathLinux()))
return -1;
if (virFileExists(present_path)) {
ncpu = virHostCPUParseCountLinux(present_path);
goto cleanup;
}
if (virAsprintf(&cpupath, "%s/cpu/cpu0", sysfs_system_path) < 0)
goto cleanup;
if (virFileExists(cpupath)) {
ncpu = 0;
do {
ncpu++;
VIR_FREE(cpupath);
if (virAsprintf(&cpupath, "%s/cpu/cpu%d",
sysfs_system_path, ncpu) < 0) {
ncpu = -1;
goto cleanup;
}
} while (virFileExists(cpupath));
} else {
/* no cpu/cpu0: we give up */
virReportError(VIR_ERR_NO_SUPPORT, "%s",
_("host cpu counting not supported on this node"));
}
cleanup:
VIR_FREE(present_path);
VIR_FREE(cpupath);
return ncpu;
#elif defined(__FreeBSD__) || defined(__APPLE__)
return virHostCPUGetCountAppleFreeBSD();
#else
virReportError(VIR_ERR_NO_SUPPORT, "%s",
_("host cpu counting not implemented on this platform"));
return -1;
#endif
}
bool
virHostCPUHasBitmap(void)
{
#ifdef __linux__
return true;
#else
return false;
#endif
}
virBitmapPtr
virHostCPUGetPresentBitmap(void)
{
#ifdef __linux__
virBitmapPtr present_cpus = NULL;
char *present_path = NULL;
int npresent_cpus;
if ((npresent_cpus = virHostCPUGetCount()) < 0)
goto cleanup;
if (!(present_path = virHostCPUGetPresentPathLinux()))
goto cleanup;
/* If the cpu/present file is available, parse it and exit */
if (virFileExists(present_path)) {
present_cpus = virHostCPUParseMapLinux(npresent_cpus, present_path);
goto cleanup;
}
/* If the file is not available, we can assume that the kernel is
* too old to support non-consecutive CPU ids and just mark all
* possible CPUs as present */
if (!(present_cpus = virBitmapNew(npresent_cpus)))
goto cleanup;
virBitmapSetAll(present_cpus);
cleanup:
VIR_FREE(present_path);
return present_cpus;
#endif
virReportError(VIR_ERR_NO_SUPPORT, "%s",
_("node present CPU map not implemented on this platform"));
return NULL;
}
virBitmapPtr
virHostCPUGetOnlineBitmap(void)
{
#ifdef __linux__
char *online_path = NULL;
char *cpudir = NULL;
virBitmapPtr cpumap;
int present;
present = virHostCPUGetCount();
if (present < 0)
return NULL;
if (!(online_path = virHostCPUGetOnlinePathLinux()))
return NULL;
if (virFileExists(online_path)) {
cpumap = virHostCPUParseMapLinux(present, online_path);
} else {
size_t i;
cpumap = virBitmapNew(present);
if (!cpumap)
goto cleanup;
if (virAsprintf(&cpudir, "%s/cpu", sysfs_system_path) < 0)
goto cleanup;
for (i = 0; i < present; i++) {
int online = virHostCPUGetValue(cpudir, i, "online", 1);
if (online < 0) {
virBitmapFree(cpumap);
cpumap = NULL;
goto cleanup;
}
if (online)
ignore_value(virBitmapSetBit(cpumap, i));
}
}
cleanup:
VIR_FREE(online_path);
VIR_FREE(cpudir);
return cpumap;
#else
virReportError(VIR_ERR_NO_SUPPORT, "%s",
_("node online CPU map not implemented on this platform"));
return NULL;
#endif
}
int
virHostCPUGetMap(unsigned char **cpumap,
unsigned int *online,
unsigned int flags)
{
virBitmapPtr cpus = NULL;
int ret = -1;
int dummy;
virCheckFlags(0, -1);
if (!cpumap && !online)
return virHostCPUGetCount();
if (!(cpus = virHostCPUGetOnlineBitmap()))
goto cleanup;
if (cpumap && virBitmapToData(cpus, cpumap, &dummy) < 0)
goto cleanup;
if (online)
*online = virBitmapCountBits(cpus);
ret = virBitmapSize(cpus);
cleanup:
if (ret < 0 && cpumap)
VIR_FREE(*cpumap);
virBitmapFree(cpus);
return ret;
}
#if HAVE_LINUX_KVM_H && defined(KVM_CAP_PPC_SMT)
/* Get the number of threads per subcore.
*
* This will be 2, 4 or 8 on POWER hosts, depending on the current
* micro-threading configuration, and 0 everywhere else.
*
* Returns the number of threads per subcore if subcores are in use, zero
* if subcores are not in use, and a negative value on error */
int
virHostCPUGetThreadsPerSubcore(virArch arch)
{
int threads_per_subcore = 0;
int kvmfd;
if (ARCH_IS_PPC64(arch)) {
/* It's okay if /dev/kvm doesn't exist, because
* a. we might be running in a guest
* b. the kvm module might not be installed or enabled
* In either case, falling back to the subcore-unaware thread
* counting logic is the right thing to do */
if (!virFileExists(KVM_DEVICE))
goto out;
if ((kvmfd = open(KVM_DEVICE, O_RDONLY)) < 0) {
/* This can happen when running as a regular user if
* permissions are tight enough, in which case erroring out
* is better than silently falling back and reporting
* different nodeinfo depending on the user */
virReportSystemError(errno,
_("Failed to open '%s'"),
KVM_DEVICE);
threads_per_subcore = -1;
goto out;
}
/* For Phyp and KVM based guests the ioctl for KVM_CAP_PPC_SMT
* returns zero and both primary and secondary threads will be
* online */
threads_per_subcore = ioctl(kvmfd,
KVM_CHECK_EXTENSION,
KVM_CAP_PPC_SMT);
VIR_FORCE_CLOSE(kvmfd);
}
out:
return threads_per_subcore;
}
#else
/* Fallback for nodeGetThreadsPerSubcore() used when KVM headers
* are not available on the system */
int
virHostCPUGetThreadsPerSubcore(virArch arch ATTRIBUTE_UNUSED)
{
return 0;
}
#endif /* HAVE_LINUX_KVM_H && defined(KVM_CAP_PPC_SMT) */
#if HAVE_LINUX_KVM_H
int
virHostCPUGetKVMMaxVCPUs(void)
{
int fd;
int ret;
if ((fd = open(KVM_DEVICE, O_RDONLY)) < 0) {
virReportSystemError(errno, _("Unable to open %s"), KVM_DEVICE);
return -1;
}
# ifdef KVM_CAP_MAX_VCPUS
/* at first try KVM_CAP_MAX_VCPUS to determine the maximum count */
if ((ret = ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_MAX_VCPUS)) > 0)
goto cleanup;
# endif /* KVM_CAP_MAX_VCPUS */
/* as a fallback get KVM_CAP_NR_VCPUS (the recommended maximum number of
* vcpus). Note that on most machines this is set to 160. */
if ((ret = ioctl(fd, KVM_CHECK_EXTENSION, KVM_CAP_NR_VCPUS)) > 0)
goto cleanup;
/* if KVM_CAP_NR_VCPUS doesn't exist either, kernel documentation states
* that 4 should be used as the maximum number of cpus */
ret = 4;
cleanup:
VIR_FORCE_CLOSE(fd);
return ret;
}
#else
int
virHostCPUGetKVMMaxVCPUs(void)
{
virReportSystemError(ENOSYS, "%s",
_("KVM is not supported on this platform"));
return -1;
}
#endif /* HAVE_LINUX_KVM_H */
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