Re: [libvirt] [PATCH 6/8] qemu_driver: add support to perf event

This patch implement the internal driver API for perf event into qemu driver. In addition, this patch extend virDomainListGetStats API to get the statistics for perf event. To do so, we add a 'VIR_DOMAIN_STATS_PERF' enum to causes reporting of all previously enabled perf events. Signed-off-by: Qiaowei Ren <qiaowei.ren(a)intel.com&gt; --- include/libvirt/libvirt-domain.h | 1 + src/qemu/qemu_domain.h | 3 + src/qemu/qemu_driver.c | 181 +++++++++++++++++++++++++++++++++++++++ src/qemu/qemu_process.c | 6 ++ 4 files changed, 191 insertions(+) diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h index 69965e6..5e74b29 100644 --- a/include/libvirt/libvirt-domain.h +++ b/include/libvirt/libvirt-domain.h @@ -1771,6 +1771,7 @@ typedef enum { VIR_DOMAIN_STATS_VCPU = (1 << 3), /* return domain virtual CPU info */ VIR_DOMAIN_STATS_INTERFACE = (1 << 4), /* return domain interfaces info */ VIR_DOMAIN_STATS_BLOCK = (1 << 5), /* return domain block info */ + VIR_DOMAIN_STATS_PERF = (1 << 6), /* return domain perf event info */ } virDomainStatsTypes; typedef enum { diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 4be998c..0348d4a 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -26,6 +26,7 @@ # include "virthread.h" # include "vircgroup.h" +# include "virperf.h" # include "domain_addr.h" # include "domain_conf.h" # include "snapshot_conf.h" @@ -190,6 +191,8 @@ struct _qemuDomainObjPrivate { virCgroupPtr cgroup; + virPerfPtr perf; + virCond unplugFinished; /* signals that unpluggingDevice was unplugged */ const char *unpluggingDevice; /* alias of the device that is being unplugged */ char **qemuDevices; /* NULL-terminated list of devices aliases known to QEMU */ diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 92a9961..5ad4d79 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -98,6 +98,7 @@ #include "virhostdev.h" #include "domain_capabilities.h" #include "vircgroup.h" +#include "virperf.h" #include "virnuma.h" #include "dirname.h" #include "network/bridge_driver.h" @@ -113,6 +114,8 @@ VIR_LOG_INIT("qemu.qemu_driver"); #define QEMU_NB_NUMA_PARAM 2 +#define QEMU_NB_PERF_PARAM VIR_PERF_EVENT_LAST +

#define QEMU_SCHED_MIN_PERIOD 1000LL #define QEMU_SCHED_MAX_PERIOD 1000000LL #define QEMU_SCHED_MIN_QUOTA 1000LL @@ -10244,6 +10247,106 @@ qemuDomainGetNumaParameters(virDomainPtr dom, } static int +qemuDomainSetPerfEvents(virDomainPtr dom, + virTypedParameterPtr params, + int nparams) +{ + size_t i; + virDomainObjPtr vm = NULL; + qemuDomainObjPrivatePtr priv; + int ret = -1; + bool enabled; + + if (virTypedParamsValidate(params, nparams, + VIR_DOMAIN_PERF_CMT, + VIR_TYPED_PARAM_BOOLEAN, + NULL) < 0) + return -1;

+ + if (!(vm = qemuDomObjFromDomain(dom))) + return -1; + + priv = vm->privateData; + + if (virDomainGetPerfEventsEnsureACL(dom->conn, vm->def) < 0) + goto cleanup; + + for (i = 0; i < nparams; i++) { + virTypedParameterPtr param = &params[i]; + enabled = params[i].value.b; + + if (STREQ(param->field, VIR_DOMAIN_PERF_CMT)) {

+ if (!enabled && virPerfEventDisable(VIR_PERF_EVENT_CMT, priv->perf)) { + virReportError(VIR_ERR_NO_SUPPORT, + _("can't disable perf event: %s"), + VIR_DOMAIN_PERF_CMT); + goto cleanup; + } + if (enabled && virPerfCmtEnable(vm->pid, priv->perf)) { + virReportError(VIR_ERR_NO_SUPPORT, + _("can't enable perf event: %s"), + VIR_DOMAIN_PERF_CMT); + goto cleanup; + }

+ } + } + + ret = 0; + + cleanup: + virDomainObjEndAPI(&vm); + return ret; +} + +static int +qemuDomainGetPerfEvents(virDomainPtr dom, + virTypedParameterPtr params, + int * nparams) +{ + size_t i; + virDomainObjPtr vm = NULL; + qemuDomainObjPrivatePtr priv; + int ret = -1; + + if (!(vm = qemuDomObjFromDomain(dom))) + goto cleanup; + + priv = vm->privateData; + + if (virDomainGetPerfEventsEnsureACL(dom->conn, vm->def) < 0) + goto cleanup; + + if ((*nparams) == 0) { + *nparams = QEMU_NB_PERF_PARAM; + ret = 0; + goto cleanup; + } + + for (i = 0; i < QEMU_NB_PERF_PARAM && i < *nparams; i++) { + virMemoryParameterPtr param = &params[i];

+ + switch (i) { + case VIR_PERF_EVENT_CMT: + if (virTypedParameterAssign(param, VIR_DOMAIN_PERF_CMT, + VIR_TYPED_PARAM_BOOLEAN, + priv->perf->events[VIR_PERF_EVENT_CMT].enabled) < 0)

+ goto cleanup; + break; + default: + break; + } + } + + if (*nparams > QEMU_NB_PERF_PARAM) + *nparams = QEMU_NB_PERF_PARAM; + ret = 0; + + cleanup: + virDomainObjEndAPI(&vm); + return ret; +} + +static int qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup, unsigned long long period, long long quota) { @@ -19419,6 +19522,81 @@ qemuDomainGetStatsBlock(virQEMUDriverPtr driver, #undef QEMU_ADD_COUNT_PARAM +static int +qemuDomainGetStatsPerfCmt(virPerfEventPtr eventPtr, + virDomainStatsRecordPtr record, + int *maxparams) +{ + FILE *fd; + unsigned long long cache = 0; + int scaling_factor = 0; + + if (eventPtr->fd <= 0 || !eventPtr->enabled) + return -1; + + if (read(eventPtr->fd, &cache, sizeof(uint64_t)) < 0) { + virReportSystemError(errno, "%s", + _("Unable to read cache data")); + return -1; + } + + fd = fopen("/sys/devices/intel_cqm/events/llc_occupancy.scale", "r");

+ if (!fd) { + virReportSystemError(errno, "%s", + _("Unable to open CMT scale file")); + return -1; + } + if (fscanf(fd, "%d", &scaling_factor) != 1) { + virReportSystemError(errno, "%s", + _("Unable to read CMT scale file")); + VIR_FORCE_FCLOSE(fd); + return -1; + } + VIR_FORCE_FCLOSE(fd);

+ cache *= scaling_factor; + + if (virTypedParamsAddULLong(&record->params, + &record->nparams, + maxparams, + "perf.cache", + cache) < 0) + return -1; + + return 0; +} + +static int +qemuDomainGetStatsPerf(virQEMUDriverPtr driver ATTRIBUTE_UNUSED, + virDomainObjPtr dom, + virDomainStatsRecordPtr record, + int *maxparams, + unsigned int privflags ATTRIBUTE_UNUSED) +{ + size_t i; + qemuDomainObjPrivatePtr priv = dom->privateData; + int ret = -1; + + for (i = 0; i < VIR_PERF_EVENT_LAST; i++) { + virPerfEventPtr event = virPerfEventOfType(priv->perf, i); + if (!event->enabled) + continue; + + switch (i) {

+ case VIR_PERF_EVENT_CMT: + if (qemuDomainGetStatsPerfCmt(event, record, maxparams)) + goto cleanup; + break; + default: + break;

+ } + } + + ret = 0; + cleanup: + return ret; +} + typedef int (*qemuDomainGetStatsFunc)(virQEMUDriverPtr driver, virDomainObjPtr dom, @@ -19439,6 +19617,7 @@ static struct qemuDomainGetStatsWorker qemuDomainGetStatsWorkers[] = { { qemuDomainGetStatsVcpu, VIR_DOMAIN_STATS_VCPU, false }, { qemuDomainGetStatsInterface, VIR_DOMAIN_STATS_INTERFACE, false }, { qemuDomainGetStatsBlock, VIR_DOMAIN_STATS_BLOCK, true }, + { qemuDomainGetStatsPerf, VIR_DOMAIN_STATS_PERF, false }, { NULL, 0, false } }; @@ -20227,6 +20406,8 @@ static virHypervisorDriver qemuHypervisorDriver = { .domainMigrateFinish3 = qemuDomainMigrateFinish3, /* 0.9.2 */ .domainMigrateConfirm3 = qemuDomainMigrateConfirm3, /* 0.9.2 */ .domainSendKey = qemuDomainSendKey, /* 0.9.4 */ + .domainGetPerfEvents = qemuDomainGetPerfEvents, /* 1.2.23 */ + .domainSetPerfEvents = qemuDomainSetPerfEvents, /* 1.2.23 */ .domainBlockJobAbort = qemuDomainBlockJobAbort, /* 0.9.4 */ .domainGetBlockJobInfo = qemuDomainGetBlockJobInfo, /* 0.9.4 */ .domainBlockJobSetSpeed = qemuDomainBlockJobSetSpeed, /* 0.9.4 */ diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 4545f77..2d81069 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -4680,6 +4680,10 @@ int qemuProcessStart(virConnectPtr conn, if (qemuSetupCgroup(driver, vm, nnicindexes, nicindexes) < 0) goto error; + VIR_DEBUG("Initializing perf event"); + if (virPerfInitialize(&(priv->perf)) < 0) + goto cleanup;

+ /* This must be done after cgroup placement to avoid resetting CPU * affinity */ if (!vm->def->cputune.emulatorpin && @@ -5187,6 +5191,8 @@ void qemuProcessStop(virQEMUDriverPtr driver, } virCgroupFree(&priv->cgroup); + virPerfFree(&(priv->perf)); + qemuProcessRemoveDomainStatus(driver, vm); /* Remove VNC and Spice ports from port reservation bitmap, but only if