[libvirt] [PATCH RFC v5 5/6] qemu: Implement cfs_period and cfs_quota's modification

--- src/qemu/qemu_driver.c | 312 ++++++++++++++++++++++++++++++++++++++++++++---- 1 files changed, 287 insertions(+), 25 deletions(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index cd65bce..fd80537 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -5139,11 +5139,46 @@ cleanup: } +/* + * check whether the host supports CFS bandwidth + * + * Return 1 when CFS bandwidth is supported, 0 when CFS bandwidth is not + * supported, -1 on error. + */ +static int qemuGetCpuBWStatus(virCgroupPtr cgroup) +{ + char *cfs_period_path = NULL; + int ret = -1; + + if (!cgroup) + return 0; + + if (virCgroupPathOfController(cgroup, VIR_CGROUP_CONTROLLER_CPU, + "cpu.cfs_period_us", &cfs_period_path) < 0) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + "%s", + _("cannot get the path of cgroup CPU controller")); + goto cleanup; + } + + if (access(cfs_period_path, F_OK) < 0) { + ret = 0; + } else { + ret = 1; + } + +cleanup: + VIR_FREE(cfs_period_path); + return ret; +} + + static char *qemuGetSchedulerType(virDomainPtr dom, int *nparams) { struct qemud_driver *driver = dom->conn->privateData; char *ret = NULL; + int rc; qemuDriverLock(driver); if (!qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) { @@ -5152,8 +5187,15 @@ static char *qemuGetSchedulerType(virDomainPtr dom, goto cleanup; } - if (nparams) - *nparams = 1; + if (nparams) { + rc = qemuGetCpuBWStatus(driver->cgroup); + if (rc < 0) + goto cleanup; + else if (rc == 0) + *nparams = 1; + else + *nparams = 3; + } ret = strdup("posix"); if (!ret) @@ -5786,6 +5828,58 @@ cleanup: return ret; } +static int +qemuSetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup, + unsigned long long period, long long quota) +{ + int i; + qemuDomainObjPrivatePtr priv = vm->privateData; + virCgroupPtr cgroup_vcpu = NULL; + int rc; + + if (period == 0 && quota == 0) + return 0; + + if (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid) { + /* If we does not know VCPU<->PID mapping or all vcpu runs in the same + * thread, we can not control each vcpu. + */ + /* Ensure that we can multiply by vcpus without overflowing. */ + if (quota > LLONG_MAX / vm->def->vcpus) { + virReportSystemError(EINVAL, + _("%s"), + "Unable to set cpu bandwidth quota"); + goto cleanup; + } + + if (quota > 0) + quota *= vm->def->vcpus; + return qemuSetupCgroupVcpuBW(cgroup, period, quota); + } + + for (i = 0; i < priv->nvcpupids; i++) { + rc = virCgroupForVcpu(cgroup, i, &cgroup_vcpu, 0); + if (rc < 0) { + virReportSystemError(-rc, + _("Unable to find vcpu cgroup for %s(vcpu:" + " %d)"), + vm->def->name, i); + goto cleanup; + } + + if (qemuSetupCgroupVcpuBW(cgroup_vcpu, period, quota) < 0) + goto cleanup; + + virCgroupFree(&cgroup_vcpu); + } + + return 0; + +cleanup: + virCgroupFree(&cgroup_vcpu); + return -1; +} + static int qemuSetSchedulerParametersFlags(virDomainPtr dom, virTypedParameterPtr params, int nparams, @@ -5795,9 +5889,10 @@ static int qemuSetSchedulerParametersFlags(virDomainPtr dom, int i; virCgroupPtr group = NULL; virDomainObjPtr vm = NULL; - virDomainDefPtr persistentDef = NULL; + virDomainDefPtr vmdef = NULL; int ret = -1; bool isActive; + int rc; virCheckFlags(VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_AFFECT_CONFIG, -1); @@ -5821,10 +5916,17 @@ static int qemuSetSchedulerParametersFlags(virDomainPtr dom, flags = VIR_DOMAIN_AFFECT_CONFIG; } - if ((flags & VIR_DOMAIN_AFFECT_CONFIG) && !vm->persistent) { - qemuReportError(VIR_ERR_OPERATION_INVALID, "%s", - _("cannot change persistent config of a transient domain")); - goto cleanup; + if (flags & VIR_DOMAIN_AFFECT_CONFIG) { + if (!vm->persistent) { + qemuReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("cannot change persistent config of a transient domain")); + goto cleanup; + } + + /* Make a copy for updated domain. */ + vmdef = virDomainObjCopyPersistentDef(driver->caps, vm); + if (!vmdef) + goto cleanup; } if (flags & VIR_DOMAIN_AFFECT_LIVE) { @@ -5851,7 +5953,6 @@ static int qemuSetSchedulerParametersFlags(virDomainPtr dom, virTypedParameterPtr param = &params[i]; if (STREQ(param->field, "cpu_shares")) { - int rc; if (param->type != VIR_TYPED_PARAM_ULLONG) { qemuReportError(VIR_ERR_INVALID_ARG, "%s", _("invalid type for cpu_shares tunable, expected a 'ullong'")); @@ -5870,19 +5971,47 @@ static int qemuSetSchedulerParametersFlags(virDomainPtr dom, } if (flags & VIR_DOMAIN_AFFECT_CONFIG) { - persistentDef = virDomainObjGetPersistentDef(driver->caps, vm); - if (!persistentDef) { - qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", - _("can't get persistentDef")); + vmdef->cputune.shares = params[i].value.ul; + } + } else if (STREQ(param->field, "cfs_period")) { + if (param->type != VIR_TYPED_PARAM_ULLONG) { + qemuReportError(VIR_ERR_INVALID_ARG, "%s", + _("invalid type for cfs_period tunable," + " expected a 'ullong'")); + goto cleanup; + } + + if (flags & VIR_DOMAIN_AFFECT_LIVE) { + rc = qemuSetVcpusBWLive(vm, group, params[i].value.ul, 0); + if (rc != 0) goto cleanup; - } - persistentDef->cputune.shares = params[i].value.ul; - rc = virDomainSaveConfig(driver->configDir, persistentDef); - if (rc) { - qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s", - _("can't save config")); + + if (params[i].value.ul) + vm->def->cputune.period = params[i].value.ul; + } + + if (flags & VIR_DOMAIN_AFFECT_CONFIG) { + vmdef->cputune.period = params[i].value.ul; + } + } else if (STREQ(param->field, "cfs_quota")) { + if (param->type != VIR_TYPED_PARAM_LLONG) { + qemuReportError(VIR_ERR_INVALID_ARG, "%s", + _("invalid type for cfs_quota tunable," + " expected a 'llong'")); + goto cleanup; + } + + if (flags & VIR_DOMAIN_AFFECT_LIVE) { + rc = qemuSetVcpusBWLive(vm, group, 0, params[i].value.l); + if (rc != 0) goto cleanup; - } + + if (params[i].value.l) + vm->def->cputune.quota = params[i].value.l; + } + + if (flags & VIR_DOMAIN_AFFECT_CONFIG) { + vmdef->cputune.quota = params[i].value.l; } } else { qemuReportError(VIR_ERR_INVALID_ARG, @@ -5891,9 +6020,23 @@ static int qemuSetSchedulerParametersFlags(virDomainPtr dom, } } + if (virDomainSaveStatus(driver->caps, driver->stateDir, vm) < 0) + goto cleanup; + + + if (flags & VIR_DOMAIN_AFFECT_CONFIG) { + rc = virDomainSaveConfig(driver->configDir, vmdef); + if (rc < 0) + goto cleanup; + + virDomainObjAssignDef(vm, vmdef, false); + vmdef = NULL; + } + ret = 0; cleanup: + virDomainDefFree(vmdef); virCgroupFree(&group); if (vm) virDomainObjUnlock(vm); @@ -5912,6 +6055,71 @@ static int qemuSetSchedulerParameters(virDomainPtr dom, } static int +qemuGetVcpuBWLive(virCgroupPtr cgroup, unsigned long long *period, + long long *quota) +{ + int rc; + + rc = virCgroupGetCpuCfsPeriod(cgroup, period); + if (rc < 0) { + virReportSystemError(-rc, "%s", + _("unable to get cpu bandwidth period tunable")); + return -1; + } + + rc = virCgroupGetCpuCfsQuota(cgroup, quota); + if (rc < 0) { + virReportSystemError(-rc, "%s", + _("unable to get cpu bandwidth tunable")); + return -1; + } + + return 0; +} + +static int +qemuGetVcpusBWLive(virDomainObjPtr vm, virCgroupPtr cgroup, + unsigned long long *period, long long *quota) +{ + virCgroupPtr cgroup_vcpu = NULL; + qemuDomainObjPrivatePtr priv = NULL; + int rc; + int ret = -1; + + priv = vm->privateData; + if (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid) { + /* We do not create sub dir for each vcpu */ + rc = qemuGetVcpuBWLive(cgroup, period, quota); + if (rc < 0) + goto cleanup; + + if (*quota > 0) + *quota /= vm->def->vcpus; + goto out; + } + + /* get period and quota for vcpu0 */ + rc = virCgroupForVcpu(cgroup, 0, &cgroup_vcpu, 0); + if (!cgroup_vcpu) { + virReportSystemError(-rc, + _("Unable to find vcpu cgroup for %s(vcpu: 0)"), + vm->def->name); + goto cleanup; + } + + rc = qemuGetVcpuBWLive(cgroup_vcpu, period, quota); + if (rc < 0) + goto cleanup; + +out: + ret = 0; + +cleanup: + virCgroupFree(&cgroup_vcpu); + return ret; +} + +static int qemuGetSchedulerParametersFlags(virDomainPtr dom, virTypedParameterPtr params, int *nparams, @@ -5920,10 +6128,14 @@ qemuGetSchedulerParametersFlags(virDomainPtr dom, struct qemud_driver *driver = dom->conn->privateData; virCgroupPtr group = NULL; virDomainObjPtr vm = NULL; - unsigned long long val; + unsigned long long shares; + unsigned long long period; + long long quota; int ret = -1; int rc; bool isActive; + bool cpu_bw_status; + int saved_nparams = 0; virCheckFlags(VIR_DOMAIN_AFFECT_LIVE | VIR_DOMAIN_AFFECT_CONFIG, -1); @@ -5943,6 +6155,13 @@ qemuGetSchedulerParametersFlags(virDomainPtr dom, goto cleanup; } + if (*nparams > 1) { + rc = qemuGetCpuBWStatus(driver->cgroup); + if (rc < 0) + goto cleanup; + cpu_bw_status = !!rc; + } + vm = virDomainFindByUUID(&driver->domains, dom->uuid); if (vm == NULL) { @@ -5976,9 +6195,17 @@ qemuGetSchedulerParametersFlags(virDomainPtr dom, _("can't get persistentDef")); goto cleanup; } - val = persistentDef->cputune.shares; + shares = persistentDef->cputune.shares; + if (*nparams > 1 && cpu_bw_status) { + period = persistentDef->cputune.period; + quota = persistentDef->cputune.quota; + } } else { - val = vm->def->cputune.shares; + shares = vm->def->cputune.shares; + if (*nparams > 1 && cpu_bw_status) { + period = vm->def->cputune.period; + quota = vm->def->cputune.quota; + } } goto out; } @@ -6001,14 +6228,20 @@ qemuGetSchedulerParametersFlags(virDomainPtr dom, goto cleanup; } - rc = virCgroupGetCpuShares(group, &val); + rc = virCgroupGetCpuShares(group, &shares); if (rc != 0) { virReportSystemError(-rc, "%s", _("unable to get cpu shares tunable")); goto cleanup; } + + if (*nparams > 1 && cpu_bw_status) { + rc = qemuGetVcpusBWLive(vm, group, &period, &quota); + if (rc != 0) + goto cleanup; + } out: - params[0].value.ul = val; + params[0].value.ul = shares; params[0].type = VIR_TYPED_PARAM_ULLONG; if (virStrcpyStatic(params[0].field, "cpu_shares") == NULL) { qemuReportError(VIR_ERR_INTERNAL_ERROR, @@ -6016,7 +6249,36 @@ out: goto cleanup; } - *nparams = 1; + saved_nparams++; + + if (cpu_bw_status) { + if (*nparams > saved_nparams) { + params[1].value.ul = period; + params[1].type = VIR_TYPED_PARAM_ULLONG; + if (virStrcpyStatic(params[1].field, "cfs_period") == NULL) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + "%s", + _("Field cfs_period too long for destination")); + goto cleanup; + } + saved_nparams++; + } + + if (*nparams > saved_nparams) { + params[2].value.ul = quota; + params[2].type = VIR_TYPED_PARAM_LLONG; + if (virStrcpyStatic(params[2].field, "cfs_quota") == NULL) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + "%s", + _("Field cfs_quota too long for destination")); + goto cleanup; + } + saved_nparams++; + } + } + + *nparams = saved_nparams; + ret = 0; cleanup: -- 1.7.1