[libvirt] [PATCH 5/5] blkiotune: add qemu support for blkiotune.device_weight

Implement setting/getting per-device blkio weights in qemu, using the cgroups blkio.weight_device tunable. --- src/libvirt_private.syms | 1 + src/qemu/qemu_cgroup.c | 22 +++++ src/qemu/qemu_driver.c | 216 ++++++++++++++++++++++++++++++++++++++++++++- src/util/cgroup.c | 20 ++++ src/util/cgroup.h | 3 + 5 files changed, 257 insertions(+), 5 deletions(-) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index f7d0fb2..b32d5de 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -89,6 +89,7 @@ virCgroupKillRecursive; virCgroupMounted; virCgroupPathOfController; virCgroupRemove; +virCgroupSetBlkioDeviceWeight; virCgroupSetBlkioWeight; virCgroupSetCpuShares; virCgroupSetCpuCfsPeriod; diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c index 2a10bd2..d397578 100644 --- a/src/qemu/qemu_cgroup.c +++ b/src/qemu/qemu_cgroup.c @@ -312,6 +312,28 @@ int qemuSetupCgroup(struct qemud_driver *driver, } } + if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_BLKIO)) { + char *tmp; + if (virBlkioDeviceWeightToStr(vm->def->blkio.devices, + vm->def->blkio.ndevices, + &tmp) < 0) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + _("Unable to set io device weight for domain %s"), + vm->def->name); + goto cleanup; + } + if (tmp) { + rc = virCgroupSetBlkioDeviceWeight(cgroup, tmp); + VIR_FREE(tmp); + if (rc != 0) { + virReportSystemError(-rc, + _("Unable to set io device weight for domain %s"), + vm->def->name); + goto cleanup; + } + } + } + if (vm->def->mem.hard_limit != 0 || vm->def->mem.soft_limit != 0 || vm->def->mem.swap_hard_limit != 0) { diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index c8a858e..40568d0 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -112,7 +112,7 @@ # define KVM_CAP_NR_VCPUS 9 /* returns max vcpus per vm */ #endif -#define QEMU_NB_BLKIO_PARAM 1 +#define QEMU_NB_BLKIO_PARAM 2 static void processWatchdogEvent(void *data, void *opaque); @@ -5888,6 +5888,86 @@ cleanup: return ret; } +/* deviceWeightStr in the form of /device/path,weight,/device/path,weight + * for example, /dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0,800 + */ +static int +parseBlkioWeightDeviceStr(char *deviceWeightStr, + virBlkioDeviceWeightPtr *dw, int *size) +{ + char *temp; + int ndevices = 0; + int nsep = 0; + int i; + virBlkioDeviceWeightPtr result = NULL; + + temp = deviceWeightStr; + while (temp) { + temp = strchr(temp, ','); + if (temp) { + temp++; + nsep++; + } + } + + /* a valid string must have even number of fields */ + if (!(nsep & 1)) + goto error; + + ndevices = (nsep + 1) / 2; + + if (VIR_ALLOC_N(result, ndevices) < 0) { + virReportOOMError(); + return -1; + } + + i = 0; + temp = deviceWeightStr; + while (temp && i < ndevices) { + char *p = temp; + + /* device path */ + + p = strchr(p, ','); + if (!p) + goto error; + + result[i].path = strndup(temp, p - temp); + if (!result[i].path) { + virReportOOMError(); + goto cleanup; + } + + /* weight */ + temp = p + 1; + + if (virStrToLong_ui(temp, &p, 10, &result[i].weight) < 0) + goto error; + + i++; + if (*p == '\0') + break; + else if (*p != ',') + goto error; + temp = p + 1; + } + if (i != ndevices) + goto error; + + *dw = result; + *size = i; + + return 0; + +error: + qemuReportError(VIR_ERR_INVALID_ARG, + _("unable to parse %s"), deviceWeightStr); +cleanup: + virBlkioDeviceWeightArrayClear(result, ndevices); + VIR_FREE(result); + return -1; +} + static int qemuDomainSetBlkioParameters(virDomainPtr dom, virTypedParameterPtr params, int nparams, @@ -5954,10 +6034,10 @@ static int qemuDomainSetBlkioParameters(virDomainPtr dom, ret = 0; if (flags & VIR_DOMAIN_AFFECT_LIVE) { for (i = 0; i < nparams; i++) { + int rc; virTypedParameterPtr param = &params[i]; if (STREQ(param->field, VIR_DOMAIN_BLKIO_WEIGHT)) { - int rc; if (param->type != VIR_TYPED_PARAM_UINT) { qemuReportError(VIR_ERR_INVALID_ARG, "%s", _("invalid type for blkio weight tunable, expected a 'unsigned int'")); @@ -5978,6 +6058,53 @@ static int qemuDomainSetBlkioParameters(virDomainPtr dom, _("unable to set blkio weight tunable")); ret = -1; } + } else if (STREQ(param->field, VIR_DOMAIN_BLKIO_DEVICE_WEIGHT)) { + int ndevices; + virBlkioDeviceWeightPtr devices = NULL; + char *tmp; + if (param->type != VIR_TYPED_PARAM_STRING) { + qemuReportError(VIR_ERR_INVALID_ARG, "%s", + _("invalid type for device_weight tunable, expected a 'char *'")); + ret = -1; + continue; + } + + if (parseBlkioWeightDeviceStr(params[i].value.s, + &devices, + &ndevices) < 0) { + ret = -1; + continue; + } + if (virBlkioDeviceWeightToStr(devices, + ndevices, + &tmp) < 0) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + _("Unable to set blkio weight_device tunable")); + virBlkioDeviceWeightArrayClear(devices, ndevices); + VIR_FREE(devices); + ret = -1; + continue; + } + if (tmp) { + rc = virCgroupSetBlkioDeviceWeight(group, tmp); + VIR_FREE(tmp); + if (rc != 0) { + virReportSystemError(-rc, "%s", + _("unable to set blkio weight_device tunable")); + ret = -1; + virBlkioDeviceWeightArrayClear(devices, ndevices); + VIR_FREE(devices); + continue; + } + virBlkioDeviceWeightArrayClear(vm->def->blkio.devices, + vm->def->blkio.ndevices); + VIR_FREE(vm->def->blkio.devices); + vm->def->blkio.devices = devices; + vm->def->blkio.ndevices = ndevices; + } else { + virBlkioDeviceWeightArrayClear(devices, ndevices); + VIR_FREE(devices); + } } else { qemuReportError(VIR_ERR_INVALID_ARG, _("Parameter `%s' not supported"), param->field); @@ -6007,9 +6134,24 @@ static int qemuDomainSetBlkioParameters(virDomainPtr dom, } persistentDef->blkio.weight = params[i].value.ui; + } else if (STREQ(param->field, VIR_DOMAIN_BLKIO_DEVICE_WEIGHT)) { + virBlkioDeviceWeightPtr devices = NULL; + int ndevices; + if (parseBlkioWeightDeviceStr(params[i].value.s, + &devices, + &ndevices) < 0) { + ret = -1; + continue; + } + virBlkioDeviceWeightArrayClear(persistentDef->blkio.devices, + persistentDef->blkio.ndevices); + VIR_FREE(persistentDef->blkio.devices); + persistentDef->blkio.devices = devices; + persistentDef->blkio.ndevices = ndevices; } else { qemuReportError(VIR_ERR_INVALID_ARG, - _("Parameter `%s' not supported"), param->field); + _("Parameter `%s' not supported"), + param->field); ret = -1; } } @@ -6032,7 +6174,7 @@ static int qemuDomainGetBlkioParameters(virDomainPtr dom, unsigned int flags) { struct qemud_driver *driver = dom->conn->privateData; - int i; + int i, j; virCgroupPtr group = NULL; virDomainObjPtr vm = NULL; virDomainDefPtr persistentDef = NULL; @@ -6046,7 +6188,8 @@ static int qemuDomainGetBlkioParameters(virDomainPtr dom, VIR_TYPED_PARAM_STRING_OKAY, -1); qemuDriverLock(driver); - /* We don't return strings, and thus trivially support this flag. */ + /* We blindly return a string, and let libvirt.c do the filtering + * on behalf of older clients that can't parse it. */ flags &= ~VIR_TYPED_PARAM_STRING_OKAY; vm = virDomainFindByUUID(&driver->domains, dom->uuid); @@ -6125,6 +6268,37 @@ static int qemuDomainGetBlkioParameters(virDomainPtr dom, } param->value.ui = val; break; + case 1: /* blkiotune.device_weight */ + if (vm->def->blkio.ndevices > 0) { + virBuffer buf = VIR_BUFFER_INITIALIZER; + for (j = 0; j < vm->def->blkio.ndevices; j++) { + if (j) + virBufferAddChar(&buf, ','); + virBufferAsprintf(&buf, "%s,%u", + vm->def->blkio.devices[j].path, + vm->def->blkio.devices[j].weight); + } + if (virBufferError(&buf)) { + virReportOOMError(); + goto cleanup; + } + param->value.s = virBufferContentAndReset(&buf); + } else { + param->value.s = strdup(""); + if (!param->value.s) { + virReportOOMError(); + goto cleanup; + } + } + param->type = VIR_TYPED_PARAM_STRING; + if (virStrcpyStatic(param->field, + VIR_DOMAIN_BLKIO_DEVICE_WEIGHT) == NULL) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + _("Field name '%s' too long"), + VIR_DOMAIN_BLKIO_DEVICE_WEIGHT); + goto cleanup; + } + break; default: break; @@ -6149,6 +6323,38 @@ static int qemuDomainGetBlkioParameters(virDomainPtr dom, param->value.ui = persistentDef->blkio.weight; break; + case 1: /* blkiotune.device_weight */ + if (persistentDef->blkio.ndevices > 0) { + virBuffer buf = VIR_BUFFER_INITIALIZER; + for (j = 0; j < persistentDef->blkio.ndevices; j++) { + if (j) + virBufferAddChar(&buf, ','); + virBufferAsprintf(&buf, "%s,%u", + persistentDef->blkio.devices[j].path, + persistentDef->blkio.devices[j].weight); + } + if (virBufferError(&buf)) { + virReportOOMError(); + goto cleanup; + } + param->value.s = virBufferContentAndReset(&buf); + } else { + param->value.s = strdup(""); + if (!param->value.s) { + virReportOOMError(); + goto cleanup; + } + } + param->type = VIR_TYPED_PARAM_STRING; + if (virStrcpyStatic(param->field, + VIR_DOMAIN_BLKIO_DEVICE_WEIGHT) == NULL) { + qemuReportError(VIR_ERR_INTERNAL_ERROR, + _("Field name '%s' too long"), + VIR_DOMAIN_BLKIO_DEVICE_WEIGHT); + goto cleanup; + } + break; + default: break; /* should not hit here */ diff --git a/src/util/cgroup.c b/src/util/cgroup.c index c8d1f33..b510640 100644 --- a/src/util/cgroup.c +++ b/src/util/cgroup.c @@ -982,6 +982,26 @@ int virCgroupGetBlkioWeight(virCgroupPtr group, unsigned int *weight) } /** + * virCgroupSetBlkioDeviceWeight: + * + * @group: The cgroup to change io device weight device for + * @device_weight: The device weight for this cgroup + * + * device_weight is treated as a write-only parameter, so + * there isn't a getter counterpart. + * + * Returns: 0 on success + */ +int virCgroupSetBlkioDeviceWeight(virCgroupPtr group, + const char *device_weight) +{ + return virCgroupSetValueStr(group, + VIR_CGROUP_CONTROLLER_BLKIO, + "blkio.weight_device", + device_weight); +} + +/** * virCgroupSetMemory: * * @group: The cgroup to change memory for diff --git a/src/util/cgroup.h b/src/util/cgroup.h index d190bb3..9972671 100644 --- a/src/util/cgroup.h +++ b/src/util/cgroup.h @@ -55,6 +55,9 @@ int virCgroupAddTask(virCgroupPtr group, pid_t pid); int virCgroupSetBlkioWeight(virCgroupPtr group, unsigned int weight); int virCgroupGetBlkioWeight(virCgroupPtr group, unsigned int *weight); +int virCgroupSetBlkioDeviceWeight(virCgroupPtr group, + const char *device_weight); + int virCgroupSetMemory(virCgroupPtr group, unsigned long long kb); int virCgroupGetMemoryUsage(virCgroupPtr group, unsigned long *kb); -- 1.7.3.1