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 = ¶ms[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
--
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