[PATCH RFC v3 11/16] qemu: command: Support throttle groups during qemuProcessLaunch

[wucf@xxxxxxxxxxxxx]

From: Chun Feng Wu <wucf@xxxxxxxxxxxxx>

* Add qemuBuildThrottleGroupCommandLine in qemuBuildCommandLine to add "object" of throttle-group
* Verify throttle group definition when lauching vm
* Check QEMU_CAPS_OBJECT_JSON before "qemuBuildObjectCommandlineFromJSON", which is to build "-object" option

Signed-off-by: Chun Feng Wu <wucf@xxxxxxxxxxxxx>
---
 src/conf/domain_validate.c | 20 +++++++++++++
 src/qemu/qemu_command.c    | 58 ++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_command.h    |  3 ++
 3 files changed, 81 insertions(+)

diff --git a/src/conf/domain_validate.c b/src/conf/domain_validate.c
index d724046004..27d7a9968b 100644
--- a/src/conf/domain_validate.c
+++ b/src/conf/domain_validate.c
@@ -1818,6 +1818,23 @@ virDomainDefValidateIOThreads(const virDomainDef *def)
 }
 
 
+static int
+virDomainDefValidateThrottleGroups(const virDomainDef *def)
+{
+    size_t i;
+
+    for (i = 0; i < def->nthrottlegroups; i++) {
+        virDomainThrottleGroupDef *throttleGroup = def->throttlegroups[i];
+
+        /* Validate Throttle Group */
+        if (virDomainDiskIoTuneValidate(*throttleGroup) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+
 static int
 virDomainDefValidateInternal(const virDomainDef *def,
                              virDomainXMLOption *xmlopt)
@@ -1873,6 +1890,9 @@ virDomainDefValidateInternal(const virDomainDef *def,
     if (virDomainDefValidateIOThreads(def) < 0)
         return -1;
 
+    if (virDomainDefValidateThrottleGroups(def) < 0)
+        return -1;
+
     return 0;
 }
 
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 5ccae956d3..863544938f 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -1589,6 +1589,14 @@ qemuDiskConfigThrottleFiltersEnabled(const virDomainDiskDef *disk)
 }
 
 
+bool
+qemuDiskConfigThrottleFilterEnabled(const virDomainThrottleGroupDef *group)
+{
+    return !!group->group_name &&
+           virDomainBlockIoTuneInfoHasAny(group);
+}
+
+
 /**
  * qemuDiskBusIsSD:
  * @bus: disk bus
@@ -7475,6 +7483,53 @@ qemuBuildIOThreadCommandLine(virCommand *cmd,
 }
 
 
+/**
+ * qemuBuildThrottleGroupCommandLine:
+ * @cmd: the command to modify
+ * @def: domain definition
+ * @qemuCaps: qemu capabilities object
+ *
+ * build throttle group object in json format
+ * e.g. -object '{"qom-type":"throttle-group","id":"limit0","limits":{"iops-total":200}}'
+ */
+static int
+qemuBuildThrottleGroupCommandLine(virCommand *cmd,
+                                  const virDomainDef *def,
+                                  virQEMUCaps *qemuCaps)
+{
+    size_t i;
+
+    for (i = 0; i < def->nthrottlegroups; i++) {
+        g_autoptr(virJSONValue) props = NULL;
+        g_autoptr(virJSONValue) limits = virJSONValueNewObject();
+        virDomainThrottleGroupDef *group = def->throttlegroups[i];
+
+        if (!qemuDiskConfigThrottleFilterEnabled(group)) {
+            continue;
+        }
+
+        if (qemuMonitorThrottleGroupLimits(limits, group)<0)
+            return -1;
+
+        if (qemuMonitorCreateObjectProps(&props, "throttle-group", group->group_name,
+                                         "a:limits", &limits,
+                                         NULL) < 0)
+            return -1;
+
+        /* this throttle group feature requires "QEMU_CAPS_OBJECT_JSON" */
+        if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_OBJECT_JSON)) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                           _("QEMU_CAPS_OBJECT_JSON support is required for throttle group creation"));
+            return -1;
+        }
+        if (qemuBuildObjectCommandlineFromJSON(cmd, props, qemuCaps) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+
 static int
 qemuBuildNumaCellCache(virCommand *cmd,
                        const virDomainDef *def,
@@ -10509,6 +10564,9 @@ qemuBuildCommandLine(virDomainObj *vm,
     if (qemuBuildIOThreadCommandLine(cmd, def, qemuCaps) < 0)
         return NULL;
 
+    if (qemuBuildThrottleGroupCommandLine(cmd, def, qemuCaps) < 0)
+        return NULL;
+
     if (virDomainNumaGetNodeCount(def->numa) &&
         qemuBuildNumaCommandLine(cfg, def, cmd, priv) < 0)
         return NULL;
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index ce39acfb2c..ddc7a45fd9 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -125,6 +125,9 @@ qemuBuildThrottleFiltersDetachPrepareBlockdev(virDomainDiskDef *disk);
 bool
 qemuDiskConfigThrottleFiltersEnabled(const virDomainDiskDef *disk);
 
+bool
+qemuDiskConfigThrottleFilterEnabled(const virDomainThrottleGroupDef *group);
+
 virJSONValue *
 qemuBuildDiskDeviceProps(const virDomainDef *def,
                          virDomainDiskDef *disk,
-- 
2.34.1