qemu: enable resctrl monitor in qemu

Add functions for creating, destroying, reconnecting resctrl
monitor in qemu according to the configuration in domain XML.

Signed-off-by: Wang Huaqiang <huaqiang.wang@intel.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>

src/qemu/qemu_process.c

@@ -2597,10 +2597,20 @@ qemuProcessResctrlCreate(virQEMUDriverPtr driver,
         return -1;
 
     for (i = 0; i < vm->def->nresctrls; i++) {
+        size_t j = 0;
         if (virResctrlAllocCreate(caps->host.resctrl,
                                   vm->def->resctrls[i]->alloc,
                                   priv->machineName) < 0)
             goto cleanup;
+
+        for (j = 0; j < vm->def->resctrls[i]->nmonitors; j++) {
+            virDomainResctrlMonDefPtr mon = NULL;
+
+            mon = vm->def->resctrls[i]->monitors[j];
+            if (virResctrlMonitorCreate(mon->instance,
+                                        priv->machineName) < 0)
+                goto cleanup;
+        }
     }
 
     ret = 0;
@@ -5414,6 +5424,7 @@ qemuProcessSetupVcpu(virDomainObjPtr vm,
 {
     pid_t vcpupid = qemuDomainGetVcpuPid(vm, vcpuid);
     virDomainVcpuDefPtr vcpu = virDomainDefGetVcpu(vm->def, vcpuid);
+    virDomainResctrlMonDefPtr mon = NULL;
     size_t i = 0;
 
     if (qemuProcessSetupPid(vm, vcpupid, VIR_CGROUP_THREAD_VCPU,
@@ -5424,11 +5435,26 @@ qemuProcessSetupVcpu(virDomainObjPtr vm,
         return -1;
 
     for (i = 0; i < vm->def->nresctrls; i++) {
+        size_t j = 0;
         virDomainResctrlDefPtr ct = vm->def->resctrls[i];
 
         if (virBitmapIsBitSet(ct->vcpus, vcpuid)) {
             if (virResctrlAllocAddPID(ct->alloc, vcpupid) < 0)
                 return -1;
+
+            for (j = 0; j < ct->nmonitors; j++) {
+                mon = ct->monitors[j];
+
+                if (virBitmapEqual(ct->vcpus, mon->vcpus))
+                    continue;
+
+                if (virBitmapIsBitSet(mon->vcpus, vcpuid)) {
+                    if (virResctrlMonitorAddPID(mon->instance, vcpupid) < 0)
+                        return -1;
+                    break;
+                }
+            }
+
             break;
         }
     }
@@ -7190,8 +7216,18 @@ void qemuProcessStop(virQEMUDriverPtr driver,
     /* Remove resctrl allocation after cgroups are cleaned up which makes it
      * kind of safer (although removing the allocation should work even with
      * pids in tasks file */
-    for (i = 0; i < vm->def->nresctrls; i++)
+    for (i = 0; i < vm->def->nresctrls; i++) {
+        size_t j = 0;
+
+        for (j = 0; j < vm->def->resctrls[i]->nmonitors; j++) {
+            virDomainResctrlMonDefPtr mon = NULL;
+
+            mon = vm->def->resctrls[i]->monitors[j];
+            virResctrlMonitorRemove(mon->instance);
+        }
+
         virResctrlAllocRemove(vm->def->resctrls[i]->alloc);
+    }
 
     qemuProcessRemoveDomainStatus(driver, vm);
 
@@ -7926,9 +7962,20 @@ qemuProcessReconnect(void *opaque)
         goto error;
 
     for (i = 0; i < obj->def->nresctrls; i++) {
+        size_t j = 0;
+
         if (virResctrlAllocDeterminePath(obj->def->resctrls[i]->alloc,
                                          priv->machineName) < 0)
             goto error;
+
+        for (j = 0; j < obj->def->resctrls[i]->nmonitors; j++) {
+            virDomainResctrlMonDefPtr mon = NULL;
+
+            mon = obj->def->resctrls[i]->monitors[j];
+            if (virResctrlMonitorDeterminePath(mon->instance,
+                                               priv->machineName) < 0)
+                goto error;
+        }
     }
 
     /* update domain state XML with possibly updated state in virDomainObj */