qemu: fix some api cannot work when disable cpuset in conf

If cpuset is disabled or not available, it libvirt must not use it.
Mainly for actions that do not need it and can use sched_setaffinity()
or numa_membind() instead, because they will fail without good reason.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1244664Signed-off-by: NLuyao Huang <lhuang@redhat.com>

src/qemu/qemu_cgroup.c

@@ -1025,10 +1025,6 @@ qemuSetupCgroupForVcpu(virDomainObjPtr vm)
         if (virCgroupAddTask(cgroup_vcpu, priv->vcpupids[i]) < 0)
             goto cleanup;
 
-        if (mem_mask &&
-            virCgroupSetCpusetMems(cgroup_vcpu, mem_mask) < 0)
-            goto cleanup;
-
         if (period || quota) {
             if (qemuSetupCgroupVcpuBW(cgroup_vcpu, period, quota) < 0)
                 goto cleanup;
@@ -1038,6 +1034,10 @@ qemuSetupCgroupForVcpu(virDomainObjPtr vm)
         if (virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
             virBitmapPtr cpumap = NULL;
 
+            if (mem_mask &&
+                virCgroupSetCpusetMems(cgroup_vcpu, mem_mask) < 0)
+                goto cleanup;
+
             /* try to use the default cpu maps */
             if (vm->def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)
                 cpumap = priv->autoCpuset;
@@ -1202,15 +1202,15 @@ qemuSetupCgroupForIOThreads(virDomainObjPtr vm)
                 goto cleanup;
         }
 
-        if (mem_mask &&
-            virCgroupSetCpusetMems(cgroup_iothread, mem_mask) < 0)
-            goto cleanup;
-
         /* Set iothreadpin in cgroup if iothreadpin xml is provided */
         if (virCgroupHasController(priv->cgroup,
                                    VIR_CGROUP_CONTROLLER_CPUSET)) {
             virBitmapPtr cpumask = NULL;
 
+            if (mem_mask &&
+                virCgroupSetCpusetMems(cgroup_iothread, mem_mask) < 0)
+                goto cleanup;
+
             if (def->iothreadids[i]->cpumask)
                 cpumask = def->iothreadids[i]->cpumask;
             else if (def->placement_mode == VIR_DOMAIN_CPU_PLACEMENT_MODE_AUTO)

src/qemu/qemu_driver.c

@@ -4597,7 +4597,9 @@ qemuDomainAddCgroupForThread(virCgroupPtr cgroup,
     if (virCgroupNewThread(cgroup, nameval, idx, true, &new_cgroup) < 0)
         return NULL;
 
-    if (mem_mask && virCgroupSetCpusetMems(new_cgroup, mem_mask) < 0)
+    if (mem_mask &&
+        virCgroupHasController(cgroup, VIR_CGROUP_CONTROLLER_CPUSET) &&
+        virCgroupSetCpusetMems(new_cgroup, mem_mask) < 0)
         goto error;
 
     /* Add pid/thread to the cgroup */
@@ -4653,7 +4655,8 @@ qemuDomainHotplugPinThread(virBitmapPtr cpumask,
 {
     int ret = -1;
 
-    if (cgroup) {
+    if (cgroup &&
+        virCgroupHasController(cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
         if (qemuSetupCgroupCpusetCpus(cgroup, cpumask) < 0) {
             virReportError(VIR_ERR_OPERATION_INVALID,
                            _("failed to set cpuset.cpus in cgroup for id %d"),
@@ -4896,7 +4899,8 @@ qemuDomainSetVcpusFlags(virDomainPtr dom, unsigned int nvcpus,
     if (virDomainObjGetDefs(vm, flags, &def, &persistentDef) < 0)
         goto endjob;
 
-    if (def && !(flags & VIR_DOMAIN_VCPU_GUEST) && virNumaIsAvailable()) {
+    if (def && !(flags & VIR_DOMAIN_VCPU_GUEST) && virNumaIsAvailable() &&
+        virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET)) {
         if (virCgroupNewThread(priv->cgroup, VIR_CGROUP_THREAD_EMULATOR, 0,
                                false, &cgroup_temp) < 0)
             goto endjob;