qemu: vcpu: Reuse qemuProcessSetupVcpu in vcpu hotplug

Since majority of the steps is shared, the function can be reused to
simplify code.

Additionally this resolves
https://bugzilla.redhat.com/show_bug.cgi?id=1244128 since the cpu
bandwidth limiting with cgroups would not be set on the hotplug path.

Additionally the code now sets the thread affinity and honors autoCpuset
as in the regular startup code path.

src/qemu/qemu_driver.c

@@ -4743,10 +4743,6 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
     int ret = -1;
     int rc;
     int oldvcpus = virDomainDefGetVcpus(vm->def);
-    virCgroupPtr cgroup_vcpu = NULL;
-    char *mem_mask = NULL;
-    virDomainNumatuneMemMode mem_mode;
-    pid_t vcpupid;
 
     if (!(vcpuinfo = virDomainDefGetVcpu(vm->def, vcpu)))
         return -1;
@@ -4779,41 +4775,12 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
         goto cleanup;
     }
 
-    vcpupid = qemuDomainGetVcpuPid(vm, vcpu);
-
-    if (virDomainNumatuneGetMode(vm->def->numa, -1, &mem_mode) == 0 &&
-        mem_mode == VIR_DOMAIN_NUMATUNE_MEM_STRICT &&
-        virDomainNumatuneMaybeFormatNodeset(vm->def->numa,
-                                            priv->autoNodeset,
-                                            &mem_mask, -1) < 0)
-        goto cleanup;
-
-    if (priv->cgroup) {
-        cgroup_vcpu = qemuDomainAddCgroupForThread(priv->cgroup,
-                                                   VIR_CGROUP_THREAD_VCPU,
-                                                   vcpu, mem_mask, vcpupid);
-        if (!cgroup_vcpu)
-            goto cleanup;
-    }
-
-    /* Inherit def->cpuset */
-    if (vm->def->cpumask) {
-        if (qemuDomainHotplugPinThread(vm->def->cpumask, vcpu, vcpupid,
-                                       cgroup_vcpu) < 0) {
-            goto cleanup;
-        }
-    }
-
-    if (vcpuinfo->sched.policy != VIR_PROC_POLICY_NONE &&
-        virProcessSetScheduler(vcpupid, vcpuinfo->sched.policy,
-                               vcpuinfo->sched.priority) < 0)
+    if (qemuProcessSetupVcpu(vm, vcpu) < 0)
         goto cleanup;
 
     ret = 0;
 
  cleanup:
-    VIR_FREE(mem_mask);
-    virCgroupFree(&cgroup_vcpu);
     return ret;
 }