qemu: Add helper to retrieve vCPU pid

Instead of directly accessing the array add a helper to do this.

src/qemu/qemu_cgroup.c

@@ -1043,7 +1043,8 @@ qemuSetupCgroupForVcpu(virDomainObjPtr vm)
             goto cleanup;
 
         /* move the thread for vcpu to sub dir */
-        if (virCgroupAddTask(cgroup_vcpu, priv->vcpupids[i]) < 0)
+        if (virCgroupAddTask(cgroup_vcpu,
+                             qemuDomainGetVcpuPid(vm, i)) < 0)
             goto cleanup;
 
         if (period || quota) {

src/qemu/qemu_domain.c

@@ -4131,3 +4131,23 @@ qemuDomainHasVcpuPids(virDomainObjPtr vm)
 
     return priv->nvcpupids > 0;
 }
+
+
+/**
+ * qemuDomainGetVcpuPid:
+ * @vm: domain object
+ * @vcpu: cpu id
+ *
+ * Returns the vCPU pid. If @vcpu is offline or out of range 0 is returned.
+ */
+pid_t
+qemuDomainGetVcpuPid(virDomainObjPtr vm,
+                     unsigned int vcpu)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+
+    if (vcpu >= priv->nvcpupids)
+        return 0;
+
+    return priv->vcpupids[vcpu];
+}

src/qemu/qemu_domain.h

@@ -506,5 +506,6 @@ int qemuDomainDefValidateMemoryHotplug(const virDomainDef *def,
                                        const virDomainMemoryDef *mem);
 
 bool qemuDomainHasVcpuPids(virDomainObjPtr vm);
+pid_t qemuDomainGetVcpuPid(virDomainObjPtr vm, unsigned int vcpu);
 
 #endif /* __QEMU_DOMAIN_H__ */

src/qemu/qemu_driver.c

@@ -1449,7 +1449,7 @@ qemuDomainHelperGetVcpus(virDomainObjPtr vm, virVcpuInfoPtr info, int maxinfo,
                                        &(info[i].cpu),
                                        NULL,
                                        vm->pid,
-                                       priv->vcpupids[i]) < 0) {
+                                       qemuDomainGetVcpuPid(vm, i)) < 0) {
                     virReportSystemError(errno, "%s",
                                          _("cannot get vCPU placement & pCPU time"));
                     return -1;
@@ -1462,7 +1462,7 @@ qemuDomainHelperGetVcpus(virDomainObjPtr vm, virVcpuInfoPtr info, int maxinfo,
                 unsigned char *cpumap = VIR_GET_CPUMAP(cpumaps, maplen, v);
                 virBitmapPtr map = NULL;
 
-                if (!(map = virProcessGetAffinity(priv->vcpupids[v])))
+                if (!(map = virProcessGetAffinity(qemuDomainGetVcpuPid(vm, v))))
                     return -1;
 
                 virBitmapToDataBuf(map, cpumap, maplen);
@@ -5156,7 +5156,8 @@ qemuDomainPinVcpuFlags(virDomainPtr dom,
                 goto endjob;
             }
         } else {
-            if (virProcessSetAffinity(priv->vcpupids[vcpu], pcpumap) < 0) {
+            if (virProcessSetAffinity(qemuDomainGetVcpuPid(vm, vcpu),
+                                      pcpumap) < 0) {
                 virReportError(VIR_ERR_SYSTEM_ERROR,
                                _("failed to set cpu affinity for vcpu %d"),
                                vcpu);

src/qemu/qemu_process.c

@@ -2234,7 +2234,6 @@ qemuProcessSetLinkStates(virQEMUDriverPtr driver,
 static int
 qemuProcessSetVcpuAffinities(virDomainObjPtr vm)
 {
-    qemuDomainObjPrivatePtr priv = vm->privateData;
     virDomainDefPtr def = vm->def;
     virDomainPinDefPtr pininfo;
     int n;
@@ -2267,7 +2266,7 @@ qemuProcessSetVcpuAffinities(virDomainObjPtr vm)
                                          n)))
             continue;
 
-        if (virProcessSetAffinity(priv->vcpupids[n],
+        if (virProcessSetAffinity(qemuDomainGetVcpuPid(vm, n),
                                   pininfo->cpumask) < 0) {
             goto cleanup;
         }
@@ -2355,7 +2354,7 @@ qemuProcessSetSchedulers(virDomainObjPtr vm)
     size_t i = 0;
 
     for (i = 0; i < priv->nvcpupids; i++) {
-        if (qemuProcessSetSchedParams(i, priv->vcpupids[i],
+        if (qemuProcessSetSchedParams(i, qemuDomainGetVcpuPid(vm, i),
                                       vm->def->cputune.nvcpusched,
                                       vm->def->cputune.vcpusched) < 0)
             return -1;