qemu: hotplug: Don't save status XML when monitor is closed

In the vcpu hotplug code if exit from the monitor failed we would still
attempt to save the status XML. When the daemon is terminated the
monitor socket is closed. In such case, the written status XML would not
contain the monitor path and thus be invalid.

Avoid this issue by only saving status XML on success of the monitor
command.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1439452

src/qemu/qemu_hotplug.c

@@ -5386,6 +5386,7 @@ qemuDomainRemoveVcpuAlias(virQEMUDriverPtr driver,
 
 static int
 qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
+                         virQEMUDriverConfigPtr cfg,
                          virDomainObjPtr vm,
                          unsigned int vcpu)
 {
@@ -5427,6 +5428,11 @@ qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
     if (qemuDomainRemoveVcpu(driver, vm, vcpu) < 0)
         goto cleanup;
 
+    qemuDomainVcpuPersistOrder(vm->def);
+
+    if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm, driver->caps) < 0)
+        goto cleanup;
+
     ret = 0;
 
  cleanup:
@@ -5437,6 +5443,7 @@ qemuDomainHotplugDelVcpu(virQEMUDriverPtr driver,
 
 static int
 qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
+                         virQEMUDriverConfigPtr cfg,
                          virDomainObjPtr vm,
                          unsigned int vcpu)
 {
@@ -5497,6 +5504,11 @@ qemuDomainHotplugAddVcpu(virQEMUDriverPtr driver,
     if (qemuDomainValidateVcpuInfo(vm) < 0)
         goto cleanup;
 
+    qemuDomainVcpuPersistOrder(vm->def);
+
+    if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm, driver->caps) < 0)
+        goto cleanup;
+
     ret = 0;
 
  cleanup:
@@ -5611,7 +5623,6 @@ qemuDomainSetVcpusLive(virQEMUDriverPtr driver,
     qemuDomainObjPrivatePtr priv = vm->privateData;
     qemuCgroupEmulatorAllNodesDataPtr emulatorCgroup = NULL;
     ssize_t nextvcpu = -1;
-    int rc = 0;
     int ret = -1;
 
     if (qemuCgroupEmulatorAllNodesAllow(priv->cgroup, &emulatorCgroup) < 0)
@@ -5619,27 +5630,19 @@ qemuDomainSetVcpusLive(virQEMUDriverPtr driver,
 
     if (enable) {
         while ((nextvcpu = virBitmapNextSetBit(vcpumap, nextvcpu)) != -1) {
-            if ((rc = qemuDomainHotplugAddVcpu(driver, vm, nextvcpu)) < 0)
-                break;
+            if (qemuDomainHotplugAddVcpu(driver, cfg, vm, nextvcpu) < 0)
+                goto cleanup;
         }
     } else {
         for (nextvcpu = virDomainDefGetVcpusMax(vm->def) - 1; nextvcpu >= 0; nextvcpu--) {
             if (!virBitmapIsBitSet(vcpumap, nextvcpu))
                 continue;
 
-            if ((rc = qemuDomainHotplugDelVcpu(driver, vm, nextvcpu)) < 0)
-                break;
+            if (qemuDomainHotplugDelVcpu(driver, cfg, vm, nextvcpu) < 0)
+                goto cleanup;
         }
     }
 
-    qemuDomainVcpuPersistOrder(vm->def);
-
-    if (virDomainSaveStatus(driver->xmlopt, cfg->stateDir, vm, driver->caps) < 0)
-        goto cleanup;
-
-    if (rc < 0)
-        goto cleanup;
-
     ret = 0;
 
  cleanup: