From dcf68b272e27c4706285a919309a6202bf7c2e8f Mon Sep 17 00:00:00 2001
From: Suresh Kumar Anaparti <sureshkumar.anaparti@gmail.com>
Date: Thu, 26 May 2022 20:54:33 +0530
Subject: [PATCH] Validate VM state before the reboot operation (#156)

* Prevent NPE on reboot stopped VM and start VM output with null display name
* Upstream PR: apache/cloudstack#6397
---
 engine/schema/src/main/java/com/cloud/vm/UserVmVO.java |  6 ++++++
 .../com/cloud/api/query/dao/UserVmJoinDaoImpl.java     |  2 +-
 .../src/main/java/com/cloud/vm/UserVmManagerImpl.java  | 10 ++++++++--
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/engine/schema/src/main/java/com/cloud/vm/UserVmVO.java b/engine/schema/src/main/java/com/cloud/vm/UserVmVO.java
index e62162e2596..6733a878595 100644
--- a/engine/schema/src/main/java/com/cloud/vm/UserVmVO.java
+++ b/engine/schema/src/main/java/com/cloud/vm/UserVmVO.java
@@ -26,6 +26,8 @@ import javax.persistence.FetchType;
 import javax.persistence.PrimaryKeyJoinColumn;
 import javax.persistence.Table;
 
+import org.apache.commons.lang3.StringUtils;
+
 import com.cloud.hypervisor.Hypervisor.HypervisorType;
 import com.cloud.uservm.UserVm;
 
@@ -141,4 +143,8 @@ public class UserVmVO extends VMInstanceVO implements UserVm {
     public String getName() {
         return instanceName;
     }
+
+    public String getDisplayNameOrHostName() {
+        return StringUtils.isNotBlank(displayName) ? displayName : getHostName();
+    }
 }
diff --git a/server/src/main/java/com/cloud/api/query/dao/UserVmJoinDaoImpl.java b/server/src/main/java/com/cloud/api/query/dao/UserVmJoinDaoImpl.java
index 7a867620900..03fdb542d2f 100644
--- a/server/src/main/java/com/cloud/api/query/dao/UserVmJoinDaoImpl.java
+++ b/server/src/main/java/com/cloud/api/query/dao/UserVmJoinDaoImpl.java
@@ -127,7 +127,7 @@ public class UserVmJoinDaoImpl extends GenericDaoBaseWithTagInformation<UserVmJo
         userVmResponse.setName(userVm.getName());
 
         if (userVm.getDisplayName() != null) {
-        userVmResponse.setDisplayName(userVm.getDisplayName());
+            userVmResponse.setDisplayName(userVm.getDisplayName());
         } else {
             userVmResponse.setDisplayName(userVm.getName());
         }
diff --git a/server/src/main/java/com/cloud/vm/UserVmManagerImpl.java b/server/src/main/java/com/cloud/vm/UserVmManagerImpl.java
index 24081745469..0be2e482b2a 100644
--- a/server/src/main/java/com/cloud/vm/UserVmManagerImpl.java
+++ b/server/src/main/java/com/cloud/vm/UserVmManagerImpl.java
@@ -3132,6 +3132,11 @@ public class UserVmManagerImpl extends ManagerBase implements UserVmManager, Vir
             throw new InvalidParameterValueException("Unable to find a virtual machine with id " + vmId);
         }
 
+        if (vmInstance.getState() != State.Running) {
+            throw new InvalidParameterValueException(String.format("The VM %s (%s) is not running, unable to reboot it",
+                    vmInstance.getUuid(), vmInstance.getDisplayNameOrHostName()));
+        }
+
         _accountMgr.checkAccess(caller, null, true, vmInstance);
 
         checkIfHostOfVMIsInPrepareForMaintenanceState(vmInstance.getHostId(), vmId, "Reboot");
@@ -5121,8 +5126,9 @@ public class UserVmManagerImpl extends ManagerBase implements UserVmManager, Vir
             throw new InvalidParameterValueException("unable to find a virtual machine with id " + vmId);
         }
 
-        if (vm.getState()== State.Running) {
-            throw new InvalidParameterValueException("The virtual machine "+ vm.getUuid()+ " ("+ vm.getDisplayName()+ ") is already running");
+        if (vm.getState() == State.Running) {
+            throw new InvalidParameterValueException(String.format("The virtual machine %s (%s) is already running",
+                    vm.getUuid(), vm.getDisplayNameOrHostName()));
         }
 
         _accountMgr.checkAccess(callerAccount, null, true, vm);