Handle null host in VM restore to prevent NPE on deleted host records

Author: mprokopchuk

server/src/main/java/com/cloud/vm/UserVmManagerImpl.java

@@ -9267,9 +9267,14 @@ private void handleManagedStorage(UserVmVO vm, VolumeVO root) {
             Long hostId = vm.getHostId() != null ? vm.getHostId() : vm.getLastHostId();
 
             if (hostId != null) {
-                VolumeInfo volumeInfo = volFactory.getVolume(root.getId());
                 Host host = _hostDao.findByIdIncludingRemoved(hostId);
 
+                // host row may have been hard-deleted from DB, treat like removed
+                if (host == null) {
+                    s_logger.warn(String.format("Host with id %s not found in DB for VM %s (%s)",
+                            hostId, vm.getUuid(), vm.getName()));
+                    return;
+                }
                 // host could be in removed state, in which case no operation is performed.
                 if (host.getStatus() == Status.Removed) {
                     logger.warn("Host {} ({}) for VM {} ({}) removed on {}",
@@ -9279,6 +9284,7 @@ private void handleManagedStorage(UserVmVO vm, VolumeVO root) {
 
                 final Command cmd;
 
+                VolumeInfo volumeInfo = volFactory.getVolume(root.getId());
                 if (host.getHypervisorType() == HypervisorType.XenServer) {
                     DiskTO disk = new DiskTO(volumeInfo.getTO(), root.getDeviceId(), root.getPath(), root.getVolumeType());
 

server/src/test/java/com/cloud/vm/UserVmManagerImplTest.java

@@ -1720,6 +1720,7 @@ public void testRestoreVirtualMachineWhenHostRemoved() throws ResourceUnavailabl
         when(templateDataStoreDao.findByTemplateZoneReady(1L, 1L)).thenReturn(templateStore);
 
         ServiceOfferingVO serviceOffering = mock(ServiceOfferingVO.class);
+        when(vm.getServiceOfferingId()).thenReturn(serviceOfferingId);
         when(_serviceOfferingDao.findById(vmId, vm.getServiceOfferingId())).thenReturn(serviceOffering);
 
         List<VolumeVO> rootVols = new ArrayList<>();
@@ -1759,7 +1760,6 @@ public void testRestoreVirtualMachineWhenHostRemoved() throws ResourceUnavailabl
                 .thenReturn(newVolume);
         when(newVolume.getId()).thenReturn(11L);
         when(newVolume.getState()).thenReturn(Volume.State.Ready);
-        when(newVolume.getState()).thenReturn(Volume.State.Ready);
         doReturn(20L * 1024 * 1024 * 1024L).when(userVmManagerImpl).getRootVolumeSizeForVmRestore(
                 any(Volume.class), any(VMTemplateVO.class), any(UserVmVO.class),
                 any(DiskOffering.class), anyMap(), Mockito.anyBoolean());