linstor: use the target host's CPU shares for live migration with storage

LinstorDataMotionStrategy set the MigrateCommand CPU shares to the raw
cpus * speed value, which is only valid on cgroup v1. On cgroup v2 hosts
the source agent's updateVmSharesIfNeeded() sees that it differs from its
own scaled value and writes it into the migration XML, so libvirt on the
target rejects VMs above 10000 with "shares '<n>' must be in range
[1, 10000]", and smaller VMs end up with an unscaled CPU weight.

Use the value the target host calculated and returned in the
PrepareForMigrationAnswer, as StorageSystemDataMotionStrategy and
VirtualMachineManagerImpl do.

A unit test checks that the target host's value is sent, not cpus * speed.

Author: rp-

plugins/storage/volume/linstor/CHANGELOG.md

@@ -31,6 +31,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Live migration with storage into Linstor failed with "cannot precreate storage for disk type 'block'"
   if the auto-placement didn't put a copy of the new resource on the target host; the resource is
   now made available on the target host before the migration starts.
+- Live migration with storage into Linstor failed on cgroup v2 hosts with
+  "shares '<n>' must be in range [1, 10000]" for VMs with more than 10000 cpus * MHz, and smaller
+  VMs ended up with an unscaled CPU weight; the CPU shares calculated by the target host are now used.
 
 ## [2026-07-30]
 

plugins/storage/volume/linstor/src/main/java/org/apache/cloudstack/storage/motion/LinstorDataMotionStrategy.java

@@ -40,6 +40,7 @@
 import com.cloud.agent.api.CheckVirtualMachineCommand;
 import com.cloud.agent.api.MigrateAnswer;
 import com.cloud.agent.api.MigrateCommand;
+import com.cloud.agent.api.PrepareForMigrationAnswer;
 import com.cloud.agent.api.PrepareForMigrationCommand;
 import com.cloud.agent.api.to.DataObjectType;
 import com.cloud.agent.api.to.VirtualMachineTO;
@@ -78,7 +79,6 @@
 import org.apache.cloudstack.storage.datastore.util.LinstorUtil;
 import org.apache.commons.collections.CollectionUtils;
 import org.apache.commons.collections.MapUtils;
-import org.apache.commons.lang3.ObjectUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.springframework.stereotype.Component;
@@ -426,8 +426,9 @@ public void copyAsync(Map<VolumeInfo, DataStore> volumeDataStoreMap, VirtualMach
             }
 
             PrepareForMigrationCommand pfmc = new PrepareForMigrationCommand(vmTO);
+            Answer pfma;
             try {
-                Answer pfma = _agentManager.send(destHost.getId(), pfmc);
+                pfma = _agentManager.send(destHost.getId(), pfmc);
 
                 if (pfma == null || !pfma.getResult()) {
                     String details = pfma != null ? pfma.getDetails() : "null answer returned";
@@ -449,8 +450,12 @@ public void copyAsync(Map<VolumeInfo, DataStore> volumeDataStoreMap, VirtualMach
             migrateCommand.setWait(StorageManager.KvmStorageOnlineMigrationWait.value());
             migrateCommand.setMigrateStorage(migrateStorage);
             migrateCommand.setMigrateStorageManaged(true);
-            migrateCommand.setNewVmCpuShares(
-                    vmTO.getCpus() * ObjectUtils.defaultIfNull(vmTO.getMinSpeed(), vmTO.getSpeed()));
+            // the target host scales the shares to its cgroup version (v2 only accepts 1-10000),
+            // the raw cpus * speed value is only valid on cgroup v1
+            Integer newVmCpuShares = ((PrepareForMigrationAnswer) pfma).getNewVmCpuShares();
+            if (newVmCpuShares != null) {
+                migrateCommand.setNewVmCpuShares(newVmCpuShares);
+            }
             migrateCommand.setMigrateDiskInfoList(migrateDiskInfoList);
 
             boolean kvmAutoConvergence = StorageManager.KvmAutoConvergence.value();

plugins/storage/volume/linstor/src/test/java/org/apache/cloudstack/storage/motion/LinstorDataMotionStrategyTest.java

@@ -143,6 +143,7 @@ public void setUp() throws Exception {
         when(destHost.getName()).thenReturn(DEST_HOST_NAME);
         when(destHost.getPrivateIpAddress()).thenReturn("192.168.0.3");
 
+        // 2 vCPUs * 5001 MHz: raw shares 10002, more than cgroup v2 accepts
         vmTO = mock(VirtualMachineTO.class);
         when(vmTO.getId()).thenReturn(100L);
         when(vmTO.getName()).thenReturn("i-2-100-VM");
@@ -252,6 +253,17 @@ public void copyAsyncMakesNewResourceAvailableOnTargetHostBeforeMigrating() thro
         Assert.assertTrue(completedResult().isSuccess());
     }
 
+    @Test
+    public void copyAsyncUsesCpuSharesCalculatedByTargetHost() throws Exception {
+        prepareForMigrationAnswers(8335);
+        migrateSucceeds();
+
+        strategy.copyAsync(volumeMap(), vmTO, srcHost, destHost, callback);
+
+        // not the raw cpus * speed (10002), which cgroup v2 hosts reject
+        Assert.assertEquals(8335, sentMigrateCommand().getNewVmCpuShares());
+    }
+
     @Test
     public void copyAsyncRemovesDestinationVolumeWhenCreateResourceFails() throws Exception {
         linstorUtil.when(() -> LinstorUtil.createResource(any(), any(), any(), anyBoolean()))