Chapter 2. Release notes

2.1. OpenShift Virtualization release notes

2.1.1. Providing documentation feedback

To report an error or to improve our documentation, log in to your Red Hat Jira account and submit a Jira issue.

2.1.2. About Red Hat OpenShift Virtualization

With Red Hat OpenShift Virtualization, you can bring traditional virtual machines (VMs) into OpenShift Container Platform and run them alongside containers. In OpenShift Virtualization, VMs are native Kubernetes objects that you can manage by using the OpenShift Container Platform web console or the command line.

OpenShift Virtualization is represented by the icon.

You can use OpenShift Virtualization the OVN-Kubernetes Container Network Interface (CNI) network provider.

Learn more about what you can do with OpenShift Virtualization.

Learn more about OpenShift Virtualization architecture and deployments.

Prepare your cluster for OpenShift Virtualization.

2.1.2.1. Supported cluster versions for OpenShift Virtualization

The latest stable release of OpenShift Virtualization 4.19 is 4.19.0.

OpenShift Virtualization 4.19 is supported for use on OpenShift Container Platform 4.19 clusters. To use the latest z-stream release of OpenShift Virtualization, you must first upgrade to the latest version of OpenShift Container Platform.

2.1.2.2. Supported guest operating systems

To view the supported guest operating systems for OpenShift Virtualization, see Certified Guest Operating Systems in Red Hat OpenStack Platform, Red Hat Virtualization, OpenShift Virtualization and Red Hat Enterprise Linux with KVM.

2.1.2.3. Microsoft Windows SVVP certification

OpenShift Virtualization is certified in Microsoft’s Windows Server Virtualization Validation Program (SVVP) to run Windows Server workloads.

The SVVP certification applies to:

Red Hat Enterprise Linux CoreOS workers. In the Microsoft SVVP Catalog, they are named Red Hat OpenShift Container Platform 4 on RHEL CoreOS 9.
Intel and AMD CPUs.

2.1.3. Quick starts

Quick start tours are available for several OpenShift Virtualization features. To view the tours, click the Help icon ? in the menu bar on the header of the OpenShift Container Platform web console and then select Quick Starts. You can filter the available tours by entering the keyword virtualization in the Filter field.

2.1.4. New and changed features

This release adds new features and enhancements related to the following components and concepts:

2.1.4.1. Infrastructure

You can now prevent the inadvertent deletion of a virtual machine (VM) by enabling delete protection for the VM. You can also disable delete protection that has been set for a VM.
As a cluster administrator, you can prevent users from enabling VM delete protection by removing the option at the cluster level.

2.1.4.2. Virtualization

You can now choose to expand virtual machines (VMs) using instance types and preferences. For more information, see Using InstancetypeReferencePolicy to expand VirtualMachines in the Red Hat Customer Portal.
Red Hat Enterprise Linux (RHEL) 10 is added as a certified guest operating system. For a complete list of supported guest operating systems, see Certified Guest Operating Systems in OpenShift Virtualization.

You can now update the machine type of multiple virtual machines (VMs) at the same time from the OpenShift CLI (oc).

2.1.4.3. Networking

You can now configure a NodeNetworkConfigurationPolicy manifest to enable the Link Layer Discovery Protocol (LLDP) listener for all ethernet ports in your OpenShift Container Platform cluster.
You can now create a new Node Network Configuration Policy (NNCP) in the topology view of the cluster and see its graphical representation in real time. Clicking Create on the Node network configuration page opens a form for configuring the elements of the new NNCP, and the NNCP is also displayed as a diagram.

You can now use the OVN-Kubernetes localnet network topology to connect a VM to a secondary user-defined network.

2.1.4.4. Storage

You can now use a PVC as the source of a custom DataImportCron in the dataImportCronTemplates section of the HyperConverged custom resource (CR). See Managing automatic boot source updates for more information.

2.1.4.5. Web console

You can now configure multiple IOThreads for virtual machines that use fast storage, such as SSD (solid-state drive) or NVMe (non-volatile memory express). This improves I/O performance by enabling multiple threads for disk access.

On the VirtualMachines page, you can now see the summary of CPU, memory, and storage usage by your VMs. To restrict this summary to the VMs in a specific project, select the project name in the tree view.

On the VirtualMachines page, you can now navigate between your VMs by using the tree view.

An attempt to stop, restart, or pause a VM or multiple VMs now displays a confirmation dialog.

You can now access the commands of the Options menu from the tree view by right-clicking the VM. If you right-click a project and select a command, the action is applied to all VMs in the project.
You can now perform bulk actions on multiple virtual machines (VMs), including adding or removing labels, viewing the number of VMs selected for deletion, and moving VMs to a folder within the same namespace.

On the VirtualMachines page, you can now use the tree view to organize VMs in folders and drag and drop VMs to these folders.

You can now search for virtual machines by fields such as name, project, description, labels, date created, vCPU, and memory. You can also save frequently used search queries.

2.1.4.6. Monitoring

The following alerts for the OpenShift Virtualization Operator are now included in the OpenShift Container Platform runbooks:
- HAControlPlaneDown
- HighCPUWorkload
- NodeNetworkInterfaceDown

New metrics are now available and improve the observability of virtual machines (VMs) and virtual machine instances (VMIs). You can use these metrics to monitor the following VM lifecycle events, resource usage, and migration details:
- Migration metrics
- vNIC networking information metrics
- Allocated storage size metrics for running and stopped VMs
In addition, the following VM and VMI metadata metrics are now available:
- The pod_name label in kubevirt_vmi_info
- UID in VM and VMI metrics
- The VM creation date
For a complete list of virtualization metrics, see KubeVirt components metrics.

2.1.4.7. Notable technical changes

VirtualMachines that use instance types and preferences no longer have their specification mutated at runtime to include derived metadata, such as revisionName. This metadata is now stored in the status field to preserve the declarative VM specification and ensure compatibility.

In OpenShift Virtualization 4.19, the default permissions for live migration have changed to improve cluster security. Users must now be explicitly granted the kubevirt.io:migrate cluster role to create, delete, or update live migration requests. Previously, namespace administrators had these permissions by default. For more information, see About live migration permissions.

2.1.5. Deprecated and removed features

2.1.5.1. Deprecated features

Deprecated features are included in the current release and supported. However, they will be removed in a future release and are not recommended for new deployments.

The OperatorConditionsUnhealthy alert is deprecated. You can safely silence it.

The following HyperConverged custom resource (CR) fields have been deprecated and copied from their original location under the spec.featureGates fields to a new location in the spec field, where they can be used if needed:
- DeployVmConsoleProxy
- EnableApplicationAwareQuota
- EnableCommonBootImageImport
If used in the spec.featureGates location, the old fields are ignored.

2.1.6. Technology Preview features

Some features in this release are currently in Technology Preview. These experimental features are not intended for production use. Note the following scope of support on the Red Hat Customer Portal for these features:

Technology Preview Features Support Scope

You can now manage the link state of a primary or secondary virtual machine (VM) interface by using the OpenShift Container Platform web console or the CLI.

OpenShift Virtualization is now supported on Azure Boost.

The DevKubeVirtRelieveAndMigrate descheduler profile is now available. This profile enhances the LongLifecycle profile by supporting load-aware descheduling, dynamic soft taints, and improved workload rebalancing.

You can now deploy OpenShift Virtualization on IPv6 single-stack clusters. Support for IPv6 single-stack is limited to the OVN-Kubernetes localnet and Linux bridge Container Network Interface (CNI) plugins.

By using the OpenShift Container Platform web console, you can now migrate VMs in bulk from one storage class to another storage class.

2.1.7. Known issues

Networking

When you update from OpenShift Container Platform 4.12 to a newer minor version, VMs that use the cnv-bridge Container Network Interface (CNI) fail to live migrate. (https://access.redhat.com/solutions/7069807)
- As a workaround, change the spec.config.type field in your NetworkAttachmentDefinition manifest from cnv-bridge to bridge before performing the update.

Nodes

Uninstalling OpenShift Virtualization does not remove the feature.node.kubevirt.io node labels created by OpenShift Virtualization. You must remove the labels manually. (CNV-38543)

Storage

Restoring a snapshot of a virtual machine (VM) migrated using Migration Toolkit for Containers (MTC) fails. The restore creates a persistent volume claim (PVC) but not a data volume (DV). The VM spec references a DataVolumeTemplate missing from the volumes list. (CNV-61279)
- As a workaround, restart the VM after storage migration and before taking the snapshot. This creates a new controller revision that avoids the issue.

If you perform storage class migration for a stopped VM, the VM might not be able to start because of a missing bootable device. To prevent this, do not attempt storage class migration if the VM is not running. (CNV-55104)
Important
Storage class migration is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.
For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

Virtualization

When the mode of live migration is PostCopy, hot-plugging CPU or memory resource fails. (CNV-48348)

OpenShift Virtualization links a service account token in use by a pod to that specific pod. OpenShift Virtualization implements a service account volume by creating a disk image that contains a token. If you migrate a VM, then the service account volume becomes invalid. (CNV-33835)
- As a workaround, use user accounts rather than service accounts because user account tokens are not bound to a specific pod.

When adding a virtual Trusted Platform Module (vTPM) device to a Windows VM, the BitLocker Drive Encryption system check passes even if the vTPM device is not persistent. This is because a vTPM device that is not persistent stores and recovers encryption keys using ephemeral storage for the lifetime of the virt-launcher pod. When the VM migrates or is shut down and restarts, the vTPM data is lost. (CNV-36448)

IBM Z and IBM LinuxONE

Important

Using OpenShift Virtualization in a cluster deployed on s390x architecture is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

If you create a VM from a template and select Boot from CD, the VM fails to boot and the error unsupported configuration: SATA is not supported with this QEMU binary is logged. This occurs because the CD-ROM is automatically mounted as a SATA device, which is not supported on s390x architecture. (CNV-61740)
- As a workaround, navigate to the VM’s Configuration Storage tab, select the CD-ROM, and change the interface type from SATA to SCSI.

GPU devices appear in the Hardware Devices list for s390x VMs, but GPU support is not available for s390x architecture. You can disregard these list entries. (CNV-61957)

When you create a VM by using Red Hat Enterprise Linux (RHEL) container disk images for s390x architecture, call traces referencing virtio_balloon free page reporting print to the VM console. This is due to a kernel bug. (OCPBUGS-51113)
- As a workaround, disable memory ballooning for the VM by adding the following parameter to the VM YAML configuration: spec.domain.devices.autoattachMemBalloon: false.
  You can also disable free page reporting of memory ballooning for all new VMs. To do so, edit the HyperConverged CR and add the parameter spec.virtualMachineOptions.disableFreePageReporting: true.

VMs based on s390x architecture can only use the IPL boot mode. However, in the OpenShift Container Platform web console, the Boot mode list for s390x VMs incorrectly includes BIOS, UEFI, and UEFI (secure) boot modes. If you select one of these modes for an s390x-based VM, the operation fails. (CNV-56889)

In the OpenShift Container Platform web console, it is erroneously possible to define multiple CPU threads for a VM based on s390x architecture. If you define multiple CPU threads, the VM enters a CrashLoopBackOff state with the qemu-kvm: S390 does not support more than 1 threads error. (CNV-56890)