Security policies¶

OpenShift Virtualization provides built-in security features and authorization policies to protect virtual machine workloads and ensure secure cluster operations across your environment.

Key points

• OpenShift Virtualization adheres to the restricted Kubernetes pod security standards profile, which aims to enforce the current best practices for pod security.
• Virtual machine (VM) workloads run as unprivileged pods.
• Security context constraints (SCCs) are defined for the kubevirt-controller service account. For more information about SSCs, see "Additional resources".
• TLS certificates for OpenShift Virtualization components are renewed and rotated automatically.

About workload security¶

By default, virtual machine (VM) workloads do not run with root privileges in OpenShift Virtualization, and there are no supported OpenShift Virtualization features that require root privileges.

For each VM, a virt-launcher pod runs an instance of libvirt in session mode to manage the VM process. In session mode, the libvirt daemon runs as a non-root user account and only permits connections from clients that are running under the same user identifier (UID). Therefore, VMs run as unprivileged pods, adhering to the security principle of least privilege.

TLS certificates¶

TLS certificates for OpenShift Virtualization components are renewed and rotated automatically. You are not required to refresh them manually.

Automatic renewal schedules¶

TLS certificates are automatically deleted and replaced according to the following schedule:

• KubeVirt certificates are renewed daily.
• Containerized Data Importer controller (CDI) certificates are renewed every 15 days.
• MAC pool certificates are renewed every year. Automatic TLS certificate rotation does not disrupt any operations. For example, the following operations continue to function without any disruption:
• Migrations
• Image uploads
• VNC and console connections

Authorization¶

OpenShift Virtualization uses role-based access control (RBAC) to define permissions for human users and service accounts. The permissions defined for service accounts control the actions that OpenShift Virtualization components can perform.

You can also use RBAC roles to manage user access to virtualization features. For example, an administrator can create an RBAC role that provides the permissions required to launch a virtual machine. The administrator can then restrict access by binding the role to specific users.

Default cluster roles for OpenShift Virtualization¶

By using cluster role aggregation, OpenShift Virtualization extends the default OpenShift Container Platform cluster roles to include permissions for accessing virtualization objects. Roles unique to OpenShift Virtualization are not aggregated with OpenShift Container Platform roles.

OpenShift Virtualization cluster roles

RBAC roles for storage features in OpenShift Virtualization¶

Cluster-wide and namespaced RBAC roles enable the Containerized Data Importer (CDI) to manage storage resources, data volumes, and virtual machine disk operations.

Cluster-wide RBAC roles¶

Aggregated cluster roles for the cdi.kubevirt.io API group

Cluster-wide roles for the cdi-operator service account

Cluster-wide roles for the cdi-controller service account

Namespaced RBAC roles¶

Namespaced roles for the cdi-operator service account

Namespaced roles for the cdi-controller service account

Additional SCCs and permissions for the kubevirt-controller service account¶

Security context constraints (SCCs) control permissions for pods. These permissions include actions that a pod, a collection of containers, can perform and what resources it can access. You can use SCCs to define a set of conditions that a pod must run with to be accepted into the system.

The virt-controller is a cluster controller that creates the virt-launcher pods for virtual machines in the cluster.

The kubevirt-controller service account is granted additional SCCs and Linux capabilities so that it can create virt-launcher pods with the appropriate permissions. These extended permissions allow virtual machines to use OpenShift Virtualization features that are beyond the scope of typical pods.

The kubevirt-controller service account is granted the following SCCs:

scc.AllowHostDirVolumePlugin = true

This allows virtual machines to use the hostpath volume plugin.

scc.AllowPrivilegedContainer = false

This ensures the virt-launcher pod is not run as a privileged container.

scc.AllowedCapabilities = []corev1.Capability{"SYS_NICE", "NET_BIND_SERVICE"}

• SYS_NICE allows setting the CPU affinity.
• NET_BIND_SERVICE allows DHCP and Slirp operations.

Viewing the SCC and RBAC definitions for the kubevirt-controller¶

You can view the SecurityContextConstraints definition for the kubevirt-controller by using the oc tool:

$ oc get scc kubevirt-controller -o yaml

You can view the RBAC definition for the kubevirt-controller clusterrole by using the oc tool:

$ oc get clusterrole kubevirt-controller -o yaml