Files
home-network-k3s-impl/platform/kubevirt
jakman85andClaude Opus 4.8 3a59ef1918 fix(kubevirt): boot VMs via CDI DataVolume + EFI + real KVM (Phase 5)
VMs did not boot on the dev cluster. Three distinct live-verified causes,
all fixed GitOps-side:

1. containerDisk root failed at OCI init:
   exec "/container-disk-binary/usr/bin/container-disk": no such file.
   KubeVirt v1.9 supplies that binary to the volumerootdisk init container
   via a k8s-native `image` volume (VolumeSource.Image), gated by the ALPHA
   `ImageVolume` feature gate. k3s v1.31 has it DISABLED, so the apiserver
   silently prunes the image volume + its mount -> binary missing -> crash.
   (Proved: a server-side dry-run of a pod with an `image` volume drops it.)
   Fix: convert the VM roots in all three tests to CDI DataVolumes imported
   onto Longhorn PVCs (mounted disks bypass the container-disk/image-volume
   path). This is also the spec-required disk model (docs/06, R-STATE-01).
   vm-lifecycle now PASSES green live (VMI Running on start + restart).

2. Guest dropped to emergency mode: the containerdisks/fedora:41 image is
   UEFI-native (ESP + /boot mounted via systemd GPT auto-discovery); under
   KubeVirt's SeaBIOS default the ESP+/boot by-uuid mounts time out ->
   local-fs.target fails -> cloud-init runcmd/poweroff never runs.
   Fix: boot the VMs with EFI (OVMF, secureBoot:false) in all three tests
   and fixtures/vm.yaml. Confirmed live: emergency mode gone with EFI.

3. VMs ran under TCG software emulation (guests ~10x slow, saturating nodes
   until one went NotReady and VMs were evicted). Cause: useEmulation:true
   in the KubeVirt CR makes virt-controller NOT request devices.kubevirt.io/
   kvm, so /dev/kvm is never mounted and qemu falls back to TCG even though
   all nodes advertise kvm=1k / hypervisor=true. (Proved: `ls /dev/kvm` in a
   virt-launcher compute container = "No such file"; qemu accel = tcg.)
   Fix: useEmulation:false so the kvm device is requested and VMs run on real
   (nested) KVM. Requires Flux reconcile to take effect live (PM action).

The virt-handler clientcertificates tls.crt error is UNRELATED: node-labeller
(294 labels, hypervisor=true), device plugins, and VMI scheduling all work.

Also raised test exec timeouts to 30m (CDI import + boot) and, in
vm-default-deny, import the root BEFORE applying the default-deny NetworkPolicy
so the CDI importer's egress to quay.io is not severed by the policy.

Co-Authored-By: Claude Opus 4.8 <[email protected]>
2026-08-24 23:07:10 -05:00
..

platform/kubevirt

KubeVirt + CDI — run application VMs (IaaS) as Kubernetes resources on the same control plane, network, storage, and GitOps flow as containers.

What this stub is

A Kustomization that will pull the pinned KubeVirt operator + CDI operator release manifests (commented TODO — added in Phase 5), plus the KubeVirt and CDI custom resources that tune them. VM disks land on Longhorn PVCs via CDI; VMs inherit Cilium default-deny + egress classes.

Layer distinction (docs/01): these are Layer-2 application VMs (a feature the platform offers), NOT the Layer-1 cluster-node VMs (which WS-INFRA provisions with OpenTofu/libvirt). Do not conflate them.

Cross-workstream prerequisite

Nodes must expose virtualization extensions (nested virt in dev KVMs; native on prod) — a node baseline prerequisite owned by WS-INFRA (docs/02). Coordinate before Phase 5.

TODO (later phases — Phase 5, gated on Phases 2–3)

  • Add pinned operator release manifests as Kustomize bases; let Renovate maintain versions.
  • Run one representative application VM via a ServiceDefinition kind: vm; prove create/start/stop/ destroy via kubectl/virtctl, Longhorn-backed disk survives rebuild, default-deny + egress apply, guest auto-updates (Phase-5 exit gates).