KubeVirt virtual machines use the q35 machine type, which relies on PCIe root ports for device attachment. Each device — disk, network interface, controller — occupies one root port. To support hotplug volumes and hotplug interfaces after boot, empty root ports must be reserved at VM creation time because libvirt does not allow adding root ports to a running VM.
The way these ports are reserved determines the PCI bus addresses assigned to all devices. If the reservation strategy changes between reboots, devices can