The scope of this spike is to create a libvirt XML definition that can be used
to emulate a compute node with multiple NVMe devices that can be managed and
partitioned. To enable this functionality, the domain should be defined with
a vIOMMU and utilize the q35 machine type to ensure proper PCIe bus handling.

This involves adding multiple virtual NVMe controllers or emulated NVMe
drives to the guest topology. The goal is to create a configuration that
emulates a host environment where storage resources can be assigned,
grouped, or isolated at the hardware level.

The important part of this spike is to create a working domain XML that is
capable of nested NVMe passthrough or assignment, documenting the setup,
and testing it with a nested libvirt VM or DevStack if time permits.

The intent is to enable the initial development work into extending Cyborg to
support NVMe management and orchestration in the next sprint. This should be
time-boxed to 4–5 days at most.