Unikernel frameworks like Mirage either provide all those features, or in the case of drivers, are just targeting virtio/veth/etc. paravirtualized devices offer

Unikernel frameworks like Mirage either provide all those features, or in the case of drivers, are just targeting virtio/veth/etc. paravirtualized devices offered by the hypervisor. So the domU doesn't have any abstraction to worry about other than just targeting a particular Hypervisor's representation of storage and networking. Xen provides very basic (but safe) message/event channels between VMs. Basically this becomes your IPC, and the VMs become user processes. With a new enough CPU with the correct memory virtualization features, xen can scale to many thousands of domUs. And with each domU only taking up slightly more resources than a typical user process, this is a completely reasonable approach. Again, your Hypervisor becomes the OS which has to worry about the baremetal, and the VMs replace user processes. I intend to playing with MirageOS seriously myself next year. Edit: some dependencies in an example MirageOS app: https://mirage.io/wiki/technical-background#ModularOSLibraries https://mirage.io/wiki/technical-background#ModularOSLibrari...