Yep. I think this is how it works. Kernel becomes a library the application uses instead of something that jumps over the CPU context. Application runs as ro

Yep. I think this is how it works. Kernel becomes a library the application uses instead of something that jumps over the CPU context. Application runs as root with the rump kernel or unikernel liked in. Only portions of kernel actually used need to be present. System calls become function calls. Multitasking support provided by a threading library. You shouldn't run multiple applications in a unikernel. If you have a number of servers running a hypervisor as a base OS, and your applications on its VMs are network-centric like web servers, load balancers, database services, or microservices, and you don't really use the user-level security of a traditional OS, this can enhance performance by eliminating the user-kernel CPU context switch and consume less RAM.