I'm curious as to why this isn't 0ms for a VM. The entire state of the system can be known ahead of time. Why does the kernel need to do any kind of dynamic initialization? Why aren't all data structures and variables statically assigned to proper values for the given VM. So at VM start up time it simply enters the main dispatch loop.
Mostly because that's not how the kernel is designed. While what you're saying is true, it would require a fundamentally different kernel design. The kernel as it is today is designed to work on a variety of devices, not just VMs, so it behaves in a way in which it doesn't have specific knowledge of the device prior to initialization. To do what you're suggesting, the kernel would need to have a special mode where it supports injection of this information from the VM host in advance of initialization, and there's probably a bunch of possible security issues involved as well.