OK no problem, it would be interesting to see a comparison between the two styles of VM! I remember that there is at least one talk here which goes into the difference:

http://soft-dev.org/events/vmss16/

I forget what the different names he used. He distinguished between runtimes like the JVM and runtimes like Xen, which emulate an operating system too. A CPU emulator seems closer to Xen than the JVM.

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EDIT: The names were "system" and "process" VMs, mentioned here:

https://news.ycombinator.com/item?id=16777564

So I think you are talking about a "system VM", where this book is more about "process" VMs. They are related, but distinct -- it even says so in that book's title!

It's definitely true that in something like Xen you would want to avoid allocating memory more than in something like a JavaScript VM. (And it would be easier to avoid allocating, too.)

I don't like that terminology, but it's a useful distinction.