No, that means that only having 48 bits of physically addressable memory gives you the ability to have many times that amount of virtual memory -- and that virt

No, that means that only having 48 bits of physically addressable memory gives you the ability to have many times that amount of virtual memory -- and that virtual memory can be used to implement this fun page-faulting shenanigans without worrying about taking up any real memory address space. You have enough virtual memory for all your physical memory, and these tricks, and then some.