It might technically be possible but I wouldn't recommend it.
As soon as your OS touches that memory, it's going to run into some weird issues as the host OS starts paging that memory.
When an OS does paging, it's aware of the fact that it's dealing with slow memory and takes measures to minimize that access, in your case, the guest will continue to believe that the memory is standard fast RAM and access it as such. This is not ideal for any of the parties involved.