How to run two operating systems in parallel in hardware, one of which will be in the background?

Question

virtual box

How to run Hackintosh Sierra (Clover) and Windows 10 (UEFI/MBR) at the same time via BIOS or additional bootloader? Resource allocation is preferably dynamic or configurable (half RAM and kernel).
I assume a low-level virtual machine, but it would be interesting to use other solutions.
I want to connect to windows through Parallels in a hackintosh without performance loss due to virtualization.
The hackintosh itself is needed primarily because of XCode.

Answer 1

And climb on the Christmas tree and not be kicked out of the holiday.