1 - extensive support from the host kernel above and beyond what is required to execute for regular programs
2 - the guest kernel to be specially compiled to be a UML guest
In other words, even though UML allows a guest Linux kernel to execute as a process on a host Linux kernel, that Linux kernel is not “just a program” like every other user mode application is.
Point taken but….
UML requires:
1 - extensive support from the host kernel above and beyond what is required to execute for regular programs
2 - the guest kernel to be specially compiled to be a UML guest
In other words, even though UML allows a guest Linux kernel to execute as a process on a host Linux kernel, that Linux kernel is not “just a program” like every other user mode application is.