I want to know if we can make a kernel memory read only?

If yes then ,

What are the possible ways to make kernel read only?

Shortcomings of making kernel read only?

Possible way to develop a mechanism at host kernel to make pages

assigned for guest machine readonly?

We need to isolate threat of rootkit in guest machine in VM. What are

the way to achieve this ? What categories of rootkit threat can be isolated

in such way?