At first glance, the sheer overhead introduced due to virtual memory and the associated address-translation would seem to warrant not using it. Yes, the overhead is high, but the reality is given as follows:

• Modern hardware-acceleration (via TLBs/CPU caches/prefetching) mitigates this overhead and provides decent enough performance
• The benefits one derives from VM outweigh the performance issues

On a VM-based system, we get the following benefits:

• Process-isolation
• The programmer need not worry about physical memory
• Memory-region protection

It's important to understand these a bit better.