Protection Through Virtual Memory
A multi-user environment requires protection
Virtual address spaces are logically separate as long as they never reference the same physical page
Operating System sets page tables
Two execution modes: user/supervisor
Page table address must be supervisor readable
Sharing can be assisted with "write protection" or read/write bits
Context switching can be assisted when there is a TLB by extending the tag field of TLB entry with a process ID
Matches require both the address and the ID to match