Virtual addresses

Question 1

What are some basic rules about virtualization?

Answer 1

• A way to run multiple operating systems on the same hardware
• Only virtual machine manager has full system control
• Virtual machines completely isolated from each other

Question 2

What are the types of virtualization?

Answer 2

• Full virtualization - guest OS runs unmodified
• Para-virtualization - guest OS must be aware of virtualization, source-code modifications required.

Question 3

What are the advantages of virtualization?

Answer 3

• Multiple virtual machines/operating systems/services on single physical machine
• various forms of computation as a service
• good for security
• great for reliability and recovery
• Work on multiple OS in parallel
• Develop and debug OS in user mode

Question 4

When a machine can be virtualized?

Answer 4

• A machine can be virtualized if every sensitive instruction is privileged.*
• sensitive:*
• CPU
  
  • some registers
• MMU
  
  • Page table
  • Segments
• Interrupts
• Timers
• I/O devices