04-04-2011, 04:27 PM
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VIRTUAL MACHINE OVERVIEW
PROBLEMS WITH TRADITIONAL COMPUTER SYSTEM
Software compatibility
Limitation by the need to support old interfaces
Optimization across interfaces
Hardware restriction
Virtual machine basics
A virtual machine is a software implementation of a machine (computer) that executes programs like a real machine.
Công việc cần làm:
Mapping of virtual resources to hardware resources
Using real machine instructions to carry out the actions specified by the VM instructions
Virtual machine applications
Emulation
Emulating one instruction set with another
Virtual machine applications
Optimization
Optimizing an existing application binary for the same instruction set
Virtual machine applications
Replication
Replicating a virtual machine so that multiple Oses can be supported simultaneously
Virtual machine applications
Sự kết hợp:
Composing virtual machine software to form a more complex flexible system
Virtual machine definition
A virtual machine is a software implementation of a machine (computer) that executes programs like a real machine.
Process and system VM
A process virtual machine is capable of supporting an individual process.
A process virtual machine is created along with its guest process and terminates when the guest process terminates
A system virtual machine provides a complete system enviroment.
This enviroment can support multiple user processes: a file system, I/O devices, GUI…
Application binary interface
ABI= User ISA + System Calls
User ISA = set of all user instructions
System calls
Instruction set architecture interface
ISA : major division between hardware and software