Compaq BL10e - HP ProLiant - 512 MB RAM Introduction Manual page 17

Figure A2. In a virtual machine environment such as VMware ESX Server that uses binary translation, the guest
OS operates in ring 1 or ring 3.
Typical multitasking
operating system
Application
OS kernel/
device drivers
Processor
With processor-assisted virtualization, hypervisor software will be able to run in a more privileged
ring layer. This will allow guest operating systems to run in their normal ring 0 layer. In addition,
AMD-V and Intel VT-x include new instructions that are specific to hypervisors. The combination of
these two factors (higher-privilege ring level and new hardware instructions) may provide a more
efficient way for hypervisors to virtualize server hardware.
Multitasking OS in a
virtual machine environment
Guest application
Ring 3
Ring 2
Guest OS kernel
Ring 1
Ring 0
Virtualization layer
Guest application
Guest OS kernel
Processor
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