Processors (Intel® Core™, Intel® Xeon®, etc); processor utilities and programs (Intel® Processor Identification Utility, Intel® Extreme Tuning Utility, Intel® Easy Streaming Wizard, etc.)
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Are Ring 1 and Ring 2 memory protections are still supported?


It seems that modern OSes are no longer using Ring 1 and Ring 2 memory protection modes.


And I also heard that AMD removed ring1 and ring2 when they were designing x86-64.


However, I could not find any evidences that the two modes are deprecated in intel 64 architecture.

So, I want to know whether the two protection modes are still supported in intel 64, or they are depreciated.

Is there any official documents of announcement about the two modes?


Any comments or suggestions are welcomed!

Thanks :)


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Super User Retired Employee

As far as I know they are still supported. This is documented in the Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 3: System Programming Guide. See Chapter 5.