Question Layer 3-0 & -1 (Just Questions)? About PC Privilege Layers.

AntiCorp

Commendable
Aug 14, 2019
8
0
1,510
Hi, my name is AntiCorp. redundant I know just wanted to say hi. My question today is something perhaps im not understanding. Ring 3 is the application layer. Ring 2 is Device driver & ring 1 is device drivers? and lastly, Ring 0 is the kernel. I have been exploring this for quite some time now trying to understand what this means per se. By that, I mean what is the Difference between Ring 2 and 1 Drivers. Just privilege levels? and the kernel. how is that even interfaced with? Windows drivers? or is that the layer above. The last question for this post Ring -1 is there currently anything below this and I have heard the layer -1 is a Hypervisor. is this correct and what is a hypervisor. I was experimenting with KVM's with GPU passthrough and I see this in the Linux Files. and I guess I just don't understand. I get layer 3 to make perfect sense.

So to recap

What is the difference between Layer 2 & 1?

What does ring 0 even modify I get the kernel but can I have an example?

lastly. Hyper visors I have looked into it but I don't understand it. What is Ring -1 does this actually exist and What does it modify?

This info is purely to learn how applications modify and interface with the PC and how they work.

Thanks. Anti
 
Last edited:

Colif

Win 11 Master
Moderator
I don't have all the answers but I see what I can do :)

rings 1 & 2 are hardly used, many operating systems only use 2 rings, kernel & user - https://stackoverflow.com/questions/6710040/cpu-privilege-rings-why-rings-1-and-2-arent-used - this might help you with the differences as well

part 2 of this mentions what ring -1 is, not sure if its helpful - I link part 1 as it might help as well, and link to part 2 is at bottom of page - https://fawzi.wordpress.com/2009/05/24/virtualization-and-protection-rings-welcome-to-ring-1-part-i/