[dijit]

Appreciate the detailed reply!

> This detailed architectural overview of the 360 discusses the hypervisor:

> https://www.copetti.org/writings/consoles/xbox-360/

Yes, the 128KB of key storage and W^X. That's not a hypervisor in the sense that the XB1/HyperV or VMWare have a hypervisor, they shouldn't even share a name it's not the same thing at all.

It's like calling the JVM is a virtual machine in the same way QEMU is.

The 360 "Hypervisor" is more akin to a software T2 chip than anything that actually virtualises.

[robocat]

I don’t think you are showing respect when you simplistically repeat your assertion without effort, after two people expended their precious time to tell you in detail that you are wrong with examples. I don’t know anything, but a few minutes following the provided links and I find https://cxsecurity.com/issue/WLB-2007030065 which says:

  The Xbox 360 security system is designed around a hypervisor concept. All games and other applications, which must be cryptographically signed with Microsoft's private key, run in non-privileged mode, while only a small hypervisor runs in privileged ("hypervisor") mode. The hypervisor controls access to memory and provides encryption and decryption services.

  The policy implemented in the hypervisor forces all executable code to be read-only and encrypted. Therefore, unprivileged code cannot change executable code. A physical memory attack could modify code; however, code memory is encrypted with a unique per-session key, making meaningful modification of code memory in a broadly distributable fashion difficult. In addition, the stack and heap are always marked as non-executable, and therefore data loaded there can never be jumped to by unpriviledged code.

  Unprivileged code interacts with the hypervisor via the "sc" ("syscall") instruction, which causes the machine to enter hypervisor mode.

You can argue your own definition of what a hypervisor is, but I suspect you won’t get any respect for doing so.