Popek and Goldberg virtualization requirements - Wikipedia

I just found a reference (click title link) to this info in a Slashdot posting:

System/370

All sensitive instructions in the System/370 are privileged: it satisfies the virtualization requirements.

Motorola MC68000

The Motorola MC68000 has a single unprivileged sensitive instruction:

* MOVE from SR

This instruction is sensitive because it allows access to the entire status register, which includes not only the condition codes but also the user/supervisor bit, interrupt level, and trace control. In most later family members, starting with the MC68010, the MOVE from SR instruction was made privileged, and a new MOVE from CCR instruction was provided to allow access to the condition code register only.

IA-32 (x86)

(Main article:X86 virtualization)

The IA-32 instruction set contains 17 sensitive, unprivileged instructions[3]. They can be categorized in two groups:

* Sensitive register instructions: read or change sensitive registers and/or memory locations such as a clock register or interrupt registers:
o SGDT, SIDT, SLDT
o SMSW
o PUSHF, POPF
* Protection system instructions: reference the storage protection system, memory or address relocation system:
o LAR, LSL, VERR, VERW
o POP
o PUSH
o CALL, JMP, INT n, RET
o STR
o MOV

The Slashdot article here, concerns a new Google initiative to allow direct execution of X86 code from within the browser (and most likely the end goal would be a faster web based desktop replacement (which is a good goal). My comment:

Thanks for your comment and the links. Every time I run across an article like this and sigh, wishing I had the technical cojones to explain why it is that we were doing things like this on mainframes in the 80s with complete safety... and continuing to wonder why Intel couldn't just COPY the damned concepts if they can't figure out how to implement them from scratch.

Our world continues to be saddled with a half assed operating system running on a third rate architecture and for no other reason that technology takes a back seat (or maybe it's more like back of the bus) to marketing, bribery and collusion (with an unhealthy dose of buyer ignorance thrown in for good measure).

I continue to hope that good technology will win out eventually, although I'm almost convinced at this point that it will have to come from some country that hasn't been bought out by the Borg.

I wonder though, and maybe you know, why isn't the Power-PC mentioned in the Wikepedia article. I would assume because of its origin that it is closer to the 370 than to the Intel architecture in being fully virtualizable, a concept apparently not on the "roadmap" that Steve Jobs kept referring to in his rationale for Apple's switch to Intel. The Power-PC represented our best hope of escaping the Intel monoculture and I'd like nothing better than to once again have a mainstream non-Intel (and non-Intel-like) choice when I pick my next laptop.

Of course if Intel had a deserved (I'm being generous) third of the market then what Google is doing with this initiative would be dead in the water (as it probably should be).