For those curious about the "what" and who don't know x86 opcodes from memory, from the first link and in its earliest incarnation,

"LOADALL restores the microprocessor state from the State Save Map that is saved during the transition from user mode to ICE mode. LOADALL loads enough of the microprocessor state to ensure return to any processor operating mode."

Why would the US military be pressuring Intel to remove obscure instructions in ancient CPU designs?

Not sure what to love here, it's a debug feature which, according to your source, Intel promised the US Mil to remove for some reasons but ultimately didn't.

There certainly are undocumented debug facilities in modern CPUs. For one example, the leaked Socket AM3 datasheet clearly shows a JTAG interface, though I don't know if it's operational in production silicon.

Hopefully, debug capabilities cannot be used to pwn the CPU from unprivileged code without external debug hardware which could pwn the CPU anyway by itself. It's not even clear if they are enabled in production chips at all.

LOADALL for example worked only in RING0 and got ultimately removed early in the 486 days so it seems Intel cared about security somewhat (and probably also about future compatibility, to be honest, it's not fun when software relies on features you want to change in the next generation).

Nowadays they should care even more - if software backdoors were available and leaked to the public, the magnitude of shit happening in all those cloud companies would be monumental.

> if software backdoors were available and leaked to the public

https://www.blackhat.com/us-15/briefings.html#the-memory-sin...

conveniently "discovered" by a 3 letter agency favorite principle contractor (Batelle Memorial Institute - have fun researching them) employee just after everybody switched to the next(fixed) cpu generation.

I doubt that this can be used for VM escape because it requires access to the physical LAPIC and afaik hypervisors wouldn't allow VMs to touch this.

It also doesn't work from userspace so pretty much all you can do with it is hacking SMM from a kernel running on the bare metal. Maybe useful for rootkits, but truth be told 3LAs seem to have no problem making non-SMM malware undetectable by commercial AVs. See stuxnet :)

> conveniently "discovered" by a 3 letter agency favorite principle contractor

Not sure what you are alluding to. 3LAs wouldn't want this to be known if it was their job, methinks.

I think he's saying that the 3LAs knew about it for a long time, but publicly "discovered" the flaw when it was no longer useful to them (after everyone had upgraded)