[talk] Holidaze, AWS, and astounding "clock drift outage"

[Jim Thompson]

Newer Intel CPUs implement Process-Context Identifiers (PCIDs), though no BSD or Linux uses them yet AFAIK.

These should help a lot on TLB shoot downs. 
http://forum.osdev.org/viewtopic.php?f=1&t=29935

Though there is a pending patch on CR3 flush during context switch that would preclude same:

https://patchwork.kernel.org/patch/10138835/

The best layperson accessible write-up I’ve seen is this:

https://www.theregister.co.uk/2018/01/02/intel_cpu_design_flaw/

If you just want the cloud rant: http://market-ticker.org/akcs-www?post=232732

The issue seems to be related to speculative execution. AMD gives a clue:

https://lkml.org/lkml/2017/12/27/2

I found this pseudocode as a light reading example of what may be occurring

https://twitter.com/pwnallthethings/status/947978927284383744

Jim
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