Fwd: VAX + Spectre

[Jon Elson]

On 09/17/2019 08:55 AM, Paul Koning via cctalk wrote:
> "Spectre" is one of two notorious bugs of modern CPUs involving speculative execution.  I rather doubt that VAX is affected by this but I suspect others here have a lot more knowledge.
>
>
You need an extremely high resolution timer to detect slight 
differences in execution time of speculatively-executed 
threads. The VAX 11/780 certainly did not do speculative 
execution, and my guess is that all VAXen did not, either.  
Also, I don't think the timer was high enough resolution to 
detect such a difference.

The Alpha did do speculative execution, so it is remotely 
possible that you could play such games on that platform.

Without a deep understanding of how these exploits really 
work, I'm still a bit skeptical that it could actually be 
performed on real-world systems in a shared host data center.

Jon