Has AMD processors been confirmed as not vulnerable? As I recall the original investigation only covered Intel processors, but hypothesized that AMD would be affected as well, as they more or less have the same fundamentals around branch prediction.
Time to go off the beaten path.
A few ARM SoCs -- including the entire line used in Raspberry Pi boards -- are safe, but the vast majority of recent ARM devices are affected by one or more of the attack vectors. This means virtually any flagship and most if not all midrange smartphones and tablets, even iPhones and iPads, are vulnerable.
This is the most complete list of affected CPUs and SoCs I've found, and they appear to be keeping it updated:
https://www.techarp.com/guides/complete-meltdown-spectre-cpu...