We should move forward. Apple did a great job with the M{1,2} processors. Not only they are fantastic in terms of performance and energy usage, but also (to this moment) they don't seem to suffer from these issues. The reason is that the CPU is simpler, and a simpler thing is easy to design right in the first place.
This would also require changes at the OS-makers to tag thread forks for trusted and untrusted behavior.
Essentially: instead of shutting down SMT for the entire machine, make the customer "prove" the code is safe for elevation or else it gets scheduled as non-SMT.
Yes. I did not mean to imply the real problem had a simple solution.
Even if we could say for sure that x86 has been disproportionately affected by speculative execution bugs (which already seems dubious), that could easily be due to a kind of selection bias. Presumably security researchers as a group more or less focus on the most popular and relevant ISAs/microarchitectures.
That's a highly optimistic position, to the point of being almost wishful thinking.
The vulnerability being talked about today has been around since 2014 according to the report. Possibly being exploited for unknown number of years since. Sure, maybe we can workaround this one, now.
Other similar ones to be published years into the future are also there today being likely exploited as we speak.
Running untrusted code on the same silicon as sensitive code (data), is unlikely to ever actually be truly safe.