Meltdown is not a fundamental bug in speculation, its a bug in various Intel implementations of it. AMD, for example, say they are not vulnerable even though they implement the same x86 ISA. I think its safe to say that Meltdown won’t work on future Intel CPUs – speculating page faults is game-over and the mitigation with KAISER so expensive that Intel will disable it.
Needless to say, Meltdown doesn’t work on the Mill either.
Spectre is a whole different ballgame. Its named because its going to haunt the industry for a long time 🙁
At first and second reading, Spectre as narrowly described doesn’t work on the Mill. After a third reading we’ll make a more detailed post explaining exactly why – please give us time.