> In fact, the original spectre and meltdown vulnerabilities impacted the kernel on the same machine so process A could read process B's memory Not quite; proc

> In fact, the original spectre and meltdown vulnerabilities impacted the kernel on the same machine so process A could read process B's memory Not quite; process A could read kernel memory, but reading process B's memory requires a further security problem[0] such as the kernel having the entire physical memory space identity mapped (for Meltdown or for Spectre with gadgets) or the kernel running ('near' enough to speculate) specter-exploitable gadgets when context-switched to process B (for Spectre). 0: It argubly wasn't a vulnerability until Meltdown and Spectre entered the threat model, but it evidently should have been, since they in fact did.