My understanding from a Google blog that talked about it indicated that Google felt like almost any speculative execution... is a risk. So while there might not be someone exploiting it now, they considered the practice potentially an issue. Accordingly future performance will possibly still degrade later as further changes are possibly needed?
As a friend and coworker liked to say, "speed kills", and Google is right that it's a risk, just one a lot of people are willing to take.
Every company with high performance single thread designs has out-of-order with speculative execution designs, ARM, AMD, IBM POWER and mainframe/Z, Intel, MIPS, and SPARC. RISC-V is working on it, with the Berkeley Out-of-Order Machine (BOOM) and perhaps other cores.
Yes. All modern processors do. That’s why they’re all vulnerable to the Spectre attack, which is a fundamental consequence of speculative execution.
The other vulnerabilities: Meltdown, Fallout, the recent MDS attacks (RIDL, ZombieLoad, Store to Leak forwarding), are Intel specific because they’re caused by the way Intel specifically chose to skip/defer security enforcement checks in parts of their implementation.
It's pretty clear it wasn't pervasive for ARM because they're climbing to ever higher performance, while Intel reached a conceptual peak in 1995 with the Pentium Pro, and in turn has used mostly Pentium superscalar based cores in their lower performance Atom line. It's implied by the dates of vulnerabilities cited by Google Project Zero I think that Intel's Meltdown original sin goes all the way back to the first Pentium Pro.
My understanding from a Google blog that talked about it indicated that Google felt like almost any speculative execution... is a risk. So while there might not be someone exploiting it now, they considered the practice potentially an issue. Accordingly future performance will possibly still degrade later as further changes are possibly needed?