This is harder than it seems, because once cache is deleted you can't just un-delete it, you'd have to go back to memory and pull it again.
Only the "extra copy of processor state" thing is really viable. You have to have a speculative cache and buffer in reads that only get flushed to the main cache once they're confirmed to be valid, which is enormously complicated. This facility already exists for writes, but now it needs to exist for reads too.
GP is absolutely correct that this is a fundamental assault on processor design as we know it, the speculative execution concept is going back to the drawing board for a major re-think.
Only the "extra copy of processor state" thing is really viable. You have to have a speculative cache and buffer in reads that only get flushed to the main cache once they're confirmed to be valid, which is enormously complicated. This facility already exists for writes, but now it needs to exist for reads too.
GP is absolutely correct that this is a fundamental assault on processor design as we know it, the speculative execution concept is going back to the drawing board for a major re-think.