[ahh]

> I don't see why that would have to add latency to all (or any) memory access. The addresses generated by programs (except in real mode, when everything has access to everything anyway so we don't care about these issues then) are virtual addresses, so they have to be translated to get the actual memory address.

L1 caches are generally virtually indexed for exactly this reason: to allow a L1 cache read to happen in parallel with the TLB lookup. (They're also usually, I believe, physically tagged, so we have to check for collisions at some point, but making sure there's no side channel information at that point is, obviously given recent events, hard.)