On 08/20/2018 03:35 PM, Tycho Andersen wrote: > Since meltdown hit, I haven't worked seriously on understand and > implementing his suggestions, in part because it wasn't clear to me > what pieces of the infrastructure we might be able to re-use. Someone > who knows more about mm/ might be able to suggest an approach, though Unfortunately, I'm not sure there's much of KPTI we can reuse. KPTI still has a very static kernel map (well, two static kernel maps) and XPFO really needs a much more dynamic map. We do have a bit of infrastructure now to do TLB flushes near the kernel exit point, but it's entirely for the user address space, which isn't affected by XPFO.
