Re: swapping with MMU Notifiers V2

Avi Kivity
2008-01-29T17:02:52Z

Carsten Otte wrote:
> Avi Kivity wrote:
>> Every arch except s390 needs it. An ugly #ifndef
>> CONFIG_KVM_HARDWARE_TLB_SYNC is preferred to duplicating the code.
> BTW, from reading AMDs spec I don't expect NPT to need this vehicle
> for swapping either. They can just let core-vm page out guest pages
> and will receive a proper page fault in the host. Jörg can you confirm
> that?
>

No, that doesn't work:

- even though npt can use the same pagetable for guest and host, that
isn't workable for kvm as npt doesn't have an offset/size thing. so kvm
uses a separate pagetable for guest and host.
- npt doesn't have a dual-tagged tlb, where a host tlb invalidate also
invalidates all guest tlbs that point to the same page

Try again in 25 years, maybe x86 will reach where s390 is now by that
timeframe.

--
error compiling committee.c: too many arguments to function