On Tue, Jan 29, 2008 at 07:02:52PM +0200, Avi Kivity wrote: > 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.
Right. We can't reuse page tables from the Linux MM for Nested Paging. > - npt doesn't have a dual-tagged tlb, where a host tlb invalidate also > invalidates all guest tlbs that point > to the same page Since we have our own page table for Nested Paging this is also true. Joerg -- | AMD Saxony Limited Liability Company & Co. KG Operating | Wilschdorfer Landstr. 101, 01109 Dresden, Germany System | Register Court Dresden: HRA 4896 Research | General Partner authorized to represent: Center | AMD Saxony LLC (Wilmington, Delaware, US) | General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel