On Fri, Mar 28, 2014 at 10:39:25AM -0700, Mario Smarduch wrote: > Hello > > I've been working on live migration for ARM-KVM, and noticed > problem completing migration with huge 2nd stage tables. > > > Aafter write protecting the VM, for write fault 512 page bits > are set in dirty_bitmap[] to take into account future writes to > huge page.The pmd is write protected again when QEMU reads the > dirty log, and the cycle repeats. With this not even a idle > 32MB VM completes live migration. > > If QEMU uses THPs, and 2nd stage tables use pte's, then there > is no problem, live migration is quick. I'm assumung QEMU and Guest > huge pages with 2nd stage page table pte's should work fine too. > > I'm wondering how this has been solved (for any architecture)? > I don't know if there's a generic solution (have you looked at x86/PPC what they do?), but I don't see any conceptual problem with putting the VM into use-pte-for-2nd-stage-mappings-I'm-migrating-mode. -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
