Hello Antonio (@arcimboldo) The fix only makes sense for newer QEMUs (>= Xenial, like the one from Mitaka Ubuntu Cloud Archive).
OBS: The "migration check" is done in VHOST initialization functions when the devices are virtually attached to the virtual machine. If you are using kernel 3.13 and have apparmor enabled, then all the running instances have the "migration blocker" ON - because of this buggy migration check - and won't be able to live migration. Unfortunately there is a "in-memory" linked list telling qemu that is has a blocker (with the reason). This blocker was added during instance startup and will be checked/used only when instance is live-migrated. Check this: http://pastebin.ubuntu.com/23517175/ If you started the instance in a host not running apparmor (or not having libvirt profile loaded, for example) it won't block the creation of /tmp/memfd-XXX files during instance initialization. That won't trigger the "blocker flag" inside the running program and, if/when needed, the live migration will be able to occur. This means that, after installing the new package, if you're using apparmor, yes, you would have to RESTART running instances that were affected by this bug in order to live migrating them. Sorry for the bad news! Even if you remove the apparmor rules, the migration blocker is already set. Hacking your process virtual memory would jeopardize the contents of the virtual memory (could be catastrophic specially for a virtual machine). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1626972 Title: QEMU memfd_create fallback mechanism change for security drivers To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-archive/+bug/1626972/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs