So this quite likely might be a "feature" that got introduced with qemu 2.2:
commit 75d373ef9729bd22fbc46bfd8dcd158cbf6d9777 Author: Eduardo Habkost <ehabk...@redhat.com> Date: Fri Oct 3 16:39:51 2014 -0300 target-i386: Disable SVM by default in KVM mode Make SVM be disabled by default on all CPU models when in KVM mode. Nested SVM is enabled by default in the KVM kernel module, but it is probably less stable than nested VMX (which is already disabled by default). Add a new compat function, x86_cpu_compat_kvm_no_autodisable(), to keep compatibility on previous machine-types. I saw both machine types (pc-i440fx-trusty and pc-i440fx-utopic) mentioned in some xml configs. Not sure which is which. Might be worth checking the config in the currently not working case and if that is not trusty, try to replace it with that. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to qemu in Ubuntu. https://bugs.launchpad.net/bugs/1494602 Title: qemu-system-x86 nested virtualisation is broken on AMD system To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1494602/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs