I can reproduce this using kvm from the command line, so libvirt appears unrelated:
kvm -hda lucid.img -m 512M -smp 2 -vnc :1 -redir tcp:2222::22 -cdrom lucid-server-amd64.iso The simplest 'bzr branch grub grub-b' pins my cpu. ** Changed in: libvirt (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to libvirt in ubuntu. https://bugs.launchpad.net/bugs/716528 Title: kvm 100% when performing apparently IO operations -- 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