Also check dmesg for debug info. For example, the bios may have disabled vmx for you. Here's how that might look:
$ dmesg | grep kvm [ 1077.438583] kvm: disabled by bios -- could not initialize KVM on clean feisty 20070117 https://launchpad.net/bugs/80363 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
