Comment 12 for bug 1661693

For further reference, DigitalOcean sets sys_vendor to 'DigitalOcean'.
AWS's is described at http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/identify_ec2_instances.html
its crappy as they abuse UUID, which will result in false-positive if randomly generated uuid starts with 'ec2'. Its better on kvm guests there then it is on xen in that system-serial-number and system-uuid have to be equal and start with ec2, so a false positive there is pretty unlikely.