From the article: "Secure Virtualized Encyrption (SEV). SEV in many ways resembles the SME, but in this case, it enables owners to encrypt virtual machines, is

From the article: "Secure Virtualized Encyrption (SEV). SEV in many ways resembles the SME, but in this case, it enables owners to encrypt virtual machines, isolating them from each other, hypervisors, and hosting software. " Sounds like the keys are managed by VMs can isolated from hypervisors/hosting software.