Linux Security Summit 2021

Confidential computing establishes a new security model for data-in-use protection - a large volume of sensitive data is processed in public clouds, where the trusted computing base (TCB) is large including hypervisors, host operating system, operators, orchestration software, devices (with firmware), and BIOS/SMM. Intel TDX (Trust Domain Extensions) provides capabilities to limit the TCB for VM workloads, with the goal to removing the host software from the TCB (by running the VM as a TD VM). At the same time, cloud and enterprise operators require capabilities such as live migration of VM workloads to support reliability and availability of the infrastructure. This talk describes the Intel TDX architecture to enable live migration of TD VMs running confidential workloads. The proposed architecture provides live-migration while maintaining the baseline functionality and security requirements of Intel TDX. The talk will describe the expanded threat model, and the platform capabilities to address these potential new threats, followed by a summary of the modifications to KVM/QEMU and implications to the TD VM owners when opting-in to live migration of TD VMs.