Updates on Coconut SVSM: Secure Services and Stateful Devices for Confidential Virtual Machines

The Coconut community is actively developing the Secure VM Service Module (SVSM) to provide secure services and trusted device emulation for guest operating systems running in Confidential Virtual Machines (CVMs). Originally designed for AMD SEV-SNP, Coconut SVSM is evolving into a multi-platform solution, with ongoing efforts to integrate support for Intel TDX Partitioning.

This talk will dive into the current progress of Coconut SVSM, focusing on the emulation of devices such as the virtual Trusted Platform Module (vTPM), based on the reference implementation from the Trusted Computing Group (TCG). At this stage, the vTPM in Coconut SVSM is ephemeral, being re-manufactured with each boot. To unlock broader use cases, the community is working on introducing a persistent state for SVSM, enabling the vTPM to preserve its state across reboots. This enhancement will also allows us to support UEFI variable store to support Secure Boot.

Achieving this persistence requires storing encrypted state securely on the untrusted host, with early boot-time attestation to decrypt and validate the state. This process raises several technical challenges that we are actively tackling.

Join us to explore the latest progress in Coconut SVSM, the challenges we’ve overcome, and the exciting opportunities still ahead.