This is the source code repository for the COCONUT Secure VM Service Module (SVSM), a software which aims to provide secure services and device emulations to guest operating systems in confidential virtual machines (CVMs). It requires AMD Secure Encrypted Virtualization with Secure Nested Paging (AMD SEV-SNP), especially the VM Privilege Level (VMPL) feature.
The COCONUT-SVSM is dual-licensed under the MIT or Apache-2.0 licenses. The licenses are included in the LICENSE.MIT or LICENSE-APACHE-2.0.txt files.
The project builds on support code written for the linux-svsm, a software written and published by AMD. This includes the necessary hypervisor changes for KVM host, guest, and for the EDK2 firmware.
Some of the key parts already implemented are:
- SVSM core protocol support
- Boots SMP Linux guests
- Buddy and slab-based memory allocator
- PerCPU page-tables with dedicated address space areas for shared and PerCPU mappings
- Backtraces
- Exception fixups
- Multi-stage launch process so it can run from any guest physical address
In the future the COCONUT-SVSM will gain support to run modules at ring 3. These modules can extend the SVSM base functionality and implement advanced features like TPM emulation and live migration.
Detailed installation instructions are in the INSTALL.md file. It walks through the process of building all the necessary parts to get a virtual machine powered by the COCONUT-SVSM up and running.
Any issues, bugs or feature requests for the SVSM project can be reported via https://github.com/coconut-svsm/svsm/issues.
Contributing to the project is as easy as sending a pull-request via GitHub. For detailed instructions on patch formatting and contribution guidelines please have a look at CONTRIBUTING.md.
The project is far from being ready. Here is an list of next steps that are planned for the COCONUT-SVSM. The items are not sorted in any way:
- Improve documentation
- Support for modules running in ring 3
- vTPM emulation
- Attestation support
- Persistency layer (needed for TPM and others)
- Carry FW as payload of SVSM to make the SVSM binary a drop-in replacement for the FW when launching QEMU
- Live migration
The COCONUT-SVSM project would not have been possible without the close relationship to AMD. AMD provided the Linux kernel and OVMF modifications to complete the SVSM host and guest stack. Many thanks for the work and our continuous cooperation!