Automatic Measurement and Provisioning Utility for AMD SEV-SNP

This repository contains utility scripts to automate the setup and operation of virtualized environments using AMD's Secure Encrypted Virtualization - Secure Nested Paging (SEV-SNP). The utility provides a complete flow for creating an SEV-SNP-enabled environment, from provisioning the host machine to calculating measurements for a modified guest image, kernel, and OVMF.

Acknowledgments

This utility script (snp.sh) is adapted from sev-utils.

Table of Contents

• Overview
• Prerequisites
• Installation
• Usage
  • Host Setup
  • Launching a Guest
  • Attesting a Guest
  • Stopping All Guests
  • Using Your Own Image
  • SSH Access to Guest
  • Measurement Calculation
• Caveats and Warnings
• Contributing
• License

Overview

The utility performs the following tasks:

1. Provisions an AMD EPYC CPU-powered server by building the required patched versions of qemu, OVMF, and the Linux kernel.
2. Allows for the launching of an SNP-enabled guest directly with QEMU.
3. Facilitates attestation of the SNP guest using the virtee/snpguest CLI tool.

Tested OS Distributions:

• Ubuntu 20.04
• Ubuntu 22.04

Supported Image Formats:

• qcow2

Prerequisites

• Enable SNP features on your AMD EPYC CPU from the system BIOS. Follow the detailed instructions for enabling these options.

Installation

Clone this repository and navigate to its directory:

git clone https://github.com/your-repo-link
cd your-repo-directory

Make the script executable:

chmod +x snp.sh

Usage

Host Setup

To set up the host with the default UPM-enabled version of the kernel:

./snp.sh setup-host

For users who require support for Confidential Containers (CoCo), which currently does not support UPM, use the --non-upm option:

./snp.sh setup-host --non-upm

Build Guest OVMF, Kernel, and Image Only

If you only need to build the guest OVMF, kernel, and image, use the following command:

./snp.sh build-guest

Note that only buiding OVM, guest kernel and image does not require KVM supported.

This command is also used in Github Actions for automatic measurement calculation.

Launching a Guest

To launch a guest with the default UPM-enabled version of the kernel:

./snp.sh launch-guest

Again, for CoCo users, specify the --non-upm option if you've set up the host using the same:

./snp.sh launch-guest --non-upm

Note: If you intend to use the --non-upm option for launching a guest, ensure you've also used it during the host setup phase.

Attesting a Guest

./snp.sh attest-guest

Stopping All Guests

./snp.sh stop-guests

Using Your Own Image

To use your own guest image, set these environment variables:

export IMAGE="guest.img"
export GUEST_USER="user"
export GUEST_SSH_KEY_PATH="guest-key"

And then:

./snp.sh launch-guest

SSH Access to Guest

ssh -p 10022 -i snp-guest-key amd@localhost

Measurement Calculation

Generate the golden measurement with:

chmod +x cal-measurement.sh
./cal-measurement.sh

Caveats and Warnings

1. The script installs developer packages. Check install_dependencies for admin concerns.
2. Grub settings will be modified.