Linux Stack for Intel® TDX (Trust Domain Extensions)

1. Overview

Intel® Trust Domain Extensions(TDX) refers to an Intel technology that extends Virtual Machine Extensions(VMX) and Multi-Key Total Memory Encryption(MK-TME) with a new kind of virtual machine guest called a Trust Domain(TD). A TD runs in a CPU mode that protects the confidentiality of its memory contents and its CPU state from any other software, including the hosting Virtual Machine Monitor (VMM). Please get more details from TDX White Papers and Specifications

This repository helps to:

• Build individual component's package or install pre-build binaries on IaaS host or create PaaS guest image for quick evaluation
• Generate the patchsets for deep dive in source code level
• Test, hack and debug the TDX technology
• Dump guest VM measurement and generate TD quote report for TDX E2E attestation
• Measured boot and Secure boot for TDX guest VM

2. Components

Intel® TDX(Trust Domain Extensions) MVP Stack includes the components in below diagram:

Name	Stack	Description
SPR Kernel	Host + Guest	Linux kernel for Sapphire Rapids platform
SPR Qemu-KVM	Host	Qemu VMM for Sapphire Rapids platform
TDX SEAM Module	Host	TDX Secure Arbitration Module
TDX Libvirt	Host	The modified libvirt to create TDX guest domain via Qemu
TDVF	Host	The modified OVMF(Open Source Virtual Firmware) to support TDX guest boot like page accept, TDX measurement
TDX Grub2	Guest	The modified grub for guest VM to support TDX measurement
TDX shim	Guest	The modified shim for guest VM to support TDX measurement

3. Getting Started

3.1 Install TDX Linux Stack

3.1.1 Build Packages from scratch

To build all components, run the following commands:

cd build/centos-stream-8
./build-repo.sh

NOTE: Please refer detail instructions for different distros in build directory.

This will build all packages and create two repositories, one for guest and one for host.

3.1.1 Install RPM repo on the target host

Move the host repo to a known location:

sudo mkdir -p /srv/
sudo mv repo/host /srv/tdx-host

To use the repo, create the following file as /etc/yum.repos.d/tdx-host-local.repo:

[tdx-host-local]
name=tdx-host-local
baseurl=file:///srv/tdx-host
enabled=1
gpgcheck=0
module_hotfixes=true

Finally, install packages as follows:

sudo dnf install intel-mvp-spr-kernel intel-mvp-tdx-tdvf intel-mvp-spr-qemu-kvm intel-mvp-tdx-libvirt

NOTE: Please get separated RPM for signed build TDX SEAM Module and install via sudo dnf install intel-mvp-tdx-module-spr. After installation, please reboot machine with tdx_host=on in host kernel command via grub menu. Finally, please verify TDX host.

3.2 Prepare TDX Guest Image

After building TDX components packages please refer to Setup TDX Guest Image to install them into a cloud image. It uses CentOS Stream 8 as example distro.

4. Launch TD VM Guest

You can start-qemu.sh to create TD guest quickly as below. Please get detail grub/direct boot template for qemu-kvm and libvirt at Launch TD Guest.

• Launch a TDX guest via direct boot

./start-qemu.sh -i td-guest-rhel-8.5.qcow2 -k vmlinuz-rhel-8.5

• Launch a TDX guest via grub boot

./start-qemu.sh -i td-guest-rhel-8.5.qcow2 -b grub

• Launch a debug version TDX guest with debug version OVMF

./start-qemu.sh -i td-guest-rhel-8.5.qcow2 -k vmlinuz-rhel-8.5 -d

• Launch a non-TDX guest

./start-qemu.sh -i td-guest-rhel-8.5.qcow2 -k vmlinuz-rhel-8.5 -t efi

5. Test

After TDX guest image is created, please refer to TDX Tests to run tests. It uses CentOS Stream 8 as example distro.

6. FAQ & BKM

• How to check memory encryption for TDX guest
• How to debug a TDX guest via Qemu GDB server
• Secure boot for TDX
• Measured boot and TDX tool