Confidential computing (Intel TDX)

Confidential computing protects workloads by reducing trust in the hypervisor, host OS, and platform operator for data in use. Intel Trust Domain Extensions (TDX) is Intel’s hardware technology for confidential virtual machines (Trust Domain guests).

Experimental — no verified production procedure

Status: Planned (Feature availability). This page covers confidential-computing concepts and planning. Public AtomOS docs do not yet include a verified production install procedure or supported specfile fields for TDX. Contact Elemento when evaluating a release that advertises TDX.

Concepts

Idea	Summary
Trust domain	Guest whose memory is encrypted and integrity-protected by CPU/firmware
Attestation	Remote party verifies firmware, TDX module, and guest launch measurements
Root of trust	Chain from hardware → firmware → TDX module → guest

TDX targets threats such as malicious or compromised hypervisors reading guest memory. It complements — but does not replace — transport TLS, disk encryption, and access control.

Stack layers (generic industry model)

flowchart TB
  HW[Intel TDX-capable CPU + firmware]
  BIOS[BIOS/UEFI TDX enabled]
  K[Host kernel with confidential virt support]
  Q[QEMU/KVM TDX-enabled build]
  G[TDX guest / Trust Domain VM]
  HW --> BIOS --> K --> Q --> G

Confirm for AtomOS release: which host OS versions, kernel builds, and QEMU packages Elemento qualifies for TDX guests.

Attestation principles

1. Measurements are recorded at launch (firmware, TD module, guest image).
2. A verifier (your security service or cloud policy engine) compares quotes against golden values.
3. Secrets are released to the guest only after successful attestation (optional pattern).

AtomOS-specific attestation endpoints, quote formats, and Electros integration are not verified in this documentation revision.

TDX vs vTPM vs Secure Boot

Mechanism	Primary guarantee
Intel TDX	Confidentiality/integrity of guest memory and reduced hypervisor trust
vTPM	Guest-visible TPM for keys and sealed storage; does not alone encrypt all RAM
Secure Boot	Verified boot chain for OS/firmware loading

Security architecture mentions Secure Boot and vTPM for guests when firmware and images support them — separate maturity from TDX.

Limitations (confirm for AtomOS release)

Industry-wide and expected constraints — validate on your build:

Area	Typical constraint
PCIe / GPU passthrough	Often incompatible or severely limited with confidential VMs
Live migration	Generally not available or immature for TDX guests
Debugging	Standard memory inspection tools may not apply
Performance	Encryption overhead on memory-intensive workloads
USB and legacy devices	Often restricted

Passthrough and migration guidance for standard VMs: GPU / PCI passthrough, Availability & recovery.

Project status on AtomOS

Item	Status
Productized TDX VM create flow in Electros/GUI	Planned — see Feature availability
Documented atomos-cli TDX enablement	Not available in public docs
Hardware compatibility list	Follow Hardware & platforms; confirm TDX-capable SKUs with Elemento

Treat lab demos as non-production until release notes advertise TDX support and this matrix is updated.

Related pages

• Glossary (term Confidential computing)
• Feature availability
• Security architecture