Support TPM devices

[klausenbusk]

"TPM (Trusted Platform Module) is a computer chip (microcontroller) that can securely store artifacts used to authenticate the platform (your PC or laptop). These artifacts can include passwords, certificates, or encryption keys. A TPM can also be used to store platform measurements that help ensure that the platform remains trustworthy. Authentication (ensuring that the platform can prove that it is what it claims to be) and attestation (a process helping to prove that a platform is trustworthy and has not been breached) are necessary steps to ensure safer computing in all environments."[1]

A TPM device is required by Windows 11 and it is also useful for testing TPM support and can be used for protecting secrets in guests.

[1] https://trustedcomputinggroup.org/resource/trusted-platform-module-tpm-summary/ [2] https://docs.microsoft.com/en-us/windows/whats-new/windows-11-requirements

Fix #888

[osherdp]

+1 for that amazing feature, and I'm definitely need it @dmacvicar what will it take to make that in? :)

[dmacvicar]

Thanks for the contribution @klausenbusk.

If I hesitate to take code that add libvirt features in is mostly because:

• I dislike that to avoid complexity on the Terraform schema, we flatten the original XML schema.
• Acceptance tests

In this case, I consider the feature important enough to push the schema discussion for later, and that is a topic I expect to solve some day using code generation.

About tests, I see in this case it is not trivial (passthrough or emulator).

[osherdp]

@dmacvicar is there any due date for the next release?

[osherdp]

@ybettan

[dmacvicar]

In the next weeks.