[DISCUSSION] svsm: attestation + CocoonFs:

Hi Tyler,

I've been told in one of the svsm devel calls that a capability for
storing some info in plaintext in CocoonFs would be helpful for your
attestation efforts.

Before I go and implement something, let me ask about the nature of that
data.
- What exactly are you planning to store there?
- Presumably the filesystem salt from the image header, supposed to also
  serve as a filesystem ID ([1]), is not sufficient?
- Is the data considered immutable over the lifetime of the FS?
- Is it Ok if that data is not authenticated?

Thanks!

Nicolai

[1] https://coconut-svsm.github.io/cocoon-tpm/cocoonfs/cocoonfs-format.html#image-header