There appears to be no way to verify from the guest OS whether the vTPM is persistent or not.

The non-persistent vTPM setup successfully stores and recovers encryption keys using ephemeral storage for the lifetime of the virt-launcher Pod. Once the Pod is deleted, the encryption keys are gone, so allowing key storage and recovery against an ephemeral backend gives a false positive to MS Windows' BitLocker Disk Encryption system check.

The result is that a VM with tpm, but without persistence will successfully check that the vTPM can store keys, encrypt its drive using Bitlocker, and reboot successfully while the VM is assigned the same virt-launcher Pod.

As soon as the VM migrates or is shut down and restarts, the vTPM will be wiped, and subsequent startups will go into key recovery.

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