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I agree that it seems like "just" an enumeration problem, but despite attending the presentation and rereading the slides, I'm still not clear on the precise scope. Are we saying that, inside an opaque blob that a customer provides to a CSP to run we might have: * a paravisor and an unaware OS, or * svsm and a fully-aware OS, or * something in-between these two. and we're looking a way to describe which piece of the interior stack owns which capability/service? If so, it can't come in from the outside; given that it's the capability enumeration, there's a chicken/egg problem with verifying the integrity. It seems like it needs to be produced by whatever the first code to run is, after gathering capabilities in a vendor-specific way, and deciding which services it wants to provide, and which to delegate. And if so, then it definitely cannot be in CPUID because that needs to be fixed from prior to the guest starting to run, and doesn't express dynamic properties of the system[*] I think the discussion would benefit greatly from having a couple of concrete examples of data this wants to hold, and how it is to be used at different levels of the interior software stack. Thanks, ~Andrew [*] Yes, I know CPUID does have some dynamic properties.  I think most people would agree that life would be better without them.