On Wed, Jun 11, 2025, Rick P Edgecombe wrote: > On Wed, 2025-06-11 at 07:54 -0700, Sean Christopherson wrote: > > > Let's see what Paolo and Sean will say. > > > > Kicking this to userspace seems premature. AIUI, no "optional" VMCALL > > features > > are defined at this time, i.e. there's nothing to enumerate. And there's no > > guarantee that there will ever be capabilties that require enumeration from > > *userspace*. E.g. if fancy feature XYZ requires enumeration, but that feature > > requires explicit KVM support, then forcing userspace will be messy. > > > > So I don't see why KVM should anything other than return '0' to the guest (or > > whatever value says "there's nothing here"). > > GetQuote is not part of the "Base" TDVMCALLs and so has a bit in > GetTdVmCallInfo. We could move it to base? Is GetQuote actually optional? TDX without attestation seems rather pointless. > Paolo seemed keen on GetTdVmCallInfo exiting to userspace, but this was before > the spec overhaul. If GetQuote is truly optional, then exiting to userspace makes sense. But as above, that seems odd to me.
