On Tue, 3 Jan 2023, Borislav Petkov wrote: > On Tue, Jan 03, 2023 at 09:07:14AM +0530, Nikunj A. Dadhania wrote: > > Currently, GHCBData[24:63] is unused. If we intend to use the bit range(40bits), GHCB spec > > will need to be updated. And probably would not be enough. > > My fear too... > > > As the termination request is done using GHCB MSR protocol, exit codes cannot be used. > > We need to figure out some other way of communicating to the guest owner because > of which feature the guest refused booting. > Yeah, this was exactly the thought. If the guest terminates because SNP_FEAT_NOT_IMPLEMENTED, it seems necessary to provide information on which feature(s) the guest is lacking an implementation for that the hypervisor has enabled. Otherwise this becomes a frustrating trial and error for the customer.
