> >+ return cpu_feature_enabled(X86_FEATURE_FRED) && > >+ kvm_is_cr4_bit_set(vcpu, X86_CR4_FRED); > > FRED is enabled when CR4.FRED = IA32_EFER.LMA = 1. Any reason to omit the > check about long mode? It won' t allow CR4.FRED to be set if not in long mode, I don't expect it at runtime. Or you have one? If you are talking about save/restore a corrupted vCPU state, a following VM entry should fail anyway.
