RE: [PATCH v1 11/23] KVM: x86: Add kvm_is_fred_enabled()

[Li, Xin3]

> >+	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.