Re: [PATCH] Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS

[Paolo Bonzini <pbonzini@redhat.com>]

On 01/10/2015 13:43, Dirk Müller wrote:
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 94b7d15..0a42859 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -514,7 +514,7 @@ static void skip_emulated_instruction(struct kvm_vcpu *vcpu)
>  	struct vcpu_svm *svm = to_svm(vcpu);
>  
>  	if (svm->vmcb->control.next_rip != 0) {
> -		WARN_ON(!static_cpu_has(X86_FEATURE_NRIPS));
> +		WARN_ON_ONCE(!static_cpu_has(X86_FEATURE_NRIPS));
>  		svm->next_rip = svm->vmcb->control.next_rip;
>  	}
>  

Bandan, what was the reason for warning here?

Should we change the "if" condition to static_cpu_has(X86_FEATURE_NRIPS)
instead of Dirk's patch?

Paolo