Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS

commit d2922422c48df93f3edff7d872ee4f3191fefb08 upstream.

The cpu feature flags are not ever going to change, so warning
everytime can cause a lot of kernel log spam
(in our case more than 10GB/hour).

The warning seems to only occur when nested virtualization is
enabled, so it's probably triggered by a KVM bug.  This is a
sensible and safe change anyway, and the KVM bug fix might not
be suitable for stable releases anyway.

Signed-off-by: Dirk Mueller <dmueller@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 224d2ef754cc68d1cffdb6c9299e3504d177313c..3deddd796f769ed647d63d44305f70a6411af36d 100644 (file)
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -496,7 +496,7 @@ 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;
        }