Messages in this thread | | | Subject | Re: [PATCH 29/61] KVM: x86: Add Kconfig-controlled auditing of reverse CPUID lookups | From | Paolo Bonzini <> | Date | Tue, 25 Feb 2020 16:00:49 +0100 |
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On 24/02/20 14:54, Vitaly Kuznetsov wrote: >> --- a/arch/x86/kvm/cpuid.h >> +++ b/arch/x86/kvm/cpuid.h >> @@ -98,6 +98,11 @@ static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned x86_feature) >> static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, >> const struct cpuid_reg *cpuid) >> { >> +#ifdef CONFIG_KVM_CPUID_AUDIT >> + WARN_ON_ONCE(entry->function != cpuid->function); >> + WARN_ON_ONCE(entry->index != cpuid->index); >> +#endif >> + >> switch (cpuid->reg) { >> case CPUID_EAX: >> return &entry->eax; > Honestly, I was thinking we should BUG_ON() and even in production builds > but not everyone around is so rebellious I guess, so
BUG_ON is too much, but I agree the cost is so small that unconditional WARN_ON makes sense.
Paolo
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