kvm_cpuid_check_equal() should also check .flags equality but instead of adding it to the existing check, just switch to using memcmp() for the whole 'struct kvm_cpuid_entry2'. When .flags are not checked, kvm_cpuid_check_equal() may allow an update which it shouldn't but kvm_set_cpuid() does not actually update anything and just returns success. Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- arch/x86/kvm/cpuid.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 89d7822a8f5b..7dd9c8f4f46e 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -123,20 +123,11 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu, static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, int nent) { - struct kvm_cpuid_entry2 *orig; - int i; - if (nent != vcpu->arch.cpuid_nent) return -EINVAL; - for (i = 0; i < nent; i++) { - orig = &vcpu->arch.cpuid_entries[i]; - if (e2[i].function != orig->function || - e2[i].index != orig->index || - e2[i].eax != orig->eax || e2[i].ebx != orig->ebx || - e2[i].ecx != orig->ecx || e2[i].edx != orig->edx) - return -EINVAL; - } + if (memcmp(e2, vcpu->arch.cpuid_entries, nent * sizeof(*e2))) + return -EINVAL; return 0; } -- 2.34.1