KVM: x86: Check .flags in kvm_cpuid_check_equal() too

kvm_cpuid_check_equal() checks for the (full) equality of the supplied
CPUID data so .flags need to be checked too.
Reported-by: NSean Christopherson <seanjc@google.com>
Fixes: c6617c61 ("KVM: x86: Partially allow KVM_SET_CPUID{,2} after KVM_RUN")
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220126131804.2839410-1-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/cpuid.c

@@ -133,6 +133,7 @@ static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2
 		orig = &vcpu->arch.cpuid_entries[i];
 		if (e2[i].function != orig->function ||
 		    e2[i].index != orig->index ||
+		    e2[i].flags != orig->flags ||
 		    e2[i].eax != orig->eax || e2[i].ebx != orig->ebx ||
 		    e2[i].ecx != orig->ecx || e2[i].edx != orig->edx)
 			return -EINVAL;