KVM: arm64: Share the parts of get/set events useful to 32bit

The get/set events helpers to do some work to check reserved
and padding fields are zero. This is useful on 32bit too.

Move this code into virt/kvm/arm/arm.c, and give the arch
code some underscores.

This is temporarily hidden behind __KVM_HAVE_VCPU_EVENTS until
32bit is wired up.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Dongjiu Geng <gengdongjiu@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

virt/kvm/arm/arm.c

@@ -1050,6 +1050,34 @@ static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
+#ifdef __KVM_HAVE_VCPU_EVENTS	/* temporary: until 32bit is wired up */
+static int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
+				   struct kvm_vcpu_events *events)
+{
+	memset(events, 0, sizeof(*events));
+
+	return __kvm_arm_vcpu_get_events(vcpu, events);
+}
+
+static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
+				   struct kvm_vcpu_events *events)
+{
+	int i;
+
+	/* check whether the reserved field is zero */
+	for (i = 0; i < ARRAY_SIZE(events->reserved); i++)
+		if (events->reserved[i])
+			return -EINVAL;
+
+	/* check whether the pad field is zero */
+	for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++)
+		if (events->exception.pad[i])
+			return -EINVAL;
+
+	return __kvm_arm_vcpu_set_events(vcpu, events);
+}
+#endif /* __KVM_HAVE_VCPU_EVENTS */
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg)
 {