Re: [PATCH v9 08/23] coco/tdx-host: Expose P-SEAMLDR information via sysfs

[Chao Gao]

>> +static umode_t seamldr_group_visible(struct kobject *kobj, struct attribute *attr, int idx)
>> +{
>> +	const struct tdx_sys_info *sysinfo = tdx_get_sysinfo();
>> +
>> +	if (!sysinfo)
>> +		return 0;
>> +
>> +	return tdx_supports_runtime_update(sysinfo) ? attr->mode : 0;
>> +}
>> +
>> +static const struct attribute_group seamldr_group = {
>> +	.attrs = seamldr_attrs,
>> +	.is_visible = seamldr_group_visible,
>> +};
>
>I feel like we need to mention *somewhere* that these are kinda nasty.
>tdx_get_sysinfo() is slow and single-threaded. These very much are and
>need to stay 0400 for good reason.
>
>Talk about the DEVICE_ATTR_ADMIN_RO() choice _somewhere_, please.

I will add a comment to make the DEVICE_ATTR_ADMIN_RO() choice
explicit.

+/*
+ * These attributes are intended for admins managing TDX module updates.
+ * Reading them issues a slow, serialized P-SEAMLDR query, so keep them
+ * admin-only.
+ */
 static DEVICE_ATTR_ADMIN_RO(seamldr_version);
 static DEVICE_ATTR_ADMIN_RO(num_remaining_updates);