Re: [PATCH v6 06/22] coco/tdx-host: Expose P-SEAMLDR information via sysfs

[Kiryl Shutsemau]

On Thu, Mar 26, 2026 at 01:43:57AM -0700, Chao Gao wrote:
> TDX module updates require userspace to select the appropriate module
> to load. Expose necessary information to facilitate this decision. Two
> values are needed:
> 
> - P-SEAMLDR version: for compatibility checks between TDX module and
> 		     P-SEAMLDR
> - num_remaining_updates: indicates how many updates can be performed
> 
> Expose them as tdx-host device attributes. Make seamldr attributes
> visible only when the update feature is supported, as that's their sole
> purpose. Unconditional exposure is also problematic because reading them
> triggers P-SEAMLDR calls that break KVM on CPUs with a specific erratum
> (to be enumerated and handled in a later patch).
> 
> Signed-off-by: Chao Gao <chao.gao@xxxxxxxxx>

Reviewed-by: Kiryl Shutsemau (Meta) <kas@xxxxxxxxxx>

One nit is below.

> @@ -46,7 +47,80 @@ static struct attribute *tdx_host_attrs[] = {
>  	&dev_attr_version.attr,
>  	NULL,
>  };
> -ATTRIBUTE_GROUPS(tdx_host);
> +
> +static const struct attribute_group tdx_host_group = {
> +	.attrs = tdx_host_attrs,
> +};
> +
> +static ssize_t seamldr_version_show(struct device *dev, struct device_attribute *attr,
> +				    char *buf)
> +{
> +	struct seamldr_info info;
> +	int ret;
> +
> +	ret = seamldr_get_info(&info);
> +	if (ret)
> +		return ret;
> +
> +	return sysfs_emit(buf, TDX_VERSION_FMT"\n", info.major_version,

Space after _FMT, please.

> +						    info.minor_version,
> +						    info.update_version);
> +}

-- 
  Kiryl Shutsemau / Kirill A. Shutemov