Re: [PATCH v2 2/2] s390/uv: Provide host-key hashes in sysfs

[Janosch Frank <frankja@linux.ibm.com>]

On 10/2/24 6:04 PM, Steffen Eiden wrote:
> Utilize the new Query Ultravisor Keys UVC to give user space the
> information which host-keys are installed on the system.
> 
> Create a new sysfs directory 'firmware/uv/keys' that contains the hash
> of the host-key and the backup host-key of that system. Additionally,
> the file 'all' contains the response from the UVC possibly containing
> more key-hashes than currently known.
> 
> Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

Two nits below.

> ---
>   arch/s390/include/asm/uv.h | 16 +++++++++
>   arch/s390/kernel/uv.c      | 71 ++++++++++++++++++++++++++++++++++++++
>   2 files changed, 87 insertions(+)
> 

[...]

> +struct uv_key_hash {
> +	u64 dword[4];
> +} __packed __aligned(8);
> +
> +#define UVC_QUERY_KEYS_IDX_HK		0
> +#define UVC_QUERY_KEYS_IDX_BACK_HK		1
> +
> +/* Query Ultravisor Keys */
> +struct uv_cb_query_keys {
> +	struct uv_cb_header header;	/* 0x0000 */
> +	u64 reserved08[3];		/* 0x0008 */
> +	struct uv_key_hash keys[15];	/* 0x0020 */

s/keys/key_hash/ or something similar?

> +} __packed __aligned(8);
>

We could add a static size assert here.