Re: [PATCH v3 5/5] docs: Update s390 vfio-ap doc for ap_config sysfs attribute

Anthony Krowiak
2024-03-15T14:46:34Z

Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>

On 3/13/24 4:58 PM, Jason J. Herne wrote:
> A new sysfs attribute, ap_config, for the vfio_ap driver is
> documented.
>
> Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
> ---
> Documentation/arch/s390/vfio-ap.rst | 30 +++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/Documentation/arch/s390/vfio-ap.rst b/Documentation/arch/s390/vfio-ap.rst
> index 929ee1c1c940..6056a50ee841 100644
> --- a/Documentation/arch/s390/vfio-ap.rst
> +++ b/Documentation/arch/s390/vfio-ap.rst
> @@ -380,6 +380,36 @@ matrix device.
> control_domains:
> A read-only file for displaying the control domain numbers assigned to the
> vfio_ap mediated device.
> + ap_config:
> + A read/write file that, when written to, allows all three of the
> + vfio_ap mediated device's ap matrix masks to be replaced in one shot.
> + Three masks are given, one for adapters, one for domains, and one for
> + control domains. If the given state cannot be set then no changes are
> + made to the vfio-ap mediated device.
> +
> + The format of the data written to ap_config is as follows:
> + {amask},{dmask},{cmask}\n
> +
> + \n is a newline character.
> +
> + amask, dmask, and cmask are masks identifying which adapters, domains,
> + and control domains should be assigned to the mediated device.
> +
> + The format of a mask is as follows:
> + 0xNN..NN
> +
> + Where NN..NN is 64 hexadecimal characters representing a 256-bit value.
> + The leftmost (highest order) bit represents adapter/domain 0.
> +
> + For an example set of masks that represent your mdev's current
> + configuration, simply cat ap_config.
> +
> + Setting an adapter or domain number greater than the maximum allowed for
> + the system will result in an error.
> +
> + This attribute is intended to be used by automation. End users would be
> + better served using the respective assign/unassign attributes for
> + adapters, domains, and control domains.
>
> * functions:
>