Re: [PATCH 2/3] s390/vfio-ap: Add sysfs attr, queue_configuration, to export mdev state

[Anthony Krowiak <akrowiak@linux.ibm.com>]

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

On 1/26/24 9:35 AM, Jason J. Herne wrote:
> Add ap_config sysfs attribute. This will provide the means for
> setting or displaying the adapters, domains and control domains assigned
> to the vfio-ap mediated device in a single operation. This sysfs
> attribute is comprised of three masks: One for adapters, one for domains,
> and one for control domains.
>
> This attribute is intended to be used by mdevctl to query a vfio-ap
> mediated device's state.
>
> Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
> ---
>   drivers/s390/crypto/vfio_ap_ops.c | 27 +++++++++++++++++++++++++++
>   1 file changed, 27 insertions(+)
>
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index 243d252bc631..96293683b939 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -1508,6 +1508,32 @@ static ssize_t guest_matrix_show(struct device *dev,
>   }
>   static DEVICE_ATTR_RO(guest_matrix);
>   
> +static ssize_t write_ap_bitmap(unsigned long *bitmap, char *buf, int offset, char sep)
> +{
> +	return sysfs_emit_at(buf, offset, "0x%016lx%016lx%016lx%016lx%c",
> +			 bitmap[0], bitmap[1], bitmap[2], bitmap[3], sep);
> +}
> +
> +static ssize_t ap_config_show(struct device *dev, struct device_attribute *attr,
> +			      char *buf)
> +{
> +	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(dev);
> +	int idx = 0;
> +
> +	idx += write_ap_bitmap(matrix_mdev->matrix.apm, buf, idx, ',');
> +	idx += write_ap_bitmap(matrix_mdev->matrix.aqm, buf, idx, ',');
> +	idx += write_ap_bitmap(matrix_mdev->matrix.adm, buf, idx, '\n');
> +
> +	return idx;
> +}
> +
> +static ssize_t ap_config_store(struct device *dev, struct device_attribute *attr,
> +			       const char *buf, size_t count)
> +{
> +	return count;
> +}
> +static DEVICE_ATTR_RW(ap_config);
> +
>   static struct attribute *vfio_ap_mdev_attrs[] = {
>   	&dev_attr_assign_adapter.attr,
>   	&dev_attr_unassign_adapter.attr,
> @@ -1515,6 +1541,7 @@ static struct attribute *vfio_ap_mdev_attrs[] = {
>   	&dev_attr_unassign_domain.attr,
>   	&dev_attr_assign_control_domain.attr,
>   	&dev_attr_unassign_control_domain.attr,
> +	&dev_attr_ap_config.attr,
>   	&dev_attr_control_domains.attr,
>   	&dev_attr_matrix.attr,
>   	&dev_attr_guest_matrix.attr,