Re: [PATCH v7 13/15] s390/vfio-ap: Callback to get the size of data to be migrated during guest migration

["Jason J. Herne" <jjherne@linux.ibm.com>]

On 8/7/26 6:18 PM, Anthony Krowiak wrote:
> Callback to get the estimated data length of the data that will be required
> to complete reading of the vfio device's internal state. It's mandatory for
> VFIO_DEVICE_FEATURE_MIGRATION migration support.
> 
> The function pointer for this callback is specified via the
> 'migration_get_data_size' field of the 'vfio_migration_ops' structure
> which is stored with the VFIO device when the 'vfio_device'
> structure representing the mediated device is initialized.
> 
> Signed-off-by: Anthony Krowiak <akrowiak@linux.ibm.com>
> ---
>   drivers/s390/crypto/vfio_ap_migration.c | 10 +++++++++-
>   1 file changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/s390/crypto/vfio_ap_migration.c b/drivers/s390/crypto/vfio_ap_migration.c
> index 24955f70e13e..01933a62dab9 100644
> --- a/drivers/s390/crypto/vfio_ap_migration.c
> +++ b/drivers/s390/crypto/vfio_ap_migration.c
> @@ -1636,7 +1636,15 @@ static int vfio_ap_get_state(struct vfio_device *vdev,
>   static int vfio_ap_get_data_size(struct vfio_device *vdev,
>   				 unsigned long *stop_copy_length)
>   {
> -	return -EOPNOTSUPP;
> +	struct ap_matrix_mdev *matrix_mdev;
> +	int num_queues;
> +
> +	mutex_lock(&matrix_dev->mdevs_lock);
> +	matrix_mdev = container_of(vdev, struct ap_matrix_mdev, vdev);
> +	*stop_copy_length = vfio_ap_config_size(matrix_mdev, &num_queues);
> +	mutex_unlock(&matrix_dev->mdevs_lock);
> +
> +	return 0;
>   }
>   
>   static const struct vfio_migration_ops vfio_ap_migration_ops = {

Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>