Re: [PATCH v6 09/21] s390: vfio-ap: structure for storing mdev matrix

Halil Pasic
2018-07-06T14:26:23Z

On 06/29/2018 11:11 PM, Tony Krowiak wrote:
> From: Tony Krowiak <akrowiak@linux.ibm.com>
>
> Introduces a new structure for storing the AP matrix configured
> for the mediated matrix device via its sysfs attributes files.
>
> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
> ---
> drivers/s390/crypto/vfio_ap_ops.c | 12 ++++++++++++
> drivers/s390/crypto/vfio_ap_private.h | 24 ++++++++++++++++++++++++
> 2 files changed, 36 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
> index 4e61e33..bf7ed9f 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -20,6 +20,17 @@
> DEFINE_SPINLOCK(mdev_list_lock);
> LIST_HEAD(mdev_list);
>
> +static void vfio_ap_matrix_init(struct ap_matrix *matrix)
> +{
> + /* Test if PQAP(QCI) instruction is available */
> + if (test_facility(12))
> + ap_qci(&matrix->info);
> +
> + matrix->apm_max = matrix->info.apxa ? matrix->info.Na : 63;
> + matrix->aqm_max = matrix->info.apxa ? matrix->info.Nd : 15;
> + matrix->adm_max = matrix->info.apxa ? matrix->info.Nd : 15;
> +}
> +
> static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
> {
> struct ap_matrix_dev *matrix_dev =
> @@ -31,6 +42,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
> return -ENOMEM;
>
> matrix_mdev->name = dev_name(mdev_dev(mdev));
> + vfio_ap_matrix_init(&matrix_mdev->matrix);
> mdev_set_drvdata(mdev, matrix_mdev);
>
> if (atomic_dec_if_positive(&matrix_dev->available_instances) < 0) {
> diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
> index 3de1275..ae771f5 100644
> --- a/drivers/s390/crypto/vfio_ap_private.h
> +++ b/drivers/s390/crypto/vfio_ap_private.h
> @@ -29,9 +29,33 @@ struct ap_matrix_dev {
> atomic_t available_instances;
> };
>
> +/**
> + * The AP matrix is comprised of three bit masks identifying the adapters,
> + * queues (domains) and control domains that belong to an AP matrix. The bits i
> + * each mask, from least significant to most significant bit, correspond to IDs
> + * 0 to 255. When a bit is set, the corresponding ID belongs to the matrix.
> + *
> + * @apm identifies the AP adapters in the matrix
> + * @apm_max: max adapter number in @apm
> + * @aqm identifies the AP queues (domains) in the matrix
> + * @aqm_max: max domain number in @aqm
> + * @adm identifies the AP control domains in the matrix
> + * @adm_max: max domain number in @adm
> + */
> +struct ap_matrix {
> + unsigned long apm_max;
> + DECLARE_BITMAP(apm, 256);
> + unsigned long aqm_max;
> + DECLARE_BITMAP(aqm, 256);
> + unsigned long adm_max;
> + DECLARE_BITMAP(adm, 256);
> + struct ap_config_info info;

Why do we maintain (and populate by doing a QCI) the info member on a
per mdev device basis?

> +};
> +
> struct ap_matrix_mdev {
> const char *name;
> struct list_head list;
> + struct ap_matrix matrix;
> };
>
> static struct ap_matrix_dev *to_ap_matrix_dev(struct device *dev)
>