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

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

On 07/06/2018 04:26 PM, Halil Pasic wrote:
>
>
> 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?

That is a mistake, I am going to move it to struct ap_matrix_dev and
execute the QCI instruction when the matrix device is registered
with mdev during driver initialization.

>
>
>> +};
>> +
>>   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)
>>
>