Re: [PATCH v3 11/14] s390: vfio-ap: sysfs interface to view matrix mdev matrix

[Pierre Morel <pmorel@linux.vnet.ibm.com>]

On 15/03/2018 15:52, Tony Krowiak wrote:
> On 03/15/2018 05:42 AM, Pierre Morel wrote:
>> On 14/03/2018 19:25, Tony Krowiak wrote:
>>> Provides a sysfs interface to view the AP matrix configured for the
>>> mediated matrix device.
>>>
>>> The relevant sysfs structures are:
>>>
>>> /sys/devices/vfio_ap
>>> ... [matrix]
>>> ...... [mdev_supported_types]
>>> ......... [vfio_ap-passthrough]
>>> ............ [devices]
>>> ...............[$uuid]
>>> .................. matrix
>>>
>>> To view the matrix configured for the mediated matrix device,
>>> print the matrix file:
>>>
>>>     cat matrix
>>>
>>> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>>> ---
>>>   drivers/s390/crypto/vfio_ap_ops.c |   39 
>>> +++++++++++++++++++++++++++++++++++++
>>>   1 files changed, 39 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c 
>>> b/drivers/s390/crypto/vfio_ap_ops.c
>>> index 461d450..04f7a92 100644
>>> --- a/drivers/s390/crypto/vfio_ap_ops.c
>>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>>> @@ -692,6 +692,44 @@ static ssize_t control_domains_show(struct 
>>> device *dev,
>>>   }
>>>   DEVICE_ATTR_RO(control_domains);
>>>
>>> +static ssize_t matrix_show(struct device *dev, struct 
>>> device_attribute *attr,
>>> +               char *buf)
>>> +{
>>> +    struct mdev_device *mdev = mdev_from_dev(dev);
>>> +    struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
>>> +    char *bufpos = buf;
>>> +    unsigned long apid;
>>> +    unsigned long apqi;
>>> +    int nchars = 0;
>>> +    int n;
>>> +
>>> +    n = sprintf(bufpos, "ADAPTER.DOMAIN\n");
>>
>> For easy parsing it is better to only report the interesting data
>> and let a user space utility make fancy presentation.
> Is that your way of saying take the above line out?

yes, (also wanted to explain why)

>>
>>
>>> +    bufpos += n;
>>> +    nchars += n;
>>> +
>>> +    n = sprintf(bufpos, "--------------\n");
>>> +    bufpos += n;
>>> +    nchars += n;
>>> +
>>> +    for_each_set_bit_inv(apid, matrix_mdev->matrix->apm,
>>> +                 matrix_mdev->matrix->apm_max) {
>>> +        n = sprintf(bufpos, "%02lx\n", apid);
>>> +        bufpos += n;
>>> +        nchars += n;
>>> +
>>> +        for_each_set_bit_inv(apqi, matrix_mdev->matrix->aqm,
>>> +                     matrix_mdev->matrix->aqm_max) {
>>> +            n = sprintf(bufpos, "%02lx.%04lx\n", apid, apqi);
>>> +            bufpos += n;
>>> +            nchars += n;
>>> +        }
>>> +    }
>>> +
>>> +    return nchars;
>>> +}
>>> +DEVICE_ATTR_RO(matrix);
>>> +
>>> +
>>>   static struct attribute *vfio_ap_mdev_attrs[] = {
>>>       &dev_attr_assign_adapter.attr,
>>>       &dev_attr_unassign_adapter.attr,
>>> @@ -700,6 +738,7 @@ static ssize_t control_domains_show(struct 
>>> device *dev,
>>>       &dev_attr_assign_control_domain.attr,
>>>       &dev_attr_unassign_control_domain.attr,
>>>       &dev_attr_control_domains.attr,
>>> +    &dev_attr_matrix.attr,
>>>       NULL,
>>>   };
>>>
>>
>

-- 
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany