Re: [PATCH v6 13/21] s390: vfio-ap: sysfs interface to view matrix mdev matrix

Tony Krowiak
2018-07-13T12:24:47Z

On 07/09/2018 04:38 PM, Pierre Morel wrote:
> On 09/07/2018 14:20, Pierre Morel wrote:
>> On 29/06/2018 23:11, 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.ibm.com>
>>> ---
>>> drivers/s390/crypto/vfio_ap_ops.c | 31
>>> +++++++++++++++++++++++++++++++
>>> 1 files changed, 31 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
>>> b/drivers/s390/crypto/vfio_ap_ops.c
>>> index c8f31f3..bc7398d 100644
>>> --- a/drivers/s390/crypto/vfio_ap_ops.c
>>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>>> @@ -697,6 +697,36 @@ 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;
>>> + unsigned long napm = matrix_mdev->matrix.apm_max + 1;
>>> + unsigned long naqm = matrix_mdev->matrix.aqm_max + 1;
>>> + int nchars = 0;
>>> + int n;
>>> +
>>> + for_each_set_bit_inv(apid, matrix_mdev->matrix.apm, napm) {
>>> + n = sprintf(bufpos, "%02lx\n", apid);
>>> + bufpos += n;
>>> + nchars += n;
>>> +
>>> + for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, naqm) {
>>> + 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,
>>> @@ -705,6 +735,7 @@ 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,
>>> };
>>>
>>
>> I have still the same remark: what you show here is not what is
>> currently
>> used by the SIE.
>> It is not irrelevant but what the guest really use may be more
>> interesting
>> for the admin.
>>
>>
> OK, you implement the right view it in patch 16/21.
>
> Still, what is the purpose of showing this view?

I find it to have great value when configuring the mdev. It provides a
view of
what has been configured thus far.

>
>
>