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

Pierre Morel
2018-07-09T12:20:36Z

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.

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