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

[Tony Krowiak]

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 <akrow...@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?

+    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,
  };