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

From: Pierre Morel
Date: Thu Mar 15 2018 - 05:42:46 EST


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@xxxxxxxxxxxxxxxxxx>
---
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.

+ 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 BÃblingen - Germany