[RFC 10/19] s390/zcrypt: sysfs interfaces supporting AP domain assignment

Tony Krowiak
2017-10-13T17:38:55Z

Provides the sysfs interfaces for assigning an AP usage domain
to and unassigning a usage domain from a mediated matrix device.

The relevant sysfs structures are:

/sys/devices/ap_matrix
... [matrix]
...... [mdev_supported_types]
......... [ap_matrix-passthrough]
............ [devices]
...............[$uuid]
.................. assign_domain
.................. domains
.................. unassign_domain

To assign a domain to the $uuid mediated matrix device, write
its domain ID (hex value) to the assign_domain file. To
unassign a domain, write its domain ID (hex value) to the
unassign_domain file. To view a list of domains which have
been assigned, print the contents of the domains file

For example, to assign domain 0x04 to the $uuid mediated
matrix device:

echo 4 > assign_domain

To unassign domain 0x04:

echo 4 > unassign_domain

To see the list of domains assigned:

cat domains

Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
---
drivers/s390/crypto/vfio_ap_matrix_ops.c | 80 ++++++++++++++++++++++++++++++
1 files changed, 80 insertions(+), 0 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_matrix_ops.c b/drivers/s390/crypto/vfio_ap_matrix_ops.c
index 2e63d1b..f54285c 100644
--- a/drivers/s390/crypto/vfio_ap_matrix_ops.c
+++ b/drivers/s390/crypto/vfio_ap_matrix_ops.c
@@ -329,10 +329,90 @@ static ssize_t ap_matrix_adapters_show(struct device *dev,
}
static DEVICE_ATTR(adapters, 0644, ap_matrix_adapters_show, NULL);

+static ssize_t ap_matrix_domain_assign(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned int apqi;
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ ret = ap_matrix_parse_id(buf, &apqi);
+ if (ret)
+ return ret;
+
+ set_bit_inv((unsigned long)apqi,
+ (unsigned long *)matrix_mdev->masks.aqm);
+
+ return count;
+}
+static DEVICE_ATTR(assign_domain, 0644, NULL, ap_matrix_domain_assign);
+
+static ssize_t ap_matrix_domain_unassign(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned int apqi;
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ ret = ap_matrix_parse_id(buf, &apqi);
+ if (ret)
+ return ret;
+
+ clear_bit_inv((unsigned long)apqi,
+ (unsigned long *)matrix_mdev->masks.aqm);
+
+ return count;
+}
+static DEVICE_ATTR(unassign_domain, 0644, NULL, ap_matrix_domain_unassign);
+
+static ssize_t ap_matrix_domains_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);
+ unsigned long *aqm = (unsigned long *)matrix_mdev->masks.aqm;
+ unsigned long id;
+ unsigned long nbits = 256;
+ char *bufpos = buf;
+ int nchars = 0;
+ int n;
+
+ id = find_first_bit_inv(aqm, nbits);
+ while (id < nbits) {
+ if (nchars) {
+ n = sprintf(bufpos, ",");
+ bufpos += n;
+ nchars += n;
+ }
+
+ n = sprintf(bufpos, "%04lx", id);
+ bufpos += n;
+ nchars += n;
+ id = find_next_bit_inv(aqm, nbits, id + 1);
+ }
+
+ n = sprintf(bufpos, "\n");
+ bufpos += n;
+ nchars += n;
+
+ return nchars;
+}
+
+static DEVICE_ATTR(domains, 0644, ap_matrix_domains_show,
+ NULL);
+
static struct attribute *ap_matrix_mdev_attrs[] = {
&dev_attr_assign_adapter.attr,
&dev_attr_unassign_adapter.attr,
&dev_attr_adapters.attr,
+ &dev_attr_assign_domain.attr,
+ &dev_attr_unassign_domain.attr,
+ &dev_attr_domains.attr,
NULL
};

--
1.7.1