[RFC 12/19] s390/zcrypt: sysfs support for control domain assignment

Tony Krowiak
2017-10-13T17:38:57Z

Provides the sysfs interfaces for assigning an AP control
domain to and unassigning a control 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_control_domain
.................. unassign_control_domain
.................. control_domains

To assign a control domain to the $uuid mediated matrix device,
write its domain ID (hex value) to the assign_control_domain file.
To unassign a control domain, write its domain ID to the
unassign_control_domain file. To display the list of control
domains assigned, print the domains file.

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

echo ff > assign_control_domain

To see the list of control domains assigned:

cat control_domains

To unassign control domain 0xff:

echo ff > unassign_control_domain

Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
---
drivers/s390/crypto/vfio_ap_matrix_ops.c | 82 ++++++++++++++++++++++++++++++
1 files changed, 82 insertions(+), 0 deletions(-)

diff --git a/drivers/s390/crypto/vfio_ap_matrix_ops.c b/drivers/s390/crypto/vfio_ap_matrix_ops.c
index 74d7feb..2387916 100644
--- a/drivers/s390/crypto/vfio_ap_matrix_ops.c
+++ b/drivers/s390/crypto/vfio_ap_matrix_ops.c
@@ -469,6 +469,85 @@ static ssize_t ap_matrix_domains_show(struct device *dev,
static DEVICE_ATTR(domains, 0644, ap_matrix_domains_show,
NULL);

+static ssize_t ap_matrix_control_domain_assign(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned int id;
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ ret = ap_matrix_parse_id(buf, &id);
+ if (ret)
+ return ret;
+
+ set_bit_inv((unsigned long)id,
+ (unsigned long *)matrix_mdev->masks.adm);
+
+ return count;
+}
+static DEVICE_ATTR(assign_control_domain, 0644, NULL,
+ ap_matrix_control_domain_assign);
+
+static ssize_t ap_matrix_control_domain_unassign(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned int id;
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ ret = ap_matrix_parse_id(buf, &id);
+ if (ret)
+ return ret;
+
+ clear_bit_inv((unsigned long)id,
+ (unsigned long *)matrix_mdev->masks.adm);
+
+ return count;
+}
+static DEVICE_ATTR(unassign_control_domain, 0644, NULL,
+ ap_matrix_control_domain_unassign);
+
+static ssize_t ap_matrix_control_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 *adm = (unsigned long *)matrix_mdev->masks.adm;
+ unsigned long id;
+ unsigned long nbits = 256;
+ char *bufpos = buf;
+ int nchars = 0;
+ int n;
+
+ id = find_first_bit_inv(adm, 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(adm, nbits, id + 1);
+ }
+
+ n = sprintf(bufpos, "\n");
+ bufpos += n;
+ nchars += n;
+
+ return nchars;
+}
+
+static DEVICE_ATTR(control_domains, 0644, ap_matrix_control_domains_show,
+ NULL);
+
static struct attribute *ap_matrix_mdev_attrs[] = {
&dev_attr_assign_adapter.attr,
&dev_attr_unassign_adapter.attr,
@@ -476,6 +555,9 @@ static DEVICE_ATTR(domains, 0644, ap_matrix_domains_show,
&dev_attr_assign_domain.attr,
&dev_attr_unassign_domain.attr,
&dev_attr_domains.attr,
+ &dev_attr_assign_control_domain.attr,
+ &dev_attr_unassign_control_domain.attr,
+ &dev_attr_control_domains.attr,
NULL
};

--
1.7.1