From: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Provides the sysfs interfaces for assigning AP adapters to
and unassigning AP adapters from a mediated matrix device.
The IDs of the AP adapters assigned to the mediated matrix
device are stored in an AP mask (APM). The bits in the APM,
from most significant to least significant bit, correspond to
AP adapter ID (APID) 0 to 255. When an adapter is assigned, the
bit corresponding the APID will be set in the APM.
Likewise, when an adapter is unassigned, the bit corresponding
to the APID will be cleared from the APM.
The relevant sysfs structures are:
/sys/devices/vfio_ap
... [matrix]
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
...............[$uuid]
.................. assign_adapter
.................. unassign_adapter
To assign an adapter to the $uuid mediated matrix device's APM,
write the APID to the assign_adapter file. To unassign an adapter,
write the APID to the unassign_adapter file. The APID is specified
using conventional semantics: If it begins with 0x the number will
be parsed as a hexadecimal number; if it begins with a 0 the number
will be parsed as an octal number; otherwise, it will be parsed as a
decimal number.
For example, to assign adapter 173 (0xad) to the mediated matrix
device $uuid:
echo 173 > assign_adapter
or
echo 0xad > assign_adapter
or
echo 0255 > assign_adapter
To unassign adapter 173 (0xad):
echo 173 > unassign_adapter
or
echo 0xad > unassign_adapter
or
echo 0255 > unassign_adapter
The assignment will be rejected:
* If the APID exceeds the maximum value for an AP adapter:
* If the AP Extended Addressing (APXA) facility is
installed, the max value is 255
* Else the max value is 64
* If no AP domains have yet been assigned and there are
no AP queues bound to the VFIO AP driver that have an APQN
with an APID matching that of the AP adapter being assigned.
* If any of the APQNs that can be derived from the cross product
of the APID being assigned and the AP queue index (APQI) of
each of the AP domains previously assigned can not be matched
with an APQN of an AP queue device reserved by the VFIO AP
driver.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
Reviewed-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
Tested-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
Tested-by: Farhan Ali <alifm@xxxxxxxxxxxxx>
Tested-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
drivers/s390/crypto/vfio_ap_ops.c | 119 +++++++++++++++++++++++++++++-
1 file changed, 118 insertions(+), 1 deletion(-)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index e4e8d738a043..07911fb9cdce 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -15,7 +15,6 @@
#define VFOP_AP_MDEV_TYPE_HWVIRT "passthrough"
#define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
-
static void vfio_ap_matrix_init(struct ap_config_info *info,
struct ap_matrix *matrix)
{
@@ -103,9 +102,127 @@ static struct attribute_group *vfio_ap_mdev_type_groups[] = {
NULL,
};
+/**
+ * assign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and assigns it to the mediated matrix device.
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise returns
+ * an error.
+ */
+static ssize_t assign_adapter_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned long apid;
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+ unsigned long max_apid = matrix_mdev->matrix.apm_max;
+
+ ret = kstrtoul(buf, 0, &apid);
+ if (ret || (apid > max_apid)) {
+ pr_warn("%s: %s: adapter id '%s' not a value from 0 to %02lu(%#04lx)\n",
+ VFIO_AP_MODULE_NAME, __func__, buf, max_apid, max_apid);
+
+ if (!ret)
+ ret = -EINVAL;
+
+ return ret;
+ }
+
+ /* Set the bit in the AP mask (APM) corresponding to the AP adapter
+ * number (APID). The bits in the mask, from most significant to least
+ * significant bit, correspond to APIDs 0-255.
+ */
+ mutex_lock(&matrix_dev.lock);
+ set_bit_inv(apid, matrix_mdev->matrix.apm);
+ ret = count;
+
+ mutex_unlock(&matrix_dev.lock);
+
+ return ret;
+}
+static DEVICE_ATTR_WO(assign_adapter);
+
+/**
+ * unassign_adapter_store
+ *
+ * @dev: the matrix device
+ * @attr: a mediated matrix device attribute
+ * @buf: a buffer containing the adapter ID (APID) to be assigned
+ * @count: the number of bytes in @buf
+ *
+ * Parses the APID from @buf and unassigns it from the mediated matrix device.
+ * The APID must be a valid value
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise returns
+ * an error.
+ */
+static ssize_t unassign_adapter_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ unsigned long apid;
+ struct mdev_device *mdev = mdev_from_dev(dev);
+ struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
+
+ unsigned long max_apid = matrix_mdev->matrix.apm_max;
+
+ ret = kstrtoul(buf, 0, &apid);
+ if (ret || (apid > max_apid)) {
+ pr_warn("%s: %s: adapter id '%s' must be a value from 0 to %02lu(%#04lx)\n",
+ VFIO_AP_MODULE_NAME, __func__, buf, max_apid, max_apid);
+
+ if (!ret)
+ ret = -EINVAL;
+
+ return ret;
+ }
+
+ mutex_lock(&matrix_dev.lock);
+ if (!test_bit_inv(apid, matrix_mdev->matrix.apm)) {
+ pr_warn("%s: %s: adapter id %02lu(%#04lx) not assigned\n",
+ VFIO_AP_MODULE_NAME, __func__, apid, apid);
+ ret = -ENODEV;
+ goto done;
+ }
+
+ clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+ ret = count;
+
+done:
+ mutex_unlock(&matrix_dev.lock);
+
+ return ret;
+}
+DEVICE_ATTR_WO(unassign_adapter);
+
+static struct attribute *vfio_ap_mdev_attrs[] = {
+ &dev_attr_assign_adapter.attr,
+ &dev_attr_unassign_adapter.attr,
+ NULL
+};
+
+static struct attribute_group vfio_ap_mdev_attr_group = {
+ .attrs = vfio_ap_mdev_attrs
+};
+
+static const struct attribute_group *vfio_ap_mdev_attr_groups[] = {
+ &vfio_ap_mdev_attr_group,
+ NULL
+};
+
static const struct mdev_parent_ops vfio_ap_matrix_ops = {
.owner = THIS_MODULE,
.supported_type_groups = vfio_ap_mdev_type_groups,
+ .mdev_attr_groups = vfio_ap_mdev_attr_groups,
.create = vfio_ap_mdev_create,
.remove = vfio_ap_mdev_remove,
};
--
2.17.0
