diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 99ed303..1d4f890 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -106,9 +106,304 @@ static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
 	NULL,
 };
 
+struct vfio_ap_queue_reserved {
+	unsigned long *apid;
+	unsigned long *apqi;
+	bool reserved;
+};
+
+/**
+ * vfio_ap_has_queue
+ *
+ * @dev: an AP queue device
+ * @data: a struct vfio_ap_queue_reserved reference
+ *
+ * Flags whether the AP queue device (@dev) has a queue ID containing the APQN,
+ * apid or apqi specified in @data:
+ *
+ * - If @data contains both an apid and apqi value, then @data will be flagged
+ *   as reserved if the APID and APQI fields for the AP queue device matches
+ *
+ * - If @data contains only an apid value, @data will be flagged as
+ *   reserved if the APID field in the AP queue device matches
+ *
+ * - If @data contains only an apqi value, @data will be flagged as
+ *   reserved if the APQI field in the AP queue device matches
+ *
+ * Returns 0 to indicate the input to function succeeded. Returns -EINVAL if
+ * @data does not contain either an apid or apqi.
+ */
+static int vfio_ap_has_queue(struct device *dev, void *data)
+{
+	struct vfio_ap_queue_reserved *qres = data;
+	struct ap_queue *ap_queue = to_ap_queue(dev);
+	ap_qid_t qid;
+	unsigned long id;
+
+	if (qres->apid && qres->apqi) {
+		qid = AP_MKQID(*qres->apid, *qres->apqi);
+		if (qid == ap_queue->qid)
+			qres->reserved = true;
+	} else if (qres->apid && !qres->apqi) {
+		id = AP_QID_CARD(ap_queue->qid);
+		if (id == *qres->apid)
+			qres->reserved = true;
+	} else if (!qres->apid && qres->apqi) {
+		id = AP_QID_QUEUE(ap_queue->qid);
+		if (id == *qres->apqi)
+			qres->reserved = true;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * vfio_ap_verify_queue_reserved
+ *
+ * @matrix_dev: a mediated matrix device
+ * @apid: an AP adapter ID
+ * @apqi: an AP queue index
+ *
+ * Verifies that the AP queue with @apid/@apqi is reserved by the VFIO AP device
+ * driver according to the following rules:
+ *
+ * - If both @apid and @apqi are not NULL, then there must be an AP queue
+ *   device bound to the vfio_ap driver with the APQN identified by @apid and
+ *   @apqi
+ *
+ * - If only @apid is not NULL, then there must be an AP queue device bound
+ *   to the vfio_ap driver with an APQN containing @apid
+ *
+ * - If only @apqi is not NULL, then there must be an AP queue device bound
+ *   to the vfio_ap driver with an APQN containing @apqi
+ *
+ * Returns 0 if the AP queue is reserved; otherwise, returns -EADDRNOTAVAIL.
+ */
+static int vfio_ap_verify_queue_reserved(unsigned long *apid,
+					 unsigned long *apqi)
+{
+	int ret;
+	struct vfio_ap_queue_reserved qres;
+
+	qres.apid = apid;
+	qres.apqi = apqi;
+	qres.reserved = false;
+
+	ret = driver_for_each_device(matrix_dev->device.driver, NULL, &qres,
+				     vfio_ap_has_queue);
+	if (ret)
+		return ret;
+
+	if (qres.reserved)
+		return 0;
+
+	return -EADDRNOTAVAIL;
+}
+
+static int
+vfio_ap_mdev_verify_queues_reserved_for_apid(struct ap_matrix_mdev *matrix_mdev,
+					     unsigned long apid)
+{
+	int ret;
+	unsigned long apqi;
+	unsigned long nbits = matrix_mdev->matrix.aqm_max + 1;
+
+	if (find_first_bit_inv(matrix_mdev->matrix.aqm, nbits) >= nbits)
+		return vfio_ap_verify_queue_reserved(&apid, NULL);
+
+	for_each_set_bit_inv(apqi, matrix_mdev->matrix.aqm, nbits) {
+		ret = vfio_ap_verify_queue_reserved(&apid, &apqi);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * vfio_ap_mdev_verify_no_sharing
+ *
+ * Verifies that the APQNs derived from the cross product of the AP adapter IDs
+ * and AP queue indexes comprising the AP matrix are not configured for another
+ * mediated device. AP queue sharing is not allowed.
+ *
+ * @kvm: the KVM guest
+ * @matrix: the AP matrix
+ *
+ * Returns 0 if the APQNs are not shared, otherwise; returns -EADDRINUSE.
+ */
+static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
+{
+	int nbits;
+	struct ap_matrix_mdev *lstdev;
+	unsigned long apm[BITS_TO_LONGS(matrix_mdev->matrix.apm_max + 1)];
+	unsigned long aqm[BITS_TO_LONGS(matrix_mdev->matrix.aqm_max + 1)];
+
+	list_for_each_entry(lstdev, &matrix_dev->mdev_list, node) {
+		if (matrix_mdev == lstdev)
+			continue;
+
+		memset(apm, 0, sizeof(apm));
+		memset(aqm, 0, sizeof(aqm));
+
+		/*
+		 * We work on full longs, as we can only exclude the leftover
+		 * bits in non-inverse order. The leftover is all zeros.
+		 */
+		nbits = sizeof(apm) * BITS_PER_BYTE;
+		if (!bitmap_and(apm, matrix_mdev->matrix.apm,
+				lstdev->matrix.apm, nbits))
+			continue;
+
+		nbits = sizeof(aqm) * BITS_PER_BYTE;
+		if (!bitmap_and(aqm, matrix_mdev->matrix.aqm,
+				lstdev->matrix.aqm, nbits))
+			continue;
+
+		return -EADDRINUSE;
+	}
+
+	return 0;
+}
+
+/**
+ * assign_adapter_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's assign_adapter attribute
+ * @buf:	a buffer containing the AP adapter number (APID) to
+ *		be assigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the APID from @buf and sets the corresponding bit in the mediated
+ * matrix device's APM.
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise,
+ * returns one of the following errors:
+ *
+ *	1. -EINVAL
+ *	   The APID is not a valid number
+ *
+ *	2. -ENODEV
+ *	   The APID exceeds the maximum value configured for the system
+ *
+ *	3. -EADDRNOTAVAIL
+ *	   An APQN derived from the cross product of the APID being assigned
+ *	   and the APQIs previously assigned is not bound to the vfio_ap device
+ *	   driver; or, if no APQIs have yet been assigned, the APID is not
+ *	   contained in an APQN bound to the vfio_ap device driver.
+ *
+ *	4. -EADDRINUSE
+ *	   An APQN derived from the cross product of the APID being assigned
+ *	   and the APQIs previously assigned is being used by another mediated
+ *	   matrix device
+ */
+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);
+
+	ret = kstrtoul(buf, 0, &apid);
+	if (ret)
+		return ret;
+
+	if (apid > matrix_mdev->matrix.apm_max)
+		return -ENODEV;
+
+	/* 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);
+
+	ret = vfio_ap_mdev_verify_queues_reserved_for_apid(matrix_mdev, apid);
+	if (ret)
+		goto done;
+
+	set_bit_inv(apid, matrix_mdev->matrix.apm);
+
+	ret = vfio_ap_mdev_verify_no_sharing(matrix_mdev);
+	if (ret)
+		goto share_err;
+
+	ret = count;
+	goto done;
+
+share_err:
+	clear_bit_inv(apid, matrix_mdev->matrix.apm);
+done:
+	mutex_unlock(&matrix_dev->lock);
+
+	return ret;
+}
+static DEVICE_ATTR_WO(assign_adapter);
+
+/**
+ * unassign_adapter_store
+ *
+ * @dev:	the matrix device
+ * @attr:	the mediated matrix device's unassign_adapter attribute
+ * @buf:	a buffer containing the adapter number (APID) to be unassigned
+ * @count:	the number of bytes in @buf
+ *
+ * Parses the APID from @buf and clears the corresponding bit in the mediated
+ * matrix device's APM.
+ *
+ * Returns the number of bytes processed if the APID is valid; otherwise,
+ * returns one of the following errors:
+ *	-EINVAL if the APID is not a number
+ *	-ENODEV if the APID it exceeds the maximum value configured for the
+ *		system
+ */
+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);
+
+	ret = kstrtoul(buf, 0, &apid);
+	if (ret)
+		return ret;
+
+	if (apid > matrix_mdev->matrix.apm_max)
+		return -ENODEV;
+
+	mutex_lock(&matrix_dev->lock);
+	clear_bit_inv((unsigned long)apid, matrix_mdev->matrix.apm);
+	mutex_unlock(&matrix_dev->lock);
+
+	return count;
+}
+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,
 };
