diff options
| -rw-r--r-- | drivers/s390/crypto/vfio_ap_ops.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c index 99ed30315f56..8a63473c5ae7 100644 --- a/drivers/s390/crypto/vfio_ap_ops.c +++ b/drivers/s390/crypto/vfio_ap_ops.c @@ -106,9 +106,301 @@ static struct attribute_group *vfio_ap_mdev_type_groups[] = { 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. + * + * @matrix_mdev: the mediated matrix device + * + * 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) +{ + struct ap_matrix_mdev *lstdev; + DECLARE_BITMAP(apm, AP_DEVICES); + DECLARE_BITMAP(aqm, AP_DOMAINS); + + 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. + */ + if (!bitmap_and(apm, matrix_mdev->matrix.apm, + lstdev->matrix.apm, AP_DEVICES)) + continue; + + if (!bitmap_and(aqm, matrix_mdev->matrix.aqm, + lstdev->matrix.aqm, AP_DOMAINS)) + 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, }; |