On 08/15/2018 05:52 AM, Cornelia Huck wrote:
On Mon, 13 Aug 2018 17:48:07 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
+/**
+ * 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 = 0;
You don't need to initialize this to 0, as kstrtoul will set it in any
case.
Right you are! Will change it.
+ 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)
+ return ret;
+ if (apid > max_apid)
+ return -EINVAL;
+
+ /* 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);
That function name really is a mouthful :) I don't have any better
suggestions, though.
It is, but I think it describes exactly what the function does.
+ 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: 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
A valid value, but not necessarily assigned, right?
You are correct, if the APID is not assigned, then the corresponding bit
will be
cleared regardless. In a previous version, the functions failed if the
APID is
not assigned, but a colleague removed that check. I guess it makes sense
given
it really does not hurt anything to ask to unassign an APID that isn't
assigned
to begin with. Would you prefer I update the comment, or do you feel the
user
should be made aware of an attempt to unassign an APID that is not assigned?
+ *
+ * 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);
+
+ ret = kstrtoul(buf, 0, &apid);
+ if (ret)
+ return ret;
+
+ if (apid > matrix_mdev->matrix.apm_max)
+ return -EINVAL;
+
+ 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);
In general, looks good to me.
That is good news indeed.
