On 05/07/2018 05:11 PM, Tony Krowiak wrote:
Registers the matrix device created by the VFIO AP device
driver with the VFIO mediated device framework.
Registering the matrix device will create the sysfs
structures needed to create mediated matrix devices
each of which will be used to configure the AP matrix
for a guest and connect it to the VFIO AP device driver.
[..]
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
new file mode 100644
index 0000000..d7d36fb
--- /dev/null
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Adjunct processor matrix VFIO device driver callbacks.
+ *
+ * Copyright IBM Corp. 2017
+ * Author(s): Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
+ *
+ */
+#include <linux/string.h>
+#include <linux/vfio.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/ctype.h>
+
+#include "vfio_ap_private.h"
+
+#define VFOP_AP_MDEV_TYPE_HWVIRT "passthrough"
+#define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
+
+static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
+{
+ struct ap_matrix *ap_matrix = to_ap_matrix(mdev_parent_dev(mdev));
+
+ ap_matrix->available_instances--;
+
+ return 0;
+}
+
+static int vfio_ap_mdev_remove(struct mdev_device *mdev)
+{
+ struct ap_matrix *ap_matrix = to_ap_matrix(mdev_parent_dev(mdev));
+
+ ap_matrix->available_instances++;
+
+ return 0;
+}
+
The above functions seem to be called with the lock of this auto-generated
mdev parent device held. That's why we don't have to care about synchronization
ourselves, right?
A small comment in the code could be helpful for mdev non-experts. Hell, I would
even consider documenting it for all mdev -- took me some time to figure out.
[..]
+int vfio_ap_mdev_register(struct ap_matrix *ap_matrix)
+{
+ int ret;
+
+ ret = mdev_register_device(&ap_matrix->device, &vfio_ap_matrix_ops);
+ if (ret)
+ return ret;
+
+ ap_matrix->available_instances = AP_MATRIX_MAX_AVAILABLE_INSTANCES;
+
+ return 0;
+}
+
+void vfio_ap_mdev_unregister(struct ap_matrix *ap_matrix)
+{
+ ap_matrix->available_instances--;
What is this for? I don't understand.
Regards,
Halil
+ mdev_unregister_device(&ap_matrix->device);
+}
