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linux-next/drivers/s390/crypto/vfio_ap_ops.c
Tony Krowiak 65f06713d3 s390: vfio-ap: register matrix device with VFIO mdev framework
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.

Registering the matrix device with the VFIO mediated device
framework will create the following sysfs structures:

/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ create

To create a mediated device for the AP matrix device, write a UUID
to the create file:

	uuidgen > create

A symbolic link to the mediated device's directory will be created in the
devices subdirectory named after the generated $uuid:

/sys/devices/vfio_ap/matrix/
...... [mdev_supported_types]
......... [vfio_ap-passthrough]
............ [devices]
............... [$uuid]

A symbolic link to the mediated device will also be created
in the vfio_ap matrix's directory:

/sys/devices/vfio_ap/matrix/[$uuid]

Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Tested-by: Michael Mueller <mimu@linux.ibm.com>
Tested-by: Farhan Ali <alifm@linux.ibm.com>
Message-Id: <20180925231641.4954-6-akrowiak@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2018-09-26 20:45:51 +02:00

127 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Adjunct processor matrix VFIO device driver callbacks.
*
* Copyright IBM Corp. 2018
*
* Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
* Halil Pasic <pasic@linux.ibm.com>
* Pierre Morel <pmorel@linux.ibm.com>
*/
#include <linux/string.h>
#include <linux/vfio.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/ctype.h>
#include <asm/zcrypt.h>
#include "vfio_ap_private.h"
#define VFIO_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)
{
matrix->apm_max = info->apxa ? info->Na : 63;
matrix->aqm_max = info->apxa ? info->Nd : 15;
matrix->adm_max = info->apxa ? info->Nd : 15;
}
static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct ap_matrix_mdev *matrix_mdev;
if ((atomic_dec_if_positive(&matrix_dev->available_instances) < 0))
return -EPERM;
matrix_mdev = kzalloc(sizeof(*matrix_mdev), GFP_KERNEL);
if (!matrix_mdev) {
atomic_inc(&matrix_dev->available_instances);
return -ENOMEM;
}
vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
mdev_set_drvdata(mdev, matrix_mdev);
mutex_lock(&matrix_dev->lock);
list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
mutex_unlock(&matrix_dev->lock);
return 0;
}
static int vfio_ap_mdev_remove(struct mdev_device *mdev)
{
struct ap_matrix_mdev *matrix_mdev = mdev_get_drvdata(mdev);
mutex_lock(&matrix_dev->lock);
list_del(&matrix_mdev->node);
mutex_unlock(&matrix_dev->lock);
kfree(matrix_mdev);
mdev_set_drvdata(mdev, NULL);
atomic_inc(&matrix_dev->available_instances);
return 0;
}
static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
{
return sprintf(buf, "%s\n", VFIO_AP_MDEV_NAME_HWVIRT);
}
MDEV_TYPE_ATTR_RO(name);
static ssize_t available_instances_show(struct kobject *kobj,
struct device *dev, char *buf)
{
return sprintf(buf, "%d\n",
atomic_read(&matrix_dev->available_instances));
}
MDEV_TYPE_ATTR_RO(available_instances);
static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
char *buf)
{
return sprintf(buf, "%s\n", VFIO_DEVICE_API_AP_STRING);
}
MDEV_TYPE_ATTR_RO(device_api);
static struct attribute *vfio_ap_mdev_type_attrs[] = {
&mdev_type_attr_name.attr,
&mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
static struct attribute_group vfio_ap_mdev_hwvirt_type_group = {
.name = VFIO_AP_MDEV_TYPE_HWVIRT,
.attrs = vfio_ap_mdev_type_attrs,
};
static struct attribute_group *vfio_ap_mdev_type_groups[] = {
&vfio_ap_mdev_hwvirt_type_group,
NULL,
};
static const struct mdev_parent_ops vfio_ap_matrix_ops = {
.owner = THIS_MODULE,
.supported_type_groups = vfio_ap_mdev_type_groups,
.create = vfio_ap_mdev_create,
.remove = vfio_ap_mdev_remove,
};
int vfio_ap_mdev_register(void)
{
atomic_set(&matrix_dev->available_instances, MAX_ZDEV_ENTRIES_EXT);
return mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_ops);
}
void vfio_ap_mdev_unregister(void)
{
mdev_unregister_device(&matrix_dev->device);
}