Commit fa3da00c authored by Kirti Wankhede's avatar Kirti Wankhede Committed by Alex Williamson

vfio: VFIO based driver for Mediated devices

vfio_mdev driver registers with mdev core driver.
mdev core driver creates mediated device and calls probe routine of
vfio_mdev driver for each device.
Probe routine of vfio_mdev driver adds mediated device to VFIO core module

This driver forms a shim layer that pass through VFIO devices operations
to vendor driver for mediated devices.
Signed-off-by: default avatarKirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: default avatarNeo Jia <cjia@nvidia.com>
Reviewed-by: default avatarJike Song <jike.song@intel.com>
Reviewed-by: default avatarDong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 7b96953b
......@@ -7,3 +7,10 @@ config VFIO_MDEV
Provides a framework to virtualize devices.
If you don't know what do here, say N.
config VFIO_MDEV_DEVICE
tristate "VFIO driver for Mediated devices"
depends on VFIO && VFIO_MDEV
default n
help
VFIO based driver for Mediated devices.
......@@ -2,3 +2,4 @@
mdev-y := mdev_core.o mdev_sysfs.o mdev_driver.o
obj-$(CONFIG_VFIO_MDEV) += mdev.o
obj-$(CONFIG_VFIO_MDEV_DEVICE) += vfio_mdev.o
......@@ -354,7 +354,18 @@ int mdev_device_remove(struct device *dev, bool force_remove)
static int __init mdev_init(void)
{
return mdev_bus_register();
int ret;
ret = mdev_bus_register();
/*
* Attempt to load known vfio_mdev. This gives us a working environment
* without the user needing to explicitly load vfio_mdev driver.
*/
if (!ret)
request_module_nowait("vfio_mdev");
return ret;
}
static void __exit mdev_exit(void)
......
/*
* VFIO based driver for Mediated device
*
* Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
* Author: Neo Jia <cjia@nvidia.com>
* Kirti Wankhede <kwankhede@nvidia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/vfio.h>
#include <linux/mdev.h>
#include "mdev_private.h"
#define DRIVER_VERSION "0.1"
#define DRIVER_AUTHOR "NVIDIA Corporation"
#define DRIVER_DESC "VFIO based driver for Mediated device"
static int vfio_mdev_open(void *device_data)
{
struct mdev_device *mdev = device_data;
struct parent_device *parent = mdev->parent;
int ret;
if (unlikely(!parent->ops->open))
return -EINVAL;
if (!try_module_get(THIS_MODULE))
return -ENODEV;
ret = parent->ops->open(mdev);
if (ret)
module_put(THIS_MODULE);
return ret;
}
static void vfio_mdev_release(void *device_data)
{
struct mdev_device *mdev = device_data;
struct parent_device *parent = mdev->parent;
if (likely(parent->ops->release))
parent->ops->release(mdev);
module_put(THIS_MODULE);
}
static long vfio_mdev_unlocked_ioctl(void *device_data,
unsigned int cmd, unsigned long arg)
{
struct mdev_device *mdev = device_data;
struct parent_device *parent = mdev->parent;
if (unlikely(!parent->ops->ioctl))
return -EINVAL;
return parent->ops->ioctl(mdev, cmd, arg);
}
static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
size_t count, loff_t *ppos)
{
struct mdev_device *mdev = device_data;
struct parent_device *parent = mdev->parent;
if (unlikely(!parent->ops->read))
return -EINVAL;
return parent->ops->read(mdev, buf, count, ppos);
}
static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
size_t count, loff_t *ppos)
{
struct mdev_device *mdev = device_data;
struct parent_device *parent = mdev->parent;
if (unlikely(!parent->ops->write))
return -EINVAL;
return parent->ops->write(mdev, buf, count, ppos);
}
static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
{
struct mdev_device *mdev = device_data;
struct parent_device *parent = mdev->parent;
if (unlikely(!parent->ops->mmap))
return -EINVAL;
return parent->ops->mmap(mdev, vma);
}
static const struct vfio_device_ops vfio_mdev_dev_ops = {
.name = "vfio-mdev",
.open = vfio_mdev_open,
.release = vfio_mdev_release,
.ioctl = vfio_mdev_unlocked_ioctl,
.read = vfio_mdev_read,
.write = vfio_mdev_write,
.mmap = vfio_mdev_mmap,
};
int vfio_mdev_probe(struct device *dev)
{
struct mdev_device *mdev = to_mdev_device(dev);
return vfio_add_group_dev(dev, &vfio_mdev_dev_ops, mdev);
}
void vfio_mdev_remove(struct device *dev)
{
vfio_del_group_dev(dev);
}
struct mdev_driver vfio_mdev_driver = {
.name = "vfio_mdev",
.probe = vfio_mdev_probe,
.remove = vfio_mdev_remove,
};
static int __init vfio_mdev_init(void)
{
return mdev_register_driver(&vfio_mdev_driver, THIS_MODULE);
}
static void __exit vfio_mdev_exit(void)
{
mdev_unregister_driver(&vfio_mdev_driver);
}
module_init(vfio_mdev_init)
module_exit(vfio_mdev_exit)
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
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