From fa3da00cb8c0d403030f4805ae615b444f0d2f3c Mon Sep 17 00:00:00 2001 From: Kirti Wankhede Date: Thu, 17 Nov 2016 02:16:14 +0530 Subject: [PATCH] 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: Kirti Wankhede Signed-off-by: Neo Jia Reviewed-by: Jike Song Reviewed-by: Dong Jia Shi Signed-off-by: Alex Williamson --- drivers/vfio/mdev/Kconfig | 7 ++ drivers/vfio/mdev/Makefile | 1 + drivers/vfio/mdev/mdev_core.c | 13 ++- drivers/vfio/mdev/vfio_mdev.c | 148 ++++++++++++++++++++++++++++++++++ 4 files changed, 168 insertions(+), 1 deletion(-) create mode 100644 drivers/vfio/mdev/vfio_mdev.c diff --git a/drivers/vfio/mdev/Kconfig b/drivers/vfio/mdev/Kconfig index 258481d65ebd..424ddebee55d 100644 --- a/drivers/vfio/mdev/Kconfig +++ b/drivers/vfio/mdev/Kconfig @@ -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. diff --git a/drivers/vfio/mdev/Makefile b/drivers/vfio/mdev/Makefile index 31bc04801d94..fa2d5ea466ee 100644 --- a/drivers/vfio/mdev/Makefile +++ b/drivers/vfio/mdev/Makefile @@ -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 diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 613e8a8a3b2a..be1ee89ee917 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -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) diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c new file mode 100644 index 000000000000..ffc36758cb84 --- /dev/null +++ b/drivers/vfio/mdev/vfio_mdev.c @@ -0,0 +1,148 @@ +/* + * VFIO based driver for Mediated device + * + * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. + * Author: Neo Jia + * Kirti Wankhede + * + * 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 +#include +#include +#include +#include +#include +#include + +#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); -- 2.20.1