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OpenCloudOS-Kernel/drivers/vfio/vfio_main.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* VFIO core
*
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
* Author: Alex Williamson <alex.williamson@redhat.com>
*
* Derived from original vfio:
* Copyright 2010 Cisco Systems, Inc. All rights reserved.
* Author: Tom Lyon, pugs@cisco.com
*/
#include <linux/cdev.h>
#include <linux/compat.h>
#include <linux/device.h>
#include <linux/file.h>
#include <linux/anon_inodes.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/iommu.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <linux/wait.h>
#include <linux/sched/signal.h>
#include <linux/pm_runtime.h>
#include <linux/interval_tree.h>
#include <linux/iova_bitmap.h>
#include "vfio.h"
#define DRIVER_VERSION "0.3"
#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
#define DRIVER_DESC "VFIO - User Level meta-driver"
static struct vfio {
struct class *class;
struct list_head group_list;
struct mutex group_lock; /* locks group_list */
struct ida group_ida;
dev_t group_devt;
struct class *device_class;
struct ida device_ida;
} vfio;
static DEFINE_XARRAY(vfio_device_set_xa);
static const struct file_operations vfio_group_fops;
int vfio_assign_device_set(struct vfio_device *device, void *set_id)
{
unsigned long idx = (unsigned long)set_id;
struct vfio_device_set *new_dev_set;
struct vfio_device_set *dev_set;
if (WARN_ON(!set_id))
return -EINVAL;
/*
* Atomically acquire a singleton object in the xarray for this set_id
*/
xa_lock(&vfio_device_set_xa);
dev_set = xa_load(&vfio_device_set_xa, idx);
if (dev_set)
goto found_get_ref;
xa_unlock(&vfio_device_set_xa);
new_dev_set = kzalloc(sizeof(*new_dev_set), GFP_KERNEL);
if (!new_dev_set)
return -ENOMEM;
mutex_init(&new_dev_set->lock);
INIT_LIST_HEAD(&new_dev_set->device_list);
new_dev_set->set_id = set_id;
xa_lock(&vfio_device_set_xa);
dev_set = __xa_cmpxchg(&vfio_device_set_xa, idx, NULL, new_dev_set,
GFP_KERNEL);
if (!dev_set) {
dev_set = new_dev_set;
goto found_get_ref;
}
kfree(new_dev_set);
if (xa_is_err(dev_set)) {
xa_unlock(&vfio_device_set_xa);
return xa_err(dev_set);
}
found_get_ref:
dev_set->device_count++;
xa_unlock(&vfio_device_set_xa);
mutex_lock(&dev_set->lock);
device->dev_set = dev_set;
list_add_tail(&device->dev_set_list, &dev_set->device_list);
mutex_unlock(&dev_set->lock);
return 0;
}
EXPORT_SYMBOL_GPL(vfio_assign_device_set);
static void vfio_release_device_set(struct vfio_device *device)
{
struct vfio_device_set *dev_set = device->dev_set;
if (!dev_set)
return;
mutex_lock(&dev_set->lock);
list_del(&device->dev_set_list);
mutex_unlock(&dev_set->lock);
xa_lock(&vfio_device_set_xa);
if (!--dev_set->device_count) {
__xa_erase(&vfio_device_set_xa,
(unsigned long)dev_set->set_id);
mutex_destroy(&dev_set->lock);
kfree(dev_set);
}
xa_unlock(&vfio_device_set_xa);
}
/*
* Group objects - create, release, get, put, search
*/
static struct vfio_group *
__vfio_group_get_from_iommu(struct iommu_group *iommu_group)
{
struct vfio_group *group;
/*
* group->iommu_group from the vfio.group_list cannot be NULL
* under the vfio.group_lock.
*/
list_for_each_entry(group, &vfio.group_list, vfio_next) {
if (group->iommu_group == iommu_group) {
refcount_inc(&group->drivers);
return group;
}
}
return NULL;
}
static struct vfio_group *
vfio_group_get_from_iommu(struct iommu_group *iommu_group)
{
struct vfio_group *group;
mutex_lock(&vfio.group_lock);
group = __vfio_group_get_from_iommu(iommu_group);
mutex_unlock(&vfio.group_lock);
return group;
}
static void vfio_group_release(struct device *dev)
{
struct vfio_group *group = container_of(dev, struct vfio_group, dev);
mutex_destroy(&group->device_lock);
mutex_destroy(&group->group_lock);
WARN_ON(group->iommu_group);
ida_free(&vfio.group_ida, MINOR(group->dev.devt));
kfree(group);
}
static struct vfio_group *vfio_group_alloc(struct iommu_group *iommu_group,
enum vfio_group_type type)
{
struct vfio_group *group;
int minor;
group = kzalloc(sizeof(*group), GFP_KERNEL);
if (!group)
return ERR_PTR(-ENOMEM);
minor = ida_alloc_max(&vfio.group_ida, MINORMASK, GFP_KERNEL);
if (minor < 0) {
kfree(group);
return ERR_PTR(minor);
}
device_initialize(&group->dev);
group->dev.devt = MKDEV(MAJOR(vfio.group_devt), minor);
group->dev.class = vfio.class;
group->dev.release = vfio_group_release;
cdev_init(&group->cdev, &vfio_group_fops);
group->cdev.owner = THIS_MODULE;
refcount_set(&group->drivers, 1);
mutex_init(&group->group_lock);
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
group->iommu_group = iommu_group;
/* put in vfio_group_release() */
iommu_group_ref_get(iommu_group);
group->type = type;
BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
return group;
}
static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group,
enum vfio_group_type type)
{
struct vfio_group *group;
struct vfio_group *ret;
int err;
group = vfio_group_alloc(iommu_group, type);
if (IS_ERR(group))
return group;
err = dev_set_name(&group->dev, "%s%d",
group->type == VFIO_NO_IOMMU ? "noiommu-" : "",
iommu_group_id(iommu_group));
if (err) {
ret = ERR_PTR(err);
goto err_put;
}
mutex_lock(&vfio.group_lock);
/* Did we race creating this group? */
ret = __vfio_group_get_from_iommu(iommu_group);
if (ret)
goto err_unlock;
err = cdev_device_add(&group->cdev, &group->dev);
if (err) {
ret = ERR_PTR(err);
goto err_unlock;
}
list_add(&group->vfio_next, &vfio.group_list);
mutex_unlock(&vfio.group_lock);
return group;
err_unlock:
mutex_unlock(&vfio.group_lock);
err_put:
put_device(&group->dev);
return ret;
}
static void vfio_device_remove_group(struct vfio_device *device)
{
struct vfio_group *group = device->group;
struct iommu_group *iommu_group;
if (group->type == VFIO_NO_IOMMU || group->type == VFIO_EMULATED_IOMMU)
iommu_group_remove_device(device->dev);
/* Pairs with vfio_create_group() / vfio_group_get_from_iommu() */
if (!refcount_dec_and_mutex_lock(&group->drivers, &vfio.group_lock))
return;
list_del(&group->vfio_next);
/*
* We could concurrently probe another driver in the group that might
* race vfio_device_remove_group() with vfio_get_group(), so we have to
* ensure that the sysfs is all cleaned up under lock otherwise the
* cdev_device_add() will fail due to the name aready existing.
*/
cdev_device_del(&group->cdev, &group->dev);
mutex_lock(&group->group_lock);
/*
* These data structures all have paired operations that can only be
* undone when the caller holds a live reference on the device. Since
* all pairs must be undone these WARN_ON's indicate some caller did not
* properly hold the group reference.
*/
WARN_ON(!list_empty(&group->device_list));
WARN_ON(group->notifier.head);
/*
* Revoke all users of group->iommu_group. At this point we know there
* are no devices active because we are unplugging the last one. Setting
* iommu_group to NULL blocks all new users.
*/
if (group->container)
vfio_group_detach_container(group);
iommu_group = group->iommu_group;
group->iommu_group = NULL;
mutex_unlock(&group->group_lock);
mutex_unlock(&vfio.group_lock);
iommu_group_put(iommu_group);
put_device(&group->dev);
}
/*
* Device objects - create, release, get, put, search
*/
/* Device reference always implies a group reference */
static void vfio_device_put_registration(struct vfio_device *device)
{
if (refcount_dec_and_test(&device->refcount))
complete(&device->comp);
}
static bool vfio_device_try_get_registration(struct vfio_device *device)
{
return refcount_inc_not_zero(&device->refcount);
}
static struct vfio_device *vfio_group_get_device(struct vfio_group *group,
struct device *dev)
{
struct vfio_device *device;
mutex_lock(&group->device_lock);
list_for_each_entry(device, &group->device_list, group_next) {
if (device->dev == dev &&
vfio_device_try_get_registration(device)) {
mutex_unlock(&group->device_lock);
return device;
}
}
mutex_unlock(&group->device_lock);
return NULL;
}
/*
* VFIO driver API
*/
/* Release helper called by vfio_put_device() */
static void vfio_device_release(struct device *dev)
{
struct vfio_device *device =
container_of(dev, struct vfio_device, device);
vfio_release_device_set(device);
ida_free(&vfio.device_ida, device->index);
/*
* kvfree() cannot be done here due to a life cycle mess in
* vfio-ccw. Before the ccw part is fixed all drivers are
* required to support @release and call vfio_free_device()
* from there.
*/
device->ops->release(device);
}
/*
* Allocate and initialize vfio_device so it can be registered to vfio
* core.
*
* Drivers should use the wrapper vfio_alloc_device() for allocation.
* @size is the size of the structure to be allocated, including any
* private data used by the driver.
*
* Driver may provide an @init callback to cover device private data.
*
* Use vfio_put_device() to release the structure after success return.
*/
struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
const struct vfio_device_ops *ops)
{
struct vfio_device *device;
int ret;
if (WARN_ON(size < sizeof(struct vfio_device)))
return ERR_PTR(-EINVAL);
device = kvzalloc(size, GFP_KERNEL);
if (!device)
return ERR_PTR(-ENOMEM);
ret = vfio_init_device(device, dev, ops);
if (ret)
goto out_free;
return device;
out_free:
kvfree(device);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(_vfio_alloc_device);
/*
* Initialize a vfio_device so it can be registered to vfio core.
*
* Only vfio-ccw driver should call this interface.
*/
int vfio_init_device(struct vfio_device *device, struct device *dev,
const struct vfio_device_ops *ops)
{
int ret;
ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
if (ret < 0) {
dev_dbg(dev, "Error to alloc index\n");
return ret;
}
device->index = ret;
init_completion(&device->comp);
device->dev = dev;
device->ops = ops;
if (ops->init) {
ret = ops->init(device);
if (ret)
goto out_uninit;
}
device_initialize(&device->device);
device->device.release = vfio_device_release;
device->device.class = vfio.device_class;
device->device.parent = device->dev;
return 0;
out_uninit:
vfio_release_device_set(device);
ida_free(&vfio.device_ida, device->index);
return ret;
}
EXPORT_SYMBOL_GPL(vfio_init_device);
/*
* The helper called by driver @release callback to free the device
* structure. Drivers which don't have private data to clean can
* simply use this helper as its @release.
*/
void vfio_free_device(struct vfio_device *device)
{
kvfree(device);
}
EXPORT_SYMBOL_GPL(vfio_free_device);
static struct vfio_group *vfio_noiommu_group_alloc(struct device *dev,
enum vfio_group_type type)
{
struct iommu_group *iommu_group;
struct vfio_group *group;
int ret;
iommu_group = iommu_group_alloc();
if (IS_ERR(iommu_group))
return ERR_CAST(iommu_group);
ret = iommu_group_set_name(iommu_group, "vfio-noiommu");
if (ret)
goto out_put_group;
ret = iommu_group_add_device(iommu_group, dev);
if (ret)
goto out_put_group;
group = vfio_create_group(iommu_group, type);
if (IS_ERR(group)) {
ret = PTR_ERR(group);
goto out_remove_device;
}
iommu_group_put(iommu_group);
return group;
out_remove_device:
iommu_group_remove_device(dev);
out_put_group:
iommu_group_put(iommu_group);
return ERR_PTR(ret);
}
static struct vfio_group *vfio_group_find_or_alloc(struct device *dev)
{
struct iommu_group *iommu_group;
struct vfio_group *group;
iommu_group = iommu_group_get(dev);
if (!iommu_group && vfio_noiommu) {
/*
* With noiommu enabled, create an IOMMU group for devices that
* don't already have one, implying no IOMMU hardware/driver
* exists. Taint the kernel because we're about to give a DMA
* capable device to a user without IOMMU protection.
*/
group = vfio_noiommu_group_alloc(dev, VFIO_NO_IOMMU);
if (!IS_ERR(group)) {
add_taint(TAINT_USER, LOCKDEP_STILL_OK);
dev_warn(dev, "Adding kernel taint for vfio-noiommu group on device\n");
}
return group;
}
if (!iommu_group)
return ERR_PTR(-EINVAL);
/*
* VFIO always sets IOMMU_CACHE because we offer no way for userspace to
* restore cache coherency. It has to be checked here because it is only
* valid for cases where we are using iommu groups.
*/
if (!device_iommu_capable(dev, IOMMU_CAP_CACHE_COHERENCY)) {
iommu_group_put(iommu_group);
return ERR_PTR(-EINVAL);
}
group = vfio_group_get_from_iommu(iommu_group);
if (!group)
group = vfio_create_group(iommu_group, VFIO_IOMMU);
/* The vfio_group holds a reference to the iommu_group */
iommu_group_put(iommu_group);
return group;
}
static int __vfio_register_dev(struct vfio_device *device,
struct vfio_group *group)
{
struct vfio_device *existing_device;
int ret;
/*
* In all cases group is the output of one of the group allocation
* functions and we have group->drivers incremented for us.
*/
if (IS_ERR(group))
return PTR_ERR(group);
/*
* If the driver doesn't specify a set then the device is added to a
* singleton set just for itself.
*/
if (!device->dev_set)
vfio_assign_device_set(device, device);
existing_device = vfio_group_get_device(group, device->dev);
if (existing_device) {
/*
* group->iommu_group is non-NULL because we hold the drivers
* refcount.
*/
dev_WARN(device->dev, "Device already exists on group %d\n",
iommu_group_id(group->iommu_group));
vfio_device_put_registration(existing_device);
ret = -EBUSY;
goto err_out;
}
/* Our reference on group is moved to the device */
device->group = group;
ret = dev_set_name(&device->device, "vfio%d", device->index);
if (ret)
goto err_out;
ret = device_add(&device->device);
if (ret)
goto err_out;
/* Refcounting can't start until the driver calls register */
refcount_set(&device->refcount, 1);
mutex_lock(&group->device_lock);
list_add(&device->group_next, &group->device_list);
mutex_unlock(&group->device_lock);
return 0;
err_out:
vfio_device_remove_group(device);
return ret;
}
int vfio_register_group_dev(struct vfio_device *device)
{
return __vfio_register_dev(device,
vfio_group_find_or_alloc(device->dev));
}
EXPORT_SYMBOL_GPL(vfio_register_group_dev);
/*
* Register a virtual device without IOMMU backing. The user of this
* device must not be able to directly trigger unmediated DMA.
*/
int vfio_register_emulated_iommu_dev(struct vfio_device *device)
{
return __vfio_register_dev(device,
vfio_noiommu_group_alloc(device->dev, VFIO_EMULATED_IOMMU));
}
EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
char *buf)
{
struct vfio_device *it, *device = ERR_PTR(-ENODEV);
mutex_lock(&group->device_lock);
list_for_each_entry(it, &group->device_list, group_next) {
int ret;
if (it->ops->match) {
ret = it->ops->match(it, buf);
if (ret < 0) {
device = ERR_PTR(ret);
break;
}
} else {
ret = !strcmp(dev_name(it->dev), buf);
}
if (ret && vfio_device_try_get_registration(it)) {
device = it;
break;
}
}
mutex_unlock(&group->device_lock);
return device;
}
/*
* Decrement the device reference count and wait for the device to be
* removed. Open file descriptors for the device... */
void vfio_unregister_group_dev(struct vfio_device *device)
{
struct vfio_group *group = device->group;
unsigned int i = 0;
bool interrupted = false;
long rc;
vfio_device_put_registration(device);
rc = try_wait_for_completion(&device->comp);
while (rc <= 0) {
if (device->ops->request)
device->ops->request(device, i++);
if (interrupted) {
rc = wait_for_completion_timeout(&device->comp,
HZ * 10);
} else {
rc = wait_for_completion_interruptible_timeout(
&device->comp, HZ * 10);
if (rc < 0) {
interrupted = true;
dev_warn(device->dev,
"Device is currently in use, task"
" \"%s\" (%d) "
"blocked until device is released",
current->comm, task_pid_nr(current));
}
}
}
mutex_lock(&group->device_lock);
list_del(&device->group_next);
mutex_unlock(&group->device_lock);
/* Balances device_add in register path */
device_del(&device->device);
vfio_device_remove_group(device);
}
EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
/*
* VFIO Group fd, /dev/vfio/$GROUP
*/
/*
* VFIO_GROUP_UNSET_CONTAINER should fail if there are other users or
* if there was no container to unset. Since the ioctl is called on
* the group, we know that still exists, therefore the only valid
* transition here is 1->0.
*/
static int vfio_group_ioctl_unset_container(struct vfio_group *group)
{
int ret = 0;
mutex_lock(&group->group_lock);
if (!group->container) {
ret = -EINVAL;
goto out_unlock;
}
if (group->container_users != 1) {
ret = -EBUSY;
goto out_unlock;
}
vfio_group_detach_container(group);
out_unlock:
mutex_unlock(&group->group_lock);
return ret;
}
static int vfio_group_ioctl_set_container(struct vfio_group *group,
int __user *arg)
{
struct vfio_container *container;
struct fd f;
int ret;
int fd;
if (get_user(fd, arg))
return -EFAULT;
f = fdget(fd);
if (!f.file)
return -EBADF;
mutex_lock(&group->group_lock);
if (group->container || WARN_ON(group->container_users)) {
ret = -EINVAL;
goto out_unlock;
}
if (!group->iommu_group) {
ret = -ENODEV;
goto out_unlock;
}
container = vfio_container_from_file(f.file);
ret = -EINVAL;
if (container) {
ret = vfio_container_attach_group(container, group);
goto out_unlock;
}
out_unlock:
mutex_unlock(&group->group_lock);
fdput(f);
return ret;
}
static const struct file_operations vfio_device_fops;
/* true if the vfio_device has open_device() called but not close_device() */
bool vfio_assert_device_open(struct vfio_device *device)
{
return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
}
static struct file *vfio_device_open(struct vfio_device *device)
{
struct file *filep;
int ret;
mutex_lock(&device->group->group_lock);
ret = vfio_device_assign_container(device);
mutex_unlock(&device->group->group_lock);
if (ret)
return ERR_PTR(ret);
if (!try_module_get(device->dev->driver->owner)) {
ret = -ENODEV;
goto err_unassign_container;
}
mutex_lock(&device->dev_set->lock);
device->open_count++;
if (device->open_count == 1) {
/*
* Here we pass the KVM pointer with the group under the read
* lock. If the device driver will use it, it must obtain a
* reference and release it during close_device.
*/
mutex_lock(&device->group->group_lock);
device->kvm = device->group->kvm;
if (device->ops->open_device) {
ret = device->ops->open_device(device);
if (ret)
goto err_undo_count;
}
vfio_device_container_register(device);
mutex_unlock(&device->group->group_lock);
}
mutex_unlock(&device->dev_set->lock);
/*
* We can't use anon_inode_getfd() because we need to modify
* the f_mode flags directly to allow more than just ioctls
*/
filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
device, O_RDWR);
if (IS_ERR(filep)) {
ret = PTR_ERR(filep);
goto err_close_device;
}
/*
* TODO: add an anon_inode interface to do this.
* Appears to be missing by lack of need rather than
* explicitly prevented. Now there's need.
*/
filep->f_mode |= (FMODE_PREAD | FMODE_PWRITE);
if (device->group->type == VFIO_NO_IOMMU)
dev_warn(device->dev, "vfio-noiommu device opened by user "
"(%s:%d)\n", current->comm, task_pid_nr(current));
/*
* On success the ref of device is moved to the file and
* put in vfio_device_fops_release()
*/
return filep;
err_close_device:
mutex_lock(&device->dev_set->lock);
mutex_lock(&device->group->group_lock);
if (device->open_count == 1 && device->ops->close_device) {
device->ops->close_device(device);
vfio_device_container_unregister(device);
}
err_undo_count:
mutex_unlock(&device->group->group_lock);
device->open_count--;
if (device->open_count == 0 && device->kvm)
device->kvm = NULL;
mutex_unlock(&device->dev_set->lock);
module_put(device->dev->driver->owner);
err_unassign_container:
vfio_device_unassign_container(device);
return ERR_PTR(ret);
}
static int vfio_group_ioctl_get_device_fd(struct vfio_group *group,
char __user *arg)
{
struct vfio_device *device;
struct file *filep;
char *buf;
int fdno;
int ret;
buf = strndup_user(arg, PAGE_SIZE);
if (IS_ERR(buf))
return PTR_ERR(buf);
device = vfio_device_get_from_name(group, buf);
kfree(buf);
if (IS_ERR(device))
return PTR_ERR(device);
fdno = get_unused_fd_flags(O_CLOEXEC);
if (fdno < 0) {
ret = fdno;
goto err_put_device;
}
filep = vfio_device_open(device);
if (IS_ERR(filep)) {
ret = PTR_ERR(filep);
goto err_put_fdno;
}
fd_install(fdno, filep);
return fdno;
err_put_fdno:
put_unused_fd(fdno);
err_put_device:
vfio_device_put_registration(device);
return ret;
}
static int vfio_group_ioctl_get_status(struct vfio_group *group,
struct vfio_group_status __user *arg)
{
unsigned long minsz = offsetofend(struct vfio_group_status, flags);
struct vfio_group_status status;
if (copy_from_user(&status, arg, minsz))
return -EFAULT;
if (status.argsz < minsz)
return -EINVAL;
status.flags = 0;
mutex_lock(&group->group_lock);
if (!group->iommu_group) {
mutex_unlock(&group->group_lock);
return -ENODEV;
}
if (group->container)
status.flags |= VFIO_GROUP_FLAGS_CONTAINER_SET |
VFIO_GROUP_FLAGS_VIABLE;
else if (!iommu_group_dma_owner_claimed(group->iommu_group))
status.flags |= VFIO_GROUP_FLAGS_VIABLE;
mutex_unlock(&group->group_lock);
if (copy_to_user(arg, &status, minsz))
return -EFAULT;
return 0;
}
static long vfio_group_fops_unl_ioctl(struct file *filep,
unsigned int cmd, unsigned long arg)
{
struct vfio_group *group = filep->private_data;
void __user *uarg = (void __user *)arg;
switch (cmd) {
case VFIO_GROUP_GET_DEVICE_FD:
return vfio_group_ioctl_get_device_fd(group, uarg);
case VFIO_GROUP_GET_STATUS:
return vfio_group_ioctl_get_status(group, uarg);
case VFIO_GROUP_SET_CONTAINER:
return vfio_group_ioctl_set_container(group, uarg);
case VFIO_GROUP_UNSET_CONTAINER:
return vfio_group_ioctl_unset_container(group);
default:
return -ENOTTY;
}
}
static int vfio_group_fops_open(struct inode *inode, struct file *filep)
{
struct vfio_group *group =
container_of(inode->i_cdev, struct vfio_group, cdev);
int ret;
mutex_lock(&group->group_lock);
/*
* drivers can be zero if this races with vfio_device_remove_group(), it
* will be stable at 0 under the group rwsem
*/
if (refcount_read(&group->drivers) == 0) {
ret = -ENODEV;
goto out_unlock;
}
if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO)) {
ret = -EPERM;
goto out_unlock;
}
/*
* Do we need multiple instances of the group open? Seems not.
*/
if (group->opened_file) {
ret = -EBUSY;
goto out_unlock;
}
group->opened_file = filep;
filep->private_data = group;
ret = 0;
out_unlock:
mutex_unlock(&group->group_lock);
return ret;
}
static int vfio_group_fops_release(struct inode *inode, struct file *filep)
{
struct vfio_group *group = filep->private_data;
filep->private_data = NULL;
mutex_lock(&group->group_lock);
/*
* Device FDs hold a group file reference, therefore the group release
* is only called when there are no open devices.
*/
WARN_ON(group->notifier.head);
if (group->container)
vfio_group_detach_container(group);
group->opened_file = NULL;
mutex_unlock(&group->group_lock);
return 0;
}
static const struct file_operations vfio_group_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = vfio_group_fops_unl_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = vfio_group_fops_open,
.release = vfio_group_fops_release,
};
/*
* Wrapper around pm_runtime_resume_and_get().
* Return error code on failure or 0 on success.
*/
static inline int vfio_device_pm_runtime_get(struct vfio_device *device)
{
struct device *dev = device->dev;
if (dev->driver && dev->driver->pm) {
int ret;
ret = pm_runtime_resume_and_get(dev);
if (ret) {
dev_info_ratelimited(dev,
"vfio: runtime resume failed %d\n", ret);
return -EIO;
}
}
return 0;
}
/*
* Wrapper around pm_runtime_put().
*/
static inline void vfio_device_pm_runtime_put(struct vfio_device *device)
{
struct device *dev = device->dev;
if (dev->driver && dev->driver->pm)
pm_runtime_put(dev);
}
/*
* VFIO Device fd
*/
static int vfio_device_fops_release(struct inode *inode, struct file *filep)
{
struct vfio_device *device = filep->private_data;
mutex_lock(&device->dev_set->lock);
vfio_assert_device_open(device);
mutex_lock(&device->group->group_lock);
if (device->open_count == 1 && device->ops->close_device)
device->ops->close_device(device);
vfio_device_container_unregister(device);
mutex_unlock(&device->group->group_lock);
device->open_count--;
if (device->open_count == 0)
device->kvm = NULL;
mutex_unlock(&device->dev_set->lock);
module_put(device->dev->driver->owner);
vfio_device_unassign_container(device);
vfio_device_put_registration(device);
return 0;
}
/*
* vfio_mig_get_next_state - Compute the next step in the FSM
* @cur_fsm - The current state the device is in
* @new_fsm - The target state to reach
* @next_fsm - Pointer to the next step to get to new_fsm
*
* Return 0 upon success, otherwise -errno
* Upon success the next step in the state progression between cur_fsm and
* new_fsm will be set in next_fsm.
*
* This breaks down requests for combination transitions into smaller steps and
* returns the next step to get to new_fsm. The function may need to be called
* multiple times before reaching new_fsm.
*
*/
int vfio_mig_get_next_state(struct vfio_device *device,
enum vfio_device_mig_state cur_fsm,
enum vfio_device_mig_state new_fsm,
enum vfio_device_mig_state *next_fsm)
{
enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_RUNNING_P2P + 1 };
/*
* The coding in this table requires the driver to implement the
* following FSM arcs:
* RESUMING -> STOP
* STOP -> RESUMING
* STOP -> STOP_COPY
* STOP_COPY -> STOP
*
* If P2P is supported then the driver must also implement these FSM
* arcs:
* RUNNING -> RUNNING_P2P
* RUNNING_P2P -> RUNNING
* RUNNING_P2P -> STOP
* STOP -> RUNNING_P2P
* Without P2P the driver must implement:
* RUNNING -> STOP
* STOP -> RUNNING
*
* The coding will step through multiple states for some combination
* transitions; if all optional features are supported, this means the
* following ones:
* RESUMING -> STOP -> RUNNING_P2P
* RESUMING -> STOP -> RUNNING_P2P -> RUNNING
* RESUMING -> STOP -> STOP_COPY
* RUNNING -> RUNNING_P2P -> STOP
* RUNNING -> RUNNING_P2P -> STOP -> RESUMING
* RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY
* RUNNING_P2P -> STOP -> RESUMING
* RUNNING_P2P -> STOP -> STOP_COPY
* STOP -> RUNNING_P2P -> RUNNING
* STOP_COPY -> STOP -> RESUMING
* STOP_COPY -> STOP -> RUNNING_P2P
* STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING
*/
static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = {
[VFIO_DEVICE_STATE_STOP] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
},
[VFIO_DEVICE_STATE_RUNNING] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
},
[VFIO_DEVICE_STATE_STOP_COPY] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
},
[VFIO_DEVICE_STATE_RESUMING] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
},
[VFIO_DEVICE_STATE_RUNNING_P2P] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
},
[VFIO_DEVICE_STATE_ERROR] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR,
[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR,
[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
},
};
static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY,
[VFIO_DEVICE_STATE_RUNNING_P2P] =
VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P,
[VFIO_DEVICE_STATE_ERROR] = ~0U,
};
if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
(state_flags_table[cur_fsm] & device->migration_flags) !=
state_flags_table[cur_fsm]))
return -EINVAL;
if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
(state_flags_table[new_fsm] & device->migration_flags) !=
state_flags_table[new_fsm])
return -EINVAL;
/*
* Arcs touching optional and unsupported states are skipped over. The
* driver will instead see an arc from the original state to the next
* logical state, as per the above comment.
*/
*next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm];
while ((state_flags_table[*next_fsm] & device->migration_flags) !=
state_flags_table[*next_fsm])
*next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm];
return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL;
}
EXPORT_SYMBOL_GPL(vfio_mig_get_next_state);
/*
* Convert the drivers's struct file into a FD number and return it to userspace
*/
static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg,
struct vfio_device_feature_mig_state *mig)
{
int ret;
int fd;
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0) {
ret = fd;
goto out_fput;
}
mig->data_fd = fd;
if (copy_to_user(arg, mig, sizeof(*mig))) {
ret = -EFAULT;
goto out_put_unused;
}
fd_install(fd, filp);
return 0;
out_put_unused:
put_unused_fd(fd);
out_fput:
fput(filp);
return ret;
}
static int
vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device,
u32 flags, void __user *arg,
size_t argsz)
{
size_t minsz =
offsetofend(struct vfio_device_feature_mig_state, data_fd);
struct vfio_device_feature_mig_state mig;
struct file *filp = NULL;
int ret;
if (!device->mig_ops)
return -ENOTTY;
ret = vfio_check_feature(flags, argsz,
VFIO_DEVICE_FEATURE_SET |
VFIO_DEVICE_FEATURE_GET,
sizeof(mig));
if (ret != 1)
return ret;
if (copy_from_user(&mig, arg, minsz))
return -EFAULT;
if (flags & VFIO_DEVICE_FEATURE_GET) {
enum vfio_device_mig_state curr_state;
ret = device->mig_ops->migration_get_state(device,
&curr_state);
if (ret)
return ret;
mig.device_state = curr_state;
goto out_copy;
}
/* Handle the VFIO_DEVICE_FEATURE_SET */
filp = device->mig_ops->migration_set_state(device, mig.device_state);
if (IS_ERR(filp) || !filp)
goto out_copy;
return vfio_ioct_mig_return_fd(filp, arg, &mig);
out_copy:
mig.data_fd = -1;
if (copy_to_user(arg, &mig, sizeof(mig)))
return -EFAULT;
if (IS_ERR(filp))
return PTR_ERR(filp);
return 0;
}
static int vfio_ioctl_device_feature_migration(struct vfio_device *device,
u32 flags, void __user *arg,
size_t argsz)
{
struct vfio_device_feature_migration mig = {
.flags = device->migration_flags,
};
int ret;
if (!device->mig_ops)
return -ENOTTY;
ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
sizeof(mig));
if (ret != 1)
return ret;
if (copy_to_user(arg, &mig, sizeof(mig)))
return -EFAULT;
return 0;
}
/* Ranges should fit into a single kernel page */
#define LOG_MAX_RANGES \
(PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range))
static int
vfio_ioctl_device_feature_logging_start(struct vfio_device *device,
u32 flags, void __user *arg,
size_t argsz)
{
size_t minsz =
offsetofend(struct vfio_device_feature_dma_logging_control,
ranges);
struct vfio_device_feature_dma_logging_range __user *ranges;
struct vfio_device_feature_dma_logging_control control;
struct vfio_device_feature_dma_logging_range range;
struct rb_root_cached root = RB_ROOT_CACHED;
struct interval_tree_node *nodes;
u64 iova_end;
u32 nnodes;
int i, ret;
if (!device->log_ops)
return -ENOTTY;
ret = vfio_check_feature(flags, argsz,
VFIO_DEVICE_FEATURE_SET,
sizeof(control));
if (ret != 1)
return ret;
if (copy_from_user(&control, arg, minsz))
return -EFAULT;
nnodes = control.num_ranges;
if (!nnodes)
return -EINVAL;
if (nnodes > LOG_MAX_RANGES)
return -E2BIG;
ranges = u64_to_user_ptr(control.ranges);
nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
GFP_KERNEL);
if (!nodes)
return -ENOMEM;
for (i = 0; i < nnodes; i++) {
if (copy_from_user(&range, &ranges[i], sizeof(range))) {
ret = -EFAULT;
goto end;
}
if (!IS_ALIGNED(range.iova, control.page_size) ||
!IS_ALIGNED(range.length, control.page_size)) {
ret = -EINVAL;
goto end;
}
if (check_add_overflow(range.iova, range.length, &iova_end) ||
iova_end > ULONG_MAX) {
ret = -EOVERFLOW;
goto end;
}
nodes[i].start = range.iova;
nodes[i].last = range.iova + range.length - 1;
if (interval_tree_iter_first(&root, nodes[i].start,
nodes[i].last)) {
/* Range overlapping */
ret = -EINVAL;
goto end;
}
interval_tree_insert(nodes + i, &root);
}
ret = device->log_ops->log_start(device, &root, nnodes,
&control.page_size);
if (ret)
goto end;
if (copy_to_user(arg, &control, sizeof(control))) {
ret = -EFAULT;
device->log_ops->log_stop(device);
}
end:
kfree(nodes);
return ret;
}
static int
vfio_ioctl_device_feature_logging_stop(struct vfio_device *device,
u32 flags, void __user *arg,
size_t argsz)
{
int ret;
if (!device->log_ops)
return -ENOTTY;
ret = vfio_check_feature(flags, argsz,
VFIO_DEVICE_FEATURE_SET, 0);
if (ret != 1)
return ret;
return device->log_ops->log_stop(device);
}
static int vfio_device_log_read_and_clear(struct iova_bitmap *iter,
unsigned long iova, size_t length,
void *opaque)
{
struct vfio_device *device = opaque;
return device->log_ops->log_read_and_clear(device, iova, length, iter);
}
static int
vfio_ioctl_device_feature_logging_report(struct vfio_device *device,
u32 flags, void __user *arg,
size_t argsz)
{
size_t minsz =
offsetofend(struct vfio_device_feature_dma_logging_report,
bitmap);
struct vfio_device_feature_dma_logging_report report;
struct iova_bitmap *iter;
u64 iova_end;
int ret;
if (!device->log_ops)
return -ENOTTY;
ret = vfio_check_feature(flags, argsz,
VFIO_DEVICE_FEATURE_GET,
sizeof(report));
if (ret != 1)
return ret;
if (copy_from_user(&report, arg, minsz))
return -EFAULT;
if (report.page_size < SZ_4K || !is_power_of_2(report.page_size))
return -EINVAL;
if (check_add_overflow(report.iova, report.length, &iova_end) ||
iova_end > ULONG_MAX)
return -EOVERFLOW;
iter = iova_bitmap_alloc(report.iova, report.length,
report.page_size,
u64_to_user_ptr(report.bitmap));
if (IS_ERR(iter))
return PTR_ERR(iter);
ret = iova_bitmap_for_each(iter, device,
vfio_device_log_read_and_clear);
iova_bitmap_free(iter);
return ret;
}
static int vfio_ioctl_device_feature(struct vfio_device *device,
struct vfio_device_feature __user *arg)
{
size_t minsz = offsetofend(struct vfio_device_feature, flags);
struct vfio_device_feature feature;
if (copy_from_user(&feature, arg, minsz))
return -EFAULT;
if (feature.argsz < minsz)
return -EINVAL;
/* Check unknown flags */
if (feature.flags &
~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET |
VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE))
return -EINVAL;
/* GET & SET are mutually exclusive except with PROBE */
if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
(feature.flags & VFIO_DEVICE_FEATURE_SET) &&
(feature.flags & VFIO_DEVICE_FEATURE_GET))
return -EINVAL;
switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
case VFIO_DEVICE_FEATURE_MIGRATION:
return vfio_ioctl_device_feature_migration(
device, feature.flags, arg->data,
feature.argsz - minsz);
case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE:
return vfio_ioctl_device_feature_mig_device_state(
device, feature.flags, arg->data,
feature.argsz - minsz);
case VFIO_DEVICE_FEATURE_DMA_LOGGING_START:
return vfio_ioctl_device_feature_logging_start(
device, feature.flags, arg->data,
feature.argsz - minsz);
case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP:
return vfio_ioctl_device_feature_logging_stop(
device, feature.flags, arg->data,
feature.argsz - minsz);
case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT:
return vfio_ioctl_device_feature_logging_report(
device, feature.flags, arg->data,
feature.argsz - minsz);
default:
if (unlikely(!device->ops->device_feature))
return -EINVAL;
return device->ops->device_feature(device, feature.flags,
arg->data,
feature.argsz - minsz);
}
}
static long vfio_device_fops_unl_ioctl(struct file *filep,
unsigned int cmd, unsigned long arg)
{
struct vfio_device *device = filep->private_data;
int ret;
ret = vfio_device_pm_runtime_get(device);
if (ret)
return ret;
switch (cmd) {
case VFIO_DEVICE_FEATURE:
ret = vfio_ioctl_device_feature(device, (void __user *)arg);
break;
default:
if (unlikely(!device->ops->ioctl))
ret = -EINVAL;
else
ret = device->ops->ioctl(device, cmd, arg);
break;
}
vfio_device_pm_runtime_put(device);
return ret;
}
static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
size_t count, loff_t *ppos)
{
struct vfio_device *device = filep->private_data;
if (unlikely(!device->ops->read))
return -EINVAL;
return device->ops->read(device, buf, count, ppos);
}
static ssize_t vfio_device_fops_write(struct file *filep,
const char __user *buf,
size_t count, loff_t *ppos)
{
struct vfio_device *device = filep->private_data;
if (unlikely(!device->ops->write))
return -EINVAL;
return device->ops->write(device, buf, count, ppos);
}
static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
{
struct vfio_device *device = filep->private_data;
if (unlikely(!device->ops->mmap))
return -EINVAL;
return device->ops->mmap(device, vma);
}
static const struct file_operations vfio_device_fops = {
.owner = THIS_MODULE,
.release = vfio_device_fops_release,
.read = vfio_device_fops_read,
.write = vfio_device_fops_write,
.unlocked_ioctl = vfio_device_fops_unl_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.mmap = vfio_device_fops_mmap,
};
/**
* vfio_file_iommu_group - Return the struct iommu_group for the vfio group file
* @file: VFIO group file
*
* The returned iommu_group is valid as long as a ref is held on the file. This
* returns a reference on the group. This function is deprecated, only the SPAPR
* path in kvm should call it.
*/
struct iommu_group *vfio_file_iommu_group(struct file *file)
{
struct vfio_group *group = file->private_data;
struct iommu_group *iommu_group = NULL;
if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))
return NULL;
if (!vfio_file_is_group(file))
return NULL;
mutex_lock(&group->group_lock);
if (group->iommu_group) {
iommu_group = group->iommu_group;
iommu_group_ref_get(iommu_group);
}
mutex_unlock(&group->group_lock);
return iommu_group;
}
EXPORT_SYMBOL_GPL(vfio_file_iommu_group);
/**
* vfio_file_is_group - True if the file is usable with VFIO aPIS
* @file: VFIO group file
*/
bool vfio_file_is_group(struct file *file)
{
return file->f_op == &vfio_group_fops;
}
EXPORT_SYMBOL_GPL(vfio_file_is_group);
/**
* vfio_file_enforced_coherent - True if the DMA associated with the VFIO file
* is always CPU cache coherent
* @file: VFIO group file
*
* Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop
* bit in DMA transactions. A return of false indicates that the user has
* rights to access additional instructions such as wbinvd on x86.
*/
bool vfio_file_enforced_coherent(struct file *file)
{
struct vfio_group *group = file->private_data;
bool ret;
if (!vfio_file_is_group(file))
return true;
mutex_lock(&group->group_lock);
if (group->container) {
ret = vfio_container_ioctl_check_extension(group->container,
VFIO_DMA_CC_IOMMU);
} else {
/*
* Since the coherency state is determined only once a container
* is attached the user must do so before they can prove they
* have permission.
*/
ret = true;
}
mutex_unlock(&group->group_lock);
return ret;
}
EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);
/**
* vfio_file_set_kvm - Link a kvm with VFIO drivers
* @file: VFIO group file
* @kvm: KVM to link
*
* When a VFIO device is first opened the KVM will be available in
* device->kvm if one was associated with the group.
*/
void vfio_file_set_kvm(struct file *file, struct kvm *kvm)
{
struct vfio_group *group = file->private_data;
if (!vfio_file_is_group(file))
return;
mutex_lock(&group->group_lock);
group->kvm = kvm;
mutex_unlock(&group->group_lock);
}
EXPORT_SYMBOL_GPL(vfio_file_set_kvm);
/**
* vfio_file_has_dev - True if the VFIO file is a handle for device
* @file: VFIO file to check
* @device: Device that must be part of the file
*
* Returns true if given file has permission to manipulate the given device.
*/
bool vfio_file_has_dev(struct file *file, struct vfio_device *device)
{
struct vfio_group *group = file->private_data;
if (!vfio_file_is_group(file))
return false;
return group == device->group;
}
EXPORT_SYMBOL_GPL(vfio_file_has_dev);
/*
* Sub-module support
*/
/*
* Helper for managing a buffer of info chain capabilities, allocate or
* reallocate a buffer with additional @size, filling in @id and @version
* of the capability. A pointer to the new capability is returned.
*
* NB. The chain is based at the head of the buffer, so new entries are
* added to the tail, vfio_info_cap_shift() should be called to fixup the
* next offsets prior to copying to the user buffer.
*/
struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
size_t size, u16 id, u16 version)
{
void *buf;
struct vfio_info_cap_header *header, *tmp;
buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
if (!buf) {
kfree(caps->buf);
caps->buf = NULL;
caps->size = 0;
return ERR_PTR(-ENOMEM);
}
caps->buf = buf;
header = buf + caps->size;
/* Eventually copied to user buffer, zero */
memset(header, 0, size);
header->id = id;
header->version = version;
/* Add to the end of the capability chain */
for (tmp = buf; tmp->next; tmp = buf + tmp->next)
; /* nothing */
tmp->next = caps->size;
caps->size += size;
return header;
}
EXPORT_SYMBOL_GPL(vfio_info_cap_add);
void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
{
struct vfio_info_cap_header *tmp;
void *buf = (void *)caps->buf;
for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset)
tmp->next += offset;
}
EXPORT_SYMBOL(vfio_info_cap_shift);
int vfio_info_add_capability(struct vfio_info_cap *caps,
struct vfio_info_cap_header *cap, size_t size)
{
struct vfio_info_cap_header *header;
header = vfio_info_cap_add(caps, size, cap->id, cap->version);
if (IS_ERR(header))
return PTR_ERR(header);
memcpy(header + 1, cap + 1, size - sizeof(*header));
return 0;
}
EXPORT_SYMBOL(vfio_info_add_capability);
int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
int max_irq_type, size_t *data_size)
{
unsigned long minsz;
size_t size;
minsz = offsetofend(struct vfio_irq_set, count);
if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) ||
(hdr->count >= (U32_MAX - hdr->start)) ||
(hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
VFIO_IRQ_SET_ACTION_TYPE_MASK)))
return -EINVAL;
if (data_size)
*data_size = 0;
if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs)
return -EINVAL;
switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
case VFIO_IRQ_SET_DATA_NONE:
size = 0;
break;
case VFIO_IRQ_SET_DATA_BOOL:
size = sizeof(uint8_t);
break;
case VFIO_IRQ_SET_DATA_EVENTFD:
size = sizeof(int32_t);
break;
default:
return -EINVAL;
}
if (size) {
if (hdr->argsz - minsz < hdr->count * size)
return -EINVAL;
if (!data_size)
return -EINVAL;
*data_size = hdr->count * size;
}
return 0;
}
EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
/*
* Module/class support
*/
static char *vfio_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
}
static int __init vfio_init(void)
{
int ret;
ida_init(&vfio.group_ida);
ida_init(&vfio.device_ida);
mutex_init(&vfio.group_lock);
INIT_LIST_HEAD(&vfio.group_list);
ret = vfio_container_init();
if (ret)
return ret;
/* /dev/vfio/$GROUP */
vfio.class = class_create(THIS_MODULE, "vfio");
if (IS_ERR(vfio.class)) {
ret = PTR_ERR(vfio.class);
goto err_group_class;
}
vfio.class->devnode = vfio_devnode;
/* /sys/class/vfio-dev/vfioX */
vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
if (IS_ERR(vfio.device_class)) {
ret = PTR_ERR(vfio.device_class);
goto err_dev_class;
}
ret = alloc_chrdev_region(&vfio.group_devt, 0, MINORMASK + 1, "vfio");
if (ret)
goto err_alloc_chrdev;
pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
return 0;
err_alloc_chrdev:
class_destroy(vfio.device_class);
vfio.device_class = NULL;
err_dev_class:
class_destroy(vfio.class);
vfio.class = NULL;
err_group_class:
vfio_container_cleanup();
return ret;
}
static void __exit vfio_cleanup(void)
{
WARN_ON(!list_empty(&vfio.group_list));
ida_destroy(&vfio.device_ida);
ida_destroy(&vfio.group_ida);
unregister_chrdev_region(vfio.group_devt, MINORMASK + 1);
class_destroy(vfio.device_class);
vfio.device_class = NULL;
class_destroy(vfio.class);
vfio_container_cleanup();
vfio.class = NULL;
xa_destroy(&vfio_device_set_xa);
}
module_init(vfio_init);
module_exit(vfio_cleanup);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_ALIAS_MISCDEV(VFIO_MINOR);
MODULE_ALIAS("devname:vfio/vfio");
MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce");
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