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android-kvm / linux / 37d0be6a7d7d6fede952c439f8d8b9d1df5c756f / . / drivers / vfio / vfio_main.c
blob: 5177bb061b17b51b9e8e9030d9bdf13c0b6a2b4a [file] [log] [blame]
// 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/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 <linux/iommufd.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 *device_class;
struct ida device_ida;
} vfio;
static DEFINE_XARRAY(vfio_device_set_xa);
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);
}
unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
{
struct vfio_device *cur;
unsigned int open_count = 0;
lockdep_assert_held(&dev_set->lock);
list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
open_count += cur->open_count;
return open_count;
}
EXPORT_SYMBOL_GPL(vfio_device_set_open_count);
/*
* Device objects - create, release, get, put, search
*/
/* Device reference always implies a group reference */
void vfio_device_put_registration(struct vfio_device *device)
{
if (refcount_dec_and_test(&device->refcount))
complete(&device->comp);
}
bool vfio_device_try_get_registration(struct vfio_device *device)
{
return refcount_inc_not_zero(&device->refcount);
}
/*
* 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);
if (device->ops->release)
device->ops->release(device);
kvfree(device);
}
static int vfio_init_device(struct vfio_device *device, struct device *dev,
const struct vfio_device_ops *ops);
/*
* 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.
*/
static 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;
}
static int __vfio_register_dev(struct vfio_device *device,
enum vfio_group_type type)
{
int ret;
if (WARN_ON(device->ops->bind_iommufd &&
(!device->ops->unbind_iommufd ||
!device->ops->attach_ioas)))
return -EINVAL;
/*
* 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);
ret = dev_set_name(&device->device, "vfio%d", device->index);
if (ret)
return ret;
ret = vfio_device_set_group(device, type);
if (ret)
return ret;
ret = device_add(&device->device);
if (ret)
goto err_out;
/* Refcounting can't start until the driver calls register */
refcount_set(&device->refcount, 1);
vfio_device_group_register(device);
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_IOMMU);
}
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_EMULATED_IOMMU);
}
EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
/*
* 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)
{
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));
}
}
}
vfio_device_group_unregister(device);
/* Balances device_add in register path */
device_del(&device->device);
/* Balances vfio_device_set_group in register path */
vfio_device_remove_group(device);
}
EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
/* true if the vfio_device has open_device() called but not close_device() */
static bool vfio_assert_device_open(struct vfio_device *device)
{
return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
}
static int vfio_device_first_open(struct vfio_device *device,
struct iommufd_ctx *iommufd, struct kvm *kvm)
{
int ret;
lockdep_assert_held(&device->dev_set->lock);
if (!try_module_get(device->dev->driver->owner))
return -ENODEV;
if (iommufd)
ret = vfio_iommufd_bind(device, iommufd);
else
ret = vfio_device_group_use_iommu(device);
if (ret)
goto err_module_put;
device->kvm = kvm;
if (device->ops->open_device) {
ret = device->ops->open_device(device);
if (ret)
goto err_unuse_iommu;
}
return 0;
err_unuse_iommu:
device->kvm = NULL;
if (iommufd)
vfio_iommufd_unbind(device);
else
vfio_device_group_unuse_iommu(device);
err_module_put:
module_put(device->dev->driver->owner);
return ret;
}
static void vfio_device_last_close(struct vfio_device *device,
struct iommufd_ctx *iommufd)
{
lockdep_assert_held(&device->dev_set->lock);
if (device->ops->close_device)
device->ops->close_device(device);
device->kvm = NULL;
if (iommufd)
vfio_iommufd_unbind(device);
else
vfio_device_group_unuse_iommu(device);
module_put(device->dev->driver->owner);
}
int vfio_device_open(struct vfio_device *device,
struct iommufd_ctx *iommufd, struct kvm *kvm)
{
int ret = 0;
mutex_lock(&device->dev_set->lock);
device->open_count++;
if (device->open_count == 1) {
ret = vfio_device_first_open(device, iommufd, kvm);
if (ret)
device->open_count--;
}
mutex_unlock(&device->dev_set->lock);
return ret;
}
void vfio_device_close(struct vfio_device *device,
struct iommufd_ctx *iommufd)
{
mutex_lock(&device->dev_set->lock);
vfio_assert_device_open(device);
if (device->open_count == 1)
vfio_device_last_close(device, iommufd);
device->open_count--;
mutex_unlock(&device->dev_set->lock);
}
/*
* 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;
vfio_device_group_close(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_PRE_COPY_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
*
* If precopy is supported then the driver must support these additional
* FSM arcs:
* RUNNING -> PRE_COPY
* PRE_COPY -> RUNNING
* PRE_COPY -> STOP_COPY
* However, if precopy and P2P are supported together then the driver
* must support these additional arcs beyond the P2P arcs above:
* PRE_COPY -> RUNNING
* PRE_COPY -> PRE_COPY_P2P
* PRE_COPY_P2P -> PRE_COPY
* PRE_COPY_P2P -> RUNNING_P2P
* PRE_COPY_P2P -> STOP_COPY
* RUNNING -> PRE_COPY
* RUNNING_P2P -> PRE_COPY_P2P
*
* Without P2P and precopy 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:
* PRE_COPY -> PRE_COPY_P2P -> STOP_COPY
* PRE_COPY -> RUNNING -> RUNNING_P2P
* PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP
* PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP -> RESUMING
* PRE_COPY_P2P -> RUNNING_P2P -> RUNNING
* PRE_COPY_P2P -> RUNNING_P2P -> STOP
* PRE_COPY_P2P -> RUNNING_P2P -> STOP -> RESUMING
* RESUMING -> STOP -> RUNNING_P2P
* RESUMING -> STOP -> RUNNING_P2P -> PRE_COPY_P2P
* RESUMING -> STOP -> RUNNING_P2P -> RUNNING
* RESUMING -> STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY
* RESUMING -> STOP -> STOP_COPY
* RUNNING -> RUNNING_P2P -> PRE_COPY_P2P
* RUNNING -> RUNNING_P2P -> STOP
* RUNNING -> RUNNING_P2P -> STOP -> RESUMING
* RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY
* RUNNING_P2P -> RUNNING -> PRE_COPY
* RUNNING_P2P -> STOP -> RESUMING
* RUNNING_P2P -> STOP -> STOP_COPY
* STOP -> RUNNING_P2P -> PRE_COPY_P2P
* STOP -> RUNNING_P2P -> RUNNING
* STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY
* STOP_COPY -> STOP -> RESUMING
* STOP_COPY -> STOP -> RUNNING_P2P
* STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING
*
* The following transitions are blocked:
* STOP_COPY -> PRE_COPY
* STOP_COPY -> PRE_COPY_P2P
*/
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_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = 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_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
[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_PRE_COPY] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
[VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
[VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING,
[VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING,
[VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
},
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = {
[VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
[VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
[VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
[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_PRE_COPY] = VFIO_DEVICE_STATE_ERROR,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_ERROR,
[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_PRE_COPY] = VFIO_DEVICE_STATE_STOP,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = 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_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
[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_PRE_COPY] = VFIO_DEVICE_STATE_ERROR,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = 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_PRE_COPY] =
VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_PRE_COPY,
[VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_MIGRATION_STOP_COPY |
VFIO_MIGRATION_P2P |
VFIO_MIGRATION_PRE_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_data_size(struct vfio_device *device,
u32 flags, void __user *arg,
size_t argsz)
{
struct vfio_device_feature_mig_data_size data_size = {};
unsigned long stop_copy_length;
int ret;
if (!device->mig_ops)
return -ENOTTY;
ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
sizeof(data_size));
if (ret != 1)
return ret;
ret = device->mig_ops->migration_get_data_size(device, &stop_copy_length);
if (ret)
return ret;
data_size.stop_copy_length = stop_copy_length;
if (copy_to_user(arg, &data_size, sizeof(data_size)))
return -EFAULT;
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);
case VFIO_DEVICE_FEATURE_MIG_DATA_SIZE:
return vfio_ioctl_device_feature_migration_data_size(
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);
}
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,
};
/*
* 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);
/*
* Pin contiguous user pages and return their associated host pages for local
* domain only.
* @device [in] : device
* @iova [in] : starting IOVA of user pages to be pinned.
* @npage [in] : count of pages to be pinned. This count should not
* be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
* @prot [in] : protection flags
* @pages[out] : array of host pages
* Return error or number of pages pinned.
*
* A driver may only call this function if the vfio_device was created
* by vfio_register_emulated_iommu_dev() due to vfio_device_container_pin_pages().
*/
int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
int npage, int prot, struct page **pages)
{
/* group->container cannot change while a vfio device is open */
if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device)))
return -EINVAL;
if (vfio_device_has_container(device))
return vfio_device_container_pin_pages(device, iova,
npage, prot, pages);
if (device->iommufd_access) {
int ret;
if (iova > ULONG_MAX)
return -EINVAL;
/*
* VFIO ignores the sub page offset, npages is from the start of
* a PAGE_SIZE chunk of IOVA. The caller is expected to recover
* the sub page offset by doing:
* pages[0] + (iova % PAGE_SIZE)
*/
ret = iommufd_access_pin_pages(
device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE),
npage * PAGE_SIZE, pages,
(prot & IOMMU_WRITE) ? IOMMUFD_ACCESS_RW_WRITE : 0);
if (ret)
return ret;
return npage;
}
return -EINVAL;
}
EXPORT_SYMBOL(vfio_pin_pages);
/*
* Unpin contiguous host pages for local domain only.
* @device [in] : device
* @iova [in] : starting address of user pages to be unpinned.
* @npage [in] : count of pages to be unpinned. This count should not
* be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
*/
void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage)
{
if (WARN_ON(!vfio_assert_device_open(device)))
return;
if (vfio_device_has_container(device)) {
vfio_device_container_unpin_pages(device, iova, npage);
return;
}
if (device->iommufd_access) {
if (WARN_ON(iova > ULONG_MAX))
return;
iommufd_access_unpin_pages(device->iommufd_access,
ALIGN_DOWN(iova, PAGE_SIZE),
npage * PAGE_SIZE);
return;
}
}
EXPORT_SYMBOL(vfio_unpin_pages);
/*
* This interface allows the CPUs to perform some sort of virtual DMA on
* behalf of the device.
*
* CPUs read/write from/into a range of IOVAs pointing to user space memory
* into/from a kernel buffer.
*
* As the read/write of user space memory is conducted via the CPUs and is
* not a real device DMA, it is not necessary to pin the user space memory.
*
* @device [in] : VFIO device
* @iova [in] : base IOVA of a user space buffer
* @data [in] : pointer to kernel buffer
* @len [in] : kernel buffer length
* @write : indicate read or write
* Return error code on failure or 0 on success.
*/
int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data,
size_t len, bool write)
{
if (!data || len <= 0 || !vfio_assert_device_open(device))
return -EINVAL;
if (vfio_device_has_container(device))
return vfio_device_container_dma_rw(device, iova,
data, len, write);
if (device->iommufd_access) {
unsigned int flags = 0;
if (iova > ULONG_MAX)
return -EINVAL;
/* VFIO historically tries to auto-detect a kthread */
if (!current->mm)
flags |= IOMMUFD_ACCESS_RW_KTHREAD;
if (write)
flags |= IOMMUFD_ACCESS_RW_WRITE;
return iommufd_access_rw(device->iommufd_access, iova, data,
len, flags);
}
return -EINVAL;
}
EXPORT_SYMBOL(vfio_dma_rw);
/*
* Module/class support
*/
static int __init vfio_init(void)
{
int ret;
ida_init(&vfio.device_ida);
ret = vfio_group_init();
if (ret)
return ret;
ret = vfio_virqfd_init();
if (ret)
goto err_virqfd;
/* /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;
}
pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
return 0;
err_dev_class:
vfio_virqfd_exit();
err_virqfd:
vfio_group_cleanup();
return ret;
}
static void __exit vfio_cleanup(void)
{
ida_destroy(&vfio.device_ida);
class_destroy(vfio.device_class);
vfio.device_class = NULL;
vfio_virqfd_exit();
vfio_group_cleanup();
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_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce");