drivers/vfio/vfio_main.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VFIO core
   4  *
   5  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
   6  *     Author: Alex Williamson <alex.williamson@redhat.com>
   7  *
   8  * Derived from original vfio:
   9  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
  10  * Author: Tom Lyon, pugs@cisco.com
  11  */
  12
  13 #include <linux/cdev.h>
  14 #include <linux/compat.h>
  15 #include <linux/device.h>
  16 #include <linux/fs.h>
  17 #include <linux/idr.h>
  18 #include <linux/iommu.h>
  19 #include <linux/list.h>
  20 #include <linux/miscdevice.h>
  21 #include <linux/module.h>
  22 #include <linux/mutex.h>
  23 #include <linux/pci.h>
  24 #include <linux/rwsem.h>
  25 #include <linux/sched.h>
  26 #include <linux/slab.h>
  27 #include <linux/stat.h>
  28 #include <linux/string.h>
  29 #include <linux/uaccess.h>
  30 #include <linux/vfio.h>
  31 #include <linux/wait.h>
  32 #include <linux/sched/signal.h>
  33 #include <linux/pm_runtime.h>
  34 #include <linux/interval_tree.h>
  35 #include <linux/iova_bitmap.h>
  36 #include <linux/iommufd.h>
  37 #include "vfio.h"
  38
  39 #define DRIVER_VERSION  "0.3"
  40 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
  41 #define DRIVER_DESC     "VFIO - User Level meta-driver"
  42
  43 static struct vfio {
  44         struct class                    *device_class;
  45         struct ida                      device_ida;
  46 } vfio;
  47
  48 static DEFINE_XARRAY(vfio_device_set_xa);
  49
  50 int vfio_assign_device_set(struct vfio_device *device, void *set_id)
  51 {
  52         unsigned long idx = (unsigned long)set_id;
  53         struct vfio_device_set *new_dev_set;
  54         struct vfio_device_set *dev_set;
  55
  56         if (WARN_ON(!set_id))
  57                 return -EINVAL;
  58
  59         /*
  60          * Atomically acquire a singleton object in the xarray for this set_id
  61          */
  62         xa_lock(&vfio_device_set_xa);
  63         dev_set = xa_load(&vfio_device_set_xa, idx);
  64         if (dev_set)
  65                 goto found_get_ref;
  66         xa_unlock(&vfio_device_set_xa);
  67
  68         new_dev_set = kzalloc(sizeof(*new_dev_set), GFP_KERNEL);
  69         if (!new_dev_set)
  70                 return -ENOMEM;
  71         mutex_init(&new_dev_set->lock);
  72         INIT_LIST_HEAD(&new_dev_set->device_list);
  73         new_dev_set->set_id = set_id;
  74
  75         xa_lock(&vfio_device_set_xa);
  76         dev_set = __xa_cmpxchg(&vfio_device_set_xa, idx, NULL, new_dev_set,
  77                                GFP_KERNEL);
  78         if (!dev_set) {
  79                 dev_set = new_dev_set;
  80                 goto found_get_ref;
  81         }
  82
  83         kfree(new_dev_set);
  84         if (xa_is_err(dev_set)) {
  85                 xa_unlock(&vfio_device_set_xa);
  86                 return xa_err(dev_set);
  87         }
  88
  89 found_get_ref:
  90         dev_set->device_count++;
  91         xa_unlock(&vfio_device_set_xa);
  92         mutex_lock(&dev_set->lock);
  93         device->dev_set = dev_set;
  94         list_add_tail(&device->dev_set_list, &dev_set->device_list);
  95         mutex_unlock(&dev_set->lock);
  96         return 0;
  97 }
  98 EXPORT_SYMBOL_GPL(vfio_assign_device_set);
  99
 100 static void vfio_release_device_set(struct vfio_device *device)
 101 {
 102         struct vfio_device_set *dev_set = device->dev_set;
 103
 104         if (!dev_set)
 105                 return;
 106
 107         mutex_lock(&dev_set->lock);
 108         list_del(&device->dev_set_list);
 109         mutex_unlock(&dev_set->lock);
 110
 111         xa_lock(&vfio_device_set_xa);
 112         if (!--dev_set->device_count) {
 113                 __xa_erase(&vfio_device_set_xa,
 114                            (unsigned long)dev_set->set_id);
 115                 mutex_destroy(&dev_set->lock);
 116                 kfree(dev_set);
 117         }
 118         xa_unlock(&vfio_device_set_xa);
 119 }
 120
 121 unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set)
 122 {
 123         struct vfio_device *cur;
 124         unsigned int open_count = 0;
 125
 126         lockdep_assert_held(&dev_set->lock);
 127
 128         list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
 129                 open_count += cur->open_count;
 130         return open_count;
 131 }
 132 EXPORT_SYMBOL_GPL(vfio_device_set_open_count);
 133
 134 /*
 135  * Device objects - create, release, get, put, search
 136  */
 137 /* Device reference always implies a group reference */
 138 void vfio_device_put_registration(struct vfio_device *device)
 139 {
 140         if (refcount_dec_and_test(&device->refcount))
 141                 complete(&device->comp);
 142 }
 143
 144 bool vfio_device_try_get_registration(struct vfio_device *device)
 145 {
 146         return refcount_inc_not_zero(&device->refcount);
 147 }
 148
 149 /*
 150  * VFIO driver API
 151  */
 152 /* Release helper called by vfio_put_device() */
 153 static void vfio_device_release(struct device *dev)
 154 {
 155         struct vfio_device *device =
 156                         container_of(dev, struct vfio_device, device);
 157
 158         vfio_release_device_set(device);
 159         ida_free(&vfio.device_ida, device->index);
 160
 161         if (device->ops->release)
 162                 device->ops->release(device);
 163
 164         kvfree(device);
 165 }
 166
 167 static int vfio_init_device(struct vfio_device *device, struct device *dev,
 168                             const struct vfio_device_ops *ops);
 169
 170 /*
 171  * Allocate and initialize vfio_device so it can be registered to vfio
 172  * core.
 173  *
 174  * Drivers should use the wrapper vfio_alloc_device() for allocation.
 175  * @size is the size of the structure to be allocated, including any
 176  * private data used by the driver.
 177  *
 178  * Driver may provide an @init callback to cover device private data.
 179  *
 180  * Use vfio_put_device() to release the structure after success return.
 181  */
 182 struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
 183                                        const struct vfio_device_ops *ops)
 184 {
 185         struct vfio_device *device;
 186         int ret;
 187
 188         if (WARN_ON(size < sizeof(struct vfio_device)))
 189                 return ERR_PTR(-EINVAL);
 190
 191         device = kvzalloc(size, GFP_KERNEL);
 192         if (!device)
 193                 return ERR_PTR(-ENOMEM);
 194
 195         ret = vfio_init_device(device, dev, ops);
 196         if (ret)
 197                 goto out_free;
 198         return device;
 199
 200 out_free:
 201         kvfree(device);
 202         return ERR_PTR(ret);
 203 }
 204 EXPORT_SYMBOL_GPL(_vfio_alloc_device);
 205
 206 /*
 207  * Initialize a vfio_device so it can be registered to vfio core.
 208  */
 209 static int vfio_init_device(struct vfio_device *device, struct device *dev,
 210                             const struct vfio_device_ops *ops)
 211 {
 212         int ret;
 213
 214         ret = ida_alloc_max(&vfio.device_ida, MINORMASK, GFP_KERNEL);
 215         if (ret < 0) {
 216                 dev_dbg(dev, "Error to alloc index\n");
 217                 return ret;
 218         }
 219
 220         device->index = ret;
 221         init_completion(&device->comp);
 222         device->dev = dev;
 223         device->ops = ops;
 224
 225         if (ops->init) {
 226                 ret = ops->init(device);
 227                 if (ret)
 228                         goto out_uninit;
 229         }
 230
 231         device_initialize(&device->device);
 232         device->device.release = vfio_device_release;
 233         device->device.class = vfio.device_class;
 234         device->device.parent = device->dev;
 235         return 0;
 236
 237 out_uninit:
 238         vfio_release_device_set(device);
 239         ida_free(&vfio.device_ida, device->index);
 240         return ret;
 241 }
 242
 243 static int __vfio_register_dev(struct vfio_device *device,
 244                                enum vfio_group_type type)
 245 {
 246         int ret;
 247
 248         if (WARN_ON(device->ops->bind_iommufd &&
 249                     (!device->ops->unbind_iommufd ||
 250                      !device->ops->attach_ioas)))
 251                 return -EINVAL;
 252
 253         /*
 254          * If the driver doesn't specify a set then the device is added to a
 255          * singleton set just for itself.
 256          */
 257         if (!device->dev_set)
 258                 vfio_assign_device_set(device, device);
 259
 260         ret = dev_set_name(&device->device, "vfio%d", device->index);
 261         if (ret)
 262                 return ret;
 263
 264         ret = vfio_device_set_group(device, type);
 265         if (ret)
 266                 return ret;
 267
 268         ret = device_add(&device->device);
 269         if (ret)
 270                 goto err_out;
 271
 272         /* Refcounting can't start until the driver calls register */
 273         refcount_set(&device->refcount, 1);
 274
 275         vfio_device_group_register(device);
 276
 277         return 0;
 278 err_out:
 279         vfio_device_remove_group(device);
 280         return ret;
 281 }
 282
 283 int vfio_register_group_dev(struct vfio_device *device)
 284 {
 285         return __vfio_register_dev(device, VFIO_IOMMU);
 286 }
 287 EXPORT_SYMBOL_GPL(vfio_register_group_dev);
 288
 289 /*
 290  * Register a virtual device without IOMMU backing.  The user of this
 291  * device must not be able to directly trigger unmediated DMA.
 292  */
 293 int vfio_register_emulated_iommu_dev(struct vfio_device *device)
 294 {
 295         return __vfio_register_dev(device, VFIO_EMULATED_IOMMU);
 296 }
 297 EXPORT_SYMBOL_GPL(vfio_register_emulated_iommu_dev);
 298
 299 /*
 300  * Decrement the device reference count and wait for the device to be
 301  * removed.  Open file descriptors for the device... */
 302 void vfio_unregister_group_dev(struct vfio_device *device)
 303 {
 304         unsigned int i = 0;
 305         bool interrupted = false;
 306         long rc;
 307
 308         vfio_device_put_registration(device);
 309         rc = try_wait_for_completion(&device->comp);
 310         while (rc <= 0) {
 311                 if (device->ops->request)
 312                         device->ops->request(device, i++);
 313
 314                 if (interrupted) {
 315                         rc = wait_for_completion_timeout(&device->comp,
 316                                                          HZ * 10);
 317                 } else {
 318                         rc = wait_for_completion_interruptible_timeout(
 319                                 &device->comp, HZ * 10);
 320                         if (rc < 0) {
 321                                 interrupted = true;
 322                                 dev_warn(device->dev,
 323                                          "Device is currently in use, task"
 324                                          " \"%s\" (%d) "
 325                                          "blocked until device is released",
 326                                          current->comm, task_pid_nr(current));
 327                         }
 328                 }
 329         }
 330
 331         vfio_device_group_unregister(device);
 332
 333         /* Balances device_add in register path */
 334         device_del(&device->device);
 335
 336         /* Balances vfio_device_set_group in register path */
 337         vfio_device_remove_group(device);
 338 }
 339 EXPORT_SYMBOL_GPL(vfio_unregister_group_dev);
 340
 341 /* true if the vfio_device has open_device() called but not close_device() */
 342 static bool vfio_assert_device_open(struct vfio_device *device)
 343 {
 344         return !WARN_ON_ONCE(!READ_ONCE(device->open_count));
 345 }
 346
 347 static int vfio_device_first_open(struct vfio_device *device,
 348                                   struct iommufd_ctx *iommufd, struct kvm *kvm)
 349 {
 350         int ret;
 351
 352         lockdep_assert_held(&device->dev_set->lock);
 353
 354         if (!try_module_get(device->dev->driver->owner))
 355                 return -ENODEV;
 356
 357         if (iommufd)
 358                 ret = vfio_iommufd_bind(device, iommufd);
 359         else
 360                 ret = vfio_device_group_use_iommu(device);
 361         if (ret)
 362                 goto err_module_put;
 363
 364         device->kvm = kvm;
 365         if (device->ops->open_device) {
 366                 ret = device->ops->open_device(device);
 367                 if (ret)
 368                         goto err_unuse_iommu;
 369         }
 370         return 0;
 371
 372 err_unuse_iommu:
 373         device->kvm = NULL;
 374         if (iommufd)
 375                 vfio_iommufd_unbind(device);
 376         else
 377                 vfio_device_group_unuse_iommu(device);
 378 err_module_put:
 379         module_put(device->dev->driver->owner);
 380         return ret;
 381 }
 382
 383 static void vfio_device_last_close(struct vfio_device *device,
 384                                    struct iommufd_ctx *iommufd)
 385 {
 386         lockdep_assert_held(&device->dev_set->lock);
 387
 388         if (device->ops->close_device)
 389                 device->ops->close_device(device);
 390         device->kvm = NULL;
 391         if (iommufd)
 392                 vfio_iommufd_unbind(device);
 393         else
 394                 vfio_device_group_unuse_iommu(device);
 395         module_put(device->dev->driver->owner);
 396 }
 397
 398 int vfio_device_open(struct vfio_device *device,
 399                      struct iommufd_ctx *iommufd, struct kvm *kvm)
 400 {
 401         int ret = 0;
 402
 403         mutex_lock(&device->dev_set->lock);
 404         device->open_count++;
 405         if (device->open_count == 1) {
 406                 ret = vfio_device_first_open(device, iommufd, kvm);
 407                 if (ret)
 408                         device->open_count--;
 409         }
 410         mutex_unlock(&device->dev_set->lock);
 411
 412         return ret;
 413 }
 414
 415 void vfio_device_close(struct vfio_device *device,
 416                        struct iommufd_ctx *iommufd)
 417 {
 418         mutex_lock(&device->dev_set->lock);
 419         vfio_assert_device_open(device);
 420         if (device->open_count == 1)
 421                 vfio_device_last_close(device, iommufd);
 422         device->open_count--;
 423         mutex_unlock(&device->dev_set->lock);
 424 }
 425
 426 /*
 427  * Wrapper around pm_runtime_resume_and_get().
 428  * Return error code on failure or 0 on success.
 429  */
 430 static inline int vfio_device_pm_runtime_get(struct vfio_device *device)
 431 {
 432         struct device *dev = device->dev;
 433
 434         if (dev->driver && dev->driver->pm) {
 435                 int ret;
 436
 437                 ret = pm_runtime_resume_and_get(dev);
 438                 if (ret) {
 439                         dev_info_ratelimited(dev,
 440                                 "vfio: runtime resume failed %d\n", ret);
 441                         return -EIO;
 442                 }
 443         }
 444
 445         return 0;
 446 }
 447
 448 /*
 449  * Wrapper around pm_runtime_put().
 450  */
 451 static inline void vfio_device_pm_runtime_put(struct vfio_device *device)
 452 {
 453         struct device *dev = device->dev;
 454
 455         if (dev->driver && dev->driver->pm)
 456                 pm_runtime_put(dev);
 457 }
 458
 459 /*
 460  * VFIO Device fd
 461  */
 462 static int vfio_device_fops_release(struct inode *inode, struct file *filep)
 463 {
 464         struct vfio_device *device = filep->private_data;
 465
 466         vfio_device_group_close(device);
 467
 468         vfio_device_put_registration(device);
 469
 470         return 0;
 471 }
 472
 473 /*
 474  * vfio_mig_get_next_state - Compute the next step in the FSM
 475  * @cur_fsm - The current state the device is in
 476  * @new_fsm - The target state to reach
 477  * @next_fsm - Pointer to the next step to get to new_fsm
 478  *
 479  * Return 0 upon success, otherwise -errno
 480  * Upon success the next step in the state progression between cur_fsm and
 481  * new_fsm will be set in next_fsm.
 482  *
 483  * This breaks down requests for combination transitions into smaller steps and
 484  * returns the next step to get to new_fsm. The function may need to be called
 485  * multiple times before reaching new_fsm.
 486  *
 487  */
 488 int vfio_mig_get_next_state(struct vfio_device *device,
 489                             enum vfio_device_mig_state cur_fsm,
 490                             enum vfio_device_mig_state new_fsm,
 491                             enum vfio_device_mig_state *next_fsm)
 492 {
 493         enum { VFIO_DEVICE_NUM_STATES = VFIO_DEVICE_STATE_PRE_COPY_P2P + 1 };
 494         /*
 495          * The coding in this table requires the driver to implement the
 496          * following FSM arcs:
 497          *         RESUMING -> STOP
 498          *         STOP -> RESUMING
 499          *         STOP -> STOP_COPY
 500          *         STOP_COPY -> STOP
 501          *
 502          * If P2P is supported then the driver must also implement these FSM
 503          * arcs:
 504          *         RUNNING -> RUNNING_P2P
 505          *         RUNNING_P2P -> RUNNING
 506          *         RUNNING_P2P -> STOP
 507          *         STOP -> RUNNING_P2P
 508          *
 509          * If precopy is supported then the driver must support these additional
 510          * FSM arcs:
 511          *         RUNNING -> PRE_COPY
 512          *         PRE_COPY -> RUNNING
 513          *         PRE_COPY -> STOP_COPY
 514          * However, if precopy and P2P are supported together then the driver
 515          * must support these additional arcs beyond the P2P arcs above:
 516          *         PRE_COPY -> RUNNING
 517          *         PRE_COPY -> PRE_COPY_P2P
 518          *         PRE_COPY_P2P -> PRE_COPY
 519          *         PRE_COPY_P2P -> RUNNING_P2P
 520          *         PRE_COPY_P2P -> STOP_COPY
 521          *         RUNNING -> PRE_COPY
 522          *         RUNNING_P2P -> PRE_COPY_P2P
 523          *
 524          * Without P2P and precopy the driver must implement:
 525          *         RUNNING -> STOP
 526          *         STOP -> RUNNING
 527          *
 528          * The coding will step through multiple states for some combination
 529          * transitions; if all optional features are supported, this means the
 530          * following ones:
 531          *         PRE_COPY -> PRE_COPY_P2P -> STOP_COPY
 532          *         PRE_COPY -> RUNNING -> RUNNING_P2P
 533          *         PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP
 534          *         PRE_COPY -> RUNNING -> RUNNING_P2P -> STOP -> RESUMING
 535          *         PRE_COPY_P2P -> RUNNING_P2P -> RUNNING
 536          *         PRE_COPY_P2P -> RUNNING_P2P -> STOP
 537          *         PRE_COPY_P2P -> RUNNING_P2P -> STOP -> RESUMING
 538          *         RESUMING -> STOP -> RUNNING_P2P
 539          *         RESUMING -> STOP -> RUNNING_P2P -> PRE_COPY_P2P
 540          *         RESUMING -> STOP -> RUNNING_P2P -> RUNNING
 541          *         RESUMING -> STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY
 542          *         RESUMING -> STOP -> STOP_COPY
 543          *         RUNNING -> RUNNING_P2P -> PRE_COPY_P2P
 544          *         RUNNING -> RUNNING_P2P -> STOP
 545          *         RUNNING -> RUNNING_P2P -> STOP -> RESUMING
 546          *         RUNNING -> RUNNING_P2P -> STOP -> STOP_COPY
 547          *         RUNNING_P2P -> RUNNING -> PRE_COPY
 548          *         RUNNING_P2P -> STOP -> RESUMING
 549          *         RUNNING_P2P -> STOP -> STOP_COPY
 550          *         STOP -> RUNNING_P2P -> PRE_COPY_P2P
 551          *         STOP -> RUNNING_P2P -> RUNNING
 552          *         STOP -> RUNNING_P2P -> RUNNING -> PRE_COPY
 553          *         STOP_COPY -> STOP -> RESUMING
 554          *         STOP_COPY -> STOP -> RUNNING_P2P
 555          *         STOP_COPY -> STOP -> RUNNING_P2P -> RUNNING
 556          *
 557          *  The following transitions are blocked:
 558          *         STOP_COPY -> PRE_COPY
 559          *         STOP_COPY -> PRE_COPY_P2P
 560          */
 561         static const u8 vfio_from_fsm_table[VFIO_DEVICE_NUM_STATES][VFIO_DEVICE_NUM_STATES] = {
 562                 [VFIO_DEVICE_STATE_STOP] = {
 563                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
 564                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
 565                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
 566                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
 567                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
 568                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
 569                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
 570                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 571                 },
 572                 [VFIO_DEVICE_STATE_RUNNING] = {
 573                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
 574                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
 575                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
 576                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
 577                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_RUNNING_P2P,
 578                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P,
 579                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
 580                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 581                 },
 582                 [VFIO_DEVICE_STATE_PRE_COPY] = {
 583                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING,
 584                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
 585                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
 586                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
 587                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
 588                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING,
 589                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING,
 590                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 591                 },
 592                 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = {
 593                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_RUNNING_P2P,
 594                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING_P2P,
 595                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_PRE_COPY,
 596                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
 597                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
 598                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RUNNING_P2P,
 599                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
 600                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 601                 },
 602                 [VFIO_DEVICE_STATE_STOP_COPY] = {
 603                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
 604                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
 605                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_ERROR,
 606                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_ERROR,
 607                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP_COPY,
 608                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
 609                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
 610                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 611                 },
 612                 [VFIO_DEVICE_STATE_RESUMING] = {
 613                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
 614                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_STOP,
 615                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_STOP,
 616                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_STOP,
 617                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
 618                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_RESUMING,
 619                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_STOP,
 620                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 621                 },
 622                 [VFIO_DEVICE_STATE_RUNNING_P2P] = {
 623                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_STOP,
 624                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_RUNNING,
 625                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_RUNNING,
 626                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_PRE_COPY_P2P,
 627                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_STOP,
 628                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_STOP,
 629                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_RUNNING_P2P,
 630                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 631                 },
 632                 [VFIO_DEVICE_STATE_ERROR] = {
 633                         [VFIO_DEVICE_STATE_STOP] = VFIO_DEVICE_STATE_ERROR,
 634                         [VFIO_DEVICE_STATE_RUNNING] = VFIO_DEVICE_STATE_ERROR,
 635                         [VFIO_DEVICE_STATE_PRE_COPY] = VFIO_DEVICE_STATE_ERROR,
 636                         [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_DEVICE_STATE_ERROR,
 637                         [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_DEVICE_STATE_ERROR,
 638                         [VFIO_DEVICE_STATE_RESUMING] = VFIO_DEVICE_STATE_ERROR,
 639                         [VFIO_DEVICE_STATE_RUNNING_P2P] = VFIO_DEVICE_STATE_ERROR,
 640                         [VFIO_DEVICE_STATE_ERROR] = VFIO_DEVICE_STATE_ERROR,
 641                 },
 642         };
 643
 644         static const unsigned int state_flags_table[VFIO_DEVICE_NUM_STATES] = {
 645                 [VFIO_DEVICE_STATE_STOP] = VFIO_MIGRATION_STOP_COPY,
 646                 [VFIO_DEVICE_STATE_RUNNING] = VFIO_MIGRATION_STOP_COPY,
 647                 [VFIO_DEVICE_STATE_PRE_COPY] =
 648                         VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_PRE_COPY,
 649                 [VFIO_DEVICE_STATE_PRE_COPY_P2P] = VFIO_MIGRATION_STOP_COPY |
 650                                                    VFIO_MIGRATION_P2P |
 651                                                    VFIO_MIGRATION_PRE_COPY,
 652                 [VFIO_DEVICE_STATE_STOP_COPY] = VFIO_MIGRATION_STOP_COPY,
 653                 [VFIO_DEVICE_STATE_RESUMING] = VFIO_MIGRATION_STOP_COPY,
 654                 [VFIO_DEVICE_STATE_RUNNING_P2P] =
 655                         VFIO_MIGRATION_STOP_COPY | VFIO_MIGRATION_P2P,
 656                 [VFIO_DEVICE_STATE_ERROR] = ~0U,
 657         };
 658
 659         if (WARN_ON(cur_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
 660                     (state_flags_table[cur_fsm] & device->migration_flags) !=
 661                         state_flags_table[cur_fsm]))
 662                 return -EINVAL;
 663
 664         if (new_fsm >= ARRAY_SIZE(vfio_from_fsm_table) ||
 665            (state_flags_table[new_fsm] & device->migration_flags) !=
 666                         state_flags_table[new_fsm])
 667                 return -EINVAL;
 668
 669         /*
 670          * Arcs touching optional and unsupported states are skipped over. The
 671          * driver will instead see an arc from the original state to the next
 672          * logical state, as per the above comment.
 673          */
 674         *next_fsm = vfio_from_fsm_table[cur_fsm][new_fsm];
 675         while ((state_flags_table[*next_fsm] & device->migration_flags) !=
 676                         state_flags_table[*next_fsm])
 677                 *next_fsm = vfio_from_fsm_table[*next_fsm][new_fsm];
 678
 679         return (*next_fsm != VFIO_DEVICE_STATE_ERROR) ? 0 : -EINVAL;
 680 }
 681 EXPORT_SYMBOL_GPL(vfio_mig_get_next_state);
 682
 683 /*
 684  * Convert the drivers's struct file into a FD number and return it to userspace
 685  */
 686 static int vfio_ioct_mig_return_fd(struct file *filp, void __user *arg,
 687                                    struct vfio_device_feature_mig_state *mig)
 688 {
 689         int ret;
 690         int fd;
 691
 692         fd = get_unused_fd_flags(O_CLOEXEC);
 693         if (fd < 0) {
 694                 ret = fd;
 695                 goto out_fput;
 696         }
 697
 698         mig->data_fd = fd;
 699         if (copy_to_user(arg, mig, sizeof(*mig))) {
 700                 ret = -EFAULT;
 701                 goto out_put_unused;
 702         }
 703         fd_install(fd, filp);
 704         return 0;
 705
 706 out_put_unused:
 707         put_unused_fd(fd);
 708 out_fput:
 709         fput(filp);
 710         return ret;
 711 }
 712
 713 static int
 714 vfio_ioctl_device_feature_mig_device_state(struct vfio_device *device,
 715                                            u32 flags, void __user *arg,
 716                                            size_t argsz)
 717 {
 718         size_t minsz =
 719                 offsetofend(struct vfio_device_feature_mig_state, data_fd);
 720         struct vfio_device_feature_mig_state mig;
 721         struct file *filp = NULL;
 722         int ret;
 723
 724         if (!device->mig_ops)
 725                 return -ENOTTY;
 726
 727         ret = vfio_check_feature(flags, argsz,
 728                                  VFIO_DEVICE_FEATURE_SET |
 729                                  VFIO_DEVICE_FEATURE_GET,
 730                                  sizeof(mig));
 731         if (ret != 1)
 732                 return ret;
 733
 734         if (copy_from_user(&mig, arg, minsz))
 735                 return -EFAULT;
 736
 737         if (flags & VFIO_DEVICE_FEATURE_GET) {
 738                 enum vfio_device_mig_state curr_state;
 739
 740                 ret = device->mig_ops->migration_get_state(device,
 741                                                            &curr_state);
 742                 if (ret)
 743                         return ret;
 744                 mig.device_state = curr_state;
 745                 goto out_copy;
 746         }
 747
 748         /* Handle the VFIO_DEVICE_FEATURE_SET */
 749         filp = device->mig_ops->migration_set_state(device, mig.device_state);
 750         if (IS_ERR(filp) || !filp)
 751                 goto out_copy;
 752
 753         return vfio_ioct_mig_return_fd(filp, arg, &mig);
 754 out_copy:
 755         mig.data_fd = -1;
 756         if (copy_to_user(arg, &mig, sizeof(mig)))
 757                 return -EFAULT;
 758         if (IS_ERR(filp))
 759                 return PTR_ERR(filp);
 760         return 0;
 761 }
 762
 763 static int
 764 vfio_ioctl_device_feature_migration_data_size(struct vfio_device *device,
 765                                               u32 flags, void __user *arg,
 766                                               size_t argsz)
 767 {
 768         struct vfio_device_feature_mig_data_size data_size = {};
 769         unsigned long stop_copy_length;
 770         int ret;
 771
 772         if (!device->mig_ops)
 773                 return -ENOTTY;
 774
 775         ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
 776                                  sizeof(data_size));
 777         if (ret != 1)
 778                 return ret;
 779
 780         ret = device->mig_ops->migration_get_data_size(device, &stop_copy_length);
 781         if (ret)
 782                 return ret;
 783
 784         data_size.stop_copy_length = stop_copy_length;
 785         if (copy_to_user(arg, &data_size, sizeof(data_size)))
 786                 return -EFAULT;
 787
 788         return 0;
 789 }
 790
 791 static int vfio_ioctl_device_feature_migration(struct vfio_device *device,
 792                                                u32 flags, void __user *arg,
 793                                                size_t argsz)
 794 {
 795         struct vfio_device_feature_migration mig = {
 796                 .flags = device->migration_flags,
 797         };
 798         int ret;
 799
 800         if (!device->mig_ops)
 801                 return -ENOTTY;
 802
 803         ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_GET,
 804                                  sizeof(mig));
 805         if (ret != 1)
 806                 return ret;
 807         if (copy_to_user(arg, &mig, sizeof(mig)))
 808                 return -EFAULT;
 809         return 0;
 810 }
 811
 812 /* Ranges should fit into a single kernel page */
 813 #define LOG_MAX_RANGES \
 814         (PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range))
 815
 816 static int
 817 vfio_ioctl_device_feature_logging_start(struct vfio_device *device,
 818                                         u32 flags, void __user *arg,
 819                                         size_t argsz)
 820 {
 821         size_t minsz =
 822                 offsetofend(struct vfio_device_feature_dma_logging_control,
 823                             ranges);
 824         struct vfio_device_feature_dma_logging_range __user *ranges;
 825         struct vfio_device_feature_dma_logging_control control;
 826         struct vfio_device_feature_dma_logging_range range;
 827         struct rb_root_cached root = RB_ROOT_CACHED;
 828         struct interval_tree_node *nodes;
 829         u64 iova_end;
 830         u32 nnodes;
 831         int i, ret;
 832
 833         if (!device->log_ops)
 834                 return -ENOTTY;
 835
 836         ret = vfio_check_feature(flags, argsz,
 837                                  VFIO_DEVICE_FEATURE_SET,
 838                                  sizeof(control));
 839         if (ret != 1)
 840                 return ret;
 841
 842         if (copy_from_user(&control, arg, minsz))
 843                 return -EFAULT;
 844
 845         nnodes = control.num_ranges;
 846         if (!nnodes)
 847                 return -EINVAL;
 848
 849         if (nnodes > LOG_MAX_RANGES)
 850                 return -E2BIG;
 851
 852         ranges = u64_to_user_ptr(control.ranges);
 853         nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
 854                               GFP_KERNEL);
 855         if (!nodes)
 856                 return -ENOMEM;
 857
 858         for (i = 0; i < nnodes; i++) {
 859                 if (copy_from_user(&range, &ranges[i], sizeof(range))) {
 860                         ret = -EFAULT;
 861                         goto end;
 862                 }
 863                 if (!IS_ALIGNED(range.iova, control.page_size) ||
 864                     !IS_ALIGNED(range.length, control.page_size)) {
 865                         ret = -EINVAL;
 866                         goto end;
 867                 }
 868
 869                 if (check_add_overflow(range.iova, range.length, &iova_end) ||
 870                     iova_end > ULONG_MAX) {
 871                         ret = -EOVERFLOW;
 872                         goto end;
 873                 }
 874
 875                 nodes[i].start = range.iova;
 876                 nodes[i].last = range.iova + range.length - 1;
 877                 if (interval_tree_iter_first(&root, nodes[i].start,
 878                                              nodes[i].last)) {
 879                         /* Range overlapping */
 880                         ret = -EINVAL;
 881                         goto end;
 882                 }
 883                 interval_tree_insert(nodes + i, &root);
 884         }
 885
 886         ret = device->log_ops->log_start(device, &root, nnodes,
 887                                          &control.page_size);
 888         if (ret)
 889                 goto end;
 890
 891         if (copy_to_user(arg, &control, sizeof(control))) {
 892                 ret = -EFAULT;
 893                 device->log_ops->log_stop(device);
 894         }
 895
 896 end:
 897         kfree(nodes);
 898         return ret;
 899 }
 900
 901 static int
 902 vfio_ioctl_device_feature_logging_stop(struct vfio_device *device,
 903                                        u32 flags, void __user *arg,
 904                                        size_t argsz)
 905 {
 906         int ret;
 907
 908         if (!device->log_ops)
 909                 return -ENOTTY;
 910
 911         ret = vfio_check_feature(flags, argsz,
 912                                  VFIO_DEVICE_FEATURE_SET, 0);
 913         if (ret != 1)
 914                 return ret;
 915
 916         return device->log_ops->log_stop(device);
 917 }
 918
 919 static int vfio_device_log_read_and_clear(struct iova_bitmap *iter,
 920                                           unsigned long iova, size_t length,
 921                                           void *opaque)
 922 {
 923         struct vfio_device *device = opaque;
 924
 925         return device->log_ops->log_read_and_clear(device, iova, length, iter);
 926 }
 927
 928 static int
 929 vfio_ioctl_device_feature_logging_report(struct vfio_device *device,
 930                                          u32 flags, void __user *arg,
 931                                          size_t argsz)
 932 {
 933         size_t minsz =
 934                 offsetofend(struct vfio_device_feature_dma_logging_report,
 935                             bitmap);
 936         struct vfio_device_feature_dma_logging_report report;
 937         struct iova_bitmap *iter;
 938         u64 iova_end;
 939         int ret;
 940
 941         if (!device->log_ops)
 942                 return -ENOTTY;
 943
 944         ret = vfio_check_feature(flags, argsz,
 945                                  VFIO_DEVICE_FEATURE_GET,
 946                                  sizeof(report));
 947         if (ret != 1)
 948                 return ret;
 949
 950         if (copy_from_user(&report, arg, minsz))
 951                 return -EFAULT;
 952
 953         if (report.page_size < SZ_4K || !is_power_of_2(report.page_size))
 954                 return -EINVAL;
 955
 956         if (check_add_overflow(report.iova, report.length, &iova_end) ||
 957             iova_end > ULONG_MAX)
 958                 return -EOVERFLOW;
 959
 960         iter = iova_bitmap_alloc(report.iova, report.length,
 961                                  report.page_size,
 962                                  u64_to_user_ptr(report.bitmap));
 963         if (IS_ERR(iter))
 964                 return PTR_ERR(iter);
 965
 966         ret = iova_bitmap_for_each(iter, device,
 967                                    vfio_device_log_read_and_clear);
 968
 969         iova_bitmap_free(iter);
 970         return ret;
 971 }
 972
 973 static int vfio_ioctl_device_feature(struct vfio_device *device,
 974                                      struct vfio_device_feature __user *arg)
 975 {
 976         size_t minsz = offsetofend(struct vfio_device_feature, flags);
 977         struct vfio_device_feature feature;
 978
 979         if (copy_from_user(&feature, arg, minsz))
 980                 return -EFAULT;
 981
 982         if (feature.argsz < minsz)
 983                 return -EINVAL;
 984
 985         /* Check unknown flags */
 986         if (feature.flags &
 987             ~(VFIO_DEVICE_FEATURE_MASK | VFIO_DEVICE_FEATURE_SET |
 988               VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_PROBE))
 989                 return -EINVAL;
 990
 991         /* GET & SET are mutually exclusive except with PROBE */
 992         if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
 993             (feature.flags & VFIO_DEVICE_FEATURE_SET) &&
 994             (feature.flags & VFIO_DEVICE_FEATURE_GET))
 995                 return -EINVAL;
 996
 997         switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
 998         case VFIO_DEVICE_FEATURE_MIGRATION:
 999                 return vfio_ioctl_device_feature_migration(
1000                         device, feature.flags, arg->data,
1001                         feature.argsz - minsz);
1002         case VFIO_DEVICE_FEATURE_MIG_DEVICE_STATE:
1003                 return vfio_ioctl_device_feature_mig_device_state(
1004                         device, feature.flags, arg->data,
1005                         feature.argsz - minsz);
1006         case VFIO_DEVICE_FEATURE_DMA_LOGGING_START:
1007                 return vfio_ioctl_device_feature_logging_start(
1008                         device, feature.flags, arg->data,
1009                         feature.argsz - minsz);
1010         case VFIO_DEVICE_FEATURE_DMA_LOGGING_STOP:
1011                 return vfio_ioctl_device_feature_logging_stop(
1012                         device, feature.flags, arg->data,
1013                         feature.argsz - minsz);
1014         case VFIO_DEVICE_FEATURE_DMA_LOGGING_REPORT:
1015                 return vfio_ioctl_device_feature_logging_report(
1016                         device, feature.flags, arg->data,
1017                         feature.argsz - minsz);
1018         case VFIO_DEVICE_FEATURE_MIG_DATA_SIZE:
1019                 return vfio_ioctl_device_feature_migration_data_size(
1020                         device, feature.flags, arg->data,
1021                         feature.argsz - minsz);
1022         default:
1023                 if (unlikely(!device->ops->device_feature))
1024                         return -EINVAL;
1025                 return device->ops->device_feature(device, feature.flags,
1026                                                    arg->data,
1027                                                    feature.argsz - minsz);
1028         }
1029 }
1030
1031 static long vfio_device_fops_unl_ioctl(struct file *filep,
1032                                        unsigned int cmd, unsigned long arg)
1033 {
1034         struct vfio_device *device = filep->private_data;
1035         int ret;
1036
1037         ret = vfio_device_pm_runtime_get(device);
1038         if (ret)
1039                 return ret;
1040
1041         switch (cmd) {
1042         case VFIO_DEVICE_FEATURE:
1043                 ret = vfio_ioctl_device_feature(device, (void __user *)arg);
1044                 break;
1045
1046         default:
1047                 if (unlikely(!device->ops->ioctl))
1048                         ret = -EINVAL;
1049                 else
1050                         ret = device->ops->ioctl(device, cmd, arg);
1051                 break;
1052         }
1053
1054         vfio_device_pm_runtime_put(device);
1055         return ret;
1056 }
1057
1058 static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,
1059                                      size_t count, loff_t *ppos)
1060 {
1061         struct vfio_device *device = filep->private_data;
1062
1063         if (unlikely(!device->ops->read))
1064                 return -EINVAL;
1065
1066         return device->ops->read(device, buf, count, ppos);
1067 }
1068
1069 static ssize_t vfio_device_fops_write(struct file *filep,
1070                                       const char __user *buf,
1071                                       size_t count, loff_t *ppos)
1072 {
1073         struct vfio_device *device = filep->private_data;
1074
1075         if (unlikely(!device->ops->write))
1076                 return -EINVAL;
1077
1078         return device->ops->write(device, buf, count, ppos);
1079 }
1080
1081 static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)
1082 {
1083         struct vfio_device *device = filep->private_data;
1084
1085         if (unlikely(!device->ops->mmap))
1086                 return -EINVAL;
1087
1088         return device->ops->mmap(device, vma);
1089 }
1090
1091 const struct file_operations vfio_device_fops = {
1092         .owner          = THIS_MODULE,
1093         .release        = vfio_device_fops_release,
1094         .read           = vfio_device_fops_read,
1095         .write          = vfio_device_fops_write,
1096         .unlocked_ioctl = vfio_device_fops_unl_ioctl,
1097         .compat_ioctl   = compat_ptr_ioctl,
1098         .mmap           = vfio_device_fops_mmap,
1099 };
1100
1101 /*
1102  * Sub-module support
1103  */
1104 /*
1105  * Helper for managing a buffer of info chain capabilities, allocate or
1106  * reallocate a buffer with additional @size, filling in @id and @version
1107  * of the capability.  A pointer to the new capability is returned.
1108  *
1109  * NB. The chain is based at the head of the buffer, so new entries are
1110  * added to the tail, vfio_info_cap_shift() should be called to fixup the
1111  * next offsets prior to copying to the user buffer.
1112  */
1113 struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
1114                                                size_t size, u16 id, u16 version)
1115 {
1116         void *buf;
1117         struct vfio_info_cap_header *header, *tmp;
1118
1119         buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
1120         if (!buf) {
1121                 kfree(caps->buf);
1122                 caps->buf = NULL;
1123                 caps->size = 0;
1124                 return ERR_PTR(-ENOMEM);
1125         }
1126
1127         caps->buf = buf;
1128         header = buf + caps->size;
1129
1130         /* Eventually copied to user buffer, zero */
1131         memset(header, 0, size);
1132
1133         header->id = id;
1134         header->version = version;
1135
1136         /* Add to the end of the capability chain */
1137         for (tmp = buf; tmp->next; tmp = buf + tmp->next)
1138                 ; /* nothing */
1139
1140         tmp->next = caps->size;
1141         caps->size += size;
1142
1143         return header;
1144 }
1145 EXPORT_SYMBOL_GPL(vfio_info_cap_add);
1146
1147 void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
1148 {
1149         struct vfio_info_cap_header *tmp;
1150         void *buf = (void *)caps->buf;
1151
1152         for (tmp = buf; tmp->next; tmp = buf + tmp->next - offset)
1153                 tmp->next += offset;
1154 }
1155 EXPORT_SYMBOL(vfio_info_cap_shift);
1156
1157 int vfio_info_add_capability(struct vfio_info_cap *caps,
1158                              struct vfio_info_cap_header *cap, size_t size)
1159 {
1160         struct vfio_info_cap_header *header;
1161
1162         header = vfio_info_cap_add(caps, size, cap->id, cap->version);
1163         if (IS_ERR(header))
1164                 return PTR_ERR(header);
1165
1166         memcpy(header + 1, cap + 1, size - sizeof(*header));
1167
1168         return 0;
1169 }
1170 EXPORT_SYMBOL(vfio_info_add_capability);
1171
1172 int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr, int num_irqs,
1173                                        int max_irq_type, size_t *data_size)
1174 {
1175         unsigned long minsz;
1176         size_t size;
1177
1178         minsz = offsetofend(struct vfio_irq_set, count);
1179
1180         if ((hdr->argsz < minsz) || (hdr->index >= max_irq_type) ||
1181             (hdr->count >= (U32_MAX - hdr->start)) ||
1182             (hdr->flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
1183                                 VFIO_IRQ_SET_ACTION_TYPE_MASK)))
1184                 return -EINVAL;
1185
1186         if (data_size)
1187                 *data_size = 0;
1188
1189         if (hdr->start >= num_irqs || hdr->start + hdr->count > num_irqs)
1190                 return -EINVAL;
1191
1192         switch (hdr->flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
1193         case VFIO_IRQ_SET_DATA_NONE:
1194                 size = 0;
1195                 break;
1196         case VFIO_IRQ_SET_DATA_BOOL:
1197                 size = sizeof(uint8_t);
1198                 break;
1199         case VFIO_IRQ_SET_DATA_EVENTFD:
1200                 size = sizeof(int32_t);
1201                 break;
1202         default:
1203                 return -EINVAL;
1204         }
1205
1206         if (size) {
1207                 if (hdr->argsz - minsz < hdr->count * size)
1208                         return -EINVAL;
1209
1210                 if (!data_size)
1211                         return -EINVAL;
1212
1213                 *data_size = hdr->count * size;
1214         }
1215
1216         return 0;
1217 }
1218 EXPORT_SYMBOL(vfio_set_irqs_validate_and_prepare);
1219
1220 /*
1221  * Pin contiguous user pages and return their associated host pages for local
1222  * domain only.
1223  * @device [in]  : device
1224  * @iova [in]    : starting IOVA of user pages to be pinned.
1225  * @npage [in]   : count of pages to be pinned.  This count should not
1226  *                 be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
1227  * @prot [in]    : protection flags
1228  * @pages[out]   : array of host pages
1229  * Return error or number of pages pinned.
1230  *
1231  * A driver may only call this function if the vfio_device was created
1232  * by vfio_register_emulated_iommu_dev() due to vfio_device_container_pin_pages().
1233  */
1234 int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
1235                    int npage, int prot, struct page **pages)
1236 {
1237         /* group->container cannot change while a vfio device is open */
1238         if (!pages || !npage || WARN_ON(!vfio_assert_device_open(device)))
1239                 return -EINVAL;
1240         if (vfio_device_has_container(device))
1241                 return vfio_device_container_pin_pages(device, iova,
1242                                                        npage, prot, pages);
1243         if (device->iommufd_access) {
1244                 int ret;
1245
1246                 if (iova > ULONG_MAX)
1247                         return -EINVAL;
1248                 /*
1249                  * VFIO ignores the sub page offset, npages is from the start of
1250                  * a PAGE_SIZE chunk of IOVA. The caller is expected to recover
1251                  * the sub page offset by doing:
1252                  *     pages[0] + (iova % PAGE_SIZE)
1253                  */
1254                 ret = iommufd_access_pin_pages(
1255                         device->iommufd_access, ALIGN_DOWN(iova, PAGE_SIZE),
1256                         npage * PAGE_SIZE, pages,
1257                         (prot & IOMMU_WRITE) ? IOMMUFD_ACCESS_RW_WRITE : 0);
1258                 if (ret)
1259                         return ret;
1260                 return npage;
1261         }
1262         return -EINVAL;
1263 }
1264 EXPORT_SYMBOL(vfio_pin_pages);
1265
1266 /*
1267  * Unpin contiguous host pages for local domain only.
1268  * @device [in]  : device
1269  * @iova [in]    : starting address of user pages to be unpinned.
1270  * @npage [in]   : count of pages to be unpinned.  This count should not
1271  *                 be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
1272  */
1273 void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage)
1274 {
1275         if (WARN_ON(!vfio_assert_device_open(device)))
1276                 return;
1277
1278         if (vfio_device_has_container(device)) {
1279                 vfio_device_container_unpin_pages(device, iova, npage);
1280                 return;
1281         }
1282         if (device->iommufd_access) {
1283                 if (WARN_ON(iova > ULONG_MAX))
1284                         return;
1285                 iommufd_access_unpin_pages(device->iommufd_access,
1286                                            ALIGN_DOWN(iova, PAGE_SIZE),
1287                                            npage * PAGE_SIZE);
1288                 return;
1289         }
1290 }
1291 EXPORT_SYMBOL(vfio_unpin_pages);
1292
1293 /*
1294  * This interface allows the CPUs to perform some sort of virtual DMA on
1295  * behalf of the device.
1296  *
1297  * CPUs read/write from/into a range of IOVAs pointing to user space memory
1298  * into/from a kernel buffer.
1299  *
1300  * As the read/write of user space memory is conducted via the CPUs and is
1301  * not a real device DMA, it is not necessary to pin the user space memory.
1302  *
1303  * @device [in]         : VFIO device
1304  * @iova [in]           : base IOVA of a user space buffer
1305  * @data [in]           : pointer to kernel buffer
1306  * @len [in]            : kernel buffer length
1307  * @write               : indicate read or write
1308  * Return error code on failure or 0 on success.
1309  */
1310 int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova, void *data,
1311                 size_t len, bool write)
1312 {
1313         if (!data || len <= 0 || !vfio_assert_device_open(device))
1314                 return -EINVAL;
1315
1316         if (vfio_device_has_container(device))
1317                 return vfio_device_container_dma_rw(device, iova,
1318                                                     data, len, write);
1319
1320         if (device->iommufd_access) {
1321                 unsigned int flags = 0;
1322
1323                 if (iova > ULONG_MAX)
1324                         return -EINVAL;
1325
1326                 /* VFIO historically tries to auto-detect a kthread */
1327                 if (!current->mm)
1328                         flags |= IOMMUFD_ACCESS_RW_KTHREAD;
1329                 if (write)
1330                         flags |= IOMMUFD_ACCESS_RW_WRITE;
1331                 return iommufd_access_rw(device->iommufd_access, iova, data,
1332                                          len, flags);
1333         }
1334         return -EINVAL;
1335 }
1336 EXPORT_SYMBOL(vfio_dma_rw);
1337
1338 /*
1339  * Module/class support
1340  */
1341 static int __init vfio_init(void)
1342 {
1343         int ret;
1344
1345         ida_init(&vfio.device_ida);
1346
1347         ret = vfio_group_init();
1348         if (ret)
1349                 return ret;
1350
1351         ret = vfio_virqfd_init();
1352         if (ret)
1353                 goto err_virqfd;
1354
1355         /* /sys/class/vfio-dev/vfioX */
1356         vfio.device_class = class_create(THIS_MODULE, "vfio-dev");
1357         if (IS_ERR(vfio.device_class)) {
1358                 ret = PTR_ERR(vfio.device_class);
1359                 goto err_dev_class;
1360         }
1361
1362         pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
1363         return 0;
1364
1365 err_dev_class:
1366         vfio_virqfd_exit();
1367 err_virqfd:
1368         vfio_group_cleanup();
1369         return ret;
1370 }
1371
1372 static void __exit vfio_cleanup(void)
1373 {
1374         ida_destroy(&vfio.device_ida);
1375         class_destroy(vfio.device_class);
1376         vfio.device_class = NULL;
1377         vfio_virqfd_exit();
1378         vfio_group_cleanup();
1379         xa_destroy(&vfio_device_set_xa);
1380 }
1381
1382 module_init(vfio_init);
1383 module_exit(vfio_cleanup);
1384
1385 MODULE_VERSION(DRIVER_VERSION);
1386 MODULE_LICENSE("GPL v2");
1387 MODULE_AUTHOR(DRIVER_AUTHOR);
1388 MODULE_DESCRIPTION(DRIVER_DESC);
1389 MODULE_SOFTDEP("post: vfio_iommu_type1 vfio_iommu_spapr_tce");