drivers/vfio/pci/vfio

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This source file includes following definitions.
vfio_vga_disabled
vfio_pci_set_vga_decode
vfio_pci_is_vga
vfio_pci_probe_mmaps
vfio_pci_nointx
vfio_pci_probe_power_state
vfio_pci_set_power_state
vfio_pci_enable
vfio_pci_disable
vfio_pci_release
vfio_pci_open
vfio_pci_get_irq_count
vfio_pci_count_devs
vfio_pci_fill_devs
vfio_pci_validate_devs
vfio_pci_dev_below_slot
vfio_pci_walk_wrapper
vfio_pci_for_each_slot_or_bus
msix_mmappable_cap
vfio_pci_register_dev_region
vfio_pci_ioctl
vfio_pci_rw
vfio_pci_read
vfio_pci_write
vfio_pci_mmap
vfio_pci_request
vfio_pci_probe
vfio_pci_remove
vfio_pci_aer_err_detected
vfio_pci_reflck_alloc
vfio_pci_reflck_get
vfio_pci_reflck_find
vfio_pci_reflck_attach
vfio_pci_reflck_release
vfio_pci_reflck_put
vfio_pci_get_unused_devs
vfio_pci_try_bus_reset
vfio_pci_cleanup
vfio_pci_fill_ids
vfio_pci_init
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
   4  *     Author: Alex Williamson <alex.williamson@redhat.com>
   5  *
   6  * Derived from original vfio:
   7  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
   8  * Author: Tom Lyon, pugs@cisco.com
   9  */
  10 
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12 #define dev_fmt pr_fmt
  13 
  14 #include <linux/device.h>
  15 #include <linux/eventfd.h>
  16 #include <linux/file.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/iommu.h>
  19 #include <linux/module.h>
  20 #include <linux/mutex.h>
  21 #include <linux/notifier.h>
  22 #include <linux/pci.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/slab.h>
  25 #include <linux/types.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/vfio.h>
  28 #include <linux/vgaarb.h>
  29 #include <linux/nospec.h>
  30 
  31 #include "vfio_pci_private.h"
  32 
  33 #define DRIVER_VERSION  "0.2"
  34 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
  35 #define DRIVER_DESC     "VFIO PCI - User Level meta-driver"
  36 
  37 static char ids[1024] __initdata;
  38 module_param_string(ids, ids, sizeof(ids), 0);
  39 MODULE_PARM_DESC(ids, "Initial PCI IDs to add to the vfio driver, format is \"vendor:device[:subvendor[:subdevice[:class[:class_mask]]]]\" and multiple comma separated entries can be specified");
  40 
  41 static bool nointxmask;
  42 module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
  43 MODULE_PARM_DESC(nointxmask,
  44                   "Disable support for PCI 2.3 style INTx masking.  If this resolves problems for specific devices, report lspci -vvvxxx to linux-pci@vger.kernel.org so the device can be fixed automatically via the broken_intx_masking flag.");
  45 
  46 #ifdef CONFIG_VFIO_PCI_VGA
  47 static bool disable_vga;
  48 module_param(disable_vga, bool, S_IRUGO);
  49 MODULE_PARM_DESC(disable_vga, "Disable VGA resource access through vfio-pci");
  50 #endif
  51 
  52 static bool disable_idle_d3;
  53 module_param(disable_idle_d3, bool, S_IRUGO | S_IWUSR);
  54 MODULE_PARM_DESC(disable_idle_d3,
  55                  "Disable using the PCI D3 low power state for idle, unused devices");
  56 
  57 static inline bool vfio_vga_disabled(void)
  58 {
  59 #ifdef CONFIG_VFIO_PCI_VGA
  60         return disable_vga;
  61 #else
  62         return true;
  63 #endif
  64 }
  65 
  66 /*
  67  * Our VGA arbiter participation is limited since we don't know anything
  68  * about the device itself.  However, if the device is the only VGA device
  69  * downstream of a bridge and VFIO VGA support is disabled, then we can
  70  * safely return legacy VGA IO and memory as not decoded since the user
  71  * has no way to get to it and routing can be disabled externally at the
  72  * bridge.
  73  */
  74 static unsigned int vfio_pci_set_vga_decode(void *opaque, bool single_vga)
  75 {
  76         struct vfio_pci_device *vdev = opaque;
  77         struct pci_dev *tmp = NULL, *pdev = vdev->pdev;
  78         unsigned char max_busnr;
  79         unsigned int decodes;
  80 
  81         if (single_vga || !vfio_vga_disabled() || pci_is_root_bus(pdev->bus))
  82                 return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
  83                        VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
  84 
  85         max_busnr = pci_bus_max_busnr(pdev->bus);
  86         decodes = VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
  87 
  88         while ((tmp = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, tmp)) != NULL) {
  89                 if (tmp == pdev ||
  90                     pci_domain_nr(tmp->bus) != pci_domain_nr(pdev->bus) ||
  91                     pci_is_root_bus(tmp->bus))
  92                         continue;
  93 
  94                 if (tmp->bus->number >= pdev->bus->number &&
  95                     tmp->bus->number <= max_busnr) {
  96                         pci_dev_put(tmp);
  97                         decodes |= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
  98                         break;
  99                 }
 100         }
 101 
 102         return decodes;
 103 }
 104 
 105 static inline bool vfio_pci_is_vga(struct pci_dev *pdev)
 106 {
 107         return (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA;
 108 }
 109 
 110 static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev)
 111 {
 112         struct resource *res;
 113         int bar;
 114         struct vfio_pci_dummy_resource *dummy_res;
 115 
 116         INIT_LIST_HEAD(&vdev->dummy_resources_list);
 117 
 118         for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
 119                 res = vdev->pdev->resource + bar;
 120 
 121                 if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP))
 122                         goto no_mmap;
 123 
 124                 if (!(res->flags & IORESOURCE_MEM))
 125                         goto no_mmap;
 126 
 127                 /*
 128                  * The PCI core shouldn't set up a resource with a
 129                  * type but zero size. But there may be bugs that
 130                  * cause us to do that.
 131                  */
 132                 if (!resource_size(res))
 133                         goto no_mmap;
 134 
 135                 if (resource_size(res) >= PAGE_SIZE) {
 136                         vdev->bar_mmap_supported[bar] = true;
 137                         continue;
 138                 }
 139 
 140                 if (!(res->start & ~PAGE_MASK)) {
 141                         /*
 142                          * Add a dummy resource to reserve the remainder
 143                          * of the exclusive page in case that hot-add
 144                          * device's bar is assigned into it.
 145                          */
 146                         dummy_res = kzalloc(sizeof(*dummy_res), GFP_KERNEL);
 147                         if (dummy_res == NULL)
 148                                 goto no_mmap;
 149 
 150                         dummy_res->resource.name = "vfio sub-page reserved";
 151                         dummy_res->resource.start = res->end + 1;
 152                         dummy_res->resource.end = res->start + PAGE_SIZE - 1;
 153                         dummy_res->resource.flags = res->flags;
 154                         if (request_resource(res->parent,
 155                                                 &dummy_res->resource)) {
 156                                 kfree(dummy_res);
 157                                 goto no_mmap;
 158                         }
 159                         dummy_res->index = bar;
 160                         list_add(&dummy_res->res_next,
 161                                         &vdev->dummy_resources_list);
 162                         vdev->bar_mmap_supported[bar] = true;
 163                         continue;
 164                 }
 165                 /*
 166                  * Here we don't handle the case when the BAR is not page
 167                  * aligned because we can't expect the BAR will be
 168                  * assigned into the same location in a page in guest
 169                  * when we passthrough the BAR. And it's hard to access
 170                  * this BAR in userspace because we have no way to get
 171                  * the BAR's location in a page.
 172                  */
 173 no_mmap:
 174                 vdev->bar_mmap_supported[bar] = false;
 175         }
 176 }
 177 
 178 static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev);
 179 static void vfio_pci_disable(struct vfio_pci_device *vdev);
 180 
 181 /*
 182  * INTx masking requires the ability to disable INTx signaling via PCI_COMMAND
 183  * _and_ the ability detect when the device is asserting INTx via PCI_STATUS.
 184  * If a device implements the former but not the latter we would typically
 185  * expect broken_intx_masking be set and require an exclusive interrupt.
 186  * However since we do have control of the device's ability to assert INTx,
 187  * we can instead pretend that the device does not implement INTx, virtualizing
 188  * the pin register to report zero and maintaining DisINTx set on the host.
 189  */
 190 static bool vfio_pci_nointx(struct pci_dev *pdev)
 191 {
 192         switch (pdev->vendor) {
 193         case PCI_VENDOR_ID_INTEL:
 194                 switch (pdev->device) {
 195                 /* All i40e (XL710/X710/XXV710) 10/20/25/40GbE NICs */
 196                 case 0x1572:
 197                 case 0x1574:
 198                 case 0x1580 ... 0x1581:
 199                 case 0x1583 ... 0x158b:
 200                 case 0x37d0 ... 0x37d2:
 201                         return true;
 202                 default:
 203                         return false;
 204                 }
 205         }
 206 
 207         return false;
 208 }
 209 
 210 static void vfio_pci_probe_power_state(struct vfio_pci_device *vdev)
 211 {
 212         struct pci_dev *pdev = vdev->pdev;
 213         u16 pmcsr;
 214 
 215         if (!pdev->pm_cap)
 216                 return;
 217 
 218         pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &pmcsr);
 219 
 220         vdev->needs_pm_restore = !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
 221 }
 222 
 223 /*
 224  * pci_set_power_state() wrapper handling devices which perform a soft reset on
 225  * D3->D0 transition.  Save state prior to D0/1/2->D3, stash it on the vdev,
 226  * restore when returned to D0.  Saved separately from pci_saved_state for use
 227  * by PM capability emulation and separately from pci_dev internal saved state
 228  * to avoid it being overwritten and consumed around other resets.
 229  */
 230 int vfio_pci_set_power_state(struct vfio_pci_device *vdev, pci_power_t state)
 231 {
 232         struct pci_dev *pdev = vdev->pdev;
 233         bool needs_restore = false, needs_save = false;
 234         int ret;
 235 
 236         if (vdev->needs_pm_restore) {
 237                 if (pdev->current_state < PCI_D3hot && state >= PCI_D3hot) {
 238                         pci_save_state(pdev);
 239                         needs_save = true;
 240                 }
 241 
 242                 if (pdev->current_state >= PCI_D3hot && state <= PCI_D0)
 243                         needs_restore = true;
 244         }
 245 
 246         ret = pci_set_power_state(pdev, state);
 247 
 248         if (!ret) {
 249                 /* D3 might be unsupported via quirk, skip unless in D3 */
 250                 if (needs_save && pdev->current_state >= PCI_D3hot) {
 251                         vdev->pm_save = pci_store_saved_state(pdev);
 252                 } else if (needs_restore) {
 253                         pci_load_and_free_saved_state(pdev, &vdev->pm_save);
 254                         pci_restore_state(pdev);
 255                 }
 256         }
 257 
 258         return ret;
 259 }
 260 
 261 static int vfio_pci_enable(struct vfio_pci_device *vdev)
 262 {
 263         struct pci_dev *pdev = vdev->pdev;
 264         int ret;
 265         u16 cmd;
 266         u8 msix_pos;
 267 
 268         vfio_pci_set_power_state(vdev, PCI_D0);
 269 
 270         /* Don't allow our initial saved state to include busmaster */
 271         pci_clear_master(pdev);
 272 
 273         ret = pci_enable_device(pdev);
 274         if (ret)
 275                 return ret;
 276 
 277         /* If reset fails because of the device lock, fail this path entirely */
 278         ret = pci_try_reset_function(pdev);
 279         if (ret == -EAGAIN) {
 280                 pci_disable_device(pdev);
 281                 return ret;
 282         }
 283 
 284         vdev->reset_works = !ret;
 285         pci_save_state(pdev);
 286         vdev->pci_saved_state = pci_store_saved_state(pdev);
 287         if (!vdev->pci_saved_state)
 288                 pci_dbg(pdev, "%s: Couldn't store saved state\n", __func__);
 289 
 290         if (likely(!nointxmask)) {
 291                 if (vfio_pci_nointx(pdev)) {
 292                         pci_info(pdev, "Masking broken INTx support\n");
 293                         vdev->nointx = true;
 294                         pci_intx(pdev, 0);
 295                 } else
 296                         vdev->pci_2_3 = pci_intx_mask_supported(pdev);
 297         }
 298 
 299         pci_read_config_word(pdev, PCI_COMMAND, &cmd);
 300         if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
 301                 cmd &= ~PCI_COMMAND_INTX_DISABLE;
 302                 pci_write_config_word(pdev, PCI_COMMAND, cmd);
 303         }
 304 
 305         ret = vfio_config_init(vdev);
 306         if (ret) {
 307                 kfree(vdev->pci_saved_state);
 308                 vdev->pci_saved_state = NULL;
 309                 pci_disable_device(pdev);
 310                 return ret;
 311         }
 312 
 313         msix_pos = pdev->msix_cap;
 314         if (msix_pos) {
 315                 u16 flags;
 316                 u32 table;
 317 
 318                 pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
 319                 pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
 320 
 321                 vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
 322                 vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
 323                 vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
 324         } else
 325                 vdev->msix_bar = 0xFF;
 326 
 327         if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))
 328                 vdev->has_vga = true;
 329 
 330 
 331         if (vfio_pci_is_vga(pdev) &&
 332             pdev->vendor == PCI_VENDOR_ID_INTEL &&
 333             IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
 334                 ret = vfio_pci_igd_init(vdev);
 335                 if (ret) {
 336                         pci_warn(pdev, "Failed to setup Intel IGD regions\n");
 337                         goto disable_exit;
 338                 }
 339         }
 340 
 341         if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
 342             IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) {
 343                 ret = vfio_pci_nvdia_v100_nvlink2_init(vdev);
 344                 if (ret && ret != -ENODEV) {
 345                         pci_warn(pdev, "Failed to setup NVIDIA NV2 RAM region\n");
 346                         goto disable_exit;
 347                 }
 348         }
 349 
 350         if (pdev->vendor == PCI_VENDOR_ID_IBM &&
 351             IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) {
 352                 ret = vfio_pci_ibm_npu2_init(vdev);
 353                 if (ret && ret != -ENODEV) {
 354                         pci_warn(pdev, "Failed to setup NVIDIA NV2 ATSD region\n");
 355                         goto disable_exit;
 356                 }
 357         }
 358 
 359         vfio_pci_probe_mmaps(vdev);
 360 
 361         return 0;
 362 
 363 disable_exit:
 364         vfio_pci_disable(vdev);
 365         return ret;
 366 }
 367 
 368 static void vfio_pci_disable(struct vfio_pci_device *vdev)
 369 {
 370         struct pci_dev *pdev = vdev->pdev;
 371         struct vfio_pci_dummy_resource *dummy_res, *tmp;
 372         struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
 373         int i, bar;
 374 
 375         /* Stop the device from further DMA */
 376         pci_clear_master(pdev);
 377 
 378         vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
 379                                 VFIO_IRQ_SET_ACTION_TRIGGER,
 380                                 vdev->irq_type, 0, 0, NULL);
 381 
 382         /* Device closed, don't need mutex here */
 383         list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
 384                                  &vdev->ioeventfds_list, next) {
 385                 vfio_virqfd_disable(&ioeventfd->virqfd);
 386                 list_del(&ioeventfd->next);
 387                 kfree(ioeventfd);
 388         }
 389         vdev->ioeventfds_nr = 0;
 390 
 391         vdev->virq_disabled = false;
 392 
 393         for (i = 0; i < vdev->num_regions; i++)
 394                 vdev->region[i].ops->release(vdev, &vdev->region[i]);
 395 
 396         vdev->num_regions = 0;
 397         kfree(vdev->region);
 398         vdev->region = NULL; /* don't krealloc a freed pointer */
 399 
 400         vfio_config_free(vdev);
 401 
 402         for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
 403                 if (!vdev->barmap[bar])
 404                         continue;
 405                 pci_iounmap(pdev, vdev->barmap[bar]);
 406                 pci_release_selected_regions(pdev, 1 << bar);
 407                 vdev->barmap[bar] = NULL;
 408         }
 409 
 410         list_for_each_entry_safe(dummy_res, tmp,
 411                                  &vdev->dummy_resources_list, res_next) {
 412                 list_del(&dummy_res->res_next);
 413                 release_resource(&dummy_res->resource);
 414                 kfree(dummy_res);
 415         }
 416 
 417         vdev->needs_reset = true;
 418 
 419         /*
 420          * If we have saved state, restore it.  If we can reset the device,
 421          * even better.  Resetting with current state seems better than
 422          * nothing, but saving and restoring current state without reset
 423          * is just busy work.
 424          */
 425         if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
 426                 pci_info(pdev, "%s: Couldn't reload saved state\n", __func__);
 427 
 428                 if (!vdev->reset_works)
 429                         goto out;
 430 
 431                 pci_save_state(pdev);
 432         }
 433 
 434         /*
 435          * Disable INTx and MSI, presumably to avoid spurious interrupts
 436          * during reset.  Stolen from pci_reset_function()
 437          */
 438         pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
 439 
 440         /*
 441          * Try to get the locks ourselves to prevent a deadlock. The
 442          * success of this is dependent on being able to lock the device,
 443          * which is not always possible.
 444          * We can not use the "try" reset interface here, which will
 445          * overwrite the previously restored configuration information.
 446          */
 447         if (vdev->reset_works && pci_cfg_access_trylock(pdev)) {
 448                 if (device_trylock(&pdev->dev)) {
 449                         if (!__pci_reset_function_locked(pdev))
 450                                 vdev->needs_reset = false;
 451                         device_unlock(&pdev->dev);
 452                 }
 453                 pci_cfg_access_unlock(pdev);
 454         }
 455 
 456         pci_restore_state(pdev);
 457 out:
 458         pci_disable_device(pdev);
 459 
 460         vfio_pci_try_bus_reset(vdev);
 461 
 462         if (!disable_idle_d3)
 463                 vfio_pci_set_power_state(vdev, PCI_D3hot);
 464 }
 465 
 466 static void vfio_pci_release(void *device_data)
 467 {
 468         struct vfio_pci_device *vdev = device_data;
 469 
 470         mutex_lock(&vdev->reflck->lock);
 471 
 472         if (!(--vdev->refcnt)) {
 473                 vfio_spapr_pci_eeh_release(vdev->pdev);
 474                 vfio_pci_disable(vdev);
 475         }
 476 
 477         mutex_unlock(&vdev->reflck->lock);
 478 
 479         module_put(THIS_MODULE);
 480 }
 481 
 482 static int vfio_pci_open(void *device_data)
 483 {
 484         struct vfio_pci_device *vdev = device_data;
 485         int ret = 0;
 486 
 487         if (!try_module_get(THIS_MODULE))
 488                 return -ENODEV;
 489 
 490         mutex_lock(&vdev->reflck->lock);
 491 
 492         if (!vdev->refcnt) {
 493                 ret = vfio_pci_enable(vdev);
 494                 if (ret)
 495                         goto error;
 496 
 497                 vfio_spapr_pci_eeh_open(vdev->pdev);
 498         }
 499         vdev->refcnt++;
 500 error:
 501         mutex_unlock(&vdev->reflck->lock);
 502         if (ret)
 503                 module_put(THIS_MODULE);
 504         return ret;
 505 }
 506 
 507 static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
 508 {
 509         if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
 510                 u8 pin;
 511 
 512                 if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) ||
 513                     vdev->nointx || vdev->pdev->is_virtfn)
 514                         return 0;
 515 
 516                 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
 517 
 518                 return pin ? 1 : 0;
 519         } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
 520                 u8 pos;
 521                 u16 flags;
 522 
 523                 pos = vdev->pdev->msi_cap;
 524                 if (pos) {
 525                         pci_read_config_word(vdev->pdev,
 526                                              pos + PCI_MSI_FLAGS, &flags);
 527                         return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
 528                 }
 529         } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
 530                 u8 pos;
 531                 u16 flags;
 532 
 533                 pos = vdev->pdev->msix_cap;
 534                 if (pos) {
 535                         pci_read_config_word(vdev->pdev,
 536                                              pos + PCI_MSIX_FLAGS, &flags);
 537 
 538                         return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
 539                 }
 540         } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
 541                 if (pci_is_pcie(vdev->pdev))
 542                         return 1;
 543         } else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
 544                 return 1;
 545         }
 546 
 547         return 0;
 548 }
 549 
 550 static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
 551 {
 552         (*(int *)data)++;
 553         return 0;
 554 }
 555 
 556 struct vfio_pci_fill_info {
 557         int max;
 558         int cur;
 559         struct vfio_pci_dependent_device *devices;
 560 };
 561 
 562 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
 563 {
 564         struct vfio_pci_fill_info *fill = data;
 565         struct iommu_group *iommu_group;
 566 
 567         if (fill->cur == fill->max)
 568                 return -EAGAIN; /* Something changed, try again */
 569 
 570         iommu_group = iommu_group_get(&pdev->dev);
 571         if (!iommu_group)
 572                 return -EPERM; /* Cannot reset non-isolated devices */
 573 
 574         fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
 575         fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
 576         fill->devices[fill->cur].bus = pdev->bus->number;
 577         fill->devices[fill->cur].devfn = pdev->devfn;
 578         fill->cur++;
 579         iommu_group_put(iommu_group);
 580         return 0;
 581 }
 582 
 583 struct vfio_pci_group_entry {
 584         struct vfio_group *group;
 585         int id;
 586 };
 587 
 588 struct vfio_pci_group_info {
 589         int count;
 590         struct vfio_pci_group_entry *groups;
 591 };
 592 
 593 static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
 594 {
 595         struct vfio_pci_group_info *info = data;
 596         struct iommu_group *group;
 597         int id, i;
 598 
 599         group = iommu_group_get(&pdev->dev);
 600         if (!group)
 601                 return -EPERM;
 602 
 603         id = iommu_group_id(group);
 604 
 605         for (i = 0; i < info->count; i++)
 606                 if (info->groups[i].id == id)
 607                         break;
 608 
 609         iommu_group_put(group);
 610 
 611         return (i == info->count) ? -EINVAL : 0;
 612 }
 613 
 614 static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
 615 {
 616         for (; pdev; pdev = pdev->bus->self)
 617                 if (pdev->bus == slot->bus)
 618                         return (pdev->slot == slot);
 619         return false;
 620 }
 621 
 622 struct vfio_pci_walk_info {
 623         int (*fn)(struct pci_dev *, void *data);
 624         void *data;
 625         struct pci_dev *pdev;
 626         bool slot;
 627         int ret;
 628 };
 629 
 630 static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
 631 {
 632         struct vfio_pci_walk_info *walk = data;
 633 
 634         if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
 635                 walk->ret = walk->fn(pdev, walk->data);
 636 
 637         return walk->ret;
 638 }
 639 
 640 static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
 641                                          int (*fn)(struct pci_dev *,
 642                                                    void *data), void *data,
 643                                          bool slot)
 644 {
 645         struct vfio_pci_walk_info walk = {
 646                 .fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
 647         };
 648 
 649         pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
 650 
 651         return walk.ret;
 652 }
 653 
 654 static int msix_mmappable_cap(struct vfio_pci_device *vdev,
 655                               struct vfio_info_cap *caps)
 656 {
 657         struct vfio_info_cap_header header = {
 658                 .id = VFIO_REGION_INFO_CAP_MSIX_MAPPABLE,
 659                 .version = 1
 660         };
 661 
 662         return vfio_info_add_capability(caps, &header, sizeof(header));
 663 }
 664 
 665 int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
 666                                  unsigned int type, unsigned int subtype,
 667                                  const struct vfio_pci_regops *ops,
 668                                  size_t size, u32 flags, void *data)
 669 {
 670         struct vfio_pci_region *region;
 671 
 672         region = krealloc(vdev->region,
 673                           (vdev->num_regions + 1) * sizeof(*region),
 674                           GFP_KERNEL);
 675         if (!region)
 676                 return -ENOMEM;
 677 
 678         vdev->region = region;
 679         vdev->region[vdev->num_regions].type = type;
 680         vdev->region[vdev->num_regions].subtype = subtype;
 681         vdev->region[vdev->num_regions].ops = ops;
 682         vdev->region[vdev->num_regions].size = size;
 683         vdev->region[vdev->num_regions].flags = flags;
 684         vdev->region[vdev->num_regions].data = data;
 685 
 686         vdev->num_regions++;
 687 
 688         return 0;
 689 }
 690 
 691 static long vfio_pci_ioctl(void *device_data,
 692                            unsigned int cmd, unsigned long arg)
 693 {
 694         struct vfio_pci_device *vdev = device_data;
 695         unsigned long minsz;
 696 
 697         if (cmd == VFIO_DEVICE_GET_INFO) {
 698                 struct vfio_device_info info;
 699 
 700                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 701 
 702                 if (copy_from_user(&info, (void __user *)arg, minsz))
 703                         return -EFAULT;
 704 
 705                 if (info.argsz < minsz)
 706                         return -EINVAL;
 707 
 708                 info.flags = VFIO_DEVICE_FLAGS_PCI;
 709 
 710                 if (vdev->reset_works)
 711                         info.flags |= VFIO_DEVICE_FLAGS_RESET;
 712 
 713                 info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
 714                 info.num_irqs = VFIO_PCI_NUM_IRQS;
 715 
 716                 return copy_to_user((void __user *)arg, &info, minsz) ?
 717                         -EFAULT : 0;
 718 
 719         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 720                 struct pci_dev *pdev = vdev->pdev;
 721                 struct vfio_region_info info;
 722                 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
 723                 int i, ret;
 724 
 725                 minsz = offsetofend(struct vfio_region_info, offset);
 726 
 727                 if (copy_from_user(&info, (void __user *)arg, minsz))
 728                         return -EFAULT;
 729 
 730                 if (info.argsz < minsz)
 731                         return -EINVAL;
 732 
 733                 switch (info.index) {
 734                 case VFIO_PCI_CONFIG_REGION_INDEX:
 735                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 736                         info.size = pdev->cfg_size;
 737                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 738                                      VFIO_REGION_INFO_FLAG_WRITE;
 739                         break;
 740                 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
 741                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 742                         info.size = pci_resource_len(pdev, info.index);
 743                         if (!info.size) {
 744                                 info.flags = 0;
 745                                 break;
 746                         }
 747 
 748                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 749                                      VFIO_REGION_INFO_FLAG_WRITE;
 750                         if (vdev->bar_mmap_supported[info.index]) {
 751                                 info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
 752                                 if (info.index == vdev->msix_bar) {
 753                                         ret = msix_mmappable_cap(vdev, &caps);
 754                                         if (ret)
 755                                                 return ret;
 756                                 }
 757                         }
 758 
 759                         break;
 760                 case VFIO_PCI_ROM_REGION_INDEX:
 761                 {
 762                         void __iomem *io;
 763                         size_t size;
 764                         u16 orig_cmd;
 765 
 766                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 767                         info.flags = 0;
 768 
 769                         /* Report the BAR size, not the ROM size */
 770                         info.size = pci_resource_len(pdev, info.index);
 771                         if (!info.size) {
 772                                 /* Shadow ROMs appear as PCI option ROMs */
 773                                 if (pdev->resource[PCI_ROM_RESOURCE].flags &
 774                                                         IORESOURCE_ROM_SHADOW)
 775                                         info.size = 0x20000;
 776                                 else
 777                                         break;
 778                         }
 779 
 780                         /*
 781                          * Is it really there?  Enable memory decode for
 782                          * implicit access in pci_map_rom().
 783                          */
 784                         pci_read_config_word(pdev, PCI_COMMAND, &orig_cmd);
 785                         pci_write_config_word(pdev, PCI_COMMAND,
 786                                               orig_cmd | PCI_COMMAND_MEMORY);
 787 
 788                         io = pci_map_rom(pdev, &size);
 789                         if (io) {
 790                                 info.flags = VFIO_REGION_INFO_FLAG_READ;
 791                                 pci_unmap_rom(pdev, io);
 792                         } else {
 793                                 info.size = 0;
 794                         }
 795 
 796                         pci_write_config_word(pdev, PCI_COMMAND, orig_cmd);
 797                         break;
 798                 }
 799                 case VFIO_PCI_VGA_REGION_INDEX:
 800                         if (!vdev->has_vga)
 801                                 return -EINVAL;
 802 
 803                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 804                         info.size = 0xc0000;
 805                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 806                                      VFIO_REGION_INFO_FLAG_WRITE;
 807 
 808                         break;
 809                 default:
 810                 {
 811                         struct vfio_region_info_cap_type cap_type = {
 812                                         .header.id = VFIO_REGION_INFO_CAP_TYPE,
 813                                         .header.version = 1 };
 814 
 815                         if (info.index >=
 816                             VFIO_PCI_NUM_REGIONS + vdev->num_regions)
 817                                 return -EINVAL;
 818                         info.index = array_index_nospec(info.index,
 819                                                         VFIO_PCI_NUM_REGIONS +
 820                                                         vdev->num_regions);
 821 
 822                         i = info.index - VFIO_PCI_NUM_REGIONS;
 823 
 824                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 825                         info.size = vdev->region[i].size;
 826                         info.flags = vdev->region[i].flags;
 827 
 828                         cap_type.type = vdev->region[i].type;
 829                         cap_type.subtype = vdev->region[i].subtype;
 830 
 831                         ret = vfio_info_add_capability(&caps, &cap_type.header,
 832                                                        sizeof(cap_type));
 833                         if (ret)
 834                                 return ret;
 835 
 836                         if (vdev->region[i].ops->add_capability) {
 837                                 ret = vdev->region[i].ops->add_capability(vdev,
 838                                                 &vdev->region[i], &caps);
 839                                 if (ret)
 840                                         return ret;
 841                         }
 842                 }
 843                 }
 844 
 845                 if (caps.size) {
 846                         info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
 847                         if (info.argsz < sizeof(info) + caps.size) {
 848                                 info.argsz = sizeof(info) + caps.size;
 849                                 info.cap_offset = 0;
 850                         } else {
 851                                 vfio_info_cap_shift(&caps, sizeof(info));
 852                                 if (copy_to_user((void __user *)arg +
 853                                                   sizeof(info), caps.buf,
 854                                                   caps.size)) {
 855                                         kfree(caps.buf);
 856                                         return -EFAULT;
 857                                 }
 858                                 info.cap_offset = sizeof(info);
 859                         }
 860 
 861                         kfree(caps.buf);
 862                 }
 863 
 864                 return copy_to_user((void __user *)arg, &info, minsz) ?
 865                         -EFAULT : 0;
 866 
 867         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 868                 struct vfio_irq_info info;
 869 
 870                 minsz = offsetofend(struct vfio_irq_info, count);
 871 
 872                 if (copy_from_user(&info, (void __user *)arg, minsz))
 873                         return -EFAULT;
 874 
 875                 if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
 876                         return -EINVAL;
 877 
 878                 switch (info.index) {
 879                 case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
 880                 case VFIO_PCI_REQ_IRQ_INDEX:
 881                         break;
 882                 case VFIO_PCI_ERR_IRQ_INDEX:
 883                         if (pci_is_pcie(vdev->pdev))
 884                                 break;
 885                 /* fall through */
 886                 default:
 887                         return -EINVAL;
 888                 }
 889 
 890                 info.flags = VFIO_IRQ_INFO_EVENTFD;
 891 
 892                 info.count = vfio_pci_get_irq_count(vdev, info.index);
 893 
 894                 if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
 895                         info.flags |= (VFIO_IRQ_INFO_MASKABLE |
 896                                        VFIO_IRQ_INFO_AUTOMASKED);
 897                 else
 898                         info.flags |= VFIO_IRQ_INFO_NORESIZE;
 899 
 900                 return copy_to_user((void __user *)arg, &info, minsz) ?
 901                         -EFAULT : 0;
 902 
 903         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 904                 struct vfio_irq_set hdr;
 905                 u8 *data = NULL;
 906                 int max, ret = 0;
 907                 size_t data_size = 0;
 908 
 909                 minsz = offsetofend(struct vfio_irq_set, count);
 910 
 911                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 912                         return -EFAULT;
 913 
 914                 max = vfio_pci_get_irq_count(vdev, hdr.index);
 915 
 916                 ret = vfio_set_irqs_validate_and_prepare(&hdr, max,
 917                                                  VFIO_PCI_NUM_IRQS, &data_size);
 918                 if (ret)
 919                         return ret;
 920 
 921                 if (data_size) {
 922                         data = memdup_user((void __user *)(arg + minsz),
 923                                             data_size);
 924                         if (IS_ERR(data))
 925                                 return PTR_ERR(data);
 926                 }
 927 
 928                 mutex_lock(&vdev->igate);
 929 
 930                 ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 931                                               hdr.start, hdr.count, data);
 932 
 933                 mutex_unlock(&vdev->igate);
 934                 kfree(data);
 935 
 936                 return ret;
 937 
 938         } else if (cmd == VFIO_DEVICE_RESET) {
 939                 return vdev->reset_works ?
 940                         pci_try_reset_function(vdev->pdev) : -EINVAL;
 941 
 942         } else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
 943                 struct vfio_pci_hot_reset_info hdr;
 944                 struct vfio_pci_fill_info fill = { 0 };
 945                 struct vfio_pci_dependent_device *devices = NULL;
 946                 bool slot = false;
 947                 int ret = 0;
 948 
 949                 minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
 950 
 951                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 952                         return -EFAULT;
 953 
 954                 if (hdr.argsz < minsz)
 955                         return -EINVAL;
 956 
 957                 hdr.flags = 0;
 958 
 959                 /* Can we do a slot or bus reset or neither? */
 960                 if (!pci_probe_reset_slot(vdev->pdev->slot))
 961                         slot = true;
 962                 else if (pci_probe_reset_bus(vdev->pdev->bus))
 963                         return -ENODEV;
 964 
 965                 /* How many devices are affected? */
 966                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 967                                                     vfio_pci_count_devs,
 968                                                     &fill.max, slot);
 969                 if (ret)
 970                         return ret;
 971 
 972                 WARN_ON(!fill.max); /* Should always be at least one */
 973 
 974                 /*
 975                  * If there's enough space, fill it now, otherwise return
 976                  * -ENOSPC and the number of devices affected.
 977                  */
 978                 if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
 979                         ret = -ENOSPC;
 980                         hdr.count = fill.max;
 981                         goto reset_info_exit;
 982                 }
 983 
 984                 devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
 985                 if (!devices)
 986                         return -ENOMEM;
 987 
 988                 fill.devices = devices;
 989 
 990                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 991                                                     vfio_pci_fill_devs,
 992                                                     &fill, slot);
 993 
 994                 /*
 995                  * If a device was removed between counting and filling,
 996                  * we may come up short of fill.max.  If a device was
 997                  * added, we'll have a return of -EAGAIN above.
 998                  */
 999                 if (!ret)
1000                         hdr.count = fill.cur;
1001 
1002 reset_info_exit:
1003                 if (copy_to_user((void __user *)arg, &hdr, minsz))
1004                         ret = -EFAULT;
1005 
1006                 if (!ret) {
1007                         if (copy_to_user((void __user *)(arg + minsz), devices,
1008                                          hdr.count * sizeof(*devices)))
1009                                 ret = -EFAULT;
1010                 }
1011 
1012                 kfree(devices);
1013                 return ret;
1014 
1015         } else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
1016                 struct vfio_pci_hot_reset hdr;
1017                 int32_t *group_fds;
1018                 struct vfio_pci_group_entry *groups;
1019                 struct vfio_pci_group_info info;
1020                 bool slot = false;
1021                 int i, count = 0, ret = 0;
1022 
1023                 minsz = offsetofend(struct vfio_pci_hot_reset, count);
1024 
1025                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
1026                         return -EFAULT;
1027 
1028                 if (hdr.argsz < minsz || hdr.flags)
1029                         return -EINVAL;
1030 
1031                 /* Can we do a slot or bus reset or neither? */
1032                 if (!pci_probe_reset_slot(vdev->pdev->slot))
1033                         slot = true;
1034                 else if (pci_probe_reset_bus(vdev->pdev->bus))
1035                         return -ENODEV;
1036 
1037                 /*
1038                  * We can't let userspace give us an arbitrarily large
1039                  * buffer to copy, so verify how many we think there
1040                  * could be.  Note groups can have multiple devices so
1041                  * one group per device is the max.
1042                  */
1043                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1044                                                     vfio_pci_count_devs,
1045                                                     &count, slot);
1046                 if (ret)
1047                         return ret;
1048 
1049                 /* Somewhere between 1 and count is OK */
1050                 if (!hdr.count || hdr.count > count)
1051                         return -EINVAL;
1052 
1053                 group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
1054                 groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
1055                 if (!group_fds || !groups) {
1056                         kfree(group_fds);
1057                         kfree(groups);
1058                         return -ENOMEM;
1059                 }
1060 
1061                 if (copy_from_user(group_fds, (void __user *)(arg + minsz),
1062                                    hdr.count * sizeof(*group_fds))) {
1063                         kfree(group_fds);
1064                         kfree(groups);
1065                         return -EFAULT;
1066                 }
1067 
1068                 /*
1069                  * For each group_fd, get the group through the vfio external
1070                  * user interface and store the group and iommu ID.  This
1071                  * ensures the group is held across the reset.
1072                  */
1073                 for (i = 0; i < hdr.count; i++) {
1074                         struct vfio_group *group;
1075                         struct fd f = fdget(group_fds[i]);
1076                         if (!f.file) {
1077                                 ret = -EBADF;
1078                                 break;
1079                         }
1080 
1081                         group = vfio_group_get_external_user(f.file);
1082                         fdput(f);
1083                         if (IS_ERR(group)) {
1084                                 ret = PTR_ERR(group);
1085                                 break;
1086                         }
1087 
1088                         groups[i].group = group;
1089                         groups[i].id = vfio_external_user_iommu_id(group);
1090                 }
1091 
1092                 kfree(group_fds);
1093 
1094                 /* release reference to groups on error */
1095                 if (ret)
1096                         goto hot_reset_release;
1097 
1098                 info.count = hdr.count;
1099                 info.groups = groups;
1100 
1101                 /*
1102                  * Test whether all the affected devices are contained
1103                  * by the set of groups provided by the user.
1104                  */
1105                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1106                                                     vfio_pci_validate_devs,
1107                                                     &info, slot);
1108                 if (!ret)
1109                         /* User has access, do the reset */
1110                         ret = pci_reset_bus(vdev->pdev);
1111 
1112 hot_reset_release:
1113                 for (i--; i >= 0; i--)
1114                         vfio_group_put_external_user(groups[i].group);
1115 
1116                 kfree(groups);
1117                 return ret;
1118         } else if (cmd == VFIO_DEVICE_IOEVENTFD) {
1119                 struct vfio_device_ioeventfd ioeventfd;
1120                 int count;
1121 
1122                 minsz = offsetofend(struct vfio_device_ioeventfd, fd);
1123 
1124                 if (copy_from_user(&ioeventfd, (void __user *)arg, minsz))
1125                         return -EFAULT;
1126 
1127                 if (ioeventfd.argsz < minsz)
1128                         return -EINVAL;
1129 
1130                 if (ioeventfd.flags & ~VFIO_DEVICE_IOEVENTFD_SIZE_MASK)
1131                         return -EINVAL;
1132 
1133                 count = ioeventfd.flags & VFIO_DEVICE_IOEVENTFD_SIZE_MASK;
1134 
1135                 if (hweight8(count) != 1 || ioeventfd.fd < -1)
1136                         return -EINVAL;
1137 
1138                 return vfio_pci_ioeventfd(vdev, ioeventfd.offset,
1139                                           ioeventfd.data, count, ioeventfd.fd);
1140         }
1141 
1142         return -ENOTTY;
1143 }
1144 
1145 static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
1146                            size_t count, loff_t *ppos, bool iswrite)
1147 {
1148         unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
1149         struct vfio_pci_device *vdev = device_data;
1150 
1151         if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1152                 return -EINVAL;
1153 
1154         switch (index) {
1155         case VFIO_PCI_CONFIG_REGION_INDEX:
1156                 return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
1157 
1158         case VFIO_PCI_ROM_REGION_INDEX:
1159                 if (iswrite)
1160                         return -EINVAL;
1161                 return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
1162 
1163         case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
1164                 return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
1165 
1166         case VFIO_PCI_VGA_REGION_INDEX:
1167                 return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
1168         default:
1169                 index -= VFIO_PCI_NUM_REGIONS;
1170                 return vdev->region[index].ops->rw(vdev, buf,
1171                                                    count, ppos, iswrite);
1172         }
1173 
1174         return -EINVAL;
1175 }
1176 
1177 static ssize_t vfio_pci_read(void *device_data, char __user *buf,
1178                              size_t count, loff_t *ppos)
1179 {
1180         if (!count)
1181                 return 0;
1182 
1183         return vfio_pci_rw(device_data, buf, count, ppos, false);
1184 }
1185 
1186 static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
1187                               size_t count, loff_t *ppos)
1188 {
1189         if (!count)
1190                 return 0;
1191 
1192         return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
1193 }
1194 
1195 static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
1196 {
1197         struct vfio_pci_device *vdev = device_data;
1198         struct pci_dev *pdev = vdev->pdev;
1199         unsigned int index;
1200         u64 phys_len, req_len, pgoff, req_start;
1201         int ret;
1202 
1203         index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
1204 
1205         if (vma->vm_end < vma->vm_start)
1206                 return -EINVAL;
1207         if ((vma->vm_flags & VM_SHARED) == 0)
1208                 return -EINVAL;
1209         if (index >= VFIO_PCI_NUM_REGIONS) {
1210                 int regnum = index - VFIO_PCI_NUM_REGIONS;
1211                 struct vfio_pci_region *region = vdev->region + regnum;
1212 
1213                 if (region && region->ops && region->ops->mmap &&
1214                     (region->flags & VFIO_REGION_INFO_FLAG_MMAP))
1215                         return region->ops->mmap(vdev, region, vma);
1216                 return -EINVAL;
1217         }
1218         if (index >= VFIO_PCI_ROM_REGION_INDEX)
1219                 return -EINVAL;
1220         if (!vdev->bar_mmap_supported[index])
1221                 return -EINVAL;
1222 
1223         phys_len = PAGE_ALIGN(pci_resource_len(pdev, index));
1224         req_len = vma->vm_end - vma->vm_start;
1225         pgoff = vma->vm_pgoff &
1226                 ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
1227         req_start = pgoff << PAGE_SHIFT;
1228 
1229         if (req_start + req_len > phys_len)
1230                 return -EINVAL;
1231 
1232         /*
1233          * Even though we don't make use of the barmap for the mmap,
1234          * we need to request the region and the barmap tracks that.
1235          */
1236         if (!vdev->barmap[index]) {
1237                 ret = pci_request_selected_regions(pdev,
1238                                                    1 << index, "vfio-pci");
1239                 if (ret)
1240                         return ret;
1241 
1242                 vdev->barmap[index] = pci_iomap(pdev, index, 0);
1243                 if (!vdev->barmap[index]) {
1244                         pci_release_selected_regions(pdev, 1 << index);
1245                         return -ENOMEM;
1246                 }
1247         }
1248 
1249         vma->vm_private_data = vdev;
1250         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1251         vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
1252 
1253         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
1254                                req_len, vma->vm_page_prot);
1255 }
1256 
1257 static void vfio_pci_request(void *device_data, unsigned int count)
1258 {
1259         struct vfio_pci_device *vdev = device_data;
1260         struct pci_dev *pdev = vdev->pdev;
1261 
1262         mutex_lock(&vdev->igate);
1263 
1264         if (vdev->req_trigger) {
1265                 if (!(count % 10))
1266                         pci_notice_ratelimited(pdev,
1267                                 "Relaying device request to user (#%u)\n",
1268                                 count);
1269                 eventfd_signal(vdev->req_trigger, 1);
1270         } else if (count == 0) {
1271                 pci_warn(pdev,
1272                         "No device request channel registered, blocked until released by user\n");
1273         }
1274 
1275         mutex_unlock(&vdev->igate);
1276 }
1277 
1278 static const struct vfio_device_ops vfio_pci_ops = {
1279         .name           = "vfio-pci",
1280         .open           = vfio_pci_open,
1281         .release        = vfio_pci_release,
1282         .ioctl          = vfio_pci_ioctl,
1283         .read           = vfio_pci_read,
1284         .write          = vfio_pci_write,
1285         .mmap           = vfio_pci_mmap,
1286         .request        = vfio_pci_request,
1287 };
1288 
1289 static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev);
1290 static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck);
1291 
1292 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1293 {
1294         struct vfio_pci_device *vdev;
1295         struct iommu_group *group;
1296         int ret;
1297 
1298         if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
1299                 return -EINVAL;
1300 
1301         /*
1302          * Prevent binding to PFs with VFs enabled, this too easily allows
1303          * userspace instance with VFs and PFs from the same device, which
1304          * cannot work.  Disabling SR-IOV here would initiate removing the
1305          * VFs, which would unbind the driver, which is prone to blocking
1306          * if that VF is also in use by vfio-pci.  Just reject these PFs
1307          * and let the user sort it out.
1308          */
1309         if (pci_num_vf(pdev)) {
1310                 pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n");
1311                 return -EBUSY;
1312         }
1313 
1314         group = vfio_iommu_group_get(&pdev->dev);
1315         if (!group)
1316                 return -EINVAL;
1317 
1318         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
1319         if (!vdev) {
1320                 vfio_iommu_group_put(group, &pdev->dev);
1321                 return -ENOMEM;
1322         }
1323 
1324         vdev->pdev = pdev;
1325         vdev->irq_type = VFIO_PCI_NUM_IRQS;
1326         mutex_init(&vdev->igate);
1327         spin_lock_init(&vdev->irqlock);
1328         mutex_init(&vdev->ioeventfds_lock);
1329         INIT_LIST_HEAD(&vdev->ioeventfds_list);
1330 
1331         ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
1332         if (ret) {
1333                 vfio_iommu_group_put(group, &pdev->dev);
1334                 kfree(vdev);
1335                 return ret;
1336         }
1337 
1338         ret = vfio_pci_reflck_attach(vdev);
1339         if (ret) {
1340                 vfio_del_group_dev(&pdev->dev);
1341                 vfio_iommu_group_put(group, &pdev->dev);
1342                 kfree(vdev);
1343                 return ret;
1344         }
1345 
1346         if (vfio_pci_is_vga(pdev)) {
1347                 vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode);
1348                 vga_set_legacy_decoding(pdev,
1349                                         vfio_pci_set_vga_decode(vdev, false));
1350         }
1351 
1352         vfio_pci_probe_power_state(vdev);
1353 
1354         if (!disable_idle_d3) {
1355                 /*
1356                  * pci-core sets the device power state to an unknown value at
1357                  * bootup and after being removed from a driver.  The only
1358                  * transition it allows from this unknown state is to D0, which
1359                  * typically happens when a driver calls pci_enable_device().
1360                  * We're not ready to enable the device yet, but we do want to
1361                  * be able to get to D3.  Therefore first do a D0 transition
1362                  * before going to D3.
1363                  */
1364                 vfio_pci_set_power_state(vdev, PCI_D0);
1365                 vfio_pci_set_power_state(vdev, PCI_D3hot);
1366         }
1367 
1368         return ret;
1369 }
1370 
1371 static void vfio_pci_remove(struct pci_dev *pdev)
1372 {
1373         struct vfio_pci_device *vdev;
1374 
1375         vdev = vfio_del_group_dev(&pdev->dev);
1376         if (!vdev)
1377                 return;
1378 
1379         vfio_pci_reflck_put(vdev->reflck);
1380 
1381         vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
1382         kfree(vdev->region);
1383         mutex_destroy(&vdev->ioeventfds_lock);
1384 
1385         if (!disable_idle_d3)
1386                 vfio_pci_set_power_state(vdev, PCI_D0);
1387 
1388         kfree(vdev->pm_save);
1389         kfree(vdev);
1390 
1391         if (vfio_pci_is_vga(pdev)) {
1392                 vga_client_register(pdev, NULL, NULL, NULL);
1393                 vga_set_legacy_decoding(pdev,
1394                                 VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
1395                                 VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM);
1396         }
1397 }
1398 
1399 static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
1400                                                   pci_channel_state_t state)
1401 {
1402         struct vfio_pci_device *vdev;
1403         struct vfio_device *device;
1404 
1405         device = vfio_device_get_from_dev(&pdev->dev);
1406         if (device == NULL)
1407                 return PCI_ERS_RESULT_DISCONNECT;
1408 
1409         vdev = vfio_device_data(device);
1410         if (vdev == NULL) {
1411                 vfio_device_put(device);
1412                 return PCI_ERS_RESULT_DISCONNECT;
1413         }
1414 
1415         mutex_lock(&vdev->igate);
1416 
1417         if (vdev->err_trigger)
1418                 eventfd_signal(vdev->err_trigger, 1);
1419 
1420         mutex_unlock(&vdev->igate);
1421 
1422         vfio_device_put(device);
1423 
1424         return PCI_ERS_RESULT_CAN_RECOVER;
1425 }
1426 
1427 static const struct pci_error_handlers vfio_err_handlers = {
1428         .error_detected = vfio_pci_aer_err_detected,
1429 };
1430 
1431 static struct pci_driver vfio_pci_driver = {
1432         .name           = "vfio-pci",
1433         .id_table       = NULL, /* only dynamic ids */
1434         .probe          = vfio_pci_probe,
1435         .remove         = vfio_pci_remove,
1436         .err_handler    = &vfio_err_handlers,
1437 };
1438 
1439 static DEFINE_MUTEX(reflck_lock);
1440 
1441 static struct vfio_pci_reflck *vfio_pci_reflck_alloc(void)
1442 {
1443         struct vfio_pci_reflck *reflck;
1444 
1445         reflck = kzalloc(sizeof(*reflck), GFP_KERNEL);
1446         if (!reflck)
1447                 return ERR_PTR(-ENOMEM);
1448 
1449         kref_init(&reflck->kref);
1450         mutex_init(&reflck->lock);
1451 
1452         return reflck;
1453 }
1454 
1455 static void vfio_pci_reflck_get(struct vfio_pci_reflck *reflck)
1456 {
1457         kref_get(&reflck->kref);
1458 }
1459 
1460 static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data)
1461 {
1462         struct vfio_pci_reflck **preflck = data;
1463         struct vfio_device *device;
1464         struct vfio_pci_device *vdev;
1465 
1466         device = vfio_device_get_from_dev(&pdev->dev);
1467         if (!device)
1468                 return 0;
1469 
1470         if (pci_dev_driver(pdev) != &vfio_pci_driver) {
1471                 vfio_device_put(device);
1472                 return 0;
1473         }
1474 
1475         vdev = vfio_device_data(device);
1476 
1477         if (vdev->reflck) {
1478                 vfio_pci_reflck_get(vdev->reflck);
1479                 *preflck = vdev->reflck;
1480                 vfio_device_put(device);
1481                 return 1;
1482         }
1483 
1484         vfio_device_put(device);
1485         return 0;
1486 }
1487 
1488 static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev)
1489 {
1490         bool slot = !pci_probe_reset_slot(vdev->pdev->slot);
1491 
1492         mutex_lock(&reflck_lock);
1493 
1494         if (pci_is_root_bus(vdev->pdev->bus) ||
1495             vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_reflck_find,
1496                                           &vdev->reflck, slot) <= 0)
1497                 vdev->reflck = vfio_pci_reflck_alloc();
1498 
1499         mutex_unlock(&reflck_lock);
1500 
1501         return PTR_ERR_OR_ZERO(vdev->reflck);
1502 }
1503 
1504 static void vfio_pci_reflck_release(struct kref *kref)
1505 {
1506         struct vfio_pci_reflck *reflck = container_of(kref,
1507                                                       struct vfio_pci_reflck,
1508                                                       kref);
1509 
1510         kfree(reflck);
1511         mutex_unlock(&reflck_lock);
1512 }
1513 
1514 static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck)
1515 {
1516         kref_put_mutex(&reflck->kref, vfio_pci_reflck_release, &reflck_lock);
1517 }
1518 
1519 struct vfio_devices {
1520         struct vfio_device **devices;
1521         int cur_index;
1522         int max_index;
1523 };
1524 
1525 static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
1526 {
1527         struct vfio_devices *devs = data;
1528         struct vfio_device *device;
1529         struct vfio_pci_device *vdev;
1530 
1531         if (devs->cur_index == devs->max_index)
1532                 return -ENOSPC;
1533 
1534         device = vfio_device_get_from_dev(&pdev->dev);
1535         if (!device)
1536                 return -EINVAL;
1537 
1538         if (pci_dev_driver(pdev) != &vfio_pci_driver) {
1539                 vfio_device_put(device);
1540                 return -EBUSY;
1541         }
1542 
1543         vdev = vfio_device_data(device);
1544 
1545         /* Fault if the device is not unused */
1546         if (vdev->refcnt) {
1547                 vfio_device_put(device);
1548                 return -EBUSY;
1549         }
1550 
1551         devs->devices[devs->cur_index++] = device;
1552         return 0;
1553 }
1554 
1555 /*
1556  * If a bus or slot reset is available for the provided device and:
1557  *  - All of the devices affected by that bus or slot reset are unused
1558  *    (!refcnt)
1559  *  - At least one of the affected devices is marked dirty via
1560  *    needs_reset (such as by lack of FLR support)
1561  * Then attempt to perform that bus or slot reset.  Callers are required
1562  * to hold vdev->reflck->lock, protecting the bus/slot reset group from
1563  * concurrent opens.  A vfio_device reference is acquired for each device
1564  * to prevent unbinds during the reset operation.
1565  *
1566  * NB: vfio-core considers a group to be viable even if some devices are
1567  * bound to drivers like pci-stub or pcieport.  Here we require all devices
1568  * to be bound to vfio_pci since that's the only way we can be sure they
1569  * stay put.
1570  */
1571 static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
1572 {
1573         struct vfio_devices devs = { .cur_index = 0 };
1574         int i = 0, ret = -EINVAL;
1575         bool slot = false;
1576         struct vfio_pci_device *tmp;
1577 
1578         if (!pci_probe_reset_slot(vdev->pdev->slot))
1579                 slot = true;
1580         else if (pci_probe_reset_bus(vdev->pdev->bus))
1581                 return;
1582 
1583         if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
1584                                           &i, slot) || !i)
1585                 return;
1586 
1587         devs.max_index = i;
1588         devs.devices = kcalloc(i, sizeof(struct vfio_device *), GFP_KERNEL);
1589         if (!devs.devices)
1590                 return;
1591 
1592         if (vfio_pci_for_each_slot_or_bus(vdev->pdev,
1593                                           vfio_pci_get_unused_devs,
1594                                           &devs, slot))
1595                 goto put_devs;
1596 
1597         /* Does at least one need a reset? */
1598         for (i = 0; i < devs.cur_index; i++) {
1599                 tmp = vfio_device_data(devs.devices[i]);
1600                 if (tmp->needs_reset) {
1601                         ret = pci_reset_bus(vdev->pdev);
1602                         break;
1603                 }
1604         }
1605 
1606 put_devs:
1607         for (i = 0; i < devs.cur_index; i++) {
1608                 tmp = vfio_device_data(devs.devices[i]);
1609 
1610                 /*
1611                  * If reset was successful, affected devices no longer need
1612                  * a reset and we should return all the collateral devices
1613                  * to low power.  If not successful, we either didn't reset
1614                  * the bus or timed out waiting for it, so let's not touch
1615                  * the power state.
1616                  */
1617                 if (!ret) {
1618                         tmp->needs_reset = false;
1619 
1620                         if (tmp != vdev && !disable_idle_d3)
1621                                 vfio_pci_set_power_state(tmp, PCI_D3hot);
1622                 }
1623 
1624                 vfio_device_put(devs.devices[i]);
1625         }
1626 
1627         kfree(devs.devices);
1628 }
1629 
1630 static void __exit vfio_pci_cleanup(void)
1631 {
1632         pci_unregister_driver(&vfio_pci_driver);
1633         vfio_pci_uninit_perm_bits();
1634 }
1635 
1636 static void __init vfio_pci_fill_ids(void)
1637 {
1638         char *p, *id;
1639         int rc;
1640 
1641         /* no ids passed actually */
1642         if (ids[0] == '\0')
1643                 return;
1644 
1645         /* add ids specified in the module parameter */
1646         p = ids;
1647         while ((id = strsep(&p, ","))) {
1648                 unsigned int vendor, device, subvendor = PCI_ANY_ID,
1649                         subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
1650                 int fields;
1651 
1652                 if (!strlen(id))
1653                         continue;
1654 
1655                 fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
1656                                 &vendor, &device, &subvendor, &subdevice,
1657                                 &class, &class_mask);
1658 
1659                 if (fields < 2) {
1660                         pr_warn("invalid id string \"%s\"\n", id);
1661                         continue;
1662                 }
1663 
1664                 rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
1665                                    subvendor, subdevice, class, class_mask, 0);
1666                 if (rc)
1667                         pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n",
1668                                 vendor, device, subvendor, subdevice,
1669                                 class, class_mask, rc);
1670                 else
1671                         pr_info("add [%04x:%04x[%04x:%04x]] class %#08x/%08x\n",
1672                                 vendor, device, subvendor, subdevice,
1673                                 class, class_mask);
1674         }
1675 }
1676 
1677 static int __init vfio_pci_init(void)
1678 {
1679         int ret;
1680 
1681         /* Allocate shared config space permision data used by all devices */
1682         ret = vfio_pci_init_perm_bits();
1683         if (ret)
1684                 return ret;
1685 
1686         /* Register and scan for devices */
1687         ret = pci_register_driver(&vfio_pci_driver);
1688         if (ret)
1689                 goto out_driver;
1690 
1691         vfio_pci_fill_ids();
1692 
1693         return 0;
1694 
1695 out_driver:
1696         vfio_pci_uninit_perm_bits();
1697         return ret;
1698 }
1699 
1700 module_init(vfio_pci_init);
1701 module_exit(vfio_pci_cleanup);
1702 
1703 MODULE_VERSION(DRIVER_VERSION);
1704 MODULE_LICENSE("GPL v2");
1705 MODULE_AUTHOR(DRIVER_AUTHOR);
1706 MODULE_DESCRIPTION(DRIVER_DESC);
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/vfio/pci/vfio_pci.c

DEFINITIONS
