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
13 #include <linux/device.h>
14 #include <linux/eventfd.h>
15 #include <linux/file.h>
16 #include <linux/interrupt.h>
17 #include <linux/iommu.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/notifier.h>
21 #include <linux/pci.h>
22 #include <linux/pm_runtime.h>
23 #include <linux/slab.h>
24 #include <linux/types.h>
25 #include <linux/uaccess.h>
26 #include <linux/vfio.h>
27 #include <linux/vgaarb.h>
28 #include <linux/nospec.h>
29 #include <linux/sched/mm.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 bool enable_sriov;
58 #ifdef CONFIG_PCI_IOV
59 module_param(enable_sriov, bool, 0644);
60 MODULE_PARM_DESC(enable_sriov, "Enable support for SR-IOV configuration. Enabling SR-IOV on a PF typically requires support of the userspace PF driver, enabling VFs without such support may result in non-functional VFs or PF.");
61 #endif
62
63 static bool disable_denylist;
64 module_param(disable_denylist, bool, 0444);
65 MODULE_PARM_DESC(disable_denylist, "Disable use of device denylist. Disabling the denylist allows binding to devices with known errata that may lead to exploitable stability or security issues when accessed by untrusted users.");
66
vfio_vga_disabled(void)67 static inline bool vfio_vga_disabled(void)
68 {
69 #ifdef CONFIG_VFIO_PCI_VGA
70 return disable_vga;
71 #else
72 return true;
73 #endif
74 }
75
vfio_pci_dev_in_denylist(struct pci_dev * pdev)76 static bool vfio_pci_dev_in_denylist(struct pci_dev *pdev)
77 {
78 switch (pdev->vendor) {
79 case PCI_VENDOR_ID_INTEL:
80 switch (pdev->device) {
81 case PCI_DEVICE_ID_INTEL_QAT_C3XXX:
82 case PCI_DEVICE_ID_INTEL_QAT_C3XXX_VF:
83 case PCI_DEVICE_ID_INTEL_QAT_C62X:
84 case PCI_DEVICE_ID_INTEL_QAT_C62X_VF:
85 case PCI_DEVICE_ID_INTEL_QAT_DH895XCC:
86 case PCI_DEVICE_ID_INTEL_QAT_DH895XCC_VF:
87 return true;
88 default:
89 return false;
90 }
91 }
92
93 return false;
94 }
95
vfio_pci_is_denylisted(struct pci_dev * pdev)96 static bool vfio_pci_is_denylisted(struct pci_dev *pdev)
97 {
98 if (!vfio_pci_dev_in_denylist(pdev))
99 return false;
100
101 if (disable_denylist) {
102 pci_warn(pdev,
103 "device denylist disabled - allowing device %04x:%04x.\n",
104 pdev->vendor, pdev->device);
105 return false;
106 }
107
108 pci_warn(pdev, "%04x:%04x exists in vfio-pci device denylist, driver probing disallowed.\n",
109 pdev->vendor, pdev->device);
110
111 return true;
112 }
113
114 /*
115 * Our VGA arbiter participation is limited since we don't know anything
116 * about the device itself. However, if the device is the only VGA device
117 * downstream of a bridge and VFIO VGA support is disabled, then we can
118 * safely return legacy VGA IO and memory as not decoded since the user
119 * has no way to get to it and routing can be disabled externally at the
120 * bridge.
121 */
vfio_pci_set_vga_decode(void * opaque,bool single_vga)122 static unsigned int vfio_pci_set_vga_decode(void *opaque, bool single_vga)
123 {
124 struct vfio_pci_device *vdev = opaque;
125 struct pci_dev *tmp = NULL, *pdev = vdev->pdev;
126 unsigned char max_busnr;
127 unsigned int decodes;
128
129 if (single_vga || !vfio_vga_disabled() || pci_is_root_bus(pdev->bus))
130 return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
131 VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
132
133 max_busnr = pci_bus_max_busnr(pdev->bus);
134 decodes = VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
135
136 while ((tmp = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, tmp)) != NULL) {
137 if (tmp == pdev ||
138 pci_domain_nr(tmp->bus) != pci_domain_nr(pdev->bus) ||
139 pci_is_root_bus(tmp->bus))
140 continue;
141
142 if (tmp->bus->number >= pdev->bus->number &&
143 tmp->bus->number <= max_busnr) {
144 pci_dev_put(tmp);
145 decodes |= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
146 break;
147 }
148 }
149
150 return decodes;
151 }
152
vfio_pci_is_vga(struct pci_dev * pdev)153 static inline bool vfio_pci_is_vga(struct pci_dev *pdev)
154 {
155 return (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA;
156 }
157
vfio_pci_probe_mmaps(struct vfio_pci_device * vdev)158 static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev)
159 {
160 struct resource *res;
161 int i;
162 struct vfio_pci_dummy_resource *dummy_res;
163
164 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
165 int bar = i + PCI_STD_RESOURCES;
166
167 res = &vdev->pdev->resource[bar];
168
169 if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP))
170 goto no_mmap;
171
172 if (!(res->flags & IORESOURCE_MEM))
173 goto no_mmap;
174
175 /*
176 * The PCI core shouldn't set up a resource with a
177 * type but zero size. But there may be bugs that
178 * cause us to do that.
179 */
180 if (!resource_size(res))
181 goto no_mmap;
182
183 if (resource_size(res) >= PAGE_SIZE) {
184 vdev->bar_mmap_supported[bar] = true;
185 continue;
186 }
187
188 if (!(res->start & ~PAGE_MASK)) {
189 /*
190 * Add a dummy resource to reserve the remainder
191 * of the exclusive page in case that hot-add
192 * device's bar is assigned into it.
193 */
194 dummy_res = kzalloc(sizeof(*dummy_res), GFP_KERNEL);
195 if (dummy_res == NULL)
196 goto no_mmap;
197
198 dummy_res->resource.name = "vfio sub-page reserved";
199 dummy_res->resource.start = res->end + 1;
200 dummy_res->resource.end = res->start + PAGE_SIZE - 1;
201 dummy_res->resource.flags = res->flags;
202 if (request_resource(res->parent,
203 &dummy_res->resource)) {
204 kfree(dummy_res);
205 goto no_mmap;
206 }
207 dummy_res->index = bar;
208 list_add(&dummy_res->res_next,
209 &vdev->dummy_resources_list);
210 vdev->bar_mmap_supported[bar] = true;
211 continue;
212 }
213 /*
214 * Here we don't handle the case when the BAR is not page
215 * aligned because we can't expect the BAR will be
216 * assigned into the same location in a page in guest
217 * when we passthrough the BAR. And it's hard to access
218 * this BAR in userspace because we have no way to get
219 * the BAR's location in a page.
220 */
221 no_mmap:
222 vdev->bar_mmap_supported[bar] = false;
223 }
224 }
225
226 static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev);
227 static void vfio_pci_disable(struct vfio_pci_device *vdev);
228 static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data);
229
230 /*
231 * INTx masking requires the ability to disable INTx signaling via PCI_COMMAND
232 * _and_ the ability detect when the device is asserting INTx via PCI_STATUS.
233 * If a device implements the former but not the latter we would typically
234 * expect broken_intx_masking be set and require an exclusive interrupt.
235 * However since we do have control of the device's ability to assert INTx,
236 * we can instead pretend that the device does not implement INTx, virtualizing
237 * the pin register to report zero and maintaining DisINTx set on the host.
238 */
vfio_pci_nointx(struct pci_dev * pdev)239 static bool vfio_pci_nointx(struct pci_dev *pdev)
240 {
241 switch (pdev->vendor) {
242 case PCI_VENDOR_ID_INTEL:
243 switch (pdev->device) {
244 /* All i40e (XL710/X710/XXV710) 10/20/25/40GbE NICs */
245 case 0x1572:
246 case 0x1574:
247 case 0x1580 ... 0x1581:
248 case 0x1583 ... 0x158b:
249 case 0x37d0 ... 0x37d2:
250 /* X550 */
251 case 0x1563:
252 return true;
253 default:
254 return false;
255 }
256 }
257
258 return false;
259 }
260
vfio_pci_probe_power_state(struct vfio_pci_device * vdev)261 static void vfio_pci_probe_power_state(struct vfio_pci_device *vdev)
262 {
263 struct pci_dev *pdev = vdev->pdev;
264 u16 pmcsr;
265
266 if (!pdev->pm_cap)
267 return;
268
269 pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &pmcsr);
270
271 vdev->needs_pm_restore = !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
272 }
273
274 /*
275 * pci_set_power_state() wrapper handling devices which perform a soft reset on
276 * D3->D0 transition. Save state prior to D0/1/2->D3, stash it on the vdev,
277 * restore when returned to D0. Saved separately from pci_saved_state for use
278 * by PM capability emulation and separately from pci_dev internal saved state
279 * to avoid it being overwritten and consumed around other resets.
280 */
vfio_pci_set_power_state(struct vfio_pci_device * vdev,pci_power_t state)281 int vfio_pci_set_power_state(struct vfio_pci_device *vdev, pci_power_t state)
282 {
283 struct pci_dev *pdev = vdev->pdev;
284 bool needs_restore = false, needs_save = false;
285 int ret;
286
287 if (vdev->needs_pm_restore) {
288 if (pdev->current_state < PCI_D3hot && state >= PCI_D3hot) {
289 pci_save_state(pdev);
290 needs_save = true;
291 }
292
293 if (pdev->current_state >= PCI_D3hot && state <= PCI_D0)
294 needs_restore = true;
295 }
296
297 ret = pci_set_power_state(pdev, state);
298
299 if (!ret) {
300 /* D3 might be unsupported via quirk, skip unless in D3 */
301 if (needs_save && pdev->current_state >= PCI_D3hot) {
302 vdev->pm_save = pci_store_saved_state(pdev);
303 } else if (needs_restore) {
304 pci_load_and_free_saved_state(pdev, &vdev->pm_save);
305 pci_restore_state(pdev);
306 }
307 }
308
309 return ret;
310 }
311
vfio_pci_enable(struct vfio_pci_device * vdev)312 static int vfio_pci_enable(struct vfio_pci_device *vdev)
313 {
314 struct pci_dev *pdev = vdev->pdev;
315 int ret;
316 u16 cmd;
317 u8 msix_pos;
318
319 vfio_pci_set_power_state(vdev, PCI_D0);
320
321 /* Don't allow our initial saved state to include busmaster */
322 pci_clear_master(pdev);
323
324 ret = pci_enable_device(pdev);
325 if (ret)
326 return ret;
327
328 /* If reset fails because of the device lock, fail this path entirely */
329 ret = pci_try_reset_function(pdev);
330 if (ret == -EAGAIN) {
331 pci_disable_device(pdev);
332 return ret;
333 }
334
335 vdev->reset_works = !ret;
336 pci_save_state(pdev);
337 vdev->pci_saved_state = pci_store_saved_state(pdev);
338 if (!vdev->pci_saved_state)
339 pci_dbg(pdev, "%s: Couldn't store saved state\n", __func__);
340
341 if (likely(!nointxmask)) {
342 if (vfio_pci_nointx(pdev)) {
343 pci_info(pdev, "Masking broken INTx support\n");
344 vdev->nointx = true;
345 pci_intx(pdev, 0);
346 } else
347 vdev->pci_2_3 = pci_intx_mask_supported(pdev);
348 }
349
350 pci_read_config_word(pdev, PCI_COMMAND, &cmd);
351 if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
352 cmd &= ~PCI_COMMAND_INTX_DISABLE;
353 pci_write_config_word(pdev, PCI_COMMAND, cmd);
354 }
355
356 ret = vfio_config_init(vdev);
357 if (ret) {
358 kfree(vdev->pci_saved_state);
359 vdev->pci_saved_state = NULL;
360 pci_disable_device(pdev);
361 return ret;
362 }
363
364 msix_pos = pdev->msix_cap;
365 if (msix_pos) {
366 u16 flags;
367 u32 table;
368
369 pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
370 pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
371
372 vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
373 vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
374 vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
375 } else
376 vdev->msix_bar = 0xFF;
377
378 if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))
379 vdev->has_vga = true;
380
381
382 if (vfio_pci_is_vga(pdev) &&
383 pdev->vendor == PCI_VENDOR_ID_INTEL &&
384 IS_ENABLED(CONFIG_VFIO_PCI_IGD)) {
385 ret = vfio_pci_igd_init(vdev);
386 if (ret && ret != -ENODEV) {
387 pci_warn(pdev, "Failed to setup Intel IGD regions\n");
388 goto disable_exit;
389 }
390 }
391
392 if (pdev->vendor == PCI_VENDOR_ID_NVIDIA &&
393 IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) {
394 ret = vfio_pci_nvdia_v100_nvlink2_init(vdev);
395 if (ret && ret != -ENODEV) {
396 pci_warn(pdev, "Failed to setup NVIDIA NV2 RAM region\n");
397 goto disable_exit;
398 }
399 }
400
401 if (pdev->vendor == PCI_VENDOR_ID_IBM &&
402 IS_ENABLED(CONFIG_VFIO_PCI_NVLINK2)) {
403 ret = vfio_pci_ibm_npu2_init(vdev);
404 if (ret && ret != -ENODEV) {
405 pci_warn(pdev, "Failed to setup NVIDIA NV2 ATSD region\n");
406 goto disable_exit;
407 }
408 }
409
410 vfio_pci_probe_mmaps(vdev);
411
412 return 0;
413
414 disable_exit:
415 vfio_pci_disable(vdev);
416 return ret;
417 }
418
vfio_pci_disable(struct vfio_pci_device * vdev)419 static void vfio_pci_disable(struct vfio_pci_device *vdev)
420 {
421 struct pci_dev *pdev = vdev->pdev;
422 struct vfio_pci_dummy_resource *dummy_res, *tmp;
423 struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
424 int i, bar;
425
426 /* Stop the device from further DMA */
427 pci_clear_master(pdev);
428
429 vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
430 VFIO_IRQ_SET_ACTION_TRIGGER,
431 vdev->irq_type, 0, 0, NULL);
432
433 /* Device closed, don't need mutex here */
434 list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
435 &vdev->ioeventfds_list, next) {
436 vfio_virqfd_disable(&ioeventfd->virqfd);
437 list_del(&ioeventfd->next);
438 kfree(ioeventfd);
439 }
440 vdev->ioeventfds_nr = 0;
441
442 vdev->virq_disabled = false;
443
444 for (i = 0; i < vdev->num_regions; i++)
445 vdev->region[i].ops->release(vdev, &vdev->region[i]);
446
447 vdev->num_regions = 0;
448 kfree(vdev->region);
449 vdev->region = NULL; /* don't krealloc a freed pointer */
450
451 vfio_config_free(vdev);
452
453 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
454 bar = i + PCI_STD_RESOURCES;
455 if (!vdev->barmap[bar])
456 continue;
457 pci_iounmap(pdev, vdev->barmap[bar]);
458 pci_release_selected_regions(pdev, 1 << bar);
459 vdev->barmap[bar] = NULL;
460 }
461
462 list_for_each_entry_safe(dummy_res, tmp,
463 &vdev->dummy_resources_list, res_next) {
464 list_del(&dummy_res->res_next);
465 release_resource(&dummy_res->resource);
466 kfree(dummy_res);
467 }
468
469 vdev->needs_reset = true;
470
471 /*
472 * If we have saved state, restore it. If we can reset the device,
473 * even better. Resetting with current state seems better than
474 * nothing, but saving and restoring current state without reset
475 * is just busy work.
476 */
477 if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
478 pci_info(pdev, "%s: Couldn't reload saved state\n", __func__);
479
480 if (!vdev->reset_works)
481 goto out;
482
483 pci_save_state(pdev);
484 }
485
486 /*
487 * Disable INTx and MSI, presumably to avoid spurious interrupts
488 * during reset. Stolen from pci_reset_function()
489 */
490 pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
491
492 /*
493 * Try to get the locks ourselves to prevent a deadlock. The
494 * success of this is dependent on being able to lock the device,
495 * which is not always possible.
496 * We can not use the "try" reset interface here, which will
497 * overwrite the previously restored configuration information.
498 */
499 if (vdev->reset_works && pci_cfg_access_trylock(pdev)) {
500 if (device_trylock(&pdev->dev)) {
501 if (!__pci_reset_function_locked(pdev))
502 vdev->needs_reset = false;
503 device_unlock(&pdev->dev);
504 }
505 pci_cfg_access_unlock(pdev);
506 }
507
508 pci_restore_state(pdev);
509 out:
510 pci_disable_device(pdev);
511
512 vfio_pci_try_bus_reset(vdev);
513
514 if (!disable_idle_d3)
515 vfio_pci_set_power_state(vdev, PCI_D3hot);
516 }
517
518 static struct pci_driver vfio_pci_driver;
519
get_pf_vdev(struct vfio_pci_device * vdev,struct vfio_device ** pf_dev)520 static struct vfio_pci_device *get_pf_vdev(struct vfio_pci_device *vdev,
521 struct vfio_device **pf_dev)
522 {
523 struct pci_dev *physfn = pci_physfn(vdev->pdev);
524
525 if (!vdev->pdev->is_virtfn)
526 return NULL;
527
528 *pf_dev = vfio_device_get_from_dev(&physfn->dev);
529 if (!*pf_dev)
530 return NULL;
531
532 if (pci_dev_driver(physfn) != &vfio_pci_driver) {
533 vfio_device_put(*pf_dev);
534 return NULL;
535 }
536
537 return vfio_device_data(*pf_dev);
538 }
539
vfio_pci_vf_token_user_add(struct vfio_pci_device * vdev,int val)540 static void vfio_pci_vf_token_user_add(struct vfio_pci_device *vdev, int val)
541 {
542 struct vfio_device *pf_dev;
543 struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_dev);
544
545 if (!pf_vdev)
546 return;
547
548 mutex_lock(&pf_vdev->vf_token->lock);
549 pf_vdev->vf_token->users += val;
550 WARN_ON(pf_vdev->vf_token->users < 0);
551 mutex_unlock(&pf_vdev->vf_token->lock);
552
553 vfio_device_put(pf_dev);
554 }
555
vfio_pci_release(void * device_data)556 static void vfio_pci_release(void *device_data)
557 {
558 struct vfio_pci_device *vdev = device_data;
559
560 mutex_lock(&vdev->reflck->lock);
561
562 if (!(--vdev->refcnt)) {
563 vfio_pci_vf_token_user_add(vdev, -1);
564 vfio_spapr_pci_eeh_release(vdev->pdev);
565 vfio_pci_disable(vdev);
566
567 mutex_lock(&vdev->igate);
568 if (vdev->err_trigger) {
569 eventfd_ctx_put(vdev->err_trigger);
570 vdev->err_trigger = NULL;
571 }
572 if (vdev->req_trigger) {
573 eventfd_ctx_put(vdev->req_trigger);
574 vdev->req_trigger = NULL;
575 }
576 mutex_unlock(&vdev->igate);
577 }
578
579 mutex_unlock(&vdev->reflck->lock);
580
581 module_put(THIS_MODULE);
582 }
583
vfio_pci_open(void * device_data)584 static int vfio_pci_open(void *device_data)
585 {
586 struct vfio_pci_device *vdev = device_data;
587 int ret = 0;
588
589 if (!try_module_get(THIS_MODULE))
590 return -ENODEV;
591
592 mutex_lock(&vdev->reflck->lock);
593
594 if (!vdev->refcnt) {
595 ret = vfio_pci_enable(vdev);
596 if (ret)
597 goto error;
598
599 vfio_spapr_pci_eeh_open(vdev->pdev);
600 vfio_pci_vf_token_user_add(vdev, 1);
601 }
602 vdev->refcnt++;
603 error:
604 mutex_unlock(&vdev->reflck->lock);
605 if (ret)
606 module_put(THIS_MODULE);
607 return ret;
608 }
609
vfio_pci_get_irq_count(struct vfio_pci_device * vdev,int irq_type)610 static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
611 {
612 if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
613 u8 pin;
614
615 if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) ||
616 vdev->nointx || vdev->pdev->is_virtfn)
617 return 0;
618
619 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
620
621 return pin ? 1 : 0;
622 } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
623 u8 pos;
624 u16 flags;
625
626 pos = vdev->pdev->msi_cap;
627 if (pos) {
628 pci_read_config_word(vdev->pdev,
629 pos + PCI_MSI_FLAGS, &flags);
630 return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
631 }
632 } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
633 u8 pos;
634 u16 flags;
635
636 pos = vdev->pdev->msix_cap;
637 if (pos) {
638 pci_read_config_word(vdev->pdev,
639 pos + PCI_MSIX_FLAGS, &flags);
640
641 return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
642 }
643 } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
644 if (pci_is_pcie(vdev->pdev))
645 return 1;
646 } else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
647 return 1;
648 }
649
650 return 0;
651 }
652
vfio_pci_count_devs(struct pci_dev * pdev,void * data)653 static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
654 {
655 (*(int *)data)++;
656 return 0;
657 }
658
659 struct vfio_pci_fill_info {
660 int max;
661 int cur;
662 struct vfio_pci_dependent_device *devices;
663 };
664
vfio_pci_fill_devs(struct pci_dev * pdev,void * data)665 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
666 {
667 struct vfio_pci_fill_info *fill = data;
668 struct iommu_group *iommu_group;
669
670 if (fill->cur == fill->max)
671 return -EAGAIN; /* Something changed, try again */
672
673 iommu_group = iommu_group_get(&pdev->dev);
674 if (!iommu_group)
675 return -EPERM; /* Cannot reset non-isolated devices */
676
677 fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
678 fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
679 fill->devices[fill->cur].bus = pdev->bus->number;
680 fill->devices[fill->cur].devfn = pdev->devfn;
681 fill->cur++;
682 iommu_group_put(iommu_group);
683 return 0;
684 }
685
686 struct vfio_pci_group_entry {
687 struct vfio_group *group;
688 int id;
689 };
690
691 struct vfio_pci_group_info {
692 int count;
693 struct vfio_pci_group_entry *groups;
694 };
695
vfio_pci_validate_devs(struct pci_dev * pdev,void * data)696 static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
697 {
698 struct vfio_pci_group_info *info = data;
699 struct iommu_group *group;
700 int id, i;
701
702 group = iommu_group_get(&pdev->dev);
703 if (!group)
704 return -EPERM;
705
706 id = iommu_group_id(group);
707
708 for (i = 0; i < info->count; i++)
709 if (info->groups[i].id == id)
710 break;
711
712 iommu_group_put(group);
713
714 return (i == info->count) ? -EINVAL : 0;
715 }
716
vfio_pci_dev_below_slot(struct pci_dev * pdev,struct pci_slot * slot)717 static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
718 {
719 for (; pdev; pdev = pdev->bus->self)
720 if (pdev->bus == slot->bus)
721 return (pdev->slot == slot);
722 return false;
723 }
724
725 struct vfio_pci_walk_info {
726 int (*fn)(struct pci_dev *, void *data);
727 void *data;
728 struct pci_dev *pdev;
729 bool slot;
730 int ret;
731 };
732
vfio_pci_walk_wrapper(struct pci_dev * pdev,void * data)733 static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
734 {
735 struct vfio_pci_walk_info *walk = data;
736
737 if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
738 walk->ret = walk->fn(pdev, walk->data);
739
740 return walk->ret;
741 }
742
vfio_pci_for_each_slot_or_bus(struct pci_dev * pdev,int (* fn)(struct pci_dev *,void * data),void * data,bool slot)743 static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
744 int (*fn)(struct pci_dev *,
745 void *data), void *data,
746 bool slot)
747 {
748 struct vfio_pci_walk_info walk = {
749 .fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
750 };
751
752 pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
753
754 return walk.ret;
755 }
756
msix_mmappable_cap(struct vfio_pci_device * vdev,struct vfio_info_cap * caps)757 static int msix_mmappable_cap(struct vfio_pci_device *vdev,
758 struct vfio_info_cap *caps)
759 {
760 struct vfio_info_cap_header header = {
761 .id = VFIO_REGION_INFO_CAP_MSIX_MAPPABLE,
762 .version = 1
763 };
764
765 return vfio_info_add_capability(caps, &header, sizeof(header));
766 }
767
vfio_pci_register_dev_region(struct vfio_pci_device * vdev,unsigned int type,unsigned int subtype,const struct vfio_pci_regops * ops,size_t size,u32 flags,void * data)768 int vfio_pci_register_dev_region(struct vfio_pci_device *vdev,
769 unsigned int type, unsigned int subtype,
770 const struct vfio_pci_regops *ops,
771 size_t size, u32 flags, void *data)
772 {
773 struct vfio_pci_region *region;
774
775 region = krealloc(vdev->region,
776 (vdev->num_regions + 1) * sizeof(*region),
777 GFP_KERNEL);
778 if (!region)
779 return -ENOMEM;
780
781 vdev->region = region;
782 vdev->region[vdev->num_regions].type = type;
783 vdev->region[vdev->num_regions].subtype = subtype;
784 vdev->region[vdev->num_regions].ops = ops;
785 vdev->region[vdev->num_regions].size = size;
786 vdev->region[vdev->num_regions].flags = flags;
787 vdev->region[vdev->num_regions].data = data;
788
789 vdev->num_regions++;
790
791 return 0;
792 }
793
794 struct vfio_devices {
795 struct vfio_device **devices;
796 int cur_index;
797 int max_index;
798 };
799
vfio_pci_ioctl(void * device_data,unsigned int cmd,unsigned long arg)800 static long vfio_pci_ioctl(void *device_data,
801 unsigned int cmd, unsigned long arg)
802 {
803 struct vfio_pci_device *vdev = device_data;
804 unsigned long minsz;
805
806 if (cmd == VFIO_DEVICE_GET_INFO) {
807 struct vfio_device_info info;
808 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
809 unsigned long capsz;
810
811 minsz = offsetofend(struct vfio_device_info, num_irqs);
812
813 /* For backward compatibility, cannot require this */
814 capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
815
816 if (copy_from_user(&info, (void __user *)arg, minsz))
817 return -EFAULT;
818
819 if (info.argsz < minsz)
820 return -EINVAL;
821
822 if (info.argsz >= capsz) {
823 minsz = capsz;
824 info.cap_offset = 0;
825 }
826
827 info.flags = VFIO_DEVICE_FLAGS_PCI;
828
829 if (vdev->reset_works)
830 info.flags |= VFIO_DEVICE_FLAGS_RESET;
831
832 info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
833 info.num_irqs = VFIO_PCI_NUM_IRQS;
834
835 if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV)) {
836 int ret = vfio_pci_info_zdev_add_caps(vdev, &caps);
837
838 if (ret && ret != -ENODEV) {
839 pci_warn(vdev->pdev, "Failed to setup zPCI info capabilities\n");
840 return ret;
841 }
842 }
843
844 if (caps.size) {
845 info.flags |= VFIO_DEVICE_FLAGS_CAPS;
846 if (info.argsz < sizeof(info) + caps.size) {
847 info.argsz = sizeof(info) + caps.size;
848 } else {
849 vfio_info_cap_shift(&caps, sizeof(info));
850 if (copy_to_user((void __user *)arg +
851 sizeof(info), caps.buf,
852 caps.size)) {
853 kfree(caps.buf);
854 return -EFAULT;
855 }
856 info.cap_offset = sizeof(info);
857 }
858
859 kfree(caps.buf);
860 }
861
862 return copy_to_user((void __user *)arg, &info, minsz) ?
863 -EFAULT : 0;
864
865 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
866 struct pci_dev *pdev = vdev->pdev;
867 struct vfio_region_info info;
868 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
869 int i, ret;
870
871 minsz = offsetofend(struct vfio_region_info, offset);
872
873 if (copy_from_user(&info, (void __user *)arg, minsz))
874 return -EFAULT;
875
876 if (info.argsz < minsz)
877 return -EINVAL;
878
879 switch (info.index) {
880 case VFIO_PCI_CONFIG_REGION_INDEX:
881 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
882 info.size = pdev->cfg_size;
883 info.flags = VFIO_REGION_INFO_FLAG_READ |
884 VFIO_REGION_INFO_FLAG_WRITE;
885 break;
886 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
887 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
888 info.size = pci_resource_len(pdev, info.index);
889 if (!info.size) {
890 info.flags = 0;
891 break;
892 }
893
894 info.flags = VFIO_REGION_INFO_FLAG_READ |
895 VFIO_REGION_INFO_FLAG_WRITE;
896 if (vdev->bar_mmap_supported[info.index]) {
897 info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
898 if (info.index == vdev->msix_bar) {
899 ret = msix_mmappable_cap(vdev, &caps);
900 if (ret)
901 return ret;
902 }
903 }
904
905 break;
906 case VFIO_PCI_ROM_REGION_INDEX:
907 {
908 void __iomem *io;
909 size_t size;
910 u16 cmd;
911
912 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
913 info.flags = 0;
914
915 /* Report the BAR size, not the ROM size */
916 info.size = pci_resource_len(pdev, info.index);
917 if (!info.size) {
918 /* Shadow ROMs appear as PCI option ROMs */
919 if (pdev->resource[PCI_ROM_RESOURCE].flags &
920 IORESOURCE_ROM_SHADOW)
921 info.size = 0x20000;
922 else
923 break;
924 }
925
926 /*
927 * Is it really there? Enable memory decode for
928 * implicit access in pci_map_rom().
929 */
930 cmd = vfio_pci_memory_lock_and_enable(vdev);
931 io = pci_map_rom(pdev, &size);
932 if (io) {
933 info.flags = VFIO_REGION_INFO_FLAG_READ;
934 pci_unmap_rom(pdev, io);
935 } else {
936 info.size = 0;
937 }
938 vfio_pci_memory_unlock_and_restore(vdev, cmd);
939
940 break;
941 }
942 case VFIO_PCI_VGA_REGION_INDEX:
943 if (!vdev->has_vga)
944 return -EINVAL;
945
946 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
947 info.size = 0xc0000;
948 info.flags = VFIO_REGION_INFO_FLAG_READ |
949 VFIO_REGION_INFO_FLAG_WRITE;
950
951 break;
952 default:
953 {
954 struct vfio_region_info_cap_type cap_type = {
955 .header.id = VFIO_REGION_INFO_CAP_TYPE,
956 .header.version = 1 };
957
958 if (info.index >=
959 VFIO_PCI_NUM_REGIONS + vdev->num_regions)
960 return -EINVAL;
961 info.index = array_index_nospec(info.index,
962 VFIO_PCI_NUM_REGIONS +
963 vdev->num_regions);
964
965 i = info.index - VFIO_PCI_NUM_REGIONS;
966
967 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
968 info.size = vdev->region[i].size;
969 info.flags = vdev->region[i].flags;
970
971 cap_type.type = vdev->region[i].type;
972 cap_type.subtype = vdev->region[i].subtype;
973
974 ret = vfio_info_add_capability(&caps, &cap_type.header,
975 sizeof(cap_type));
976 if (ret)
977 return ret;
978
979 if (vdev->region[i].ops->add_capability) {
980 ret = vdev->region[i].ops->add_capability(vdev,
981 &vdev->region[i], &caps);
982 if (ret)
983 return ret;
984 }
985 }
986 }
987
988 if (caps.size) {
989 info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
990 if (info.argsz < sizeof(info) + caps.size) {
991 info.argsz = sizeof(info) + caps.size;
992 info.cap_offset = 0;
993 } else {
994 vfio_info_cap_shift(&caps, sizeof(info));
995 if (copy_to_user((void __user *)arg +
996 sizeof(info), caps.buf,
997 caps.size)) {
998 kfree(caps.buf);
999 return -EFAULT;
1000 }
1001 info.cap_offset = sizeof(info);
1002 }
1003
1004 kfree(caps.buf);
1005 }
1006
1007 return copy_to_user((void __user *)arg, &info, minsz) ?
1008 -EFAULT : 0;
1009
1010 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
1011 struct vfio_irq_info info;
1012
1013 minsz = offsetofend(struct vfio_irq_info, count);
1014
1015 if (copy_from_user(&info, (void __user *)arg, minsz))
1016 return -EFAULT;
1017
1018 if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
1019 return -EINVAL;
1020
1021 switch (info.index) {
1022 case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
1023 case VFIO_PCI_REQ_IRQ_INDEX:
1024 break;
1025 case VFIO_PCI_ERR_IRQ_INDEX:
1026 if (pci_is_pcie(vdev->pdev))
1027 break;
1028 fallthrough;
1029 default:
1030 return -EINVAL;
1031 }
1032
1033 info.flags = VFIO_IRQ_INFO_EVENTFD;
1034
1035 info.count = vfio_pci_get_irq_count(vdev, info.index);
1036
1037 if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
1038 info.flags |= (VFIO_IRQ_INFO_MASKABLE |
1039 VFIO_IRQ_INFO_AUTOMASKED);
1040 else
1041 info.flags |= VFIO_IRQ_INFO_NORESIZE;
1042
1043 return copy_to_user((void __user *)arg, &info, minsz) ?
1044 -EFAULT : 0;
1045
1046 } else if (cmd == VFIO_DEVICE_SET_IRQS) {
1047 struct vfio_irq_set hdr;
1048 u8 *data = NULL;
1049 int max, ret = 0;
1050 size_t data_size = 0;
1051
1052 minsz = offsetofend(struct vfio_irq_set, count);
1053
1054 if (copy_from_user(&hdr, (void __user *)arg, minsz))
1055 return -EFAULT;
1056
1057 max = vfio_pci_get_irq_count(vdev, hdr.index);
1058
1059 ret = vfio_set_irqs_validate_and_prepare(&hdr, max,
1060 VFIO_PCI_NUM_IRQS, &data_size);
1061 if (ret)
1062 return ret;
1063
1064 if (data_size) {
1065 data = memdup_user((void __user *)(arg + minsz),
1066 data_size);
1067 if (IS_ERR(data))
1068 return PTR_ERR(data);
1069 }
1070
1071 mutex_lock(&vdev->igate);
1072
1073 ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
1074 hdr.start, hdr.count, data);
1075
1076 mutex_unlock(&vdev->igate);
1077 kfree(data);
1078
1079 return ret;
1080
1081 } else if (cmd == VFIO_DEVICE_RESET) {
1082 int ret;
1083
1084 if (!vdev->reset_works)
1085 return -EINVAL;
1086
1087 vfio_pci_zap_and_down_write_memory_lock(vdev);
1088 ret = pci_try_reset_function(vdev->pdev);
1089 up_write(&vdev->memory_lock);
1090
1091 return ret;
1092
1093 } else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
1094 struct vfio_pci_hot_reset_info hdr;
1095 struct vfio_pci_fill_info fill = { 0 };
1096 struct vfio_pci_dependent_device *devices = NULL;
1097 bool slot = false;
1098 int ret = 0;
1099
1100 minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
1101
1102 if (copy_from_user(&hdr, (void __user *)arg, minsz))
1103 return -EFAULT;
1104
1105 if (hdr.argsz < minsz)
1106 return -EINVAL;
1107
1108 hdr.flags = 0;
1109
1110 /* Can we do a slot or bus reset or neither? */
1111 if (!pci_probe_reset_slot(vdev->pdev->slot))
1112 slot = true;
1113 else if (pci_probe_reset_bus(vdev->pdev->bus))
1114 return -ENODEV;
1115
1116 /* How many devices are affected? */
1117 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1118 vfio_pci_count_devs,
1119 &fill.max, slot);
1120 if (ret)
1121 return ret;
1122
1123 WARN_ON(!fill.max); /* Should always be at least one */
1124
1125 /*
1126 * If there's enough space, fill it now, otherwise return
1127 * -ENOSPC and the number of devices affected.
1128 */
1129 if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
1130 ret = -ENOSPC;
1131 hdr.count = fill.max;
1132 goto reset_info_exit;
1133 }
1134
1135 devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
1136 if (!devices)
1137 return -ENOMEM;
1138
1139 fill.devices = devices;
1140
1141 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1142 vfio_pci_fill_devs,
1143 &fill, slot);
1144
1145 /*
1146 * If a device was removed between counting and filling,
1147 * we may come up short of fill.max. If a device was
1148 * added, we'll have a return of -EAGAIN above.
1149 */
1150 if (!ret)
1151 hdr.count = fill.cur;
1152
1153 reset_info_exit:
1154 if (copy_to_user((void __user *)arg, &hdr, minsz))
1155 ret = -EFAULT;
1156
1157 if (!ret) {
1158 if (copy_to_user((void __user *)(arg + minsz), devices,
1159 hdr.count * sizeof(*devices)))
1160 ret = -EFAULT;
1161 }
1162
1163 kfree(devices);
1164 return ret;
1165
1166 } else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
1167 struct vfio_pci_hot_reset hdr;
1168 int32_t *group_fds;
1169 struct vfio_pci_group_entry *groups;
1170 struct vfio_pci_group_info info;
1171 struct vfio_devices devs = { .cur_index = 0 };
1172 bool slot = false;
1173 int i, group_idx, mem_idx = 0, count = 0, ret = 0;
1174
1175 minsz = offsetofend(struct vfio_pci_hot_reset, count);
1176
1177 if (copy_from_user(&hdr, (void __user *)arg, minsz))
1178 return -EFAULT;
1179
1180 if (hdr.argsz < minsz || hdr.flags)
1181 return -EINVAL;
1182
1183 /* Can we do a slot or bus reset or neither? */
1184 if (!pci_probe_reset_slot(vdev->pdev->slot))
1185 slot = true;
1186 else if (pci_probe_reset_bus(vdev->pdev->bus))
1187 return -ENODEV;
1188
1189 /*
1190 * We can't let userspace give us an arbitrarily large
1191 * buffer to copy, so verify how many we think there
1192 * could be. Note groups can have multiple devices so
1193 * one group per device is the max.
1194 */
1195 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1196 vfio_pci_count_devs,
1197 &count, slot);
1198 if (ret)
1199 return ret;
1200
1201 /* Somewhere between 1 and count is OK */
1202 if (!hdr.count || hdr.count > count)
1203 return -EINVAL;
1204
1205 group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
1206 groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
1207 if (!group_fds || !groups) {
1208 kfree(group_fds);
1209 kfree(groups);
1210 return -ENOMEM;
1211 }
1212
1213 if (copy_from_user(group_fds, (void __user *)(arg + minsz),
1214 hdr.count * sizeof(*group_fds))) {
1215 kfree(group_fds);
1216 kfree(groups);
1217 return -EFAULT;
1218 }
1219
1220 /*
1221 * For each group_fd, get the group through the vfio external
1222 * user interface and store the group and iommu ID. This
1223 * ensures the group is held across the reset.
1224 */
1225 for (group_idx = 0; group_idx < hdr.count; group_idx++) {
1226 struct vfio_group *group;
1227 struct fd f = fdget(group_fds[group_idx]);
1228 if (!f.file) {
1229 ret = -EBADF;
1230 break;
1231 }
1232
1233 group = vfio_group_get_external_user(f.file);
1234 fdput(f);
1235 if (IS_ERR(group)) {
1236 ret = PTR_ERR(group);
1237 break;
1238 }
1239
1240 groups[group_idx].group = group;
1241 groups[group_idx].id =
1242 vfio_external_user_iommu_id(group);
1243 }
1244
1245 kfree(group_fds);
1246
1247 /* release reference to groups on error */
1248 if (ret)
1249 goto hot_reset_release;
1250
1251 info.count = hdr.count;
1252 info.groups = groups;
1253
1254 /*
1255 * Test whether all the affected devices are contained
1256 * by the set of groups provided by the user.
1257 */
1258 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1259 vfio_pci_validate_devs,
1260 &info, slot);
1261 if (ret)
1262 goto hot_reset_release;
1263
1264 devs.max_index = count;
1265 devs.devices = kcalloc(count, sizeof(struct vfio_device *),
1266 GFP_KERNEL);
1267 if (!devs.devices) {
1268 ret = -ENOMEM;
1269 goto hot_reset_release;
1270 }
1271
1272 /*
1273 * We need to get memory_lock for each device, but devices
1274 * can share mmap_lock, therefore we need to zap and hold
1275 * the vma_lock for each device, and only then get each
1276 * memory_lock.
1277 */
1278 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1279 vfio_pci_try_zap_and_vma_lock_cb,
1280 &devs, slot);
1281 if (ret)
1282 goto hot_reset_release;
1283
1284 for (; mem_idx < devs.cur_index; mem_idx++) {
1285 struct vfio_pci_device *tmp;
1286
1287 tmp = vfio_device_data(devs.devices[mem_idx]);
1288
1289 ret = down_write_trylock(&tmp->memory_lock);
1290 if (!ret) {
1291 ret = -EBUSY;
1292 goto hot_reset_release;
1293 }
1294 mutex_unlock(&tmp->vma_lock);
1295 }
1296
1297 /* User has access, do the reset */
1298 ret = pci_reset_bus(vdev->pdev);
1299
1300 hot_reset_release:
1301 for (i = 0; i < devs.cur_index; i++) {
1302 struct vfio_device *device;
1303 struct vfio_pci_device *tmp;
1304
1305 device = devs.devices[i];
1306 tmp = vfio_device_data(device);
1307
1308 if (i < mem_idx)
1309 up_write(&tmp->memory_lock);
1310 else
1311 mutex_unlock(&tmp->vma_lock);
1312 vfio_device_put(device);
1313 }
1314 kfree(devs.devices);
1315
1316 for (group_idx--; group_idx >= 0; group_idx--)
1317 vfio_group_put_external_user(groups[group_idx].group);
1318
1319 kfree(groups);
1320 return ret;
1321 } else if (cmd == VFIO_DEVICE_IOEVENTFD) {
1322 struct vfio_device_ioeventfd ioeventfd;
1323 int count;
1324
1325 minsz = offsetofend(struct vfio_device_ioeventfd, fd);
1326
1327 if (copy_from_user(&ioeventfd, (void __user *)arg, minsz))
1328 return -EFAULT;
1329
1330 if (ioeventfd.argsz < minsz)
1331 return -EINVAL;
1332
1333 if (ioeventfd.flags & ~VFIO_DEVICE_IOEVENTFD_SIZE_MASK)
1334 return -EINVAL;
1335
1336 count = ioeventfd.flags & VFIO_DEVICE_IOEVENTFD_SIZE_MASK;
1337
1338 if (hweight8(count) != 1 || ioeventfd.fd < -1)
1339 return -EINVAL;
1340
1341 return vfio_pci_ioeventfd(vdev, ioeventfd.offset,
1342 ioeventfd.data, count, ioeventfd.fd);
1343 } else if (cmd == VFIO_DEVICE_FEATURE) {
1344 struct vfio_device_feature feature;
1345 uuid_t uuid;
1346
1347 minsz = offsetofend(struct vfio_device_feature, flags);
1348
1349 if (copy_from_user(&feature, (void __user *)arg, minsz))
1350 return -EFAULT;
1351
1352 if (feature.argsz < minsz)
1353 return -EINVAL;
1354
1355 /* Check unknown flags */
1356 if (feature.flags & ~(VFIO_DEVICE_FEATURE_MASK |
1357 VFIO_DEVICE_FEATURE_SET |
1358 VFIO_DEVICE_FEATURE_GET |
1359 VFIO_DEVICE_FEATURE_PROBE))
1360 return -EINVAL;
1361
1362 /* GET & SET are mutually exclusive except with PROBE */
1363 if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
1364 (feature.flags & VFIO_DEVICE_FEATURE_SET) &&
1365 (feature.flags & VFIO_DEVICE_FEATURE_GET))
1366 return -EINVAL;
1367
1368 switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
1369 case VFIO_DEVICE_FEATURE_PCI_VF_TOKEN:
1370 if (!vdev->vf_token)
1371 return -ENOTTY;
1372
1373 /*
1374 * We do not support GET of the VF Token UUID as this
1375 * could expose the token of the previous device user.
1376 */
1377 if (feature.flags & VFIO_DEVICE_FEATURE_GET)
1378 return -EINVAL;
1379
1380 if (feature.flags & VFIO_DEVICE_FEATURE_PROBE)
1381 return 0;
1382
1383 /* Don't SET unless told to do so */
1384 if (!(feature.flags & VFIO_DEVICE_FEATURE_SET))
1385 return -EINVAL;
1386
1387 if (feature.argsz < minsz + sizeof(uuid))
1388 return -EINVAL;
1389
1390 if (copy_from_user(&uuid, (void __user *)(arg + minsz),
1391 sizeof(uuid)))
1392 return -EFAULT;
1393
1394 mutex_lock(&vdev->vf_token->lock);
1395 uuid_copy(&vdev->vf_token->uuid, &uuid);
1396 mutex_unlock(&vdev->vf_token->lock);
1397
1398 return 0;
1399 default:
1400 return -ENOTTY;
1401 }
1402 }
1403
1404 return -ENOTTY;
1405 }
1406
vfio_pci_rw(void * device_data,char __user * buf,size_t count,loff_t * ppos,bool iswrite)1407 static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
1408 size_t count, loff_t *ppos, bool iswrite)
1409 {
1410 unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
1411 struct vfio_pci_device *vdev = device_data;
1412
1413 if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1414 return -EINVAL;
1415
1416 switch (index) {
1417 case VFIO_PCI_CONFIG_REGION_INDEX:
1418 return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
1419
1420 case VFIO_PCI_ROM_REGION_INDEX:
1421 if (iswrite)
1422 return -EINVAL;
1423 return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
1424
1425 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
1426 return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
1427
1428 case VFIO_PCI_VGA_REGION_INDEX:
1429 return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
1430 default:
1431 index -= VFIO_PCI_NUM_REGIONS;
1432 return vdev->region[index].ops->rw(vdev, buf,
1433 count, ppos, iswrite);
1434 }
1435
1436 return -EINVAL;
1437 }
1438
vfio_pci_read(void * device_data,char __user * buf,size_t count,loff_t * ppos)1439 static ssize_t vfio_pci_read(void *device_data, char __user *buf,
1440 size_t count, loff_t *ppos)
1441 {
1442 if (!count)
1443 return 0;
1444
1445 return vfio_pci_rw(device_data, buf, count, ppos, false);
1446 }
1447
vfio_pci_write(void * device_data,const char __user * buf,size_t count,loff_t * ppos)1448 static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
1449 size_t count, loff_t *ppos)
1450 {
1451 if (!count)
1452 return 0;
1453
1454 return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
1455 }
1456
1457 /* Return 1 on zap and vma_lock acquired, 0 on contention (only with @try) */
vfio_pci_zap_and_vma_lock(struct vfio_pci_device * vdev,bool try)1458 static int vfio_pci_zap_and_vma_lock(struct vfio_pci_device *vdev, bool try)
1459 {
1460 struct vfio_pci_mmap_vma *mmap_vma, *tmp;
1461
1462 /*
1463 * Lock ordering:
1464 * vma_lock is nested under mmap_lock for vm_ops callback paths.
1465 * The memory_lock semaphore is used by both code paths calling
1466 * into this function to zap vmas and the vm_ops.fault callback
1467 * to protect the memory enable state of the device.
1468 *
1469 * When zapping vmas we need to maintain the mmap_lock => vma_lock
1470 * ordering, which requires using vma_lock to walk vma_list to
1471 * acquire an mm, then dropping vma_lock to get the mmap_lock and
1472 * reacquiring vma_lock. This logic is derived from similar
1473 * requirements in uverbs_user_mmap_disassociate().
1474 *
1475 * mmap_lock must always be the top-level lock when it is taken.
1476 * Therefore we can only hold the memory_lock write lock when
1477 * vma_list is empty, as we'd need to take mmap_lock to clear
1478 * entries. vma_list can only be guaranteed empty when holding
1479 * vma_lock, thus memory_lock is nested under vma_lock.
1480 *
1481 * This enables the vm_ops.fault callback to acquire vma_lock,
1482 * followed by memory_lock read lock, while already holding
1483 * mmap_lock without risk of deadlock.
1484 */
1485 while (1) {
1486 struct mm_struct *mm = NULL;
1487
1488 if (try) {
1489 if (!mutex_trylock(&vdev->vma_lock))
1490 return 0;
1491 } else {
1492 mutex_lock(&vdev->vma_lock);
1493 }
1494 while (!list_empty(&vdev->vma_list)) {
1495 mmap_vma = list_first_entry(&vdev->vma_list,
1496 struct vfio_pci_mmap_vma,
1497 vma_next);
1498 mm = mmap_vma->vma->vm_mm;
1499 if (mmget_not_zero(mm))
1500 break;
1501
1502 list_del(&mmap_vma->vma_next);
1503 kfree(mmap_vma);
1504 mm = NULL;
1505 }
1506 if (!mm)
1507 return 1;
1508 mutex_unlock(&vdev->vma_lock);
1509
1510 if (try) {
1511 if (!mmap_read_trylock(mm)) {
1512 mmput(mm);
1513 return 0;
1514 }
1515 } else {
1516 mmap_read_lock(mm);
1517 }
1518 if (try) {
1519 if (!mutex_trylock(&vdev->vma_lock)) {
1520 mmap_read_unlock(mm);
1521 mmput(mm);
1522 return 0;
1523 }
1524 } else {
1525 mutex_lock(&vdev->vma_lock);
1526 }
1527 list_for_each_entry_safe(mmap_vma, tmp,
1528 &vdev->vma_list, vma_next) {
1529 struct vm_area_struct *vma = mmap_vma->vma;
1530
1531 if (vma->vm_mm != mm)
1532 continue;
1533
1534 list_del(&mmap_vma->vma_next);
1535 kfree(mmap_vma);
1536
1537 zap_vma_ptes(vma, vma->vm_start,
1538 vma->vm_end - vma->vm_start);
1539 }
1540 mutex_unlock(&vdev->vma_lock);
1541 mmap_read_unlock(mm);
1542 mmput(mm);
1543 }
1544 }
1545
vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_device * vdev)1546 void vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_device *vdev)
1547 {
1548 vfio_pci_zap_and_vma_lock(vdev, false);
1549 down_write(&vdev->memory_lock);
1550 mutex_unlock(&vdev->vma_lock);
1551 }
1552
vfio_pci_memory_lock_and_enable(struct vfio_pci_device * vdev)1553 u16 vfio_pci_memory_lock_and_enable(struct vfio_pci_device *vdev)
1554 {
1555 u16 cmd;
1556
1557 down_write(&vdev->memory_lock);
1558 pci_read_config_word(vdev->pdev, PCI_COMMAND, &cmd);
1559 if (!(cmd & PCI_COMMAND_MEMORY))
1560 pci_write_config_word(vdev->pdev, PCI_COMMAND,
1561 cmd | PCI_COMMAND_MEMORY);
1562
1563 return cmd;
1564 }
1565
vfio_pci_memory_unlock_and_restore(struct vfio_pci_device * vdev,u16 cmd)1566 void vfio_pci_memory_unlock_and_restore(struct vfio_pci_device *vdev, u16 cmd)
1567 {
1568 pci_write_config_word(vdev->pdev, PCI_COMMAND, cmd);
1569 up_write(&vdev->memory_lock);
1570 }
1571
1572 /* Caller holds vma_lock */
__vfio_pci_add_vma(struct vfio_pci_device * vdev,struct vm_area_struct * vma)1573 static int __vfio_pci_add_vma(struct vfio_pci_device *vdev,
1574 struct vm_area_struct *vma)
1575 {
1576 struct vfio_pci_mmap_vma *mmap_vma;
1577
1578 mmap_vma = kmalloc(sizeof(*mmap_vma), GFP_KERNEL);
1579 if (!mmap_vma)
1580 return -ENOMEM;
1581
1582 mmap_vma->vma = vma;
1583 list_add(&mmap_vma->vma_next, &vdev->vma_list);
1584
1585 return 0;
1586 }
1587
1588 /*
1589 * Zap mmaps on open so that we can fault them in on access and therefore
1590 * our vma_list only tracks mappings accessed since last zap.
1591 */
vfio_pci_mmap_open(struct vm_area_struct * vma)1592 static void vfio_pci_mmap_open(struct vm_area_struct *vma)
1593 {
1594 zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
1595 }
1596
vfio_pci_mmap_close(struct vm_area_struct * vma)1597 static void vfio_pci_mmap_close(struct vm_area_struct *vma)
1598 {
1599 struct vfio_pci_device *vdev = vma->vm_private_data;
1600 struct vfio_pci_mmap_vma *mmap_vma;
1601
1602 mutex_lock(&vdev->vma_lock);
1603 list_for_each_entry(mmap_vma, &vdev->vma_list, vma_next) {
1604 if (mmap_vma->vma == vma) {
1605 list_del(&mmap_vma->vma_next);
1606 kfree(mmap_vma);
1607 break;
1608 }
1609 }
1610 mutex_unlock(&vdev->vma_lock);
1611 }
1612
vfio_pci_mmap_fault(struct vm_fault * vmf)1613 static vm_fault_t vfio_pci_mmap_fault(struct vm_fault *vmf)
1614 {
1615 struct vm_area_struct *vma = vmf->vma;
1616 struct vfio_pci_device *vdev = vma->vm_private_data;
1617 struct vfio_pci_mmap_vma *mmap_vma;
1618 vm_fault_t ret = VM_FAULT_NOPAGE;
1619
1620 mutex_lock(&vdev->vma_lock);
1621 down_read(&vdev->memory_lock);
1622
1623 if (!__vfio_pci_memory_enabled(vdev)) {
1624 ret = VM_FAULT_SIGBUS;
1625 goto up_out;
1626 }
1627
1628 /*
1629 * We populate the whole vma on fault, so we need to test whether
1630 * the vma has already been mapped, such as for concurrent faults
1631 * to the same vma. io_remap_pfn_range() will trigger a BUG_ON if
1632 * we ask it to fill the same range again.
1633 */
1634 list_for_each_entry(mmap_vma, &vdev->vma_list, vma_next) {
1635 if (mmap_vma->vma == vma)
1636 goto up_out;
1637 }
1638
1639 if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
1640 vma->vm_end - vma->vm_start,
1641 vma->vm_page_prot)) {
1642 ret = VM_FAULT_SIGBUS;
1643 zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
1644 goto up_out;
1645 }
1646
1647 if (__vfio_pci_add_vma(vdev, vma)) {
1648 ret = VM_FAULT_OOM;
1649 zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
1650 }
1651
1652 up_out:
1653 up_read(&vdev->memory_lock);
1654 mutex_unlock(&vdev->vma_lock);
1655 return ret;
1656 }
1657
1658 static const struct vm_operations_struct vfio_pci_mmap_ops = {
1659 .open = vfio_pci_mmap_open,
1660 .close = vfio_pci_mmap_close,
1661 .fault = vfio_pci_mmap_fault,
1662 };
1663
vfio_pci_mmap(void * device_data,struct vm_area_struct * vma)1664 static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
1665 {
1666 struct vfio_pci_device *vdev = device_data;
1667 struct pci_dev *pdev = vdev->pdev;
1668 unsigned int index;
1669 u64 phys_len, req_len, pgoff, req_start;
1670 int ret;
1671
1672 index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
1673
1674 if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1675 return -EINVAL;
1676 if (vma->vm_end < vma->vm_start)
1677 return -EINVAL;
1678 if ((vma->vm_flags & VM_SHARED) == 0)
1679 return -EINVAL;
1680 if (index >= VFIO_PCI_NUM_REGIONS) {
1681 int regnum = index - VFIO_PCI_NUM_REGIONS;
1682 struct vfio_pci_region *region = vdev->region + regnum;
1683
1684 if (region->ops && region->ops->mmap &&
1685 (region->flags & VFIO_REGION_INFO_FLAG_MMAP))
1686 return region->ops->mmap(vdev, region, vma);
1687 return -EINVAL;
1688 }
1689 if (index >= VFIO_PCI_ROM_REGION_INDEX)
1690 return -EINVAL;
1691 if (!vdev->bar_mmap_supported[index])
1692 return -EINVAL;
1693
1694 phys_len = PAGE_ALIGN(pci_resource_len(pdev, index));
1695 req_len = vma->vm_end - vma->vm_start;
1696 pgoff = vma->vm_pgoff &
1697 ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
1698 req_start = pgoff << PAGE_SHIFT;
1699
1700 if (req_start + req_len > phys_len)
1701 return -EINVAL;
1702
1703 /*
1704 * Even though we don't make use of the barmap for the mmap,
1705 * we need to request the region and the barmap tracks that.
1706 */
1707 if (!vdev->barmap[index]) {
1708 ret = pci_request_selected_regions(pdev,
1709 1 << index, "vfio-pci");
1710 if (ret)
1711 return ret;
1712
1713 vdev->barmap[index] = pci_iomap(pdev, index, 0);
1714 if (!vdev->barmap[index]) {
1715 pci_release_selected_regions(pdev, 1 << index);
1716 return -ENOMEM;
1717 }
1718 }
1719
1720 vma->vm_private_data = vdev;
1721 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1722 vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
1723
1724 /*
1725 * See remap_pfn_range(), called from vfio_pci_fault() but we can't
1726 * change vm_flags within the fault handler. Set them now.
1727 */
1728 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
1729 vma->vm_ops = &vfio_pci_mmap_ops;
1730
1731 return 0;
1732 }
1733
vfio_pci_request(void * device_data,unsigned int count)1734 static void vfio_pci_request(void *device_data, unsigned int count)
1735 {
1736 struct vfio_pci_device *vdev = device_data;
1737 struct pci_dev *pdev = vdev->pdev;
1738
1739 mutex_lock(&vdev->igate);
1740
1741 if (vdev->req_trigger) {
1742 if (!(count % 10))
1743 pci_notice_ratelimited(pdev,
1744 "Relaying device request to user (#%u)\n",
1745 count);
1746 eventfd_signal(vdev->req_trigger, 1);
1747 } else if (count == 0) {
1748 pci_warn(pdev,
1749 "No device request channel registered, blocked until released by user\n");
1750 }
1751
1752 mutex_unlock(&vdev->igate);
1753 }
1754
vfio_pci_validate_vf_token(struct vfio_pci_device * vdev,bool vf_token,uuid_t * uuid)1755 static int vfio_pci_validate_vf_token(struct vfio_pci_device *vdev,
1756 bool vf_token, uuid_t *uuid)
1757 {
1758 /*
1759 * There's always some degree of trust or collaboration between SR-IOV
1760 * PF and VFs, even if just that the PF hosts the SR-IOV capability and
1761 * can disrupt VFs with a reset, but often the PF has more explicit
1762 * access to deny service to the VF or access data passed through the
1763 * VF. We therefore require an opt-in via a shared VF token (UUID) to
1764 * represent this trust. This both prevents that a VF driver might
1765 * assume the PF driver is a trusted, in-kernel driver, and also that
1766 * a PF driver might be replaced with a rogue driver, unknown to in-use
1767 * VF drivers.
1768 *
1769 * Therefore when presented with a VF, if the PF is a vfio device and
1770 * it is bound to the vfio-pci driver, the user needs to provide a VF
1771 * token to access the device, in the form of appending a vf_token to
1772 * the device name, for example:
1773 *
1774 * "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3"
1775 *
1776 * When presented with a PF which has VFs in use, the user must also
1777 * provide the current VF token to prove collaboration with existing
1778 * VF users. If VFs are not in use, the VF token provided for the PF
1779 * device will act to set the VF token.
1780 *
1781 * If the VF token is provided but unused, an error is generated.
1782 */
1783 if (!vdev->pdev->is_virtfn && !vdev->vf_token && !vf_token)
1784 return 0; /* No VF token provided or required */
1785
1786 if (vdev->pdev->is_virtfn) {
1787 struct vfio_device *pf_dev;
1788 struct vfio_pci_device *pf_vdev = get_pf_vdev(vdev, &pf_dev);
1789 bool match;
1790
1791 if (!pf_vdev) {
1792 if (!vf_token)
1793 return 0; /* PF is not vfio-pci, no VF token */
1794
1795 pci_info_ratelimited(vdev->pdev,
1796 "VF token incorrectly provided, PF not bound to vfio-pci\n");
1797 return -EINVAL;
1798 }
1799
1800 if (!vf_token) {
1801 vfio_device_put(pf_dev);
1802 pci_info_ratelimited(vdev->pdev,
1803 "VF token required to access device\n");
1804 return -EACCES;
1805 }
1806
1807 mutex_lock(&pf_vdev->vf_token->lock);
1808 match = uuid_equal(uuid, &pf_vdev->vf_token->uuid);
1809 mutex_unlock(&pf_vdev->vf_token->lock);
1810
1811 vfio_device_put(pf_dev);
1812
1813 if (!match) {
1814 pci_info_ratelimited(vdev->pdev,
1815 "Incorrect VF token provided for device\n");
1816 return -EACCES;
1817 }
1818 } else if (vdev->vf_token) {
1819 mutex_lock(&vdev->vf_token->lock);
1820 if (vdev->vf_token->users) {
1821 if (!vf_token) {
1822 mutex_unlock(&vdev->vf_token->lock);
1823 pci_info_ratelimited(vdev->pdev,
1824 "VF token required to access device\n");
1825 return -EACCES;
1826 }
1827
1828 if (!uuid_equal(uuid, &vdev->vf_token->uuid)) {
1829 mutex_unlock(&vdev->vf_token->lock);
1830 pci_info_ratelimited(vdev->pdev,
1831 "Incorrect VF token provided for device\n");
1832 return -EACCES;
1833 }
1834 } else if (vf_token) {
1835 uuid_copy(&vdev->vf_token->uuid, uuid);
1836 }
1837
1838 mutex_unlock(&vdev->vf_token->lock);
1839 } else if (vf_token) {
1840 pci_info_ratelimited(vdev->pdev,
1841 "VF token incorrectly provided, not a PF or VF\n");
1842 return -EINVAL;
1843 }
1844
1845 return 0;
1846 }
1847
1848 #define VF_TOKEN_ARG "vf_token="
1849
vfio_pci_match(void * device_data,char * buf)1850 static int vfio_pci_match(void *device_data, char *buf)
1851 {
1852 struct vfio_pci_device *vdev = device_data;
1853 bool vf_token = false;
1854 uuid_t uuid;
1855 int ret;
1856
1857 if (strncmp(pci_name(vdev->pdev), buf, strlen(pci_name(vdev->pdev))))
1858 return 0; /* No match */
1859
1860 if (strlen(buf) > strlen(pci_name(vdev->pdev))) {
1861 buf += strlen(pci_name(vdev->pdev));
1862
1863 if (*buf != ' ')
1864 return 0; /* No match: non-whitespace after name */
1865
1866 while (*buf) {
1867 if (*buf == ' ') {
1868 buf++;
1869 continue;
1870 }
1871
1872 if (!vf_token && !strncmp(buf, VF_TOKEN_ARG,
1873 strlen(VF_TOKEN_ARG))) {
1874 buf += strlen(VF_TOKEN_ARG);
1875
1876 if (strlen(buf) < UUID_STRING_LEN)
1877 return -EINVAL;
1878
1879 ret = uuid_parse(buf, &uuid);
1880 if (ret)
1881 return ret;
1882
1883 vf_token = true;
1884 buf += UUID_STRING_LEN;
1885 } else {
1886 /* Unknown/duplicate option */
1887 return -EINVAL;
1888 }
1889 }
1890 }
1891
1892 ret = vfio_pci_validate_vf_token(vdev, vf_token, &uuid);
1893 if (ret)
1894 return ret;
1895
1896 return 1; /* Match */
1897 }
1898
1899 static const struct vfio_device_ops vfio_pci_ops = {
1900 .name = "vfio-pci",
1901 .open = vfio_pci_open,
1902 .release = vfio_pci_release,
1903 .ioctl = vfio_pci_ioctl,
1904 .read = vfio_pci_read,
1905 .write = vfio_pci_write,
1906 .mmap = vfio_pci_mmap,
1907 .request = vfio_pci_request,
1908 .match = vfio_pci_match,
1909 };
1910
1911 static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev);
1912 static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck);
1913
vfio_pci_bus_notifier(struct notifier_block * nb,unsigned long action,void * data)1914 static int vfio_pci_bus_notifier(struct notifier_block *nb,
1915 unsigned long action, void *data)
1916 {
1917 struct vfio_pci_device *vdev = container_of(nb,
1918 struct vfio_pci_device, nb);
1919 struct device *dev = data;
1920 struct pci_dev *pdev = to_pci_dev(dev);
1921 struct pci_dev *physfn = pci_physfn(pdev);
1922
1923 if (action == BUS_NOTIFY_ADD_DEVICE &&
1924 pdev->is_virtfn && physfn == vdev->pdev) {
1925 pci_info(vdev->pdev, "Captured SR-IOV VF %s driver_override\n",
1926 pci_name(pdev));
1927 pdev->driver_override = kasprintf(GFP_KERNEL, "%s",
1928 vfio_pci_ops.name);
1929 } else if (action == BUS_NOTIFY_BOUND_DRIVER &&
1930 pdev->is_virtfn && physfn == vdev->pdev) {
1931 struct pci_driver *drv = pci_dev_driver(pdev);
1932
1933 if (drv && drv != &vfio_pci_driver)
1934 pci_warn(vdev->pdev,
1935 "VF %s bound to driver %s while PF bound to vfio-pci\n",
1936 pci_name(pdev), drv->name);
1937 }
1938
1939 return 0;
1940 }
1941
vfio_pci_vf_init(struct vfio_pci_device * vdev)1942 static int vfio_pci_vf_init(struct vfio_pci_device *vdev)
1943 {
1944 struct pci_dev *pdev = vdev->pdev;
1945 int ret;
1946
1947 if (!pdev->is_physfn)
1948 return 0;
1949
1950 vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
1951 if (!vdev->vf_token)
1952 return -ENOMEM;
1953
1954 mutex_init(&vdev->vf_token->lock);
1955 uuid_gen(&vdev->vf_token->uuid);
1956
1957 vdev->nb.notifier_call = vfio_pci_bus_notifier;
1958 ret = bus_register_notifier(&pci_bus_type, &vdev->nb);
1959 if (ret) {
1960 kfree(vdev->vf_token);
1961 return ret;
1962 }
1963 return 0;
1964 }
1965
vfio_pci_vf_uninit(struct vfio_pci_device * vdev)1966 static void vfio_pci_vf_uninit(struct vfio_pci_device *vdev)
1967 {
1968 if (!vdev->vf_token)
1969 return;
1970
1971 bus_unregister_notifier(&pci_bus_type, &vdev->nb);
1972 WARN_ON(vdev->vf_token->users);
1973 mutex_destroy(&vdev->vf_token->lock);
1974 kfree(vdev->vf_token);
1975 }
1976
vfio_pci_vga_init(struct vfio_pci_device * vdev)1977 static int vfio_pci_vga_init(struct vfio_pci_device *vdev)
1978 {
1979 struct pci_dev *pdev = vdev->pdev;
1980 int ret;
1981
1982 if (!vfio_pci_is_vga(pdev))
1983 return 0;
1984
1985 ret = vga_client_register(pdev, vdev, NULL, vfio_pci_set_vga_decode);
1986 if (ret)
1987 return ret;
1988 vga_set_legacy_decoding(pdev, vfio_pci_set_vga_decode(vdev, false));
1989 return 0;
1990 }
1991
vfio_pci_vga_uninit(struct vfio_pci_device * vdev)1992 static void vfio_pci_vga_uninit(struct vfio_pci_device *vdev)
1993 {
1994 struct pci_dev *pdev = vdev->pdev;
1995
1996 if (!vfio_pci_is_vga(pdev))
1997 return;
1998 vga_client_register(pdev, NULL, NULL, NULL);
1999 vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
2000 VGA_RSRC_LEGACY_IO |
2001 VGA_RSRC_LEGACY_MEM);
2002 }
2003
vfio_pci_probe(struct pci_dev * pdev,const struct pci_device_id * id)2004 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
2005 {
2006 struct vfio_pci_device *vdev;
2007 struct iommu_group *group;
2008 int ret;
2009
2010 if (vfio_pci_is_denylisted(pdev))
2011 return -EINVAL;
2012
2013 if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
2014 return -EINVAL;
2015
2016 /*
2017 * Prevent binding to PFs with VFs enabled, the VFs might be in use
2018 * by the host or other users. We cannot capture the VFs if they
2019 * already exist, nor can we track VF users. Disabling SR-IOV here
2020 * would initiate removing the VFs, which would unbind the driver,
2021 * which is prone to blocking if that VF is also in use by vfio-pci.
2022 * Just reject these PFs and let the user sort it out.
2023 */
2024 if (pci_num_vf(pdev)) {
2025 pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n");
2026 return -EBUSY;
2027 }
2028
2029 group = vfio_iommu_group_get(&pdev->dev);
2030 if (!group)
2031 return -EINVAL;
2032
2033 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
2034 if (!vdev) {
2035 ret = -ENOMEM;
2036 goto out_group_put;
2037 }
2038
2039 vdev->pdev = pdev;
2040 vdev->irq_type = VFIO_PCI_NUM_IRQS;
2041 mutex_init(&vdev->igate);
2042 spin_lock_init(&vdev->irqlock);
2043 mutex_init(&vdev->ioeventfds_lock);
2044 INIT_LIST_HEAD(&vdev->dummy_resources_list);
2045 INIT_LIST_HEAD(&vdev->ioeventfds_list);
2046 mutex_init(&vdev->vma_lock);
2047 INIT_LIST_HEAD(&vdev->vma_list);
2048 init_rwsem(&vdev->memory_lock);
2049
2050 ret = vfio_pci_reflck_attach(vdev);
2051 if (ret)
2052 goto out_free;
2053 ret = vfio_pci_vf_init(vdev);
2054 if (ret)
2055 goto out_reflck;
2056 ret = vfio_pci_vga_init(vdev);
2057 if (ret)
2058 goto out_vf;
2059
2060 vfio_pci_probe_power_state(vdev);
2061
2062 if (!disable_idle_d3) {
2063 /*
2064 * pci-core sets the device power state to an unknown value at
2065 * bootup and after being removed from a driver. The only
2066 * transition it allows from this unknown state is to D0, which
2067 * typically happens when a driver calls pci_enable_device().
2068 * We're not ready to enable the device yet, but we do want to
2069 * be able to get to D3. Therefore first do a D0 transition
2070 * before going to D3.
2071 */
2072 vfio_pci_set_power_state(vdev, PCI_D0);
2073 vfio_pci_set_power_state(vdev, PCI_D3hot);
2074 }
2075
2076 ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
2077 if (ret)
2078 goto out_power;
2079 return 0;
2080
2081 out_power:
2082 if (!disable_idle_d3)
2083 vfio_pci_set_power_state(vdev, PCI_D0);
2084 out_vf:
2085 vfio_pci_vf_uninit(vdev);
2086 out_reflck:
2087 vfio_pci_reflck_put(vdev->reflck);
2088 out_free:
2089 kfree(vdev->pm_save);
2090 kfree(vdev);
2091 out_group_put:
2092 vfio_iommu_group_put(group, &pdev->dev);
2093 return ret;
2094 }
2095
vfio_pci_remove(struct pci_dev * pdev)2096 static void vfio_pci_remove(struct pci_dev *pdev)
2097 {
2098 struct vfio_pci_device *vdev;
2099
2100 pci_disable_sriov(pdev);
2101
2102 vdev = vfio_del_group_dev(&pdev->dev);
2103 if (!vdev)
2104 return;
2105
2106 vfio_pci_vf_uninit(vdev);
2107 vfio_pci_reflck_put(vdev->reflck);
2108 vfio_pci_vga_uninit(vdev);
2109
2110 vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
2111
2112 if (!disable_idle_d3)
2113 vfio_pci_set_power_state(vdev, PCI_D0);
2114
2115 mutex_destroy(&vdev->ioeventfds_lock);
2116 kfree(vdev->region);
2117 kfree(vdev->pm_save);
2118 kfree(vdev);
2119 }
2120
vfio_pci_aer_err_detected(struct pci_dev * pdev,pci_channel_state_t state)2121 static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
2122 pci_channel_state_t state)
2123 {
2124 struct vfio_pci_device *vdev;
2125 struct vfio_device *device;
2126
2127 device = vfio_device_get_from_dev(&pdev->dev);
2128 if (device == NULL)
2129 return PCI_ERS_RESULT_DISCONNECT;
2130
2131 vdev = vfio_device_data(device);
2132 if (vdev == NULL) {
2133 vfio_device_put(device);
2134 return PCI_ERS_RESULT_DISCONNECT;
2135 }
2136
2137 mutex_lock(&vdev->igate);
2138
2139 if (vdev->err_trigger)
2140 eventfd_signal(vdev->err_trigger, 1);
2141
2142 mutex_unlock(&vdev->igate);
2143
2144 vfio_device_put(device);
2145
2146 return PCI_ERS_RESULT_CAN_RECOVER;
2147 }
2148
vfio_pci_sriov_configure(struct pci_dev * pdev,int nr_virtfn)2149 static int vfio_pci_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
2150 {
2151 struct vfio_pci_device *vdev;
2152 struct vfio_device *device;
2153 int ret = 0;
2154
2155 might_sleep();
2156
2157 if (!enable_sriov)
2158 return -ENOENT;
2159
2160 device = vfio_device_get_from_dev(&pdev->dev);
2161 if (!device)
2162 return -ENODEV;
2163
2164 vdev = vfio_device_data(device);
2165 if (!vdev) {
2166 vfio_device_put(device);
2167 return -ENODEV;
2168 }
2169
2170 if (nr_virtfn == 0)
2171 pci_disable_sriov(pdev);
2172 else
2173 ret = pci_enable_sriov(pdev, nr_virtfn);
2174
2175 vfio_device_put(device);
2176
2177 return ret < 0 ? ret : nr_virtfn;
2178 }
2179
2180 static const struct pci_error_handlers vfio_err_handlers = {
2181 .error_detected = vfio_pci_aer_err_detected,
2182 };
2183
2184 static struct pci_driver vfio_pci_driver = {
2185 .name = "vfio-pci",
2186 .id_table = NULL, /* only dynamic ids */
2187 .probe = vfio_pci_probe,
2188 .remove = vfio_pci_remove,
2189 .sriov_configure = vfio_pci_sriov_configure,
2190 .err_handler = &vfio_err_handlers,
2191 };
2192
2193 static DEFINE_MUTEX(reflck_lock);
2194
vfio_pci_reflck_alloc(void)2195 static struct vfio_pci_reflck *vfio_pci_reflck_alloc(void)
2196 {
2197 struct vfio_pci_reflck *reflck;
2198
2199 reflck = kzalloc(sizeof(*reflck), GFP_KERNEL);
2200 if (!reflck)
2201 return ERR_PTR(-ENOMEM);
2202
2203 kref_init(&reflck->kref);
2204 mutex_init(&reflck->lock);
2205
2206 return reflck;
2207 }
2208
vfio_pci_reflck_get(struct vfio_pci_reflck * reflck)2209 static void vfio_pci_reflck_get(struct vfio_pci_reflck *reflck)
2210 {
2211 kref_get(&reflck->kref);
2212 }
2213
vfio_pci_reflck_find(struct pci_dev * pdev,void * data)2214 static int vfio_pci_reflck_find(struct pci_dev *pdev, void *data)
2215 {
2216 struct vfio_pci_reflck **preflck = data;
2217 struct vfio_device *device;
2218 struct vfio_pci_device *vdev;
2219
2220 device = vfio_device_get_from_dev(&pdev->dev);
2221 if (!device)
2222 return 0;
2223
2224 if (pci_dev_driver(pdev) != &vfio_pci_driver) {
2225 vfio_device_put(device);
2226 return 0;
2227 }
2228
2229 vdev = vfio_device_data(device);
2230
2231 if (vdev->reflck) {
2232 vfio_pci_reflck_get(vdev->reflck);
2233 *preflck = vdev->reflck;
2234 vfio_device_put(device);
2235 return 1;
2236 }
2237
2238 vfio_device_put(device);
2239 return 0;
2240 }
2241
vfio_pci_reflck_attach(struct vfio_pci_device * vdev)2242 static int vfio_pci_reflck_attach(struct vfio_pci_device *vdev)
2243 {
2244 bool slot = !pci_probe_reset_slot(vdev->pdev->slot);
2245
2246 mutex_lock(&reflck_lock);
2247
2248 if (pci_is_root_bus(vdev->pdev->bus) ||
2249 vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_reflck_find,
2250 &vdev->reflck, slot) <= 0)
2251 vdev->reflck = vfio_pci_reflck_alloc();
2252
2253 mutex_unlock(&reflck_lock);
2254
2255 return PTR_ERR_OR_ZERO(vdev->reflck);
2256 }
2257
vfio_pci_reflck_release(struct kref * kref)2258 static void vfio_pci_reflck_release(struct kref *kref)
2259 {
2260 struct vfio_pci_reflck *reflck = container_of(kref,
2261 struct vfio_pci_reflck,
2262 kref);
2263
2264 kfree(reflck);
2265 mutex_unlock(&reflck_lock);
2266 }
2267
vfio_pci_reflck_put(struct vfio_pci_reflck * reflck)2268 static void vfio_pci_reflck_put(struct vfio_pci_reflck *reflck)
2269 {
2270 kref_put_mutex(&reflck->kref, vfio_pci_reflck_release, &reflck_lock);
2271 }
2272
vfio_pci_get_unused_devs(struct pci_dev * pdev,void * data)2273 static int vfio_pci_get_unused_devs(struct pci_dev *pdev, void *data)
2274 {
2275 struct vfio_devices *devs = data;
2276 struct vfio_device *device;
2277 struct vfio_pci_device *vdev;
2278
2279 if (devs->cur_index == devs->max_index)
2280 return -ENOSPC;
2281
2282 device = vfio_device_get_from_dev(&pdev->dev);
2283 if (!device)
2284 return -EINVAL;
2285
2286 if (pci_dev_driver(pdev) != &vfio_pci_driver) {
2287 vfio_device_put(device);
2288 return -EBUSY;
2289 }
2290
2291 vdev = vfio_device_data(device);
2292
2293 /* Fault if the device is not unused */
2294 if (vdev->refcnt) {
2295 vfio_device_put(device);
2296 return -EBUSY;
2297 }
2298
2299 devs->devices[devs->cur_index++] = device;
2300 return 0;
2301 }
2302
vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev * pdev,void * data)2303 static int vfio_pci_try_zap_and_vma_lock_cb(struct pci_dev *pdev, void *data)
2304 {
2305 struct vfio_devices *devs = data;
2306 struct vfio_device *device;
2307 struct vfio_pci_device *vdev;
2308
2309 if (devs->cur_index == devs->max_index)
2310 return -ENOSPC;
2311
2312 device = vfio_device_get_from_dev(&pdev->dev);
2313 if (!device)
2314 return -EINVAL;
2315
2316 if (pci_dev_driver(pdev) != &vfio_pci_driver) {
2317 vfio_device_put(device);
2318 return -EBUSY;
2319 }
2320
2321 vdev = vfio_device_data(device);
2322
2323 /*
2324 * Locking multiple devices is prone to deadlock, runaway and
2325 * unwind if we hit contention.
2326 */
2327 if (!vfio_pci_zap_and_vma_lock(vdev, true)) {
2328 vfio_device_put(device);
2329 return -EBUSY;
2330 }
2331
2332 devs->devices[devs->cur_index++] = device;
2333 return 0;
2334 }
2335
2336 /*
2337 * If a bus or slot reset is available for the provided device and:
2338 * - All of the devices affected by that bus or slot reset are unused
2339 * (!refcnt)
2340 * - At least one of the affected devices is marked dirty via
2341 * needs_reset (such as by lack of FLR support)
2342 * Then attempt to perform that bus or slot reset. Callers are required
2343 * to hold vdev->reflck->lock, protecting the bus/slot reset group from
2344 * concurrent opens. A vfio_device reference is acquired for each device
2345 * to prevent unbinds during the reset operation.
2346 *
2347 * NB: vfio-core considers a group to be viable even if some devices are
2348 * bound to drivers like pci-stub or pcieport. Here we require all devices
2349 * to be bound to vfio_pci since that's the only way we can be sure they
2350 * stay put.
2351 */
vfio_pci_try_bus_reset(struct vfio_pci_device * vdev)2352 static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
2353 {
2354 struct vfio_devices devs = { .cur_index = 0 };
2355 int i = 0, ret = -EINVAL;
2356 bool slot = false;
2357 struct vfio_pci_device *tmp;
2358
2359 if (!pci_probe_reset_slot(vdev->pdev->slot))
2360 slot = true;
2361 else if (pci_probe_reset_bus(vdev->pdev->bus))
2362 return;
2363
2364 if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
2365 &i, slot) || !i)
2366 return;
2367
2368 devs.max_index = i;
2369 devs.devices = kcalloc(i, sizeof(struct vfio_device *), GFP_KERNEL);
2370 if (!devs.devices)
2371 return;
2372
2373 if (vfio_pci_for_each_slot_or_bus(vdev->pdev,
2374 vfio_pci_get_unused_devs,
2375 &devs, slot))
2376 goto put_devs;
2377
2378 /* Does at least one need a reset? */
2379 for (i = 0; i < devs.cur_index; i++) {
2380 tmp = vfio_device_data(devs.devices[i]);
2381 if (tmp->needs_reset) {
2382 ret = pci_reset_bus(vdev->pdev);
2383 break;
2384 }
2385 }
2386
2387 put_devs:
2388 for (i = 0; i < devs.cur_index; i++) {
2389 tmp = vfio_device_data(devs.devices[i]);
2390
2391 /*
2392 * If reset was successful, affected devices no longer need
2393 * a reset and we should return all the collateral devices
2394 * to low power. If not successful, we either didn't reset
2395 * the bus or timed out waiting for it, so let's not touch
2396 * the power state.
2397 */
2398 if (!ret) {
2399 tmp->needs_reset = false;
2400
2401 if (tmp != vdev && !disable_idle_d3)
2402 vfio_pci_set_power_state(tmp, PCI_D3hot);
2403 }
2404
2405 vfio_device_put(devs.devices[i]);
2406 }
2407
2408 kfree(devs.devices);
2409 }
2410
vfio_pci_cleanup(void)2411 static void __exit vfio_pci_cleanup(void)
2412 {
2413 pci_unregister_driver(&vfio_pci_driver);
2414 vfio_pci_uninit_perm_bits();
2415 }
2416
vfio_pci_fill_ids(void)2417 static void __init vfio_pci_fill_ids(void)
2418 {
2419 char *p, *id;
2420 int rc;
2421
2422 /* no ids passed actually */
2423 if (ids[0] == '\0')
2424 return;
2425
2426 /* add ids specified in the module parameter */
2427 p = ids;
2428 while ((id = strsep(&p, ","))) {
2429 unsigned int vendor, device, subvendor = PCI_ANY_ID,
2430 subdevice = PCI_ANY_ID, class = 0, class_mask = 0;
2431 int fields;
2432
2433 if (!strlen(id))
2434 continue;
2435
2436 fields = sscanf(id, "%x:%x:%x:%x:%x:%x",
2437 &vendor, &device, &subvendor, &subdevice,
2438 &class, &class_mask);
2439
2440 if (fields < 2) {
2441 pr_warn("invalid id string \"%s\"\n", id);
2442 continue;
2443 }
2444
2445 rc = pci_add_dynid(&vfio_pci_driver, vendor, device,
2446 subvendor, subdevice, class, class_mask, 0);
2447 if (rc)
2448 pr_warn("failed to add dynamic id [%04x:%04x[%04x:%04x]] class %#08x/%08x (%d)\n",
2449 vendor, device, subvendor, subdevice,
2450 class, class_mask, rc);
2451 else
2452 pr_info("add [%04x:%04x[%04x:%04x]] class %#08x/%08x\n",
2453 vendor, device, subvendor, subdevice,
2454 class, class_mask);
2455 }
2456 }
2457
vfio_pci_init(void)2458 static int __init vfio_pci_init(void)
2459 {
2460 int ret;
2461
2462 /* Allocate shared config space permision data used by all devices */
2463 ret = vfio_pci_init_perm_bits();
2464 if (ret)
2465 return ret;
2466
2467 /* Register and scan for devices */
2468 ret = pci_register_driver(&vfio_pci_driver);
2469 if (ret)
2470 goto out_driver;
2471
2472 vfio_pci_fill_ids();
2473
2474 if (disable_denylist)
2475 pr_warn("device denylist disabled.\n");
2476
2477 return 0;
2478
2479 out_driver:
2480 vfio_pci_uninit_perm_bits();
2481 return ret;
2482 }
2483
2484 module_init(vfio_pci_init);
2485 module_exit(vfio_pci_cleanup);
2486
2487 MODULE_VERSION(DRIVER_VERSION);
2488 MODULE_LICENSE("GPL v2");
2489 MODULE_AUTHOR(DRIVER_AUTHOR);
2490 MODULE_DESCRIPTION(DRIVER_DESC);
2491