xref: /linux/drivers/vfio/pci/vfio_pci_core.c (revision 06a130e42a5bfc84795464bff023bff4c16f58c5)
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/aperture.h>
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/pfn_t.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/slab.h>
26 #include <linux/types.h>
27 #include <linux/uaccess.h>
28 #include <linux/vgaarb.h>
29 #include <linux/nospec.h>
30 #include <linux/sched/mm.h>
31 #include <linux/iommufd.h>
32 #if IS_ENABLED(CONFIG_EEH)
33 #include <asm/eeh.h>
34 #endif
35 
36 #include "vfio_pci_priv.h"
37 
38 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
39 #define DRIVER_DESC "core driver for VFIO based PCI devices"
40 
41 static bool nointxmask;
42 static bool disable_vga;
43 static bool disable_idle_d3;
44 
45 /* List of PF's that vfio_pci_core_sriov_configure() has been called on */
46 static DEFINE_MUTEX(vfio_pci_sriov_pfs_mutex);
47 static LIST_HEAD(vfio_pci_sriov_pfs);
48 
49 struct vfio_pci_dummy_resource {
50 	struct resource		resource;
51 	int			index;
52 	struct list_head	res_next;
53 };
54 
55 struct vfio_pci_vf_token {
56 	struct mutex		lock;
57 	uuid_t			uuid;
58 	int			users;
59 };
60 
61 static inline bool vfio_vga_disabled(void)
62 {
63 #ifdef CONFIG_VFIO_PCI_VGA
64 	return disable_vga;
65 #else
66 	return true;
67 #endif
68 }
69 
70 /*
71  * Our VGA arbiter participation is limited since we don't know anything
72  * about the device itself.  However, if the device is the only VGA device
73  * downstream of a bridge and VFIO VGA support is disabled, then we can
74  * safely return legacy VGA IO and memory as not decoded since the user
75  * has no way to get to it and routing can be disabled externally at the
76  * bridge.
77  */
78 static unsigned int vfio_pci_set_decode(struct pci_dev *pdev, bool single_vga)
79 {
80 	struct pci_dev *tmp = NULL;
81 	unsigned char max_busnr;
82 	unsigned int decodes;
83 
84 	if (single_vga || !vfio_vga_disabled() || pci_is_root_bus(pdev->bus))
85 		return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
86 		       VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
87 
88 	max_busnr = pci_bus_max_busnr(pdev->bus);
89 	decodes = VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
90 
91 	while ((tmp = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, tmp)) != NULL) {
92 		if (tmp == pdev ||
93 		    pci_domain_nr(tmp->bus) != pci_domain_nr(pdev->bus) ||
94 		    pci_is_root_bus(tmp->bus))
95 			continue;
96 
97 		if (tmp->bus->number >= pdev->bus->number &&
98 		    tmp->bus->number <= max_busnr) {
99 			pci_dev_put(tmp);
100 			decodes |= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
101 			break;
102 		}
103 	}
104 
105 	return decodes;
106 }
107 
108 static void vfio_pci_probe_mmaps(struct vfio_pci_core_device *vdev)
109 {
110 	struct resource *res;
111 	int i;
112 	struct vfio_pci_dummy_resource *dummy_res;
113 
114 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
115 		int bar = i + PCI_STD_RESOURCES;
116 
117 		res = &vdev->pdev->resource[bar];
118 
119 		if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP))
120 			goto no_mmap;
121 
122 		if (!(res->flags & IORESOURCE_MEM))
123 			goto no_mmap;
124 
125 		/*
126 		 * The PCI core shouldn't set up a resource with a
127 		 * type but zero size. But there may be bugs that
128 		 * cause us to do that.
129 		 */
130 		if (!resource_size(res))
131 			goto no_mmap;
132 
133 		if (resource_size(res) >= PAGE_SIZE) {
134 			vdev->bar_mmap_supported[bar] = true;
135 			continue;
136 		}
137 
138 		if (!(res->start & ~PAGE_MASK)) {
139 			/*
140 			 * Add a dummy resource to reserve the remainder
141 			 * of the exclusive page in case that hot-add
142 			 * device's bar is assigned into it.
143 			 */
144 			dummy_res =
145 				kzalloc(sizeof(*dummy_res), GFP_KERNEL_ACCOUNT);
146 			if (dummy_res == NULL)
147 				goto no_mmap;
148 
149 			dummy_res->resource.name = "vfio sub-page reserved";
150 			dummy_res->resource.start = res->end + 1;
151 			dummy_res->resource.end = res->start + PAGE_SIZE - 1;
152 			dummy_res->resource.flags = res->flags;
153 			if (request_resource(res->parent,
154 						&dummy_res->resource)) {
155 				kfree(dummy_res);
156 				goto no_mmap;
157 			}
158 			dummy_res->index = bar;
159 			list_add(&dummy_res->res_next,
160 					&vdev->dummy_resources_list);
161 			vdev->bar_mmap_supported[bar] = true;
162 			continue;
163 		}
164 		/*
165 		 * Here we don't handle the case when the BAR is not page
166 		 * aligned because we can't expect the BAR will be
167 		 * assigned into the same location in a page in guest
168 		 * when we passthrough the BAR. And it's hard to access
169 		 * this BAR in userspace because we have no way to get
170 		 * the BAR's location in a page.
171 		 */
172 no_mmap:
173 		vdev->bar_mmap_supported[bar] = false;
174 	}
175 }
176 
177 struct vfio_pci_group_info;
178 static void vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set);
179 static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
180 				      struct vfio_pci_group_info *groups,
181 				      struct iommufd_ctx *iommufd_ctx);
182 
183 /*
184  * INTx masking requires the ability to disable INTx signaling via PCI_COMMAND
185  * _and_ the ability detect when the device is asserting INTx via PCI_STATUS.
186  * If a device implements the former but not the latter we would typically
187  * expect broken_intx_masking be set and require an exclusive interrupt.
188  * However since we do have control of the device's ability to assert INTx,
189  * we can instead pretend that the device does not implement INTx, virtualizing
190  * the pin register to report zero and maintaining DisINTx set on the host.
191  */
192 static bool vfio_pci_nointx(struct pci_dev *pdev)
193 {
194 	switch (pdev->vendor) {
195 	case PCI_VENDOR_ID_INTEL:
196 		switch (pdev->device) {
197 		/* All i40e (XL710/X710/XXV710) 10/20/25/40GbE NICs */
198 		case 0x1572:
199 		case 0x1574:
200 		case 0x1580 ... 0x1581:
201 		case 0x1583 ... 0x158b:
202 		case 0x37d0 ... 0x37d2:
203 		/* X550 */
204 		case 0x1563:
205 			return true;
206 		default:
207 			return false;
208 		}
209 	}
210 
211 	return false;
212 }
213 
214 static void vfio_pci_probe_power_state(struct vfio_pci_core_device *vdev)
215 {
216 	struct pci_dev *pdev = vdev->pdev;
217 	u16 pmcsr;
218 
219 	if (!pdev->pm_cap)
220 		return;
221 
222 	pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &pmcsr);
223 
224 	vdev->needs_pm_restore = !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
225 }
226 
227 /*
228  * pci_set_power_state() wrapper handling devices which perform a soft reset on
229  * D3->D0 transition.  Save state prior to D0/1/2->D3, stash it on the vdev,
230  * restore when returned to D0.  Saved separately from pci_saved_state for use
231  * by PM capability emulation and separately from pci_dev internal saved state
232  * to avoid it being overwritten and consumed around other resets.
233  */
234 int vfio_pci_set_power_state(struct vfio_pci_core_device *vdev, pci_power_t state)
235 {
236 	struct pci_dev *pdev = vdev->pdev;
237 	bool needs_restore = false, needs_save = false;
238 	int ret;
239 
240 	/* Prevent changing power state for PFs with VFs enabled */
241 	if (pci_num_vf(pdev) && state > PCI_D0)
242 		return -EBUSY;
243 
244 	if (vdev->needs_pm_restore) {
245 		if (pdev->current_state < PCI_D3hot && state >= PCI_D3hot) {
246 			pci_save_state(pdev);
247 			needs_save = true;
248 		}
249 
250 		if (pdev->current_state >= PCI_D3hot && state <= PCI_D0)
251 			needs_restore = true;
252 	}
253 
254 	ret = pci_set_power_state(pdev, state);
255 
256 	if (!ret) {
257 		/* D3 might be unsupported via quirk, skip unless in D3 */
258 		if (needs_save && pdev->current_state >= PCI_D3hot) {
259 			/*
260 			 * The current PCI state will be saved locally in
261 			 * 'pm_save' during the D3hot transition. When the
262 			 * device state is changed to D0 again with the current
263 			 * function, then pci_store_saved_state() will restore
264 			 * the state and will free the memory pointed by
265 			 * 'pm_save'. There are few cases where the PCI power
266 			 * state can be changed to D0 without the involvement
267 			 * of the driver. For these cases, free the earlier
268 			 * allocated memory first before overwriting 'pm_save'
269 			 * to prevent the memory leak.
270 			 */
271 			kfree(vdev->pm_save);
272 			vdev->pm_save = pci_store_saved_state(pdev);
273 		} else if (needs_restore) {
274 			pci_load_and_free_saved_state(pdev, &vdev->pm_save);
275 			pci_restore_state(pdev);
276 		}
277 	}
278 
279 	return ret;
280 }
281 
282 static int vfio_pci_runtime_pm_entry(struct vfio_pci_core_device *vdev,
283 				     struct eventfd_ctx *efdctx)
284 {
285 	/*
286 	 * The vdev power related flags are protected with 'memory_lock'
287 	 * semaphore.
288 	 */
289 	vfio_pci_zap_and_down_write_memory_lock(vdev);
290 	if (vdev->pm_runtime_engaged) {
291 		up_write(&vdev->memory_lock);
292 		return -EINVAL;
293 	}
294 
295 	vdev->pm_runtime_engaged = true;
296 	vdev->pm_wake_eventfd_ctx = efdctx;
297 	pm_runtime_put_noidle(&vdev->pdev->dev);
298 	up_write(&vdev->memory_lock);
299 
300 	return 0;
301 }
302 
303 static int vfio_pci_core_pm_entry(struct vfio_device *device, u32 flags,
304 				  void __user *arg, size_t argsz)
305 {
306 	struct vfio_pci_core_device *vdev =
307 		container_of(device, struct vfio_pci_core_device, vdev);
308 	int ret;
309 
310 	ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, 0);
311 	if (ret != 1)
312 		return ret;
313 
314 	/*
315 	 * Inside vfio_pci_runtime_pm_entry(), only the runtime PM usage count
316 	 * will be decremented. The pm_runtime_put() will be invoked again
317 	 * while returning from the ioctl and then the device can go into
318 	 * runtime suspended state.
319 	 */
320 	return vfio_pci_runtime_pm_entry(vdev, NULL);
321 }
322 
323 static int vfio_pci_core_pm_entry_with_wakeup(
324 	struct vfio_device *device, u32 flags,
325 	struct vfio_device_low_power_entry_with_wakeup __user *arg,
326 	size_t argsz)
327 {
328 	struct vfio_pci_core_device *vdev =
329 		container_of(device, struct vfio_pci_core_device, vdev);
330 	struct vfio_device_low_power_entry_with_wakeup entry;
331 	struct eventfd_ctx *efdctx;
332 	int ret;
333 
334 	ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET,
335 				 sizeof(entry));
336 	if (ret != 1)
337 		return ret;
338 
339 	if (copy_from_user(&entry, arg, sizeof(entry)))
340 		return -EFAULT;
341 
342 	if (entry.wakeup_eventfd < 0)
343 		return -EINVAL;
344 
345 	efdctx = eventfd_ctx_fdget(entry.wakeup_eventfd);
346 	if (IS_ERR(efdctx))
347 		return PTR_ERR(efdctx);
348 
349 	ret = vfio_pci_runtime_pm_entry(vdev, efdctx);
350 	if (ret)
351 		eventfd_ctx_put(efdctx);
352 
353 	return ret;
354 }
355 
356 static void __vfio_pci_runtime_pm_exit(struct vfio_pci_core_device *vdev)
357 {
358 	if (vdev->pm_runtime_engaged) {
359 		vdev->pm_runtime_engaged = false;
360 		pm_runtime_get_noresume(&vdev->pdev->dev);
361 
362 		if (vdev->pm_wake_eventfd_ctx) {
363 			eventfd_ctx_put(vdev->pm_wake_eventfd_ctx);
364 			vdev->pm_wake_eventfd_ctx = NULL;
365 		}
366 	}
367 }
368 
369 static void vfio_pci_runtime_pm_exit(struct vfio_pci_core_device *vdev)
370 {
371 	/*
372 	 * The vdev power related flags are protected with 'memory_lock'
373 	 * semaphore.
374 	 */
375 	down_write(&vdev->memory_lock);
376 	__vfio_pci_runtime_pm_exit(vdev);
377 	up_write(&vdev->memory_lock);
378 }
379 
380 static int vfio_pci_core_pm_exit(struct vfio_device *device, u32 flags,
381 				 void __user *arg, size_t argsz)
382 {
383 	struct vfio_pci_core_device *vdev =
384 		container_of(device, struct vfio_pci_core_device, vdev);
385 	int ret;
386 
387 	ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET, 0);
388 	if (ret != 1)
389 		return ret;
390 
391 	/*
392 	 * The device is always in the active state here due to pm wrappers
393 	 * around ioctls. If the device had entered a low power state and
394 	 * pm_wake_eventfd_ctx is valid, vfio_pci_core_runtime_resume() has
395 	 * already signaled the eventfd and exited low power mode itself.
396 	 * pm_runtime_engaged protects the redundant call here.
397 	 */
398 	vfio_pci_runtime_pm_exit(vdev);
399 	return 0;
400 }
401 
402 #ifdef CONFIG_PM
403 static int vfio_pci_core_runtime_suspend(struct device *dev)
404 {
405 	struct vfio_pci_core_device *vdev = dev_get_drvdata(dev);
406 
407 	down_write(&vdev->memory_lock);
408 	/*
409 	 * The user can move the device into D3hot state before invoking
410 	 * power management IOCTL. Move the device into D0 state here and then
411 	 * the pci-driver core runtime PM suspend function will move the device
412 	 * into the low power state. Also, for the devices which have
413 	 * NoSoftRst-, it will help in restoring the original state
414 	 * (saved locally in 'vdev->pm_save').
415 	 */
416 	vfio_pci_set_power_state(vdev, PCI_D0);
417 	up_write(&vdev->memory_lock);
418 
419 	/*
420 	 * If INTx is enabled, then mask INTx before going into the runtime
421 	 * suspended state and unmask the same in the runtime resume.
422 	 * If INTx has already been masked by the user, then
423 	 * vfio_pci_intx_mask() will return false and in that case, INTx
424 	 * should not be unmasked in the runtime resume.
425 	 */
426 	vdev->pm_intx_masked = ((vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX) &&
427 				vfio_pci_intx_mask(vdev));
428 
429 	return 0;
430 }
431 
432 static int vfio_pci_core_runtime_resume(struct device *dev)
433 {
434 	struct vfio_pci_core_device *vdev = dev_get_drvdata(dev);
435 
436 	/*
437 	 * Resume with a pm_wake_eventfd_ctx signals the eventfd and exit
438 	 * low power mode.
439 	 */
440 	down_write(&vdev->memory_lock);
441 	if (vdev->pm_wake_eventfd_ctx) {
442 		eventfd_signal(vdev->pm_wake_eventfd_ctx);
443 		__vfio_pci_runtime_pm_exit(vdev);
444 	}
445 	up_write(&vdev->memory_lock);
446 
447 	if (vdev->pm_intx_masked)
448 		vfio_pci_intx_unmask(vdev);
449 
450 	return 0;
451 }
452 #endif /* CONFIG_PM */
453 
454 /*
455  * The pci-driver core runtime PM routines always save the device state
456  * before going into suspended state. If the device is going into low power
457  * state with only with runtime PM ops, then no explicit handling is needed
458  * for the devices which have NoSoftRst-.
459  */
460 static const struct dev_pm_ops vfio_pci_core_pm_ops = {
461 	SET_RUNTIME_PM_OPS(vfio_pci_core_runtime_suspend,
462 			   vfio_pci_core_runtime_resume,
463 			   NULL)
464 };
465 
466 int vfio_pci_core_enable(struct vfio_pci_core_device *vdev)
467 {
468 	struct pci_dev *pdev = vdev->pdev;
469 	int ret;
470 	u16 cmd;
471 	u8 msix_pos;
472 
473 	if (!disable_idle_d3) {
474 		ret = pm_runtime_resume_and_get(&pdev->dev);
475 		if (ret < 0)
476 			return ret;
477 	}
478 
479 	/* Don't allow our initial saved state to include busmaster */
480 	pci_clear_master(pdev);
481 
482 	ret = pci_enable_device(pdev);
483 	if (ret)
484 		goto out_power;
485 
486 	/* If reset fails because of the device lock, fail this path entirely */
487 	ret = pci_try_reset_function(pdev);
488 	if (ret == -EAGAIN)
489 		goto out_disable_device;
490 
491 	vdev->reset_works = !ret;
492 	pci_save_state(pdev);
493 	vdev->pci_saved_state = pci_store_saved_state(pdev);
494 	if (!vdev->pci_saved_state)
495 		pci_dbg(pdev, "%s: Couldn't store saved state\n", __func__);
496 
497 	if (likely(!nointxmask)) {
498 		if (vfio_pci_nointx(pdev)) {
499 			pci_info(pdev, "Masking broken INTx support\n");
500 			vdev->nointx = true;
501 			pci_intx(pdev, 0);
502 		} else
503 			vdev->pci_2_3 = pci_intx_mask_supported(pdev);
504 	}
505 
506 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
507 	if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
508 		cmd &= ~PCI_COMMAND_INTX_DISABLE;
509 		pci_write_config_word(pdev, PCI_COMMAND, cmd);
510 	}
511 
512 	ret = vfio_pci_zdev_open_device(vdev);
513 	if (ret)
514 		goto out_free_state;
515 
516 	ret = vfio_config_init(vdev);
517 	if (ret)
518 		goto out_free_zdev;
519 
520 	msix_pos = pdev->msix_cap;
521 	if (msix_pos) {
522 		u16 flags;
523 		u32 table;
524 
525 		pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
526 		pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
527 
528 		vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
529 		vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
530 		vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
531 		vdev->has_dyn_msix = pci_msix_can_alloc_dyn(pdev);
532 	} else {
533 		vdev->msix_bar = 0xFF;
534 		vdev->has_dyn_msix = false;
535 	}
536 
537 	if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))
538 		vdev->has_vga = true;
539 
540 
541 	return 0;
542 
543 out_free_zdev:
544 	vfio_pci_zdev_close_device(vdev);
545 out_free_state:
546 	kfree(vdev->pci_saved_state);
547 	vdev->pci_saved_state = NULL;
548 out_disable_device:
549 	pci_disable_device(pdev);
550 out_power:
551 	if (!disable_idle_d3)
552 		pm_runtime_put(&pdev->dev);
553 	return ret;
554 }
555 EXPORT_SYMBOL_GPL(vfio_pci_core_enable);
556 
557 void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)
558 {
559 	struct pci_dev *pdev = vdev->pdev;
560 	struct vfio_pci_dummy_resource *dummy_res, *tmp;
561 	struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
562 	int i, bar;
563 
564 	/* For needs_reset */
565 	lockdep_assert_held(&vdev->vdev.dev_set->lock);
566 
567 	/*
568 	 * This function can be invoked while the power state is non-D0.
569 	 * This non-D0 power state can be with or without runtime PM.
570 	 * vfio_pci_runtime_pm_exit() will internally increment the usage
571 	 * count corresponding to pm_runtime_put() called during low power
572 	 * feature entry and then pm_runtime_resume() will wake up the device,
573 	 * if the device has already gone into the suspended state. Otherwise,
574 	 * the vfio_pci_set_power_state() will change the device power state
575 	 * to D0.
576 	 */
577 	vfio_pci_runtime_pm_exit(vdev);
578 	pm_runtime_resume(&pdev->dev);
579 
580 	/*
581 	 * This function calls __pci_reset_function_locked() which internally
582 	 * can use pci_pm_reset() for the function reset. pci_pm_reset() will
583 	 * fail if the power state is non-D0. Also, for the devices which
584 	 * have NoSoftRst-, the reset function can cause the PCI config space
585 	 * reset without restoring the original state (saved locally in
586 	 * 'vdev->pm_save').
587 	 */
588 	vfio_pci_set_power_state(vdev, PCI_D0);
589 
590 	/* Stop the device from further DMA */
591 	pci_clear_master(pdev);
592 
593 	vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
594 				VFIO_IRQ_SET_ACTION_TRIGGER,
595 				vdev->irq_type, 0, 0, NULL);
596 
597 	/* Device closed, don't need mutex here */
598 	list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
599 				 &vdev->ioeventfds_list, next) {
600 		vfio_virqfd_disable(&ioeventfd->virqfd);
601 		list_del(&ioeventfd->next);
602 		kfree(ioeventfd);
603 	}
604 	vdev->ioeventfds_nr = 0;
605 
606 	vdev->virq_disabled = false;
607 
608 	for (i = 0; i < vdev->num_regions; i++)
609 		vdev->region[i].ops->release(vdev, &vdev->region[i]);
610 
611 	vdev->num_regions = 0;
612 	kfree(vdev->region);
613 	vdev->region = NULL; /* don't krealloc a freed pointer */
614 
615 	vfio_config_free(vdev);
616 
617 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
618 		bar = i + PCI_STD_RESOURCES;
619 		if (!vdev->barmap[bar])
620 			continue;
621 		pci_iounmap(pdev, vdev->barmap[bar]);
622 		pci_release_selected_regions(pdev, 1 << bar);
623 		vdev->barmap[bar] = NULL;
624 	}
625 
626 	list_for_each_entry_safe(dummy_res, tmp,
627 				 &vdev->dummy_resources_list, res_next) {
628 		list_del(&dummy_res->res_next);
629 		release_resource(&dummy_res->resource);
630 		kfree(dummy_res);
631 	}
632 
633 	vdev->needs_reset = true;
634 
635 	vfio_pci_zdev_close_device(vdev);
636 
637 	/*
638 	 * If we have saved state, restore it.  If we can reset the device,
639 	 * even better.  Resetting with current state seems better than
640 	 * nothing, but saving and restoring current state without reset
641 	 * is just busy work.
642 	 */
643 	if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
644 		pci_info(pdev, "%s: Couldn't reload saved state\n", __func__);
645 
646 		if (!vdev->reset_works)
647 			goto out;
648 
649 		pci_save_state(pdev);
650 	}
651 
652 	/*
653 	 * Disable INTx and MSI, presumably to avoid spurious interrupts
654 	 * during reset.  Stolen from pci_reset_function()
655 	 */
656 	pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
657 
658 	/*
659 	 * Try to get the locks ourselves to prevent a deadlock. The
660 	 * success of this is dependent on being able to lock the device,
661 	 * which is not always possible.
662 	 * We can not use the "try" reset interface here, which will
663 	 * overwrite the previously restored configuration information.
664 	 */
665 	if (vdev->reset_works && pci_dev_trylock(pdev)) {
666 		if (!__pci_reset_function_locked(pdev))
667 			vdev->needs_reset = false;
668 		pci_dev_unlock(pdev);
669 	}
670 
671 	pci_restore_state(pdev);
672 out:
673 	pci_disable_device(pdev);
674 
675 	vfio_pci_dev_set_try_reset(vdev->vdev.dev_set);
676 
677 	/* Put the pm-runtime usage counter acquired during enable */
678 	if (!disable_idle_d3)
679 		pm_runtime_put(&pdev->dev);
680 }
681 EXPORT_SYMBOL_GPL(vfio_pci_core_disable);
682 
683 void vfio_pci_core_close_device(struct vfio_device *core_vdev)
684 {
685 	struct vfio_pci_core_device *vdev =
686 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
687 
688 	if (vdev->sriov_pf_core_dev) {
689 		mutex_lock(&vdev->sriov_pf_core_dev->vf_token->lock);
690 		WARN_ON(!vdev->sriov_pf_core_dev->vf_token->users);
691 		vdev->sriov_pf_core_dev->vf_token->users--;
692 		mutex_unlock(&vdev->sriov_pf_core_dev->vf_token->lock);
693 	}
694 #if IS_ENABLED(CONFIG_EEH)
695 	eeh_dev_release(vdev->pdev);
696 #endif
697 	vfio_pci_core_disable(vdev);
698 
699 	mutex_lock(&vdev->igate);
700 	if (vdev->err_trigger) {
701 		eventfd_ctx_put(vdev->err_trigger);
702 		vdev->err_trigger = NULL;
703 	}
704 	if (vdev->req_trigger) {
705 		eventfd_ctx_put(vdev->req_trigger);
706 		vdev->req_trigger = NULL;
707 	}
708 	mutex_unlock(&vdev->igate);
709 }
710 EXPORT_SYMBOL_GPL(vfio_pci_core_close_device);
711 
712 void vfio_pci_core_finish_enable(struct vfio_pci_core_device *vdev)
713 {
714 	vfio_pci_probe_mmaps(vdev);
715 #if IS_ENABLED(CONFIG_EEH)
716 	eeh_dev_open(vdev->pdev);
717 #endif
718 
719 	if (vdev->sriov_pf_core_dev) {
720 		mutex_lock(&vdev->sriov_pf_core_dev->vf_token->lock);
721 		vdev->sriov_pf_core_dev->vf_token->users++;
722 		mutex_unlock(&vdev->sriov_pf_core_dev->vf_token->lock);
723 	}
724 }
725 EXPORT_SYMBOL_GPL(vfio_pci_core_finish_enable);
726 
727 static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_type)
728 {
729 	if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
730 		u8 pin;
731 
732 		if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) ||
733 		    vdev->nointx || vdev->pdev->is_virtfn)
734 			return 0;
735 
736 		pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
737 
738 		return pin ? 1 : 0;
739 	} else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
740 		u8 pos;
741 		u16 flags;
742 
743 		pos = vdev->pdev->msi_cap;
744 		if (pos) {
745 			pci_read_config_word(vdev->pdev,
746 					     pos + PCI_MSI_FLAGS, &flags);
747 			return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
748 		}
749 	} else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
750 		u8 pos;
751 		u16 flags;
752 
753 		pos = vdev->pdev->msix_cap;
754 		if (pos) {
755 			pci_read_config_word(vdev->pdev,
756 					     pos + PCI_MSIX_FLAGS, &flags);
757 
758 			return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
759 		}
760 	} else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
761 		if (pci_is_pcie(vdev->pdev))
762 			return 1;
763 	} else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
764 		return 1;
765 	}
766 
767 	return 0;
768 }
769 
770 static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
771 {
772 	(*(int *)data)++;
773 	return 0;
774 }
775 
776 struct vfio_pci_fill_info {
777 	struct vfio_device *vdev;
778 	struct vfio_pci_dependent_device *devices;
779 	int nr_devices;
780 	u32 count;
781 	u32 flags;
782 };
783 
784 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
785 {
786 	struct vfio_pci_dependent_device *info;
787 	struct vfio_pci_fill_info *fill = data;
788 
789 	/* The topology changed since we counted devices */
790 	if (fill->count >= fill->nr_devices)
791 		return -EAGAIN;
792 
793 	info = &fill->devices[fill->count++];
794 	info->segment = pci_domain_nr(pdev->bus);
795 	info->bus = pdev->bus->number;
796 	info->devfn = pdev->devfn;
797 
798 	if (fill->flags & VFIO_PCI_HOT_RESET_FLAG_DEV_ID) {
799 		struct iommufd_ctx *iommufd = vfio_iommufd_device_ictx(fill->vdev);
800 		struct vfio_device_set *dev_set = fill->vdev->dev_set;
801 		struct vfio_device *vdev;
802 
803 		/*
804 		 * hot-reset requires all affected devices be represented in
805 		 * the dev_set.
806 		 */
807 		vdev = vfio_find_device_in_devset(dev_set, &pdev->dev);
808 		if (!vdev) {
809 			info->devid = VFIO_PCI_DEVID_NOT_OWNED;
810 		} else {
811 			int id = vfio_iommufd_get_dev_id(vdev, iommufd);
812 
813 			if (id > 0)
814 				info->devid = id;
815 			else if (id == -ENOENT)
816 				info->devid = VFIO_PCI_DEVID_OWNED;
817 			else
818 				info->devid = VFIO_PCI_DEVID_NOT_OWNED;
819 		}
820 		/* If devid is VFIO_PCI_DEVID_NOT_OWNED, clear owned flag. */
821 		if (info->devid == VFIO_PCI_DEVID_NOT_OWNED)
822 			fill->flags &= ~VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED;
823 	} else {
824 		struct iommu_group *iommu_group;
825 
826 		iommu_group = iommu_group_get(&pdev->dev);
827 		if (!iommu_group)
828 			return -EPERM; /* Cannot reset non-isolated devices */
829 
830 		info->group_id = iommu_group_id(iommu_group);
831 		iommu_group_put(iommu_group);
832 	}
833 
834 	return 0;
835 }
836 
837 struct vfio_pci_group_info {
838 	int count;
839 	struct file **files;
840 };
841 
842 static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
843 {
844 	for (; pdev; pdev = pdev->bus->self)
845 		if (pdev->bus == slot->bus)
846 			return (pdev->slot == slot);
847 	return false;
848 }
849 
850 struct vfio_pci_walk_info {
851 	int (*fn)(struct pci_dev *pdev, void *data);
852 	void *data;
853 	struct pci_dev *pdev;
854 	bool slot;
855 	int ret;
856 };
857 
858 static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
859 {
860 	struct vfio_pci_walk_info *walk = data;
861 
862 	if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
863 		walk->ret = walk->fn(pdev, walk->data);
864 
865 	return walk->ret;
866 }
867 
868 static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
869 					 int (*fn)(struct pci_dev *,
870 						   void *data), void *data,
871 					 bool slot)
872 {
873 	struct vfio_pci_walk_info walk = {
874 		.fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
875 	};
876 
877 	pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
878 
879 	return walk.ret;
880 }
881 
882 static int msix_mmappable_cap(struct vfio_pci_core_device *vdev,
883 			      struct vfio_info_cap *caps)
884 {
885 	struct vfio_info_cap_header header = {
886 		.id = VFIO_REGION_INFO_CAP_MSIX_MAPPABLE,
887 		.version = 1
888 	};
889 
890 	return vfio_info_add_capability(caps, &header, sizeof(header));
891 }
892 
893 int vfio_pci_core_register_dev_region(struct vfio_pci_core_device *vdev,
894 				      unsigned int type, unsigned int subtype,
895 				      const struct vfio_pci_regops *ops,
896 				      size_t size, u32 flags, void *data)
897 {
898 	struct vfio_pci_region *region;
899 
900 	region = krealloc(vdev->region,
901 			  (vdev->num_regions + 1) * sizeof(*region),
902 			  GFP_KERNEL_ACCOUNT);
903 	if (!region)
904 		return -ENOMEM;
905 
906 	vdev->region = region;
907 	vdev->region[vdev->num_regions].type = type;
908 	vdev->region[vdev->num_regions].subtype = subtype;
909 	vdev->region[vdev->num_regions].ops = ops;
910 	vdev->region[vdev->num_regions].size = size;
911 	vdev->region[vdev->num_regions].flags = flags;
912 	vdev->region[vdev->num_regions].data = data;
913 
914 	vdev->num_regions++;
915 
916 	return 0;
917 }
918 EXPORT_SYMBOL_GPL(vfio_pci_core_register_dev_region);
919 
920 static int vfio_pci_info_atomic_cap(struct vfio_pci_core_device *vdev,
921 				    struct vfio_info_cap *caps)
922 {
923 	struct vfio_device_info_cap_pci_atomic_comp cap = {
924 		.header.id = VFIO_DEVICE_INFO_CAP_PCI_ATOMIC_COMP,
925 		.header.version = 1
926 	};
927 	struct pci_dev *pdev = pci_physfn(vdev->pdev);
928 	u32 devcap2;
929 
930 	pcie_capability_read_dword(pdev, PCI_EXP_DEVCAP2, &devcap2);
931 
932 	if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP32) &&
933 	    !pci_enable_atomic_ops_to_root(pdev, PCI_EXP_DEVCAP2_ATOMIC_COMP32))
934 		cap.flags |= VFIO_PCI_ATOMIC_COMP32;
935 
936 	if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP64) &&
937 	    !pci_enable_atomic_ops_to_root(pdev, PCI_EXP_DEVCAP2_ATOMIC_COMP64))
938 		cap.flags |= VFIO_PCI_ATOMIC_COMP64;
939 
940 	if ((devcap2 & PCI_EXP_DEVCAP2_ATOMIC_COMP128) &&
941 	    !pci_enable_atomic_ops_to_root(pdev,
942 					   PCI_EXP_DEVCAP2_ATOMIC_COMP128))
943 		cap.flags |= VFIO_PCI_ATOMIC_COMP128;
944 
945 	if (!cap.flags)
946 		return -ENODEV;
947 
948 	return vfio_info_add_capability(caps, &cap.header, sizeof(cap));
949 }
950 
951 static int vfio_pci_ioctl_get_info(struct vfio_pci_core_device *vdev,
952 				   struct vfio_device_info __user *arg)
953 {
954 	unsigned long minsz = offsetofend(struct vfio_device_info, num_irqs);
955 	struct vfio_device_info info = {};
956 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
957 	int ret;
958 
959 	if (copy_from_user(&info, arg, minsz))
960 		return -EFAULT;
961 
962 	if (info.argsz < minsz)
963 		return -EINVAL;
964 
965 	minsz = min_t(size_t, info.argsz, sizeof(info));
966 
967 	info.flags = VFIO_DEVICE_FLAGS_PCI;
968 
969 	if (vdev->reset_works)
970 		info.flags |= VFIO_DEVICE_FLAGS_RESET;
971 
972 	info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
973 	info.num_irqs = VFIO_PCI_NUM_IRQS;
974 
975 	ret = vfio_pci_info_zdev_add_caps(vdev, &caps);
976 	if (ret && ret != -ENODEV) {
977 		pci_warn(vdev->pdev,
978 			 "Failed to setup zPCI info capabilities\n");
979 		return ret;
980 	}
981 
982 	ret = vfio_pci_info_atomic_cap(vdev, &caps);
983 	if (ret && ret != -ENODEV) {
984 		pci_warn(vdev->pdev,
985 			 "Failed to setup AtomicOps info capability\n");
986 		return ret;
987 	}
988 
989 	if (caps.size) {
990 		info.flags |= VFIO_DEVICE_FLAGS_CAPS;
991 		if (info.argsz < sizeof(info) + caps.size) {
992 			info.argsz = sizeof(info) + caps.size;
993 		} else {
994 			vfio_info_cap_shift(&caps, sizeof(info));
995 			if (copy_to_user(arg + 1, caps.buf, caps.size)) {
996 				kfree(caps.buf);
997 				return -EFAULT;
998 			}
999 			info.cap_offset = sizeof(*arg);
1000 		}
1001 
1002 		kfree(caps.buf);
1003 	}
1004 
1005 	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
1006 }
1007 
1008 static int vfio_pci_ioctl_get_region_info(struct vfio_pci_core_device *vdev,
1009 					  struct vfio_region_info __user *arg)
1010 {
1011 	unsigned long minsz = offsetofend(struct vfio_region_info, offset);
1012 	struct pci_dev *pdev = vdev->pdev;
1013 	struct vfio_region_info info;
1014 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
1015 	int i, ret;
1016 
1017 	if (copy_from_user(&info, arg, minsz))
1018 		return -EFAULT;
1019 
1020 	if (info.argsz < minsz)
1021 		return -EINVAL;
1022 
1023 	switch (info.index) {
1024 	case VFIO_PCI_CONFIG_REGION_INDEX:
1025 		info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
1026 		info.size = pdev->cfg_size;
1027 		info.flags = VFIO_REGION_INFO_FLAG_READ |
1028 			     VFIO_REGION_INFO_FLAG_WRITE;
1029 		break;
1030 	case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
1031 		info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
1032 		info.size = pci_resource_len(pdev, info.index);
1033 		if (!info.size) {
1034 			info.flags = 0;
1035 			break;
1036 		}
1037 
1038 		info.flags = VFIO_REGION_INFO_FLAG_READ |
1039 			     VFIO_REGION_INFO_FLAG_WRITE;
1040 		if (vdev->bar_mmap_supported[info.index]) {
1041 			info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
1042 			if (info.index == vdev->msix_bar) {
1043 				ret = msix_mmappable_cap(vdev, &caps);
1044 				if (ret)
1045 					return ret;
1046 			}
1047 		}
1048 
1049 		break;
1050 	case VFIO_PCI_ROM_REGION_INDEX: {
1051 		void __iomem *io;
1052 		size_t size;
1053 		u16 cmd;
1054 
1055 		info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
1056 		info.flags = 0;
1057 
1058 		/* Report the BAR size, not the ROM size */
1059 		info.size = pci_resource_len(pdev, info.index);
1060 		if (!info.size) {
1061 			/* Shadow ROMs appear as PCI option ROMs */
1062 			if (pdev->resource[PCI_ROM_RESOURCE].flags &
1063 			    IORESOURCE_ROM_SHADOW)
1064 				info.size = 0x20000;
1065 			else
1066 				break;
1067 		}
1068 
1069 		/*
1070 		 * Is it really there?  Enable memory decode for implicit access
1071 		 * in pci_map_rom().
1072 		 */
1073 		cmd = vfio_pci_memory_lock_and_enable(vdev);
1074 		io = pci_map_rom(pdev, &size);
1075 		if (io) {
1076 			info.flags = VFIO_REGION_INFO_FLAG_READ;
1077 			pci_unmap_rom(pdev, io);
1078 		} else {
1079 			info.size = 0;
1080 		}
1081 		vfio_pci_memory_unlock_and_restore(vdev, cmd);
1082 
1083 		break;
1084 	}
1085 	case VFIO_PCI_VGA_REGION_INDEX:
1086 		if (!vdev->has_vga)
1087 			return -EINVAL;
1088 
1089 		info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
1090 		info.size = 0xc0000;
1091 		info.flags = VFIO_REGION_INFO_FLAG_READ |
1092 			     VFIO_REGION_INFO_FLAG_WRITE;
1093 
1094 		break;
1095 	default: {
1096 		struct vfio_region_info_cap_type cap_type = {
1097 			.header.id = VFIO_REGION_INFO_CAP_TYPE,
1098 			.header.version = 1
1099 		};
1100 
1101 		if (info.index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1102 			return -EINVAL;
1103 		info.index = array_index_nospec(
1104 			info.index, VFIO_PCI_NUM_REGIONS + vdev->num_regions);
1105 
1106 		i = info.index - VFIO_PCI_NUM_REGIONS;
1107 
1108 		info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
1109 		info.size = vdev->region[i].size;
1110 		info.flags = vdev->region[i].flags;
1111 
1112 		cap_type.type = vdev->region[i].type;
1113 		cap_type.subtype = vdev->region[i].subtype;
1114 
1115 		ret = vfio_info_add_capability(&caps, &cap_type.header,
1116 					       sizeof(cap_type));
1117 		if (ret)
1118 			return ret;
1119 
1120 		if (vdev->region[i].ops->add_capability) {
1121 			ret = vdev->region[i].ops->add_capability(
1122 				vdev, &vdev->region[i], &caps);
1123 			if (ret)
1124 				return ret;
1125 		}
1126 	}
1127 	}
1128 
1129 	if (caps.size) {
1130 		info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
1131 		if (info.argsz < sizeof(info) + caps.size) {
1132 			info.argsz = sizeof(info) + caps.size;
1133 			info.cap_offset = 0;
1134 		} else {
1135 			vfio_info_cap_shift(&caps, sizeof(info));
1136 			if (copy_to_user(arg + 1, caps.buf, caps.size)) {
1137 				kfree(caps.buf);
1138 				return -EFAULT;
1139 			}
1140 			info.cap_offset = sizeof(*arg);
1141 		}
1142 
1143 		kfree(caps.buf);
1144 	}
1145 
1146 	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
1147 }
1148 
1149 static int vfio_pci_ioctl_get_irq_info(struct vfio_pci_core_device *vdev,
1150 				       struct vfio_irq_info __user *arg)
1151 {
1152 	unsigned long minsz = offsetofend(struct vfio_irq_info, count);
1153 	struct vfio_irq_info info;
1154 
1155 	if (copy_from_user(&info, arg, minsz))
1156 		return -EFAULT;
1157 
1158 	if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
1159 		return -EINVAL;
1160 
1161 	switch (info.index) {
1162 	case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
1163 	case VFIO_PCI_REQ_IRQ_INDEX:
1164 		break;
1165 	case VFIO_PCI_ERR_IRQ_INDEX:
1166 		if (pci_is_pcie(vdev->pdev))
1167 			break;
1168 		fallthrough;
1169 	default:
1170 		return -EINVAL;
1171 	}
1172 
1173 	info.flags = VFIO_IRQ_INFO_EVENTFD;
1174 
1175 	info.count = vfio_pci_get_irq_count(vdev, info.index);
1176 
1177 	if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
1178 		info.flags |=
1179 			(VFIO_IRQ_INFO_MASKABLE | VFIO_IRQ_INFO_AUTOMASKED);
1180 	else if (info.index != VFIO_PCI_MSIX_IRQ_INDEX || !vdev->has_dyn_msix)
1181 		info.flags |= VFIO_IRQ_INFO_NORESIZE;
1182 
1183 	return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
1184 }
1185 
1186 static int vfio_pci_ioctl_set_irqs(struct vfio_pci_core_device *vdev,
1187 				   struct vfio_irq_set __user *arg)
1188 {
1189 	unsigned long minsz = offsetofend(struct vfio_irq_set, count);
1190 	struct vfio_irq_set hdr;
1191 	u8 *data = NULL;
1192 	int max, ret = 0;
1193 	size_t data_size = 0;
1194 
1195 	if (copy_from_user(&hdr, arg, minsz))
1196 		return -EFAULT;
1197 
1198 	max = vfio_pci_get_irq_count(vdev, hdr.index);
1199 
1200 	ret = vfio_set_irqs_validate_and_prepare(&hdr, max, VFIO_PCI_NUM_IRQS,
1201 						 &data_size);
1202 	if (ret)
1203 		return ret;
1204 
1205 	if (data_size) {
1206 		data = memdup_user(&arg->data, data_size);
1207 		if (IS_ERR(data))
1208 			return PTR_ERR(data);
1209 	}
1210 
1211 	mutex_lock(&vdev->igate);
1212 
1213 	ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index, hdr.start,
1214 				      hdr.count, data);
1215 
1216 	mutex_unlock(&vdev->igate);
1217 	kfree(data);
1218 
1219 	return ret;
1220 }
1221 
1222 static int vfio_pci_ioctl_reset(struct vfio_pci_core_device *vdev,
1223 				void __user *arg)
1224 {
1225 	int ret;
1226 
1227 	if (!vdev->reset_works)
1228 		return -EINVAL;
1229 
1230 	vfio_pci_zap_and_down_write_memory_lock(vdev);
1231 
1232 	/*
1233 	 * This function can be invoked while the power state is non-D0. If
1234 	 * pci_try_reset_function() has been called while the power state is
1235 	 * non-D0, then pci_try_reset_function() will internally set the power
1236 	 * state to D0 without vfio driver involvement. For the devices which
1237 	 * have NoSoftRst-, the reset function can cause the PCI config space
1238 	 * reset without restoring the original state (saved locally in
1239 	 * 'vdev->pm_save').
1240 	 */
1241 	vfio_pci_set_power_state(vdev, PCI_D0);
1242 
1243 	ret = pci_try_reset_function(vdev->pdev);
1244 	up_write(&vdev->memory_lock);
1245 
1246 	return ret;
1247 }
1248 
1249 static int vfio_pci_ioctl_get_pci_hot_reset_info(
1250 	struct vfio_pci_core_device *vdev,
1251 	struct vfio_pci_hot_reset_info __user *arg)
1252 {
1253 	unsigned long minsz =
1254 		offsetofend(struct vfio_pci_hot_reset_info, count);
1255 	struct vfio_pci_dependent_device *devices = NULL;
1256 	struct vfio_pci_hot_reset_info hdr;
1257 	struct vfio_pci_fill_info fill = {};
1258 	bool slot = false;
1259 	int ret, count = 0;
1260 
1261 	if (copy_from_user(&hdr, arg, minsz))
1262 		return -EFAULT;
1263 
1264 	if (hdr.argsz < minsz)
1265 		return -EINVAL;
1266 
1267 	hdr.flags = 0;
1268 
1269 	/* Can we do a slot or bus reset or neither? */
1270 	if (!pci_probe_reset_slot(vdev->pdev->slot))
1271 		slot = true;
1272 	else if (pci_probe_reset_bus(vdev->pdev->bus))
1273 		return -ENODEV;
1274 
1275 	ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
1276 					    &count, slot);
1277 	if (ret)
1278 		return ret;
1279 
1280 	if (WARN_ON(!count)) /* Should always be at least one */
1281 		return -ERANGE;
1282 
1283 	if (count > (hdr.argsz - sizeof(hdr)) / sizeof(*devices)) {
1284 		hdr.count = count;
1285 		ret = -ENOSPC;
1286 		goto header;
1287 	}
1288 
1289 	devices = kcalloc(count, sizeof(*devices), GFP_KERNEL);
1290 	if (!devices)
1291 		return -ENOMEM;
1292 
1293 	fill.devices = devices;
1294 	fill.nr_devices = count;
1295 	fill.vdev = &vdev->vdev;
1296 
1297 	if (vfio_device_cdev_opened(&vdev->vdev))
1298 		fill.flags |= VFIO_PCI_HOT_RESET_FLAG_DEV_ID |
1299 			     VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED;
1300 
1301 	mutex_lock(&vdev->vdev.dev_set->lock);
1302 	ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_fill_devs,
1303 					    &fill, slot);
1304 	mutex_unlock(&vdev->vdev.dev_set->lock);
1305 	if (ret)
1306 		goto out;
1307 
1308 	if (copy_to_user(arg->devices, devices,
1309 			 sizeof(*devices) * fill.count)) {
1310 		ret = -EFAULT;
1311 		goto out;
1312 	}
1313 
1314 	hdr.count = fill.count;
1315 	hdr.flags = fill.flags;
1316 
1317 header:
1318 	if (copy_to_user(arg, &hdr, minsz))
1319 		ret = -EFAULT;
1320 out:
1321 	kfree(devices);
1322 	return ret;
1323 }
1324 
1325 static int
1326 vfio_pci_ioctl_pci_hot_reset_groups(struct vfio_pci_core_device *vdev,
1327 				    u32 array_count, bool slot,
1328 				    struct vfio_pci_hot_reset __user *arg)
1329 {
1330 	int32_t *group_fds;
1331 	struct file **files;
1332 	struct vfio_pci_group_info info;
1333 	int file_idx, count = 0, ret = 0;
1334 
1335 	/*
1336 	 * We can't let userspace give us an arbitrarily large buffer to copy,
1337 	 * so verify how many we think there could be.  Note groups can have
1338 	 * multiple devices so one group per device is the max.
1339 	 */
1340 	ret = vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
1341 					    &count, slot);
1342 	if (ret)
1343 		return ret;
1344 
1345 	if (array_count > count)
1346 		return -EINVAL;
1347 
1348 	group_fds = kcalloc(array_count, sizeof(*group_fds), GFP_KERNEL);
1349 	files = kcalloc(array_count, sizeof(*files), GFP_KERNEL);
1350 	if (!group_fds || !files) {
1351 		kfree(group_fds);
1352 		kfree(files);
1353 		return -ENOMEM;
1354 	}
1355 
1356 	if (copy_from_user(group_fds, arg->group_fds,
1357 			   array_count * sizeof(*group_fds))) {
1358 		kfree(group_fds);
1359 		kfree(files);
1360 		return -EFAULT;
1361 	}
1362 
1363 	/*
1364 	 * Get the group file for each fd to ensure the group is held across
1365 	 * the reset
1366 	 */
1367 	for (file_idx = 0; file_idx < array_count; file_idx++) {
1368 		struct file *file = fget(group_fds[file_idx]);
1369 
1370 		if (!file) {
1371 			ret = -EBADF;
1372 			break;
1373 		}
1374 
1375 		/* Ensure the FD is a vfio group FD.*/
1376 		if (!vfio_file_is_group(file)) {
1377 			fput(file);
1378 			ret = -EINVAL;
1379 			break;
1380 		}
1381 
1382 		files[file_idx] = file;
1383 	}
1384 
1385 	kfree(group_fds);
1386 
1387 	/* release reference to groups on error */
1388 	if (ret)
1389 		goto hot_reset_release;
1390 
1391 	info.count = array_count;
1392 	info.files = files;
1393 
1394 	ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info, NULL);
1395 
1396 hot_reset_release:
1397 	for (file_idx--; file_idx >= 0; file_idx--)
1398 		fput(files[file_idx]);
1399 
1400 	kfree(files);
1401 	return ret;
1402 }
1403 
1404 static int vfio_pci_ioctl_pci_hot_reset(struct vfio_pci_core_device *vdev,
1405 					struct vfio_pci_hot_reset __user *arg)
1406 {
1407 	unsigned long minsz = offsetofend(struct vfio_pci_hot_reset, count);
1408 	struct vfio_pci_hot_reset hdr;
1409 	bool slot = false;
1410 
1411 	if (copy_from_user(&hdr, arg, minsz))
1412 		return -EFAULT;
1413 
1414 	if (hdr.argsz < minsz || hdr.flags)
1415 		return -EINVAL;
1416 
1417 	/* zero-length array is only for cdev opened devices */
1418 	if (!!hdr.count == vfio_device_cdev_opened(&vdev->vdev))
1419 		return -EINVAL;
1420 
1421 	/* Can we do a slot or bus reset or neither? */
1422 	if (!pci_probe_reset_slot(vdev->pdev->slot))
1423 		slot = true;
1424 	else if (pci_probe_reset_bus(vdev->pdev->bus))
1425 		return -ENODEV;
1426 
1427 	if (hdr.count)
1428 		return vfio_pci_ioctl_pci_hot_reset_groups(vdev, hdr.count, slot, arg);
1429 
1430 	return vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, NULL,
1431 					  vfio_iommufd_device_ictx(&vdev->vdev));
1432 }
1433 
1434 static int vfio_pci_ioctl_ioeventfd(struct vfio_pci_core_device *vdev,
1435 				    struct vfio_device_ioeventfd __user *arg)
1436 {
1437 	unsigned long minsz = offsetofend(struct vfio_device_ioeventfd, fd);
1438 	struct vfio_device_ioeventfd ioeventfd;
1439 	int count;
1440 
1441 	if (copy_from_user(&ioeventfd, arg, minsz))
1442 		return -EFAULT;
1443 
1444 	if (ioeventfd.argsz < minsz)
1445 		return -EINVAL;
1446 
1447 	if (ioeventfd.flags & ~VFIO_DEVICE_IOEVENTFD_SIZE_MASK)
1448 		return -EINVAL;
1449 
1450 	count = ioeventfd.flags & VFIO_DEVICE_IOEVENTFD_SIZE_MASK;
1451 
1452 	if (hweight8(count) != 1 || ioeventfd.fd < -1)
1453 		return -EINVAL;
1454 
1455 	return vfio_pci_ioeventfd(vdev, ioeventfd.offset, ioeventfd.data, count,
1456 				  ioeventfd.fd);
1457 }
1458 
1459 long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
1460 			 unsigned long arg)
1461 {
1462 	struct vfio_pci_core_device *vdev =
1463 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
1464 	void __user *uarg = (void __user *)arg;
1465 
1466 	switch (cmd) {
1467 	case VFIO_DEVICE_GET_INFO:
1468 		return vfio_pci_ioctl_get_info(vdev, uarg);
1469 	case VFIO_DEVICE_GET_IRQ_INFO:
1470 		return vfio_pci_ioctl_get_irq_info(vdev, uarg);
1471 	case VFIO_DEVICE_GET_PCI_HOT_RESET_INFO:
1472 		return vfio_pci_ioctl_get_pci_hot_reset_info(vdev, uarg);
1473 	case VFIO_DEVICE_GET_REGION_INFO:
1474 		return vfio_pci_ioctl_get_region_info(vdev, uarg);
1475 	case VFIO_DEVICE_IOEVENTFD:
1476 		return vfio_pci_ioctl_ioeventfd(vdev, uarg);
1477 	case VFIO_DEVICE_PCI_HOT_RESET:
1478 		return vfio_pci_ioctl_pci_hot_reset(vdev, uarg);
1479 	case VFIO_DEVICE_RESET:
1480 		return vfio_pci_ioctl_reset(vdev, uarg);
1481 	case VFIO_DEVICE_SET_IRQS:
1482 		return vfio_pci_ioctl_set_irqs(vdev, uarg);
1483 	default:
1484 		return -ENOTTY;
1485 	}
1486 }
1487 EXPORT_SYMBOL_GPL(vfio_pci_core_ioctl);
1488 
1489 static int vfio_pci_core_feature_token(struct vfio_device *device, u32 flags,
1490 				       uuid_t __user *arg, size_t argsz)
1491 {
1492 	struct vfio_pci_core_device *vdev =
1493 		container_of(device, struct vfio_pci_core_device, vdev);
1494 	uuid_t uuid;
1495 	int ret;
1496 
1497 	if (!vdev->vf_token)
1498 		return -ENOTTY;
1499 	/*
1500 	 * We do not support GET of the VF Token UUID as this could
1501 	 * expose the token of the previous device user.
1502 	 */
1503 	ret = vfio_check_feature(flags, argsz, VFIO_DEVICE_FEATURE_SET,
1504 				 sizeof(uuid));
1505 	if (ret != 1)
1506 		return ret;
1507 
1508 	if (copy_from_user(&uuid, arg, sizeof(uuid)))
1509 		return -EFAULT;
1510 
1511 	mutex_lock(&vdev->vf_token->lock);
1512 	uuid_copy(&vdev->vf_token->uuid, &uuid);
1513 	mutex_unlock(&vdev->vf_token->lock);
1514 	return 0;
1515 }
1516 
1517 int vfio_pci_core_ioctl_feature(struct vfio_device *device, u32 flags,
1518 				void __user *arg, size_t argsz)
1519 {
1520 	switch (flags & VFIO_DEVICE_FEATURE_MASK) {
1521 	case VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY:
1522 		return vfio_pci_core_pm_entry(device, flags, arg, argsz);
1523 	case VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY_WITH_WAKEUP:
1524 		return vfio_pci_core_pm_entry_with_wakeup(device, flags,
1525 							  arg, argsz);
1526 	case VFIO_DEVICE_FEATURE_LOW_POWER_EXIT:
1527 		return vfio_pci_core_pm_exit(device, flags, arg, argsz);
1528 	case VFIO_DEVICE_FEATURE_PCI_VF_TOKEN:
1529 		return vfio_pci_core_feature_token(device, flags, arg, argsz);
1530 	default:
1531 		return -ENOTTY;
1532 	}
1533 }
1534 EXPORT_SYMBOL_GPL(vfio_pci_core_ioctl_feature);
1535 
1536 static ssize_t vfio_pci_rw(struct vfio_pci_core_device *vdev, char __user *buf,
1537 			   size_t count, loff_t *ppos, bool iswrite)
1538 {
1539 	unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
1540 	int ret;
1541 
1542 	if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1543 		return -EINVAL;
1544 
1545 	ret = pm_runtime_resume_and_get(&vdev->pdev->dev);
1546 	if (ret) {
1547 		pci_info_ratelimited(vdev->pdev, "runtime resume failed %d\n",
1548 				     ret);
1549 		return -EIO;
1550 	}
1551 
1552 	switch (index) {
1553 	case VFIO_PCI_CONFIG_REGION_INDEX:
1554 		ret = vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
1555 		break;
1556 
1557 	case VFIO_PCI_ROM_REGION_INDEX:
1558 		if (iswrite)
1559 			ret = -EINVAL;
1560 		else
1561 			ret = vfio_pci_bar_rw(vdev, buf, count, ppos, false);
1562 		break;
1563 
1564 	case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
1565 		ret = vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
1566 		break;
1567 
1568 	case VFIO_PCI_VGA_REGION_INDEX:
1569 		ret = vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
1570 		break;
1571 
1572 	default:
1573 		index -= VFIO_PCI_NUM_REGIONS;
1574 		ret = vdev->region[index].ops->rw(vdev, buf,
1575 						   count, ppos, iswrite);
1576 		break;
1577 	}
1578 
1579 	pm_runtime_put(&vdev->pdev->dev);
1580 	return ret;
1581 }
1582 
1583 ssize_t vfio_pci_core_read(struct vfio_device *core_vdev, char __user *buf,
1584 		size_t count, loff_t *ppos)
1585 {
1586 	struct vfio_pci_core_device *vdev =
1587 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
1588 
1589 	if (!count)
1590 		return 0;
1591 
1592 	return vfio_pci_rw(vdev, buf, count, ppos, false);
1593 }
1594 EXPORT_SYMBOL_GPL(vfio_pci_core_read);
1595 
1596 ssize_t vfio_pci_core_write(struct vfio_device *core_vdev, const char __user *buf,
1597 		size_t count, loff_t *ppos)
1598 {
1599 	struct vfio_pci_core_device *vdev =
1600 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
1601 
1602 	if (!count)
1603 		return 0;
1604 
1605 	return vfio_pci_rw(vdev, (char __user *)buf, count, ppos, true);
1606 }
1607 EXPORT_SYMBOL_GPL(vfio_pci_core_write);
1608 
1609 static void vfio_pci_zap_bars(struct vfio_pci_core_device *vdev)
1610 {
1611 	struct vfio_device *core_vdev = &vdev->vdev;
1612 	loff_t start = VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_BAR0_REGION_INDEX);
1613 	loff_t end = VFIO_PCI_INDEX_TO_OFFSET(VFIO_PCI_ROM_REGION_INDEX);
1614 	loff_t len = end - start;
1615 
1616 	unmap_mapping_range(core_vdev->inode->i_mapping, start, len, true);
1617 }
1618 
1619 void vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_core_device *vdev)
1620 {
1621 	down_write(&vdev->memory_lock);
1622 	vfio_pci_zap_bars(vdev);
1623 }
1624 
1625 u16 vfio_pci_memory_lock_and_enable(struct vfio_pci_core_device *vdev)
1626 {
1627 	u16 cmd;
1628 
1629 	down_write(&vdev->memory_lock);
1630 	pci_read_config_word(vdev->pdev, PCI_COMMAND, &cmd);
1631 	if (!(cmd & PCI_COMMAND_MEMORY))
1632 		pci_write_config_word(vdev->pdev, PCI_COMMAND,
1633 				      cmd | PCI_COMMAND_MEMORY);
1634 
1635 	return cmd;
1636 }
1637 
1638 void vfio_pci_memory_unlock_and_restore(struct vfio_pci_core_device *vdev, u16 cmd)
1639 {
1640 	pci_write_config_word(vdev->pdev, PCI_COMMAND, cmd);
1641 	up_write(&vdev->memory_lock);
1642 }
1643 
1644 static unsigned long vma_to_pfn(struct vm_area_struct *vma)
1645 {
1646 	struct vfio_pci_core_device *vdev = vma->vm_private_data;
1647 	int index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
1648 	u64 pgoff;
1649 
1650 	pgoff = vma->vm_pgoff &
1651 		((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
1652 
1653 	return (pci_resource_start(vdev->pdev, index) >> PAGE_SHIFT) + pgoff;
1654 }
1655 
1656 static vm_fault_t vfio_pci_mmap_huge_fault(struct vm_fault *vmf,
1657 					   unsigned int order)
1658 {
1659 	struct vm_area_struct *vma = vmf->vma;
1660 	struct vfio_pci_core_device *vdev = vma->vm_private_data;
1661 	unsigned long pfn, pgoff = vmf->pgoff - vma->vm_pgoff;
1662 	vm_fault_t ret = VM_FAULT_SIGBUS;
1663 
1664 	if (order && (vmf->address & ((PAGE_SIZE << order) - 1) ||
1665 		      vmf->address + (PAGE_SIZE << order) > vma->vm_end)) {
1666 		ret = VM_FAULT_FALLBACK;
1667 		goto out;
1668 	}
1669 
1670 	pfn = vma_to_pfn(vma);
1671 
1672 	down_read(&vdev->memory_lock);
1673 
1674 	if (vdev->pm_runtime_engaged || !__vfio_pci_memory_enabled(vdev))
1675 		goto out_unlock;
1676 
1677 	switch (order) {
1678 	case 0:
1679 		ret = vmf_insert_pfn(vma, vmf->address, pfn + pgoff);
1680 		break;
1681 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
1682 	case PMD_ORDER:
1683 		ret = vmf_insert_pfn_pmd(vmf, __pfn_to_pfn_t(pfn + pgoff,
1684 							     PFN_DEV), false);
1685 		break;
1686 #endif
1687 #ifdef CONFIG_ARCH_SUPPORTS_PUD_PFNMAP
1688 	case PUD_ORDER:
1689 		ret = vmf_insert_pfn_pud(vmf, __pfn_to_pfn_t(pfn + pgoff,
1690 							     PFN_DEV), false);
1691 		break;
1692 #endif
1693 	default:
1694 		ret = VM_FAULT_FALLBACK;
1695 	}
1696 
1697 out_unlock:
1698 	up_read(&vdev->memory_lock);
1699 out:
1700 	dev_dbg_ratelimited(&vdev->pdev->dev,
1701 			   "%s(,order = %d) BAR %ld page offset 0x%lx: 0x%x\n",
1702 			    __func__, order,
1703 			    vma->vm_pgoff >>
1704 				(VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT),
1705 			    pgoff, (unsigned int)ret);
1706 
1707 	return ret;
1708 }
1709 
1710 static vm_fault_t vfio_pci_mmap_page_fault(struct vm_fault *vmf)
1711 {
1712 	return vfio_pci_mmap_huge_fault(vmf, 0);
1713 }
1714 
1715 static const struct vm_operations_struct vfio_pci_mmap_ops = {
1716 	.fault = vfio_pci_mmap_page_fault,
1717 #ifdef CONFIG_ARCH_SUPPORTS_HUGE_PFNMAP
1718 	.huge_fault = vfio_pci_mmap_huge_fault,
1719 #endif
1720 };
1721 
1722 int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
1723 {
1724 	struct vfio_pci_core_device *vdev =
1725 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
1726 	struct pci_dev *pdev = vdev->pdev;
1727 	unsigned int index;
1728 	u64 phys_len, req_len, pgoff, req_start;
1729 	int ret;
1730 
1731 	index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
1732 
1733 	if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1734 		return -EINVAL;
1735 	if (vma->vm_end < vma->vm_start)
1736 		return -EINVAL;
1737 	if ((vma->vm_flags & VM_SHARED) == 0)
1738 		return -EINVAL;
1739 	if (index >= VFIO_PCI_NUM_REGIONS) {
1740 		int regnum = index - VFIO_PCI_NUM_REGIONS;
1741 		struct vfio_pci_region *region = vdev->region + regnum;
1742 
1743 		if (region->ops && region->ops->mmap &&
1744 		    (region->flags & VFIO_REGION_INFO_FLAG_MMAP))
1745 			return region->ops->mmap(vdev, region, vma);
1746 		return -EINVAL;
1747 	}
1748 	if (index >= VFIO_PCI_ROM_REGION_INDEX)
1749 		return -EINVAL;
1750 	if (!vdev->bar_mmap_supported[index])
1751 		return -EINVAL;
1752 
1753 	phys_len = PAGE_ALIGN(pci_resource_len(pdev, index));
1754 	req_len = vma->vm_end - vma->vm_start;
1755 	pgoff = vma->vm_pgoff &
1756 		((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
1757 	req_start = pgoff << PAGE_SHIFT;
1758 
1759 	if (req_start + req_len > phys_len)
1760 		return -EINVAL;
1761 
1762 	/*
1763 	 * Even though we don't make use of the barmap for the mmap,
1764 	 * we need to request the region and the barmap tracks that.
1765 	 */
1766 	if (!vdev->barmap[index]) {
1767 		ret = pci_request_selected_regions(pdev,
1768 						   1 << index, "vfio-pci");
1769 		if (ret)
1770 			return ret;
1771 
1772 		vdev->barmap[index] = pci_iomap(pdev, index, 0);
1773 		if (!vdev->barmap[index]) {
1774 			pci_release_selected_regions(pdev, 1 << index);
1775 			return -ENOMEM;
1776 		}
1777 	}
1778 
1779 	vma->vm_private_data = vdev;
1780 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1781 	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
1782 
1783 	/*
1784 	 * Set vm_flags now, they should not be changed in the fault handler.
1785 	 * We want the same flags and page protection (decrypted above) as
1786 	 * io_remap_pfn_range() would set.
1787 	 *
1788 	 * VM_ALLOW_ANY_UNCACHED: The VMA flag is implemented for ARM64,
1789 	 * allowing KVM stage 2 device mapping attributes to use Normal-NC
1790 	 * rather than DEVICE_nGnRE, which allows guest mappings
1791 	 * supporting write-combining attributes (WC). ARM does not
1792 	 * architecturally guarantee this is safe, and indeed some MMIO
1793 	 * regions like the GICv2 VCPU interface can trigger uncontained
1794 	 * faults if Normal-NC is used.
1795 	 *
1796 	 * To safely use VFIO in KVM the platform must guarantee full
1797 	 * safety in the guest where no action taken against a MMIO
1798 	 * mapping can trigger an uncontained failure. The assumption is
1799 	 * that most VFIO PCI platforms support this for both mapping types,
1800 	 * at least in common flows, based on some expectations of how
1801 	 * PCI IP is integrated. Hence VM_ALLOW_ANY_UNCACHED is set in
1802 	 * the VMA flags.
1803 	 */
1804 	vm_flags_set(vma, VM_ALLOW_ANY_UNCACHED | VM_IO | VM_PFNMAP |
1805 			VM_DONTEXPAND | VM_DONTDUMP);
1806 	vma->vm_ops = &vfio_pci_mmap_ops;
1807 
1808 	return 0;
1809 }
1810 EXPORT_SYMBOL_GPL(vfio_pci_core_mmap);
1811 
1812 void vfio_pci_core_request(struct vfio_device *core_vdev, unsigned int count)
1813 {
1814 	struct vfio_pci_core_device *vdev =
1815 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
1816 	struct pci_dev *pdev = vdev->pdev;
1817 
1818 	mutex_lock(&vdev->igate);
1819 
1820 	if (vdev->req_trigger) {
1821 		if (!(count % 10))
1822 			pci_notice_ratelimited(pdev,
1823 				"Relaying device request to user (#%u)\n",
1824 				count);
1825 		eventfd_signal(vdev->req_trigger);
1826 	} else if (count == 0) {
1827 		pci_warn(pdev,
1828 			"No device request channel registered, blocked until released by user\n");
1829 	}
1830 
1831 	mutex_unlock(&vdev->igate);
1832 }
1833 EXPORT_SYMBOL_GPL(vfio_pci_core_request);
1834 
1835 static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
1836 				      bool vf_token, uuid_t *uuid)
1837 {
1838 	/*
1839 	 * There's always some degree of trust or collaboration between SR-IOV
1840 	 * PF and VFs, even if just that the PF hosts the SR-IOV capability and
1841 	 * can disrupt VFs with a reset, but often the PF has more explicit
1842 	 * access to deny service to the VF or access data passed through the
1843 	 * VF.  We therefore require an opt-in via a shared VF token (UUID) to
1844 	 * represent this trust.  This both prevents that a VF driver might
1845 	 * assume the PF driver is a trusted, in-kernel driver, and also that
1846 	 * a PF driver might be replaced with a rogue driver, unknown to in-use
1847 	 * VF drivers.
1848 	 *
1849 	 * Therefore when presented with a VF, if the PF is a vfio device and
1850 	 * it is bound to the vfio-pci driver, the user needs to provide a VF
1851 	 * token to access the device, in the form of appending a vf_token to
1852 	 * the device name, for example:
1853 	 *
1854 	 * "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3"
1855 	 *
1856 	 * When presented with a PF which has VFs in use, the user must also
1857 	 * provide the current VF token to prove collaboration with existing
1858 	 * VF users.  If VFs are not in use, the VF token provided for the PF
1859 	 * device will act to set the VF token.
1860 	 *
1861 	 * If the VF token is provided but unused, an error is generated.
1862 	 */
1863 	if (vdev->pdev->is_virtfn) {
1864 		struct vfio_pci_core_device *pf_vdev = vdev->sriov_pf_core_dev;
1865 		bool match;
1866 
1867 		if (!pf_vdev) {
1868 			if (!vf_token)
1869 				return 0; /* PF is not vfio-pci, no VF token */
1870 
1871 			pci_info_ratelimited(vdev->pdev,
1872 				"VF token incorrectly provided, PF not bound to vfio-pci\n");
1873 			return -EINVAL;
1874 		}
1875 
1876 		if (!vf_token) {
1877 			pci_info_ratelimited(vdev->pdev,
1878 				"VF token required to access device\n");
1879 			return -EACCES;
1880 		}
1881 
1882 		mutex_lock(&pf_vdev->vf_token->lock);
1883 		match = uuid_equal(uuid, &pf_vdev->vf_token->uuid);
1884 		mutex_unlock(&pf_vdev->vf_token->lock);
1885 
1886 		if (!match) {
1887 			pci_info_ratelimited(vdev->pdev,
1888 				"Incorrect VF token provided for device\n");
1889 			return -EACCES;
1890 		}
1891 	} else if (vdev->vf_token) {
1892 		mutex_lock(&vdev->vf_token->lock);
1893 		if (vdev->vf_token->users) {
1894 			if (!vf_token) {
1895 				mutex_unlock(&vdev->vf_token->lock);
1896 				pci_info_ratelimited(vdev->pdev,
1897 					"VF token required to access device\n");
1898 				return -EACCES;
1899 			}
1900 
1901 			if (!uuid_equal(uuid, &vdev->vf_token->uuid)) {
1902 				mutex_unlock(&vdev->vf_token->lock);
1903 				pci_info_ratelimited(vdev->pdev,
1904 					"Incorrect VF token provided for device\n");
1905 				return -EACCES;
1906 			}
1907 		} else if (vf_token) {
1908 			uuid_copy(&vdev->vf_token->uuid, uuid);
1909 		}
1910 
1911 		mutex_unlock(&vdev->vf_token->lock);
1912 	} else if (vf_token) {
1913 		pci_info_ratelimited(vdev->pdev,
1914 			"VF token incorrectly provided, not a PF or VF\n");
1915 		return -EINVAL;
1916 	}
1917 
1918 	return 0;
1919 }
1920 
1921 #define VF_TOKEN_ARG "vf_token="
1922 
1923 int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf)
1924 {
1925 	struct vfio_pci_core_device *vdev =
1926 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
1927 	bool vf_token = false;
1928 	uuid_t uuid;
1929 	int ret;
1930 
1931 	if (strncmp(pci_name(vdev->pdev), buf, strlen(pci_name(vdev->pdev))))
1932 		return 0; /* No match */
1933 
1934 	if (strlen(buf) > strlen(pci_name(vdev->pdev))) {
1935 		buf += strlen(pci_name(vdev->pdev));
1936 
1937 		if (*buf != ' ')
1938 			return 0; /* No match: non-whitespace after name */
1939 
1940 		while (*buf) {
1941 			if (*buf == ' ') {
1942 				buf++;
1943 				continue;
1944 			}
1945 
1946 			if (!vf_token && !strncmp(buf, VF_TOKEN_ARG,
1947 						  strlen(VF_TOKEN_ARG))) {
1948 				buf += strlen(VF_TOKEN_ARG);
1949 
1950 				if (strlen(buf) < UUID_STRING_LEN)
1951 					return -EINVAL;
1952 
1953 				ret = uuid_parse(buf, &uuid);
1954 				if (ret)
1955 					return ret;
1956 
1957 				vf_token = true;
1958 				buf += UUID_STRING_LEN;
1959 			} else {
1960 				/* Unknown/duplicate option */
1961 				return -EINVAL;
1962 			}
1963 		}
1964 	}
1965 
1966 	ret = vfio_pci_validate_vf_token(vdev, vf_token, &uuid);
1967 	if (ret)
1968 		return ret;
1969 
1970 	return 1; /* Match */
1971 }
1972 EXPORT_SYMBOL_GPL(vfio_pci_core_match);
1973 
1974 static int vfio_pci_bus_notifier(struct notifier_block *nb,
1975 				 unsigned long action, void *data)
1976 {
1977 	struct vfio_pci_core_device *vdev = container_of(nb,
1978 						    struct vfio_pci_core_device, nb);
1979 	struct device *dev = data;
1980 	struct pci_dev *pdev = to_pci_dev(dev);
1981 	struct pci_dev *physfn = pci_physfn(pdev);
1982 
1983 	if (action == BUS_NOTIFY_ADD_DEVICE &&
1984 	    pdev->is_virtfn && physfn == vdev->pdev) {
1985 		pci_info(vdev->pdev, "Captured SR-IOV VF %s driver_override\n",
1986 			 pci_name(pdev));
1987 		pdev->driver_override = kasprintf(GFP_KERNEL, "%s",
1988 						  vdev->vdev.ops->name);
1989 		WARN_ON(!pdev->driver_override);
1990 	} else if (action == BUS_NOTIFY_BOUND_DRIVER &&
1991 		   pdev->is_virtfn && physfn == vdev->pdev) {
1992 		struct pci_driver *drv = pci_dev_driver(pdev);
1993 
1994 		if (drv && drv != pci_dev_driver(vdev->pdev))
1995 			pci_warn(vdev->pdev,
1996 				 "VF %s bound to driver %s while PF bound to driver %s\n",
1997 				 pci_name(pdev), drv->name,
1998 				 pci_dev_driver(vdev->pdev)->name);
1999 	}
2000 
2001 	return 0;
2002 }
2003 
2004 static int vfio_pci_vf_init(struct vfio_pci_core_device *vdev)
2005 {
2006 	struct pci_dev *pdev = vdev->pdev;
2007 	struct vfio_pci_core_device *cur;
2008 	struct pci_dev *physfn;
2009 	int ret;
2010 
2011 	if (pdev->is_virtfn) {
2012 		/*
2013 		 * If this VF was created by our vfio_pci_core_sriov_configure()
2014 		 * then we can find the PF vfio_pci_core_device now, and due to
2015 		 * the locking in pci_disable_sriov() it cannot change until
2016 		 * this VF device driver is removed.
2017 		 */
2018 		physfn = pci_physfn(vdev->pdev);
2019 		mutex_lock(&vfio_pci_sriov_pfs_mutex);
2020 		list_for_each_entry(cur, &vfio_pci_sriov_pfs, sriov_pfs_item) {
2021 			if (cur->pdev == physfn) {
2022 				vdev->sriov_pf_core_dev = cur;
2023 				break;
2024 			}
2025 		}
2026 		mutex_unlock(&vfio_pci_sriov_pfs_mutex);
2027 		return 0;
2028 	}
2029 
2030 	/* Not a SRIOV PF */
2031 	if (!pdev->is_physfn)
2032 		return 0;
2033 
2034 	vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
2035 	if (!vdev->vf_token)
2036 		return -ENOMEM;
2037 
2038 	mutex_init(&vdev->vf_token->lock);
2039 	uuid_gen(&vdev->vf_token->uuid);
2040 
2041 	vdev->nb.notifier_call = vfio_pci_bus_notifier;
2042 	ret = bus_register_notifier(&pci_bus_type, &vdev->nb);
2043 	if (ret) {
2044 		kfree(vdev->vf_token);
2045 		return ret;
2046 	}
2047 	return 0;
2048 }
2049 
2050 static void vfio_pci_vf_uninit(struct vfio_pci_core_device *vdev)
2051 {
2052 	if (!vdev->vf_token)
2053 		return;
2054 
2055 	bus_unregister_notifier(&pci_bus_type, &vdev->nb);
2056 	WARN_ON(vdev->vf_token->users);
2057 	mutex_destroy(&vdev->vf_token->lock);
2058 	kfree(vdev->vf_token);
2059 }
2060 
2061 static int vfio_pci_vga_init(struct vfio_pci_core_device *vdev)
2062 {
2063 	struct pci_dev *pdev = vdev->pdev;
2064 	int ret;
2065 
2066 	if (!vfio_pci_is_vga(pdev))
2067 		return 0;
2068 
2069 	ret = aperture_remove_conflicting_pci_devices(pdev, vdev->vdev.ops->name);
2070 	if (ret)
2071 		return ret;
2072 
2073 	ret = vga_client_register(pdev, vfio_pci_set_decode);
2074 	if (ret)
2075 		return ret;
2076 	vga_set_legacy_decoding(pdev, vfio_pci_set_decode(pdev, false));
2077 	return 0;
2078 }
2079 
2080 static void vfio_pci_vga_uninit(struct vfio_pci_core_device *vdev)
2081 {
2082 	struct pci_dev *pdev = vdev->pdev;
2083 
2084 	if (!vfio_pci_is_vga(pdev))
2085 		return;
2086 	vga_client_unregister(pdev);
2087 	vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
2088 					      VGA_RSRC_LEGACY_IO |
2089 					      VGA_RSRC_LEGACY_MEM);
2090 }
2091 
2092 int vfio_pci_core_init_dev(struct vfio_device *core_vdev)
2093 {
2094 	struct vfio_pci_core_device *vdev =
2095 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
2096 
2097 	vdev->pdev = to_pci_dev(core_vdev->dev);
2098 	vdev->irq_type = VFIO_PCI_NUM_IRQS;
2099 	mutex_init(&vdev->igate);
2100 	spin_lock_init(&vdev->irqlock);
2101 	mutex_init(&vdev->ioeventfds_lock);
2102 	INIT_LIST_HEAD(&vdev->dummy_resources_list);
2103 	INIT_LIST_HEAD(&vdev->ioeventfds_list);
2104 	INIT_LIST_HEAD(&vdev->sriov_pfs_item);
2105 	init_rwsem(&vdev->memory_lock);
2106 	xa_init(&vdev->ctx);
2107 
2108 	return 0;
2109 }
2110 EXPORT_SYMBOL_GPL(vfio_pci_core_init_dev);
2111 
2112 void vfio_pci_core_release_dev(struct vfio_device *core_vdev)
2113 {
2114 	struct vfio_pci_core_device *vdev =
2115 		container_of(core_vdev, struct vfio_pci_core_device, vdev);
2116 
2117 	mutex_destroy(&vdev->igate);
2118 	mutex_destroy(&vdev->ioeventfds_lock);
2119 	kfree(vdev->region);
2120 	kfree(vdev->pm_save);
2121 }
2122 EXPORT_SYMBOL_GPL(vfio_pci_core_release_dev);
2123 
2124 int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
2125 {
2126 	struct pci_dev *pdev = vdev->pdev;
2127 	struct device *dev = &pdev->dev;
2128 	int ret;
2129 
2130 	/* Drivers must set the vfio_pci_core_device to their drvdata */
2131 	if (WARN_ON(vdev != dev_get_drvdata(dev)))
2132 		return -EINVAL;
2133 
2134 	if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
2135 		return -EINVAL;
2136 
2137 	if (vdev->vdev.mig_ops) {
2138 		if (!(vdev->vdev.mig_ops->migration_get_state &&
2139 		      vdev->vdev.mig_ops->migration_set_state &&
2140 		      vdev->vdev.mig_ops->migration_get_data_size) ||
2141 		    !(vdev->vdev.migration_flags & VFIO_MIGRATION_STOP_COPY))
2142 			return -EINVAL;
2143 	}
2144 
2145 	if (vdev->vdev.log_ops && !(vdev->vdev.log_ops->log_start &&
2146 	    vdev->vdev.log_ops->log_stop &&
2147 	    vdev->vdev.log_ops->log_read_and_clear))
2148 		return -EINVAL;
2149 
2150 	/*
2151 	 * Prevent binding to PFs with VFs enabled, the VFs might be in use
2152 	 * by the host or other users.  We cannot capture the VFs if they
2153 	 * already exist, nor can we track VF users.  Disabling SR-IOV here
2154 	 * would initiate removing the VFs, which would unbind the driver,
2155 	 * which is prone to blocking if that VF is also in use by vfio-pci.
2156 	 * Just reject these PFs and let the user sort it out.
2157 	 */
2158 	if (pci_num_vf(pdev)) {
2159 		pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n");
2160 		return -EBUSY;
2161 	}
2162 
2163 	if (pci_is_root_bus(pdev->bus)) {
2164 		ret = vfio_assign_device_set(&vdev->vdev, vdev);
2165 	} else if (!pci_probe_reset_slot(pdev->slot)) {
2166 		ret = vfio_assign_device_set(&vdev->vdev, pdev->slot);
2167 	} else {
2168 		/*
2169 		 * If there is no slot reset support for this device, the whole
2170 		 * bus needs to be grouped together to support bus-wide resets.
2171 		 */
2172 		ret = vfio_assign_device_set(&vdev->vdev, pdev->bus);
2173 	}
2174 
2175 	if (ret)
2176 		return ret;
2177 	ret = vfio_pci_vf_init(vdev);
2178 	if (ret)
2179 		return ret;
2180 	ret = vfio_pci_vga_init(vdev);
2181 	if (ret)
2182 		goto out_vf;
2183 
2184 	vfio_pci_probe_power_state(vdev);
2185 
2186 	/*
2187 	 * pci-core sets the device power state to an unknown value at
2188 	 * bootup and after being removed from a driver.  The only
2189 	 * transition it allows from this unknown state is to D0, which
2190 	 * typically happens when a driver calls pci_enable_device().
2191 	 * We're not ready to enable the device yet, but we do want to
2192 	 * be able to get to D3.  Therefore first do a D0 transition
2193 	 * before enabling runtime PM.
2194 	 */
2195 	vfio_pci_set_power_state(vdev, PCI_D0);
2196 
2197 	dev->driver->pm = &vfio_pci_core_pm_ops;
2198 	pm_runtime_allow(dev);
2199 	if (!disable_idle_d3)
2200 		pm_runtime_put(dev);
2201 
2202 	ret = vfio_register_group_dev(&vdev->vdev);
2203 	if (ret)
2204 		goto out_power;
2205 	return 0;
2206 
2207 out_power:
2208 	if (!disable_idle_d3)
2209 		pm_runtime_get_noresume(dev);
2210 
2211 	pm_runtime_forbid(dev);
2212 out_vf:
2213 	vfio_pci_vf_uninit(vdev);
2214 	return ret;
2215 }
2216 EXPORT_SYMBOL_GPL(vfio_pci_core_register_device);
2217 
2218 void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev)
2219 {
2220 	vfio_pci_core_sriov_configure(vdev, 0);
2221 
2222 	vfio_unregister_group_dev(&vdev->vdev);
2223 
2224 	vfio_pci_vf_uninit(vdev);
2225 	vfio_pci_vga_uninit(vdev);
2226 
2227 	if (!disable_idle_d3)
2228 		pm_runtime_get_noresume(&vdev->pdev->dev);
2229 
2230 	pm_runtime_forbid(&vdev->pdev->dev);
2231 }
2232 EXPORT_SYMBOL_GPL(vfio_pci_core_unregister_device);
2233 
2234 pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev,
2235 						pci_channel_state_t state)
2236 {
2237 	struct vfio_pci_core_device *vdev = dev_get_drvdata(&pdev->dev);
2238 
2239 	mutex_lock(&vdev->igate);
2240 
2241 	if (vdev->err_trigger)
2242 		eventfd_signal(vdev->err_trigger);
2243 
2244 	mutex_unlock(&vdev->igate);
2245 
2246 	return PCI_ERS_RESULT_CAN_RECOVER;
2247 }
2248 EXPORT_SYMBOL_GPL(vfio_pci_core_aer_err_detected);
2249 
2250 int vfio_pci_core_sriov_configure(struct vfio_pci_core_device *vdev,
2251 				  int nr_virtfn)
2252 {
2253 	struct pci_dev *pdev = vdev->pdev;
2254 	int ret = 0;
2255 
2256 	device_lock_assert(&pdev->dev);
2257 
2258 	if (nr_virtfn) {
2259 		mutex_lock(&vfio_pci_sriov_pfs_mutex);
2260 		/*
2261 		 * The thread that adds the vdev to the list is the only thread
2262 		 * that gets to call pci_enable_sriov() and we will only allow
2263 		 * it to be called once without going through
2264 		 * pci_disable_sriov()
2265 		 */
2266 		if (!list_empty(&vdev->sriov_pfs_item)) {
2267 			ret = -EINVAL;
2268 			goto out_unlock;
2269 		}
2270 		list_add_tail(&vdev->sriov_pfs_item, &vfio_pci_sriov_pfs);
2271 		mutex_unlock(&vfio_pci_sriov_pfs_mutex);
2272 
2273 		/*
2274 		 * The PF power state should always be higher than the VF power
2275 		 * state. The PF can be in low power state either with runtime
2276 		 * power management (when there is no user) or PCI_PM_CTRL
2277 		 * register write by the user. If PF is in the low power state,
2278 		 * then change the power state to D0 first before enabling
2279 		 * SR-IOV. Also, this function can be called at any time, and
2280 		 * userspace PCI_PM_CTRL write can race against this code path,
2281 		 * so protect the same with 'memory_lock'.
2282 		 */
2283 		ret = pm_runtime_resume_and_get(&pdev->dev);
2284 		if (ret)
2285 			goto out_del;
2286 
2287 		down_write(&vdev->memory_lock);
2288 		vfio_pci_set_power_state(vdev, PCI_D0);
2289 		ret = pci_enable_sriov(pdev, nr_virtfn);
2290 		up_write(&vdev->memory_lock);
2291 		if (ret) {
2292 			pm_runtime_put(&pdev->dev);
2293 			goto out_del;
2294 		}
2295 		return nr_virtfn;
2296 	}
2297 
2298 	if (pci_num_vf(pdev)) {
2299 		pci_disable_sriov(pdev);
2300 		pm_runtime_put(&pdev->dev);
2301 	}
2302 
2303 out_del:
2304 	mutex_lock(&vfio_pci_sriov_pfs_mutex);
2305 	list_del_init(&vdev->sriov_pfs_item);
2306 out_unlock:
2307 	mutex_unlock(&vfio_pci_sriov_pfs_mutex);
2308 	return ret;
2309 }
2310 EXPORT_SYMBOL_GPL(vfio_pci_core_sriov_configure);
2311 
2312 const struct pci_error_handlers vfio_pci_core_err_handlers = {
2313 	.error_detected = vfio_pci_core_aer_err_detected,
2314 };
2315 EXPORT_SYMBOL_GPL(vfio_pci_core_err_handlers);
2316 
2317 static bool vfio_dev_in_groups(struct vfio_device *vdev,
2318 			       struct vfio_pci_group_info *groups)
2319 {
2320 	unsigned int i;
2321 
2322 	if (!groups)
2323 		return false;
2324 
2325 	for (i = 0; i < groups->count; i++)
2326 		if (vfio_file_has_dev(groups->files[i], vdev))
2327 			return true;
2328 	return false;
2329 }
2330 
2331 static int vfio_pci_is_device_in_set(struct pci_dev *pdev, void *data)
2332 {
2333 	struct vfio_device_set *dev_set = data;
2334 
2335 	return vfio_find_device_in_devset(dev_set, &pdev->dev) ? 0 : -ENODEV;
2336 }
2337 
2338 /*
2339  * vfio-core considers a group to be viable and will create a vfio_device even
2340  * if some devices are bound to drivers like pci-stub or pcieport. Here we
2341  * require all PCI devices to be inside our dev_set since that ensures they stay
2342  * put and that every driver controlling the device can co-ordinate with the
2343  * device reset.
2344  *
2345  * Returns the pci_dev to pass to pci_reset_bus() if every PCI device to be
2346  * reset is inside the dev_set, and pci_reset_bus() can succeed. NULL otherwise.
2347  */
2348 static struct pci_dev *
2349 vfio_pci_dev_set_resettable(struct vfio_device_set *dev_set)
2350 {
2351 	struct pci_dev *pdev;
2352 
2353 	lockdep_assert_held(&dev_set->lock);
2354 
2355 	/*
2356 	 * By definition all PCI devices in the dev_set share the same PCI
2357 	 * reset, so any pci_dev will have the same outcomes for
2358 	 * pci_probe_reset_*() and pci_reset_bus().
2359 	 */
2360 	pdev = list_first_entry(&dev_set->device_list,
2361 				struct vfio_pci_core_device,
2362 				vdev.dev_set_list)->pdev;
2363 
2364 	/* pci_reset_bus() is supported */
2365 	if (pci_probe_reset_slot(pdev->slot) && pci_probe_reset_bus(pdev->bus))
2366 		return NULL;
2367 
2368 	if (vfio_pci_for_each_slot_or_bus(pdev, vfio_pci_is_device_in_set,
2369 					  dev_set,
2370 					  !pci_probe_reset_slot(pdev->slot)))
2371 		return NULL;
2372 	return pdev;
2373 }
2374 
2375 static int vfio_pci_dev_set_pm_runtime_get(struct vfio_device_set *dev_set)
2376 {
2377 	struct vfio_pci_core_device *cur;
2378 	int ret;
2379 
2380 	list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
2381 		ret = pm_runtime_resume_and_get(&cur->pdev->dev);
2382 		if (ret)
2383 			goto unwind;
2384 	}
2385 
2386 	return 0;
2387 
2388 unwind:
2389 	list_for_each_entry_continue_reverse(cur, &dev_set->device_list,
2390 					     vdev.dev_set_list)
2391 		pm_runtime_put(&cur->pdev->dev);
2392 
2393 	return ret;
2394 }
2395 
2396 static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
2397 				      struct vfio_pci_group_info *groups,
2398 				      struct iommufd_ctx *iommufd_ctx)
2399 {
2400 	struct vfio_pci_core_device *vdev;
2401 	struct pci_dev *pdev;
2402 	int ret;
2403 
2404 	mutex_lock(&dev_set->lock);
2405 
2406 	pdev = vfio_pci_dev_set_resettable(dev_set);
2407 	if (!pdev) {
2408 		ret = -EINVAL;
2409 		goto err_unlock;
2410 	}
2411 
2412 	/*
2413 	 * Some of the devices in the dev_set can be in the runtime suspended
2414 	 * state. Increment the usage count for all the devices in the dev_set
2415 	 * before reset and decrement the same after reset.
2416 	 */
2417 	ret = vfio_pci_dev_set_pm_runtime_get(dev_set);
2418 	if (ret)
2419 		goto err_unlock;
2420 
2421 	list_for_each_entry(vdev, &dev_set->device_list, vdev.dev_set_list) {
2422 		bool owned;
2423 
2424 		/*
2425 		 * Test whether all the affected devices can be reset by the
2426 		 * user.
2427 		 *
2428 		 * If called from a group opened device and the user provides
2429 		 * a set of groups, all the devices in the dev_set should be
2430 		 * contained by the set of groups provided by the user.
2431 		 *
2432 		 * If called from a cdev opened device and the user provides
2433 		 * a zero-length array, all the devices in the dev_set must
2434 		 * be bound to the same iommufd_ctx as the input iommufd_ctx.
2435 		 * If there is any device that has not been bound to any
2436 		 * iommufd_ctx yet, check if its iommu_group has any device
2437 		 * bound to the input iommufd_ctx.  Such devices can be
2438 		 * considered owned by the input iommufd_ctx as the device
2439 		 * cannot be owned by another iommufd_ctx when its iommu_group
2440 		 * is owned.
2441 		 *
2442 		 * Otherwise, reset is not allowed.
2443 		 */
2444 		if (iommufd_ctx) {
2445 			int devid = vfio_iommufd_get_dev_id(&vdev->vdev,
2446 							    iommufd_ctx);
2447 
2448 			owned = (devid > 0 || devid == -ENOENT);
2449 		} else {
2450 			owned = vfio_dev_in_groups(&vdev->vdev, groups);
2451 		}
2452 
2453 		if (!owned) {
2454 			ret = -EINVAL;
2455 			break;
2456 		}
2457 
2458 		/*
2459 		 * Take the memory write lock for each device and zap BAR
2460 		 * mappings to prevent the user accessing the device while in
2461 		 * reset.  Locking multiple devices is prone to deadlock,
2462 		 * runaway and unwind if we hit contention.
2463 		 */
2464 		if (!down_write_trylock(&vdev->memory_lock)) {
2465 			ret = -EBUSY;
2466 			break;
2467 		}
2468 
2469 		vfio_pci_zap_bars(vdev);
2470 	}
2471 
2472 	if (!list_entry_is_head(vdev,
2473 				&dev_set->device_list, vdev.dev_set_list)) {
2474 		vdev = list_prev_entry(vdev, vdev.dev_set_list);
2475 		goto err_undo;
2476 	}
2477 
2478 	/*
2479 	 * The pci_reset_bus() will reset all the devices in the bus.
2480 	 * The power state can be non-D0 for some of the devices in the bus.
2481 	 * For these devices, the pci_reset_bus() will internally set
2482 	 * the power state to D0 without vfio driver involvement.
2483 	 * For the devices which have NoSoftRst-, the reset function can
2484 	 * cause the PCI config space reset without restoring the original
2485 	 * state (saved locally in 'vdev->pm_save').
2486 	 */
2487 	list_for_each_entry(vdev, &dev_set->device_list, vdev.dev_set_list)
2488 		vfio_pci_set_power_state(vdev, PCI_D0);
2489 
2490 	ret = pci_reset_bus(pdev);
2491 
2492 	vdev = list_last_entry(&dev_set->device_list,
2493 			       struct vfio_pci_core_device, vdev.dev_set_list);
2494 
2495 err_undo:
2496 	list_for_each_entry_from_reverse(vdev, &dev_set->device_list,
2497 					 vdev.dev_set_list)
2498 		up_write(&vdev->memory_lock);
2499 
2500 	list_for_each_entry(vdev, &dev_set->device_list, vdev.dev_set_list)
2501 		pm_runtime_put(&vdev->pdev->dev);
2502 
2503 err_unlock:
2504 	mutex_unlock(&dev_set->lock);
2505 	return ret;
2506 }
2507 
2508 static bool vfio_pci_dev_set_needs_reset(struct vfio_device_set *dev_set)
2509 {
2510 	struct vfio_pci_core_device *cur;
2511 	bool needs_reset = false;
2512 
2513 	/* No other VFIO device in the set can be open. */
2514 	if (vfio_device_set_open_count(dev_set) > 1)
2515 		return false;
2516 
2517 	list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list)
2518 		needs_reset |= cur->needs_reset;
2519 	return needs_reset;
2520 }
2521 
2522 /*
2523  * If a bus or slot reset is available for the provided dev_set and:
2524  *  - All of the devices affected by that bus or slot reset are unused
2525  *  - At least one of the affected devices is marked dirty via
2526  *    needs_reset (such as by lack of FLR support)
2527  * Then attempt to perform that bus or slot reset.
2528  */
2529 static void vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set)
2530 {
2531 	struct vfio_pci_core_device *cur;
2532 	struct pci_dev *pdev;
2533 	bool reset_done = false;
2534 
2535 	if (!vfio_pci_dev_set_needs_reset(dev_set))
2536 		return;
2537 
2538 	pdev = vfio_pci_dev_set_resettable(dev_set);
2539 	if (!pdev)
2540 		return;
2541 
2542 	/*
2543 	 * Some of the devices in the bus can be in the runtime suspended
2544 	 * state. Increment the usage count for all the devices in the dev_set
2545 	 * before reset and decrement the same after reset.
2546 	 */
2547 	if (!disable_idle_d3 && vfio_pci_dev_set_pm_runtime_get(dev_set))
2548 		return;
2549 
2550 	if (!pci_reset_bus(pdev))
2551 		reset_done = true;
2552 
2553 	list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
2554 		if (reset_done)
2555 			cur->needs_reset = false;
2556 
2557 		if (!disable_idle_d3)
2558 			pm_runtime_put(&cur->pdev->dev);
2559 	}
2560 }
2561 
2562 void vfio_pci_core_set_params(bool is_nointxmask, bool is_disable_vga,
2563 			      bool is_disable_idle_d3)
2564 {
2565 	nointxmask = is_nointxmask;
2566 	disable_vga = is_disable_vga;
2567 	disable_idle_d3 = is_disable_idle_d3;
2568 }
2569 EXPORT_SYMBOL_GPL(vfio_pci_core_set_params);
2570 
2571 static void vfio_pci_core_cleanup(void)
2572 {
2573 	vfio_pci_uninit_perm_bits();
2574 }
2575 
2576 static int __init vfio_pci_core_init(void)
2577 {
2578 	/* Allocate shared config space permission data used by all devices */
2579 	return vfio_pci_init_perm_bits();
2580 }
2581 
2582 module_init(vfio_pci_core_init);
2583 module_exit(vfio_pci_core_cleanup);
2584 
2585 MODULE_LICENSE("GPL v2");
2586 MODULE_AUTHOR(DRIVER_AUTHOR);
2587 MODULE_DESCRIPTION(DRIVER_DESC);
2588