xref: /linux/drivers/vfio/pci/vfio_pci_intrs.c (revision d95c3885865b71e56d8d60c8617f2ce1f0fa079d) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VFIO PCI interrupt handling
4  *
5  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
6  *     Author: Alex Williamson <alex.williamson@redhat.com>
7  *
8  * Derived from original vfio:
9  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
10  * Author: Tom Lyon, pugs@cisco.com
11  */
12 
13 #include <linux/device.h>
14 #include <linux/interrupt.h>
15 #include <linux/eventfd.h>
16 #include <linux/msi.h>
17 #include <linux/pci.h>
18 #include <linux/file.h>
19 #include <linux/vfio.h>
20 #include <linux/wait.h>
21 #include <linux/slab.h>
22 
23 #include "vfio_pci_private.h"
24 
25 /*
26  * INTx
27  */
28 static void vfio_send_intx_eventfd(void *opaque, void *unused)
29 {
30 	struct vfio_pci_device *vdev = opaque;
31 
32 	if (likely(is_intx(vdev) && !vdev->virq_disabled))
33 		eventfd_signal(vdev->ctx[0].trigger, 1);
34 }
35 
36 void vfio_pci_intx_mask(struct vfio_pci_device *vdev)
37 {
38 	struct pci_dev *pdev = vdev->pdev;
39 	unsigned long flags;
40 
41 	spin_lock_irqsave(&vdev->irqlock, flags);
42 
43 	/*
44 	 * Masking can come from interrupt, ioctl, or config space
45 	 * via INTx disable.  The latter means this can get called
46 	 * even when not using intx delivery.  In this case, just
47 	 * try to have the physical bit follow the virtual bit.
48 	 */
49 	if (unlikely(!is_intx(vdev))) {
50 		if (vdev->pci_2_3)
51 			pci_intx(pdev, 0);
52 	} else if (!vdev->ctx[0].masked) {
53 		/*
54 		 * Can't use check_and_mask here because we always want to
55 		 * mask, not just when something is pending.
56 		 */
57 		if (vdev->pci_2_3)
58 			pci_intx(pdev, 0);
59 		else
60 			disable_irq_nosync(pdev->irq);
61 
62 		vdev->ctx[0].masked = true;
63 	}
64 
65 	spin_unlock_irqrestore(&vdev->irqlock, flags);
66 }
67 
68 /*
69  * If this is triggered by an eventfd, we can't call eventfd_signal
70  * or else we'll deadlock on the eventfd wait queue.  Return >0 when
71  * a signal is necessary, which can then be handled via a work queue
72  * or directly depending on the caller.
73  */
74 static int vfio_pci_intx_unmask_handler(void *opaque, void *unused)
75 {
76 	struct vfio_pci_device *vdev = opaque;
77 	struct pci_dev *pdev = vdev->pdev;
78 	unsigned long flags;
79 	int ret = 0;
80 
81 	spin_lock_irqsave(&vdev->irqlock, flags);
82 
83 	/*
84 	 * Unmasking comes from ioctl or config, so again, have the
85 	 * physical bit follow the virtual even when not using INTx.
86 	 */
87 	if (unlikely(!is_intx(vdev))) {
88 		if (vdev->pci_2_3)
89 			pci_intx(pdev, 1);
90 	} else if (vdev->ctx[0].masked && !vdev->virq_disabled) {
91 		/*
92 		 * A pending interrupt here would immediately trigger,
93 		 * but we can avoid that overhead by just re-sending
94 		 * the interrupt to the user.
95 		 */
96 		if (vdev->pci_2_3) {
97 			if (!pci_check_and_unmask_intx(pdev))
98 				ret = 1;
99 		} else
100 			enable_irq(pdev->irq);
101 
102 		vdev->ctx[0].masked = (ret > 0);
103 	}
104 
105 	spin_unlock_irqrestore(&vdev->irqlock, flags);
106 
107 	return ret;
108 }
109 
110 void vfio_pci_intx_unmask(struct vfio_pci_device *vdev)
111 {
112 	if (vfio_pci_intx_unmask_handler(vdev, NULL) > 0)
113 		vfio_send_intx_eventfd(vdev, NULL);
114 }
115 
116 static irqreturn_t vfio_intx_handler(int irq, void *dev_id)
117 {
118 	struct vfio_pci_device *vdev = dev_id;
119 	unsigned long flags;
120 	int ret = IRQ_NONE;
121 
122 	spin_lock_irqsave(&vdev->irqlock, flags);
123 
124 	if (!vdev->pci_2_3) {
125 		disable_irq_nosync(vdev->pdev->irq);
126 		vdev->ctx[0].masked = true;
127 		ret = IRQ_HANDLED;
128 	} else if (!vdev->ctx[0].masked &&  /* may be shared */
129 		   pci_check_and_mask_intx(vdev->pdev)) {
130 		vdev->ctx[0].masked = true;
131 		ret = IRQ_HANDLED;
132 	}
133 
134 	spin_unlock_irqrestore(&vdev->irqlock, flags);
135 
136 	if (ret == IRQ_HANDLED)
137 		vfio_send_intx_eventfd(vdev, NULL);
138 
139 	return ret;
140 }
141 
142 static int vfio_intx_enable(struct vfio_pci_device *vdev)
143 {
144 	if (!is_irq_none(vdev))
145 		return -EINVAL;
146 
147 	if (!vdev->pdev->irq)
148 		return -ENODEV;
149 
150 	vdev->ctx = kzalloc(sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
151 	if (!vdev->ctx)
152 		return -ENOMEM;
153 
154 	vdev->num_ctx = 1;
155 
156 	/*
157 	 * If the virtual interrupt is masked, restore it.  Devices
158 	 * supporting DisINTx can be masked at the hardware level
159 	 * here, non-PCI-2.3 devices will have to wait until the
160 	 * interrupt is enabled.
161 	 */
162 	vdev->ctx[0].masked = vdev->virq_disabled;
163 	if (vdev->pci_2_3)
164 		pci_intx(vdev->pdev, !vdev->ctx[0].masked);
165 
166 	vdev->irq_type = VFIO_PCI_INTX_IRQ_INDEX;
167 
168 	return 0;
169 }
170 
171 static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
172 {
173 	struct pci_dev *pdev = vdev->pdev;
174 	unsigned long irqflags = IRQF_SHARED;
175 	struct eventfd_ctx *trigger;
176 	unsigned long flags;
177 	int ret;
178 
179 	if (vdev->ctx[0].trigger) {
180 		free_irq(pdev->irq, vdev);
181 		kfree(vdev->ctx[0].name);
182 		eventfd_ctx_put(vdev->ctx[0].trigger);
183 		vdev->ctx[0].trigger = NULL;
184 	}
185 
186 	if (fd < 0) /* Disable only */
187 		return 0;
188 
189 	vdev->ctx[0].name = kasprintf(GFP_KERNEL, "vfio-intx(%s)",
190 				      pci_name(pdev));
191 	if (!vdev->ctx[0].name)
192 		return -ENOMEM;
193 
194 	trigger = eventfd_ctx_fdget(fd);
195 	if (IS_ERR(trigger)) {
196 		kfree(vdev->ctx[0].name);
197 		return PTR_ERR(trigger);
198 	}
199 
200 	vdev->ctx[0].trigger = trigger;
201 
202 	if (!vdev->pci_2_3)
203 		irqflags = 0;
204 
205 	ret = request_irq(pdev->irq, vfio_intx_handler,
206 			  irqflags, vdev->ctx[0].name, vdev);
207 	if (ret) {
208 		vdev->ctx[0].trigger = NULL;
209 		kfree(vdev->ctx[0].name);
210 		eventfd_ctx_put(trigger);
211 		return ret;
212 	}
213 
214 	/*
215 	 * INTx disable will stick across the new irq setup,
216 	 * disable_irq won't.
217 	 */
218 	spin_lock_irqsave(&vdev->irqlock, flags);
219 	if (!vdev->pci_2_3 && vdev->ctx[0].masked)
220 		disable_irq_nosync(pdev->irq);
221 	spin_unlock_irqrestore(&vdev->irqlock, flags);
222 
223 	return 0;
224 }
225 
226 static void vfio_intx_disable(struct vfio_pci_device *vdev)
227 {
228 	vfio_virqfd_disable(&vdev->ctx[0].unmask);
229 	vfio_virqfd_disable(&vdev->ctx[0].mask);
230 	vfio_intx_set_signal(vdev, -1);
231 	vdev->irq_type = VFIO_PCI_NUM_IRQS;
232 	vdev->num_ctx = 0;
233 	kfree(vdev->ctx);
234 }
235 
236 /*
237  * MSI/MSI-X
238  */
239 static irqreturn_t vfio_msihandler(int irq, void *arg)
240 {
241 	struct eventfd_ctx *trigger = arg;
242 
243 	eventfd_signal(trigger, 1);
244 	return IRQ_HANDLED;
245 }
246 
247 static int vfio_msi_enable(struct vfio_pci_device *vdev, int nvec, bool msix)
248 {
249 	struct pci_dev *pdev = vdev->pdev;
250 	unsigned int flag = msix ? PCI_IRQ_MSIX : PCI_IRQ_MSI;
251 	int ret;
252 
253 	if (!is_irq_none(vdev))
254 		return -EINVAL;
255 
256 	vdev->ctx = kcalloc(nvec, sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
257 	if (!vdev->ctx)
258 		return -ENOMEM;
259 
260 	/* return the number of supported vectors if we can't get all: */
261 	ret = pci_alloc_irq_vectors(pdev, 1, nvec, flag);
262 	if (ret < nvec) {
263 		if (ret > 0)
264 			pci_free_irq_vectors(pdev);
265 		kfree(vdev->ctx);
266 		return ret;
267 	}
268 
269 	vdev->num_ctx = nvec;
270 	vdev->irq_type = msix ? VFIO_PCI_MSIX_IRQ_INDEX :
271 				VFIO_PCI_MSI_IRQ_INDEX;
272 
273 	if (!msix) {
274 		/*
275 		 * Compute the virtual hardware field for max msi vectors -
276 		 * it is the log base 2 of the number of vectors.
277 		 */
278 		vdev->msi_qmax = fls(nvec * 2 - 1) - 1;
279 	}
280 
281 	return 0;
282 }
283 
284 static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev,
285 				      int vector, int fd, bool msix)
286 {
287 	struct pci_dev *pdev = vdev->pdev;
288 	struct eventfd_ctx *trigger;
289 	int irq, ret;
290 
291 	if (vector < 0 || vector >= vdev->num_ctx)
292 		return -EINVAL;
293 
294 	irq = pci_irq_vector(pdev, vector);
295 
296 	if (vdev->ctx[vector].trigger) {
297 		free_irq(irq, vdev->ctx[vector].trigger);
298 		irq_bypass_unregister_producer(&vdev->ctx[vector].producer);
299 		kfree(vdev->ctx[vector].name);
300 		eventfd_ctx_put(vdev->ctx[vector].trigger);
301 		vdev->ctx[vector].trigger = NULL;
302 	}
303 
304 	if (fd < 0)
305 		return 0;
306 
307 	vdev->ctx[vector].name = kasprintf(GFP_KERNEL, "vfio-msi%s[%d](%s)",
308 					   msix ? "x" : "", vector,
309 					   pci_name(pdev));
310 	if (!vdev->ctx[vector].name)
311 		return -ENOMEM;
312 
313 	trigger = eventfd_ctx_fdget(fd);
314 	if (IS_ERR(trigger)) {
315 		kfree(vdev->ctx[vector].name);
316 		return PTR_ERR(trigger);
317 	}
318 
319 	/*
320 	 * The MSIx vector table resides in device memory which may be cleared
321 	 * via backdoor resets. We don't allow direct access to the vector
322 	 * table so even if a userspace driver attempts to save/restore around
323 	 * such a reset it would be unsuccessful. To avoid this, restore the
324 	 * cached value of the message prior to enabling.
325 	 */
326 	if (msix) {
327 		struct msi_msg msg;
328 
329 		get_cached_msi_msg(irq, &msg);
330 		pci_write_msi_msg(irq, &msg);
331 	}
332 
333 	ret = request_irq(irq, vfio_msihandler, 0,
334 			  vdev->ctx[vector].name, trigger);
335 	if (ret) {
336 		kfree(vdev->ctx[vector].name);
337 		eventfd_ctx_put(trigger);
338 		return ret;
339 	}
340 
341 	vdev->ctx[vector].producer.token = trigger;
342 	vdev->ctx[vector].producer.irq = irq;
343 	ret = irq_bypass_register_producer(&vdev->ctx[vector].producer);
344 	if (unlikely(ret))
345 		dev_info(&pdev->dev,
346 		"irq bypass producer (token %p) registration fails: %d\n",
347 		vdev->ctx[vector].producer.token, ret);
348 
349 	vdev->ctx[vector].trigger = trigger;
350 
351 	return 0;
352 }
353 
354 static int vfio_msi_set_block(struct vfio_pci_device *vdev, unsigned start,
355 			      unsigned count, int32_t *fds, bool msix)
356 {
357 	int i, j, ret = 0;
358 
359 	if (start >= vdev->num_ctx || start + count > vdev->num_ctx)
360 		return -EINVAL;
361 
362 	for (i = 0, j = start; i < count && !ret; i++, j++) {
363 		int fd = fds ? fds[i] : -1;
364 		ret = vfio_msi_set_vector_signal(vdev, j, fd, msix);
365 	}
366 
367 	if (ret) {
368 		for (--j; j >= (int)start; j--)
369 			vfio_msi_set_vector_signal(vdev, j, -1, msix);
370 	}
371 
372 	return ret;
373 }
374 
375 static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
376 {
377 	struct pci_dev *pdev = vdev->pdev;
378 	int i;
379 
380 	for (i = 0; i < vdev->num_ctx; i++) {
381 		vfio_virqfd_disable(&vdev->ctx[i].unmask);
382 		vfio_virqfd_disable(&vdev->ctx[i].mask);
383 	}
384 
385 	vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
386 
387 	pci_free_irq_vectors(pdev);
388 
389 	/*
390 	 * Both disable paths above use pci_intx_for_msi() to clear DisINTx
391 	 * via their shutdown paths.  Restore for NoINTx devices.
392 	 */
393 	if (vdev->nointx)
394 		pci_intx(pdev, 0);
395 
396 	vdev->irq_type = VFIO_PCI_NUM_IRQS;
397 	vdev->num_ctx = 0;
398 	kfree(vdev->ctx);
399 }
400 
401 /*
402  * IOCTL support
403  */
404 static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev,
405 				    unsigned index, unsigned start,
406 				    unsigned count, uint32_t flags, void *data)
407 {
408 	if (!is_intx(vdev) || start != 0 || count != 1)
409 		return -EINVAL;
410 
411 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
412 		vfio_pci_intx_unmask(vdev);
413 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
414 		uint8_t unmask = *(uint8_t *)data;
415 		if (unmask)
416 			vfio_pci_intx_unmask(vdev);
417 	} else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
418 		int32_t fd = *(int32_t *)data;
419 		if (fd >= 0)
420 			return vfio_virqfd_enable((void *) vdev,
421 						  vfio_pci_intx_unmask_handler,
422 						  vfio_send_intx_eventfd, NULL,
423 						  &vdev->ctx[0].unmask, fd);
424 
425 		vfio_virqfd_disable(&vdev->ctx[0].unmask);
426 	}
427 
428 	return 0;
429 }
430 
431 static int vfio_pci_set_intx_mask(struct vfio_pci_device *vdev,
432 				  unsigned index, unsigned start,
433 				  unsigned count, uint32_t flags, void *data)
434 {
435 	if (!is_intx(vdev) || start != 0 || count != 1)
436 		return -EINVAL;
437 
438 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
439 		vfio_pci_intx_mask(vdev);
440 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
441 		uint8_t mask = *(uint8_t *)data;
442 		if (mask)
443 			vfio_pci_intx_mask(vdev);
444 	} else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
445 		return -ENOTTY; /* XXX implement me */
446 	}
447 
448 	return 0;
449 }
450 
451 static int vfio_pci_set_intx_trigger(struct vfio_pci_device *vdev,
452 				     unsigned index, unsigned start,
453 				     unsigned count, uint32_t flags, void *data)
454 {
455 	if (is_intx(vdev) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
456 		vfio_intx_disable(vdev);
457 		return 0;
458 	}
459 
460 	if (!(is_intx(vdev) || is_irq_none(vdev)) || start != 0 || count != 1)
461 		return -EINVAL;
462 
463 	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
464 		int32_t fd = *(int32_t *)data;
465 		int ret;
466 
467 		if (is_intx(vdev))
468 			return vfio_intx_set_signal(vdev, fd);
469 
470 		ret = vfio_intx_enable(vdev);
471 		if (ret)
472 			return ret;
473 
474 		ret = vfio_intx_set_signal(vdev, fd);
475 		if (ret)
476 			vfio_intx_disable(vdev);
477 
478 		return ret;
479 	}
480 
481 	if (!is_intx(vdev))
482 		return -EINVAL;
483 
484 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
485 		vfio_send_intx_eventfd(vdev, NULL);
486 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
487 		uint8_t trigger = *(uint8_t *)data;
488 		if (trigger)
489 			vfio_send_intx_eventfd(vdev, NULL);
490 	}
491 	return 0;
492 }
493 
494 static int vfio_pci_set_msi_trigger(struct vfio_pci_device *vdev,
495 				    unsigned index, unsigned start,
496 				    unsigned count, uint32_t flags, void *data)
497 {
498 	int i;
499 	bool msix = (index == VFIO_PCI_MSIX_IRQ_INDEX) ? true : false;
500 
501 	if (irq_is(vdev, index) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
502 		vfio_msi_disable(vdev, msix);
503 		return 0;
504 	}
505 
506 	if (!(irq_is(vdev, index) || is_irq_none(vdev)))
507 		return -EINVAL;
508 
509 	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
510 		int32_t *fds = data;
511 		int ret;
512 
513 		if (vdev->irq_type == index)
514 			return vfio_msi_set_block(vdev, start, count,
515 						  fds, msix);
516 
517 		ret = vfio_msi_enable(vdev, start + count, msix);
518 		if (ret)
519 			return ret;
520 
521 		ret = vfio_msi_set_block(vdev, start, count, fds, msix);
522 		if (ret)
523 			vfio_msi_disable(vdev, msix);
524 
525 		return ret;
526 	}
527 
528 	if (!irq_is(vdev, index) || start + count > vdev->num_ctx)
529 		return -EINVAL;
530 
531 	for (i = start; i < start + count; i++) {
532 		if (!vdev->ctx[i].trigger)
533 			continue;
534 		if (flags & VFIO_IRQ_SET_DATA_NONE) {
535 			eventfd_signal(vdev->ctx[i].trigger, 1);
536 		} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
537 			uint8_t *bools = data;
538 			if (bools[i - start])
539 				eventfd_signal(vdev->ctx[i].trigger, 1);
540 		}
541 	}
542 	return 0;
543 }
544 
545 static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx,
546 					   unsigned int count, uint32_t flags,
547 					   void *data)
548 {
549 	/* DATA_NONE/DATA_BOOL enables loopback testing */
550 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
551 		if (*ctx) {
552 			if (count) {
553 				eventfd_signal(*ctx, 1);
554 			} else {
555 				eventfd_ctx_put(*ctx);
556 				*ctx = NULL;
557 			}
558 			return 0;
559 		}
560 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
561 		uint8_t trigger;
562 
563 		if (!count)
564 			return -EINVAL;
565 
566 		trigger = *(uint8_t *)data;
567 		if (trigger && *ctx)
568 			eventfd_signal(*ctx, 1);
569 
570 		return 0;
571 	} else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
572 		int32_t fd;
573 
574 		if (!count)
575 			return -EINVAL;
576 
577 		fd = *(int32_t *)data;
578 		if (fd == -1) {
579 			if (*ctx)
580 				eventfd_ctx_put(*ctx);
581 			*ctx = NULL;
582 		} else if (fd >= 0) {
583 			struct eventfd_ctx *efdctx;
584 
585 			efdctx = eventfd_ctx_fdget(fd);
586 			if (IS_ERR(efdctx))
587 				return PTR_ERR(efdctx);
588 
589 			if (*ctx)
590 				eventfd_ctx_put(*ctx);
591 
592 			*ctx = efdctx;
593 		}
594 		return 0;
595 	}
596 
597 	return -EINVAL;
598 }
599 
600 static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
601 				    unsigned index, unsigned start,
602 				    unsigned count, uint32_t flags, void *data)
603 {
604 	if (index != VFIO_PCI_ERR_IRQ_INDEX || start != 0 || count > 1)
605 		return -EINVAL;
606 
607 	return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger,
608 					       count, flags, data);
609 }
610 
611 static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev,
612 				    unsigned index, unsigned start,
613 				    unsigned count, uint32_t flags, void *data)
614 {
615 	if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count > 1)
616 		return -EINVAL;
617 
618 	return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger,
619 					       count, flags, data);
620 }
621 
622 int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
623 			    unsigned index, unsigned start, unsigned count,
624 			    void *data)
625 {
626 	int (*func)(struct vfio_pci_device *vdev, unsigned index,
627 		    unsigned start, unsigned count, uint32_t flags,
628 		    void *data) = NULL;
629 
630 	switch (index) {
631 	case VFIO_PCI_INTX_IRQ_INDEX:
632 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
633 		case VFIO_IRQ_SET_ACTION_MASK:
634 			func = vfio_pci_set_intx_mask;
635 			break;
636 		case VFIO_IRQ_SET_ACTION_UNMASK:
637 			func = vfio_pci_set_intx_unmask;
638 			break;
639 		case VFIO_IRQ_SET_ACTION_TRIGGER:
640 			func = vfio_pci_set_intx_trigger;
641 			break;
642 		}
643 		break;
644 	case VFIO_PCI_MSI_IRQ_INDEX:
645 	case VFIO_PCI_MSIX_IRQ_INDEX:
646 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
647 		case VFIO_IRQ_SET_ACTION_MASK:
648 		case VFIO_IRQ_SET_ACTION_UNMASK:
649 			/* XXX Need masking support exported */
650 			break;
651 		case VFIO_IRQ_SET_ACTION_TRIGGER:
652 			func = vfio_pci_set_msi_trigger;
653 			break;
654 		}
655 		break;
656 	case VFIO_PCI_ERR_IRQ_INDEX:
657 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
658 		case VFIO_IRQ_SET_ACTION_TRIGGER:
659 			if (pci_is_pcie(vdev->pdev))
660 				func = vfio_pci_set_err_trigger;
661 			break;
662 		}
663 		break;
664 	case VFIO_PCI_REQ_IRQ_INDEX:
665 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
666 		case VFIO_IRQ_SET_ACTION_TRIGGER:
667 			func = vfio_pci_set_req_trigger;
668 			break;
669 		}
670 		break;
671 	}
672 
673 	if (!func)
674 		return -ENOTTY;
675 
676 	return func(vdev, index, start, count, flags, data);
677 }
678