xref: /linux/drivers/vfio/pci/vfio_pci_intrs.c (revision 58d416351e6df1a41d415958ccdd8eb9c2173fed) 
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 <linux/vfio_pci_core.h>
24 
25 /*
26  * INTx
27  */
28 static void vfio_send_intx_eventfd(void *opaque, void *unused)
29 {
30 	struct vfio_pci_core_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_core_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_core_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_core_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_core_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_core_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_core_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_core_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_core_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 	u16 cmd;
253 
254 	if (!is_irq_none(vdev))
255 		return -EINVAL;
256 
257 	vdev->ctx = kcalloc(nvec, sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
258 	if (!vdev->ctx)
259 		return -ENOMEM;
260 
261 	/* return the number of supported vectors if we can't get all: */
262 	cmd = vfio_pci_memory_lock_and_enable(vdev);
263 	ret = pci_alloc_irq_vectors(pdev, 1, nvec, flag);
264 	if (ret < nvec) {
265 		if (ret > 0)
266 			pci_free_irq_vectors(pdev);
267 		vfio_pci_memory_unlock_and_restore(vdev, cmd);
268 		kfree(vdev->ctx);
269 		return ret;
270 	}
271 	vfio_pci_memory_unlock_and_restore(vdev, cmd);
272 
273 	vdev->num_ctx = nvec;
274 	vdev->irq_type = msix ? VFIO_PCI_MSIX_IRQ_INDEX :
275 				VFIO_PCI_MSI_IRQ_INDEX;
276 
277 	if (!msix) {
278 		/*
279 		 * Compute the virtual hardware field for max msi vectors -
280 		 * it is the log base 2 of the number of vectors.
281 		 */
282 		vdev->msi_qmax = fls(nvec * 2 - 1) - 1;
283 	}
284 
285 	return 0;
286 }
287 
288 static int vfio_msi_set_vector_signal(struct vfio_pci_core_device *vdev,
289 				      int vector, int fd, bool msix)
290 {
291 	struct pci_dev *pdev = vdev->pdev;
292 	struct eventfd_ctx *trigger;
293 	int irq, ret;
294 	u16 cmd;
295 
296 	if (vector < 0 || vector >= vdev->num_ctx)
297 		return -EINVAL;
298 
299 	irq = pci_irq_vector(pdev, vector);
300 
301 	if (vdev->ctx[vector].trigger) {
302 		irq_bypass_unregister_producer(&vdev->ctx[vector].producer);
303 
304 		cmd = vfio_pci_memory_lock_and_enable(vdev);
305 		free_irq(irq, vdev->ctx[vector].trigger);
306 		vfio_pci_memory_unlock_and_restore(vdev, cmd);
307 
308 		kfree(vdev->ctx[vector].name);
309 		eventfd_ctx_put(vdev->ctx[vector].trigger);
310 		vdev->ctx[vector].trigger = NULL;
311 	}
312 
313 	if (fd < 0)
314 		return 0;
315 
316 	vdev->ctx[vector].name = kasprintf(GFP_KERNEL, "vfio-msi%s[%d](%s)",
317 					   msix ? "x" : "", vector,
318 					   pci_name(pdev));
319 	if (!vdev->ctx[vector].name)
320 		return -ENOMEM;
321 
322 	trigger = eventfd_ctx_fdget(fd);
323 	if (IS_ERR(trigger)) {
324 		kfree(vdev->ctx[vector].name);
325 		return PTR_ERR(trigger);
326 	}
327 
328 	/*
329 	 * The MSIx vector table resides in device memory which may be cleared
330 	 * via backdoor resets. We don't allow direct access to the vector
331 	 * table so even if a userspace driver attempts to save/restore around
332 	 * such a reset it would be unsuccessful. To avoid this, restore the
333 	 * cached value of the message prior to enabling.
334 	 */
335 	cmd = vfio_pci_memory_lock_and_enable(vdev);
336 	if (msix) {
337 		struct msi_msg msg;
338 
339 		get_cached_msi_msg(irq, &msg);
340 		pci_write_msi_msg(irq, &msg);
341 	}
342 
343 	ret = request_irq(irq, vfio_msihandler, 0,
344 			  vdev->ctx[vector].name, trigger);
345 	vfio_pci_memory_unlock_and_restore(vdev, cmd);
346 	if (ret) {
347 		kfree(vdev->ctx[vector].name);
348 		eventfd_ctx_put(trigger);
349 		return ret;
350 	}
351 
352 	vdev->ctx[vector].producer.token = trigger;
353 	vdev->ctx[vector].producer.irq = irq;
354 	ret = irq_bypass_register_producer(&vdev->ctx[vector].producer);
355 	if (unlikely(ret)) {
356 		dev_info(&pdev->dev,
357 		"irq bypass producer (token %p) registration fails: %d\n",
358 		vdev->ctx[vector].producer.token, ret);
359 
360 		vdev->ctx[vector].producer.token = NULL;
361 	}
362 	vdev->ctx[vector].trigger = trigger;
363 
364 	return 0;
365 }
366 
367 static int vfio_msi_set_block(struct vfio_pci_core_device *vdev, unsigned start,
368 			      unsigned count, int32_t *fds, bool msix)
369 {
370 	int i, j, ret = 0;
371 
372 	if (start >= vdev->num_ctx || start + count > vdev->num_ctx)
373 		return -EINVAL;
374 
375 	for (i = 0, j = start; i < count && !ret; i++, j++) {
376 		int fd = fds ? fds[i] : -1;
377 		ret = vfio_msi_set_vector_signal(vdev, j, fd, msix);
378 	}
379 
380 	if (ret) {
381 		for (--j; j >= (int)start; j--)
382 			vfio_msi_set_vector_signal(vdev, j, -1, msix);
383 	}
384 
385 	return ret;
386 }
387 
388 static void vfio_msi_disable(struct vfio_pci_core_device *vdev, bool msix)
389 {
390 	struct pci_dev *pdev = vdev->pdev;
391 	int i;
392 	u16 cmd;
393 
394 	for (i = 0; i < vdev->num_ctx; i++) {
395 		vfio_virqfd_disable(&vdev->ctx[i].unmask);
396 		vfio_virqfd_disable(&vdev->ctx[i].mask);
397 	}
398 
399 	vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
400 
401 	cmd = vfio_pci_memory_lock_and_enable(vdev);
402 	pci_free_irq_vectors(pdev);
403 	vfio_pci_memory_unlock_and_restore(vdev, cmd);
404 
405 	/*
406 	 * Both disable paths above use pci_intx_for_msi() to clear DisINTx
407 	 * via their shutdown paths.  Restore for NoINTx devices.
408 	 */
409 	if (vdev->nointx)
410 		pci_intx(pdev, 0);
411 
412 	vdev->irq_type = VFIO_PCI_NUM_IRQS;
413 	vdev->num_ctx = 0;
414 	kfree(vdev->ctx);
415 }
416 
417 /*
418  * IOCTL support
419  */
420 static int vfio_pci_set_intx_unmask(struct vfio_pci_core_device *vdev,
421 				    unsigned index, unsigned start,
422 				    unsigned count, uint32_t flags, void *data)
423 {
424 	if (!is_intx(vdev) || start != 0 || count != 1)
425 		return -EINVAL;
426 
427 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
428 		vfio_pci_intx_unmask(vdev);
429 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
430 		uint8_t unmask = *(uint8_t *)data;
431 		if (unmask)
432 			vfio_pci_intx_unmask(vdev);
433 	} else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
434 		int32_t fd = *(int32_t *)data;
435 		if (fd >= 0)
436 			return vfio_virqfd_enable((void *) vdev,
437 						  vfio_pci_intx_unmask_handler,
438 						  vfio_send_intx_eventfd, NULL,
439 						  &vdev->ctx[0].unmask, fd);
440 
441 		vfio_virqfd_disable(&vdev->ctx[0].unmask);
442 	}
443 
444 	return 0;
445 }
446 
447 static int vfio_pci_set_intx_mask(struct vfio_pci_core_device *vdev,
448 				  unsigned index, unsigned start,
449 				  unsigned count, uint32_t flags, void *data)
450 {
451 	if (!is_intx(vdev) || start != 0 || count != 1)
452 		return -EINVAL;
453 
454 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
455 		vfio_pci_intx_mask(vdev);
456 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
457 		uint8_t mask = *(uint8_t *)data;
458 		if (mask)
459 			vfio_pci_intx_mask(vdev);
460 	} else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
461 		return -ENOTTY; /* XXX implement me */
462 	}
463 
464 	return 0;
465 }
466 
467 static int vfio_pci_set_intx_trigger(struct vfio_pci_core_device *vdev,
468 				     unsigned index, unsigned start,
469 				     unsigned count, uint32_t flags, void *data)
470 {
471 	if (is_intx(vdev) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
472 		vfio_intx_disable(vdev);
473 		return 0;
474 	}
475 
476 	if (!(is_intx(vdev) || is_irq_none(vdev)) || start != 0 || count != 1)
477 		return -EINVAL;
478 
479 	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
480 		int32_t fd = *(int32_t *)data;
481 		int ret;
482 
483 		if (is_intx(vdev))
484 			return vfio_intx_set_signal(vdev, fd);
485 
486 		ret = vfio_intx_enable(vdev);
487 		if (ret)
488 			return ret;
489 
490 		ret = vfio_intx_set_signal(vdev, fd);
491 		if (ret)
492 			vfio_intx_disable(vdev);
493 
494 		return ret;
495 	}
496 
497 	if (!is_intx(vdev))
498 		return -EINVAL;
499 
500 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
501 		vfio_send_intx_eventfd(vdev, NULL);
502 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
503 		uint8_t trigger = *(uint8_t *)data;
504 		if (trigger)
505 			vfio_send_intx_eventfd(vdev, NULL);
506 	}
507 	return 0;
508 }
509 
510 static int vfio_pci_set_msi_trigger(struct vfio_pci_core_device *vdev,
511 				    unsigned index, unsigned start,
512 				    unsigned count, uint32_t flags, void *data)
513 {
514 	int i;
515 	bool msix = (index == VFIO_PCI_MSIX_IRQ_INDEX) ? true : false;
516 
517 	if (irq_is(vdev, index) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
518 		vfio_msi_disable(vdev, msix);
519 		return 0;
520 	}
521 
522 	if (!(irq_is(vdev, index) || is_irq_none(vdev)))
523 		return -EINVAL;
524 
525 	if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
526 		int32_t *fds = data;
527 		int ret;
528 
529 		if (vdev->irq_type == index)
530 			return vfio_msi_set_block(vdev, start, count,
531 						  fds, msix);
532 
533 		ret = vfio_msi_enable(vdev, start + count, msix);
534 		if (ret)
535 			return ret;
536 
537 		ret = vfio_msi_set_block(vdev, start, count, fds, msix);
538 		if (ret)
539 			vfio_msi_disable(vdev, msix);
540 
541 		return ret;
542 	}
543 
544 	if (!irq_is(vdev, index) || start + count > vdev->num_ctx)
545 		return -EINVAL;
546 
547 	for (i = start; i < start + count; i++) {
548 		if (!vdev->ctx[i].trigger)
549 			continue;
550 		if (flags & VFIO_IRQ_SET_DATA_NONE) {
551 			eventfd_signal(vdev->ctx[i].trigger, 1);
552 		} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
553 			uint8_t *bools = data;
554 			if (bools[i - start])
555 				eventfd_signal(vdev->ctx[i].trigger, 1);
556 		}
557 	}
558 	return 0;
559 }
560 
561 static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx,
562 					   unsigned int count, uint32_t flags,
563 					   void *data)
564 {
565 	/* DATA_NONE/DATA_BOOL enables loopback testing */
566 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
567 		if (*ctx) {
568 			if (count) {
569 				eventfd_signal(*ctx, 1);
570 			} else {
571 				eventfd_ctx_put(*ctx);
572 				*ctx = NULL;
573 			}
574 			return 0;
575 		}
576 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
577 		uint8_t trigger;
578 
579 		if (!count)
580 			return -EINVAL;
581 
582 		trigger = *(uint8_t *)data;
583 		if (trigger && *ctx)
584 			eventfd_signal(*ctx, 1);
585 
586 		return 0;
587 	} else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
588 		int32_t fd;
589 
590 		if (!count)
591 			return -EINVAL;
592 
593 		fd = *(int32_t *)data;
594 		if (fd == -1) {
595 			if (*ctx)
596 				eventfd_ctx_put(*ctx);
597 			*ctx = NULL;
598 		} else if (fd >= 0) {
599 			struct eventfd_ctx *efdctx;
600 
601 			efdctx = eventfd_ctx_fdget(fd);
602 			if (IS_ERR(efdctx))
603 				return PTR_ERR(efdctx);
604 
605 			if (*ctx)
606 				eventfd_ctx_put(*ctx);
607 
608 			*ctx = efdctx;
609 		}
610 		return 0;
611 	}
612 
613 	return -EINVAL;
614 }
615 
616 static int vfio_pci_set_err_trigger(struct vfio_pci_core_device *vdev,
617 				    unsigned index, unsigned start,
618 				    unsigned count, uint32_t flags, void *data)
619 {
620 	if (index != VFIO_PCI_ERR_IRQ_INDEX || start != 0 || count > 1)
621 		return -EINVAL;
622 
623 	return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger,
624 					       count, flags, data);
625 }
626 
627 static int vfio_pci_set_req_trigger(struct vfio_pci_core_device *vdev,
628 				    unsigned index, unsigned start,
629 				    unsigned count, uint32_t flags, void *data)
630 {
631 	if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count > 1)
632 		return -EINVAL;
633 
634 	return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger,
635 					       count, flags, data);
636 }
637 
638 int vfio_pci_set_irqs_ioctl(struct vfio_pci_core_device *vdev, uint32_t flags,
639 			    unsigned index, unsigned start, unsigned count,
640 			    void *data)
641 {
642 	int (*func)(struct vfio_pci_core_device *vdev, unsigned index,
643 		    unsigned start, unsigned count, uint32_t flags,
644 		    void *data) = NULL;
645 
646 	switch (index) {
647 	case VFIO_PCI_INTX_IRQ_INDEX:
648 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
649 		case VFIO_IRQ_SET_ACTION_MASK:
650 			func = vfio_pci_set_intx_mask;
651 			break;
652 		case VFIO_IRQ_SET_ACTION_UNMASK:
653 			func = vfio_pci_set_intx_unmask;
654 			break;
655 		case VFIO_IRQ_SET_ACTION_TRIGGER:
656 			func = vfio_pci_set_intx_trigger;
657 			break;
658 		}
659 		break;
660 	case VFIO_PCI_MSI_IRQ_INDEX:
661 	case VFIO_PCI_MSIX_IRQ_INDEX:
662 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
663 		case VFIO_IRQ_SET_ACTION_MASK:
664 		case VFIO_IRQ_SET_ACTION_UNMASK:
665 			/* XXX Need masking support exported */
666 			break;
667 		case VFIO_IRQ_SET_ACTION_TRIGGER:
668 			func = vfio_pci_set_msi_trigger;
669 			break;
670 		}
671 		break;
672 	case VFIO_PCI_ERR_IRQ_INDEX:
673 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
674 		case VFIO_IRQ_SET_ACTION_TRIGGER:
675 			if (pci_is_pcie(vdev->pdev))
676 				func = vfio_pci_set_err_trigger;
677 			break;
678 		}
679 		break;
680 	case VFIO_PCI_REQ_IRQ_INDEX:
681 		switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
682 		case VFIO_IRQ_SET_ACTION_TRIGGER:
683 			func = vfio_pci_set_req_trigger;
684 			break;
685 		}
686 		break;
687 	}
688 
689 	if (!func)
690 		return -ENOTTY;
691 
692 	return func(vdev, index, start, count, flags, data);
693 }
694