2 * VFIO PCI interrupt handling
4 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
5 * Author: Alex Williamson <alex.williamson@redhat.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * Derived from original vfio:
12 * Copyright 2010 Cisco Systems, Inc. All rights reserved.
13 * Author: Tom Lyon, pugs@cisco.com
16 #include <linux/device.h>
17 #include <linux/interrupt.h>
18 #include <linux/eventfd.h>
19 #include <linux/msi.h>
20 #include <linux/pci.h>
21 #include <linux/file.h>
22 #include <linux/poll.h>
23 #include <linux/vfio.h>
24 #include <linux/wait.h>
25 #include <linux/workqueue.h>
26 #include <linux/slab.h>
28 #include "vfio_pci_private.h"
34 struct vfio_pci_device
*vdev
;
35 struct eventfd_ctx
*eventfd
;
36 int (*handler
)(struct vfio_pci_device
*, void *);
37 void (*thread
)(struct vfio_pci_device
*, void *);
39 struct work_struct inject
;
42 struct work_struct shutdown
;
43 struct virqfd
**pvirqfd
;
46 static struct workqueue_struct
*vfio_irqfd_cleanup_wq
;
48 int __init
vfio_pci_virqfd_init(void)
50 vfio_irqfd_cleanup_wq
=
51 create_singlethread_workqueue("vfio-irqfd-cleanup");
52 if (!vfio_irqfd_cleanup_wq
)
58 void vfio_pci_virqfd_exit(void)
60 destroy_workqueue(vfio_irqfd_cleanup_wq
);
63 static void virqfd_deactivate(struct virqfd
*virqfd
)
65 queue_work(vfio_irqfd_cleanup_wq
, &virqfd
->shutdown
);
68 static int virqfd_wakeup(wait_queue_t
*wait
, unsigned mode
, int sync
, void *key
)
70 struct virqfd
*virqfd
= container_of(wait
, struct virqfd
, wait
);
71 unsigned long flags
= (unsigned long)key
;
74 /* An event has been signaled, call function */
75 if ((!virqfd
->handler
||
76 virqfd
->handler(virqfd
->vdev
, virqfd
->data
)) &&
78 schedule_work(&virqfd
->inject
);
81 if (flags
& POLLHUP
) {
83 spin_lock_irqsave(&virqfd
->vdev
->irqlock
, flags
);
86 * The eventfd is closing, if the virqfd has not yet been
87 * queued for release, as determined by testing whether the
88 * vdev pointer to it is still valid, queue it now. As
89 * with kvm irqfds, we know we won't race against the virqfd
90 * going away because we hold wqh->lock to get here.
92 if (*(virqfd
->pvirqfd
) == virqfd
) {
93 *(virqfd
->pvirqfd
) = NULL
;
94 virqfd_deactivate(virqfd
);
97 spin_unlock_irqrestore(&virqfd
->vdev
->irqlock
, flags
);
103 static void virqfd_ptable_queue_proc(struct file
*file
,
104 wait_queue_head_t
*wqh
, poll_table
*pt
)
106 struct virqfd
*virqfd
= container_of(pt
, struct virqfd
, pt
);
107 add_wait_queue(wqh
, &virqfd
->wait
);
110 static void virqfd_shutdown(struct work_struct
*work
)
112 struct virqfd
*virqfd
= container_of(work
, struct virqfd
, shutdown
);
115 eventfd_ctx_remove_wait_queue(virqfd
->eventfd
, &virqfd
->wait
, &cnt
);
116 flush_work(&virqfd
->inject
);
117 eventfd_ctx_put(virqfd
->eventfd
);
122 static void virqfd_inject(struct work_struct
*work
)
124 struct virqfd
*virqfd
= container_of(work
, struct virqfd
, inject
);
126 virqfd
->thread(virqfd
->vdev
, virqfd
->data
);
129 static int virqfd_enable(struct vfio_pci_device
*vdev
,
130 int (*handler
)(struct vfio_pci_device
*, void *),
131 void (*thread
)(struct vfio_pci_device
*, void *),
132 void *data
, struct virqfd
**pvirqfd
, int fd
)
135 struct eventfd_ctx
*ctx
;
136 struct virqfd
*virqfd
;
140 virqfd
= kzalloc(sizeof(*virqfd
), GFP_KERNEL
);
144 virqfd
->pvirqfd
= pvirqfd
;
146 virqfd
->handler
= handler
;
147 virqfd
->thread
= thread
;
150 INIT_WORK(&virqfd
->shutdown
, virqfd_shutdown
);
151 INIT_WORK(&virqfd
->inject
, virqfd_inject
);
159 ctx
= eventfd_ctx_fileget(irqfd
.file
);
165 virqfd
->eventfd
= ctx
;
168 * virqfds can be released by closing the eventfd or directly
169 * through ioctl. These are both done through a workqueue, so
170 * we update the pointer to the virqfd under lock to avoid
171 * pushing multiple jobs to release the same virqfd.
173 spin_lock_irq(&vdev
->irqlock
);
176 spin_unlock_irq(&vdev
->irqlock
);
182 spin_unlock_irq(&vdev
->irqlock
);
185 * Install our own custom wake-up handling so we are notified via
186 * a callback whenever someone signals the underlying eventfd.
188 init_waitqueue_func_entry(&virqfd
->wait
, virqfd_wakeup
);
189 init_poll_funcptr(&virqfd
->pt
, virqfd_ptable_queue_proc
);
191 events
= irqfd
.file
->f_op
->poll(irqfd
.file
, &virqfd
->pt
);
194 * Check if there was an event already pending on the eventfd
195 * before we registered and trigger it as if we didn't miss it.
197 if (events
& POLLIN
) {
198 if ((!handler
|| handler(vdev
, data
)) && thread
)
199 schedule_work(&virqfd
->inject
);
203 * Do not drop the file until the irqfd is fully initialized,
204 * otherwise we might race against the POLLHUP.
210 eventfd_ctx_put(ctx
);
219 static void virqfd_disable(struct vfio_pci_device
*vdev
,
220 struct virqfd
**pvirqfd
)
224 spin_lock_irqsave(&vdev
->irqlock
, flags
);
227 virqfd_deactivate(*pvirqfd
);
231 spin_unlock_irqrestore(&vdev
->irqlock
, flags
);
234 * Block until we know all outstanding shutdown jobs have completed.
235 * Even if we don't queue the job, flush the wq to be sure it's
238 flush_workqueue(vfio_irqfd_cleanup_wq
);
244 static void vfio_send_intx_eventfd(struct vfio_pci_device
*vdev
, void *unused
)
246 if (likely(is_intx(vdev
) && !vdev
->virq_disabled
))
247 eventfd_signal(vdev
->ctx
[0].trigger
, 1);
250 void vfio_pci_intx_mask(struct vfio_pci_device
*vdev
)
252 struct pci_dev
*pdev
= vdev
->pdev
;
255 spin_lock_irqsave(&vdev
->irqlock
, flags
);
258 * Masking can come from interrupt, ioctl, or config space
259 * via INTx disable. The latter means this can get called
260 * even when not using intx delivery. In this case, just
261 * try to have the physical bit follow the virtual bit.
263 if (unlikely(!is_intx(vdev
))) {
266 } else if (!vdev
->ctx
[0].masked
) {
268 * Can't use check_and_mask here because we always want to
269 * mask, not just when something is pending.
274 disable_irq_nosync(pdev
->irq
);
276 vdev
->ctx
[0].masked
= true;
279 spin_unlock_irqrestore(&vdev
->irqlock
, flags
);
283 * If this is triggered by an eventfd, we can't call eventfd_signal
284 * or else we'll deadlock on the eventfd wait queue. Return >0 when
285 * a signal is necessary, which can then be handled via a work queue
286 * or directly depending on the caller.
288 static int vfio_pci_intx_unmask_handler(struct vfio_pci_device
*vdev
,
291 struct pci_dev
*pdev
= vdev
->pdev
;
295 spin_lock_irqsave(&vdev
->irqlock
, flags
);
298 * Unmasking comes from ioctl or config, so again, have the
299 * physical bit follow the virtual even when not using INTx.
301 if (unlikely(!is_intx(vdev
))) {
304 } else if (vdev
->ctx
[0].masked
&& !vdev
->virq_disabled
) {
306 * A pending interrupt here would immediately trigger,
307 * but we can avoid that overhead by just re-sending
308 * the interrupt to the user.
311 if (!pci_check_and_unmask_intx(pdev
))
314 enable_irq(pdev
->irq
);
316 vdev
->ctx
[0].masked
= (ret
> 0);
319 spin_unlock_irqrestore(&vdev
->irqlock
, flags
);
324 void vfio_pci_intx_unmask(struct vfio_pci_device
*vdev
)
326 if (vfio_pci_intx_unmask_handler(vdev
, NULL
) > 0)
327 vfio_send_intx_eventfd(vdev
, NULL
);
330 static irqreturn_t
vfio_intx_handler(int irq
, void *dev_id
)
332 struct vfio_pci_device
*vdev
= dev_id
;
336 spin_lock_irqsave(&vdev
->irqlock
, flags
);
338 if (!vdev
->pci_2_3
) {
339 disable_irq_nosync(vdev
->pdev
->irq
);
340 vdev
->ctx
[0].masked
= true;
342 } else if (!vdev
->ctx
[0].masked
&& /* may be shared */
343 pci_check_and_mask_intx(vdev
->pdev
)) {
344 vdev
->ctx
[0].masked
= true;
348 spin_unlock_irqrestore(&vdev
->irqlock
, flags
);
350 if (ret
== IRQ_HANDLED
)
351 vfio_send_intx_eventfd(vdev
, NULL
);
356 static int vfio_intx_enable(struct vfio_pci_device
*vdev
)
358 if (!is_irq_none(vdev
))
361 if (!vdev
->pdev
->irq
)
364 vdev
->ctx
= kzalloc(sizeof(struct vfio_pci_irq_ctx
), GFP_KERNEL
);
371 * If the virtual interrupt is masked, restore it. Devices
372 * supporting DisINTx can be masked at the hardware level
373 * here, non-PCI-2.3 devices will have to wait until the
374 * interrupt is enabled.
376 vdev
->ctx
[0].masked
= vdev
->virq_disabled
;
378 pci_intx(vdev
->pdev
, !vdev
->ctx
[0].masked
);
380 vdev
->irq_type
= VFIO_PCI_INTX_IRQ_INDEX
;
385 static int vfio_intx_set_signal(struct vfio_pci_device
*vdev
, int fd
)
387 struct pci_dev
*pdev
= vdev
->pdev
;
388 unsigned long irqflags
= IRQF_SHARED
;
389 struct eventfd_ctx
*trigger
;
393 if (vdev
->ctx
[0].trigger
) {
394 free_irq(pdev
->irq
, vdev
);
395 kfree(vdev
->ctx
[0].name
);
396 eventfd_ctx_put(vdev
->ctx
[0].trigger
);
397 vdev
->ctx
[0].trigger
= NULL
;
400 if (fd
< 0) /* Disable only */
403 vdev
->ctx
[0].name
= kasprintf(GFP_KERNEL
, "vfio-intx(%s)",
405 if (!vdev
->ctx
[0].name
)
408 trigger
= eventfd_ctx_fdget(fd
);
409 if (IS_ERR(trigger
)) {
410 kfree(vdev
->ctx
[0].name
);
411 return PTR_ERR(trigger
);
414 vdev
->ctx
[0].trigger
= trigger
;
419 ret
= request_irq(pdev
->irq
, vfio_intx_handler
,
420 irqflags
, vdev
->ctx
[0].name
, vdev
);
422 vdev
->ctx
[0].trigger
= NULL
;
423 kfree(vdev
->ctx
[0].name
);
424 eventfd_ctx_put(trigger
);
429 * INTx disable will stick across the new irq setup,
432 spin_lock_irqsave(&vdev
->irqlock
, flags
);
433 if (!vdev
->pci_2_3
&& vdev
->ctx
[0].masked
)
434 disable_irq_nosync(pdev
->irq
);
435 spin_unlock_irqrestore(&vdev
->irqlock
, flags
);
440 static void vfio_intx_disable(struct vfio_pci_device
*vdev
)
442 vfio_intx_set_signal(vdev
, -1);
443 virqfd_disable(vdev
, &vdev
->ctx
[0].unmask
);
444 virqfd_disable(vdev
, &vdev
->ctx
[0].mask
);
445 vdev
->irq_type
= VFIO_PCI_NUM_IRQS
;
453 static irqreturn_t
vfio_msihandler(int irq
, void *arg
)
455 struct eventfd_ctx
*trigger
= arg
;
457 eventfd_signal(trigger
, 1);
461 static int vfio_msi_enable(struct vfio_pci_device
*vdev
, int nvec
, bool msix
)
463 struct pci_dev
*pdev
= vdev
->pdev
;
466 if (!is_irq_none(vdev
))
469 vdev
->ctx
= kzalloc(nvec
* sizeof(struct vfio_pci_irq_ctx
), GFP_KERNEL
);
476 vdev
->msix
= kzalloc(nvec
* sizeof(struct msix_entry
),
483 for (i
= 0; i
< nvec
; i
++)
484 vdev
->msix
[i
].entry
= i
;
486 ret
= pci_enable_msix_range(pdev
, vdev
->msix
, 1, nvec
);
489 pci_disable_msix(pdev
);
495 ret
= pci_enable_msi_range(pdev
, 1, nvec
);
498 pci_disable_msi(pdev
);
504 vdev
->num_ctx
= nvec
;
505 vdev
->irq_type
= msix
? VFIO_PCI_MSIX_IRQ_INDEX
:
506 VFIO_PCI_MSI_IRQ_INDEX
;
510 * Compute the virtual hardware field for max msi vectors -
511 * it is the log base 2 of the number of vectors.
513 vdev
->msi_qmax
= fls(nvec
* 2 - 1) - 1;
519 static int vfio_msi_set_vector_signal(struct vfio_pci_device
*vdev
,
520 int vector
, int fd
, bool msix
)
522 struct pci_dev
*pdev
= vdev
->pdev
;
523 int irq
= msix
? vdev
->msix
[vector
].vector
: pdev
->irq
+ vector
;
524 char *name
= msix
? "vfio-msix" : "vfio-msi";
525 struct eventfd_ctx
*trigger
;
528 if (vector
>= vdev
->num_ctx
)
531 if (vdev
->ctx
[vector
].trigger
) {
532 free_irq(irq
, vdev
->ctx
[vector
].trigger
);
533 kfree(vdev
->ctx
[vector
].name
);
534 eventfd_ctx_put(vdev
->ctx
[vector
].trigger
);
535 vdev
->ctx
[vector
].trigger
= NULL
;
541 vdev
->ctx
[vector
].name
= kasprintf(GFP_KERNEL
, "%s[%d](%s)",
542 name
, vector
, pci_name(pdev
));
543 if (!vdev
->ctx
[vector
].name
)
546 trigger
= eventfd_ctx_fdget(fd
);
547 if (IS_ERR(trigger
)) {
548 kfree(vdev
->ctx
[vector
].name
);
549 return PTR_ERR(trigger
);
553 * The MSIx vector table resides in device memory which may be cleared
554 * via backdoor resets. We don't allow direct access to the vector
555 * table so even if a userspace driver attempts to save/restore around
556 * such a reset it would be unsuccessful. To avoid this, restore the
557 * cached value of the message prior to enabling.
562 get_cached_msi_msg(irq
, &msg
);
563 pci_write_msi_msg(irq
, &msg
);
566 ret
= request_irq(irq
, vfio_msihandler
, 0,
567 vdev
->ctx
[vector
].name
, trigger
);
569 kfree(vdev
->ctx
[vector
].name
);
570 eventfd_ctx_put(trigger
);
574 vdev
->ctx
[vector
].trigger
= trigger
;
579 static int vfio_msi_set_block(struct vfio_pci_device
*vdev
, unsigned start
,
580 unsigned count
, int32_t *fds
, bool msix
)
584 if (start
+ count
> vdev
->num_ctx
)
587 for (i
= 0, j
= start
; i
< count
&& !ret
; i
++, j
++) {
588 int fd
= fds
? fds
[i
] : -1;
589 ret
= vfio_msi_set_vector_signal(vdev
, j
, fd
, msix
);
593 for (--j
; j
>= start
; j
--)
594 vfio_msi_set_vector_signal(vdev
, j
, -1, msix
);
600 static void vfio_msi_disable(struct vfio_pci_device
*vdev
, bool msix
)
602 struct pci_dev
*pdev
= vdev
->pdev
;
605 vfio_msi_set_block(vdev
, 0, vdev
->num_ctx
, NULL
, msix
);
607 for (i
= 0; i
< vdev
->num_ctx
; i
++) {
608 virqfd_disable(vdev
, &vdev
->ctx
[i
].unmask
);
609 virqfd_disable(vdev
, &vdev
->ctx
[i
].mask
);
613 pci_disable_msix(vdev
->pdev
);
616 pci_disable_msi(pdev
);
618 vdev
->irq_type
= VFIO_PCI_NUM_IRQS
;
626 static int vfio_pci_set_intx_unmask(struct vfio_pci_device
*vdev
,
627 unsigned index
, unsigned start
,
628 unsigned count
, uint32_t flags
, void *data
)
630 if (!is_intx(vdev
) || start
!= 0 || count
!= 1)
633 if (flags
& VFIO_IRQ_SET_DATA_NONE
) {
634 vfio_pci_intx_unmask(vdev
);
635 } else if (flags
& VFIO_IRQ_SET_DATA_BOOL
) {
636 uint8_t unmask
= *(uint8_t *)data
;
638 vfio_pci_intx_unmask(vdev
);
639 } else if (flags
& VFIO_IRQ_SET_DATA_EVENTFD
) {
640 int32_t fd
= *(int32_t *)data
;
642 return virqfd_enable(vdev
, vfio_pci_intx_unmask_handler
,
643 vfio_send_intx_eventfd
, NULL
,
644 &vdev
->ctx
[0].unmask
, fd
);
646 virqfd_disable(vdev
, &vdev
->ctx
[0].unmask
);
652 static int vfio_pci_set_intx_mask(struct vfio_pci_device
*vdev
,
653 unsigned index
, unsigned start
,
654 unsigned count
, uint32_t flags
, void *data
)
656 if (!is_intx(vdev
) || start
!= 0 || count
!= 1)
659 if (flags
& VFIO_IRQ_SET_DATA_NONE
) {
660 vfio_pci_intx_mask(vdev
);
661 } else if (flags
& VFIO_IRQ_SET_DATA_BOOL
) {
662 uint8_t mask
= *(uint8_t *)data
;
664 vfio_pci_intx_mask(vdev
);
665 } else if (flags
& VFIO_IRQ_SET_DATA_EVENTFD
) {
666 return -ENOTTY
; /* XXX implement me */
672 static int vfio_pci_set_intx_trigger(struct vfio_pci_device
*vdev
,
673 unsigned index
, unsigned start
,
674 unsigned count
, uint32_t flags
, void *data
)
676 if (is_intx(vdev
) && !count
&& (flags
& VFIO_IRQ_SET_DATA_NONE
)) {
677 vfio_intx_disable(vdev
);
681 if (!(is_intx(vdev
) || is_irq_none(vdev
)) || start
!= 0 || count
!= 1)
684 if (flags
& VFIO_IRQ_SET_DATA_EVENTFD
) {
685 int32_t fd
= *(int32_t *)data
;
689 return vfio_intx_set_signal(vdev
, fd
);
691 ret
= vfio_intx_enable(vdev
);
695 ret
= vfio_intx_set_signal(vdev
, fd
);
697 vfio_intx_disable(vdev
);
705 if (flags
& VFIO_IRQ_SET_DATA_NONE
) {
706 vfio_send_intx_eventfd(vdev
, NULL
);
707 } else if (flags
& VFIO_IRQ_SET_DATA_BOOL
) {
708 uint8_t trigger
= *(uint8_t *)data
;
710 vfio_send_intx_eventfd(vdev
, NULL
);
715 static int vfio_pci_set_msi_trigger(struct vfio_pci_device
*vdev
,
716 unsigned index
, unsigned start
,
717 unsigned count
, uint32_t flags
, void *data
)
720 bool msix
= (index
== VFIO_PCI_MSIX_IRQ_INDEX
) ? true : false;
722 if (irq_is(vdev
, index
) && !count
&& (flags
& VFIO_IRQ_SET_DATA_NONE
)) {
723 vfio_msi_disable(vdev
, msix
);
727 if (!(irq_is(vdev
, index
) || is_irq_none(vdev
)))
730 if (flags
& VFIO_IRQ_SET_DATA_EVENTFD
) {
734 if (vdev
->irq_type
== index
)
735 return vfio_msi_set_block(vdev
, start
, count
,
738 ret
= vfio_msi_enable(vdev
, start
+ count
, msix
);
742 ret
= vfio_msi_set_block(vdev
, start
, count
, fds
, msix
);
744 vfio_msi_disable(vdev
, msix
);
749 if (!irq_is(vdev
, index
) || start
+ count
> vdev
->num_ctx
)
752 for (i
= start
; i
< start
+ count
; i
++) {
753 if (!vdev
->ctx
[i
].trigger
)
755 if (flags
& VFIO_IRQ_SET_DATA_NONE
) {
756 eventfd_signal(vdev
->ctx
[i
].trigger
, 1);
757 } else if (flags
& VFIO_IRQ_SET_DATA_BOOL
) {
758 uint8_t *bools
= data
;
759 if (bools
[i
- start
])
760 eventfd_signal(vdev
->ctx
[i
].trigger
, 1);
766 static int vfio_pci_set_err_trigger(struct vfio_pci_device
*vdev
,
767 unsigned index
, unsigned start
,
768 unsigned count
, uint32_t flags
, void *data
)
770 int32_t fd
= *(int32_t *)data
;
772 if ((index
!= VFIO_PCI_ERR_IRQ_INDEX
) ||
773 !(flags
& VFIO_IRQ_SET_DATA_TYPE_MASK
))
776 /* DATA_NONE/DATA_BOOL enables loopback testing */
777 if (flags
& VFIO_IRQ_SET_DATA_NONE
) {
778 if (vdev
->err_trigger
)
779 eventfd_signal(vdev
->err_trigger
, 1);
781 } else if (flags
& VFIO_IRQ_SET_DATA_BOOL
) {
782 uint8_t trigger
= *(uint8_t *)data
;
783 if (trigger
&& vdev
->err_trigger
)
784 eventfd_signal(vdev
->err_trigger
, 1);
788 /* Handle SET_DATA_EVENTFD */
790 if (vdev
->err_trigger
)
791 eventfd_ctx_put(vdev
->err_trigger
);
792 vdev
->err_trigger
= NULL
;
794 } else if (fd
>= 0) {
795 struct eventfd_ctx
*efdctx
;
796 efdctx
= eventfd_ctx_fdget(fd
);
798 return PTR_ERR(efdctx
);
799 if (vdev
->err_trigger
)
800 eventfd_ctx_put(vdev
->err_trigger
);
801 vdev
->err_trigger
= efdctx
;
806 int vfio_pci_set_irqs_ioctl(struct vfio_pci_device
*vdev
, uint32_t flags
,
807 unsigned index
, unsigned start
, unsigned count
,
810 int (*func
)(struct vfio_pci_device
*vdev
, unsigned index
,
811 unsigned start
, unsigned count
, uint32_t flags
,
815 case VFIO_PCI_INTX_IRQ_INDEX
:
816 switch (flags
& VFIO_IRQ_SET_ACTION_TYPE_MASK
) {
817 case VFIO_IRQ_SET_ACTION_MASK
:
818 func
= vfio_pci_set_intx_mask
;
820 case VFIO_IRQ_SET_ACTION_UNMASK
:
821 func
= vfio_pci_set_intx_unmask
;
823 case VFIO_IRQ_SET_ACTION_TRIGGER
:
824 func
= vfio_pci_set_intx_trigger
;
828 case VFIO_PCI_MSI_IRQ_INDEX
:
829 case VFIO_PCI_MSIX_IRQ_INDEX
:
830 switch (flags
& VFIO_IRQ_SET_ACTION_TYPE_MASK
) {
831 case VFIO_IRQ_SET_ACTION_MASK
:
832 case VFIO_IRQ_SET_ACTION_UNMASK
:
833 /* XXX Need masking support exported */
835 case VFIO_IRQ_SET_ACTION_TRIGGER
:
836 func
= vfio_pci_set_msi_trigger
;
840 case VFIO_PCI_ERR_IRQ_INDEX
:
841 switch (flags
& VFIO_IRQ_SET_ACTION_TYPE_MASK
) {
842 case VFIO_IRQ_SET_ACTION_TRIGGER
:
843 if (pci_is_pcie(vdev
->pdev
))
844 func
= vfio_pci_set_err_trigger
;
852 return func(vdev
, index
, start
, count
, flags
, data
);