linux/drivers/vfio/pci/vfio_pci_intrs.c
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   1/*
   2 * VFIO PCI interrupt handling
   3 *
   4 * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
   5 *     Author: Alex Williamson <alex.williamson@redhat.com>
   6 *
   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.
  10 *
  11 * Derived from original vfio:
  12 * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
  13 * Author: Tom Lyon, pugs@cisco.com
  14 */
  15
  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/vfio.h>
  23#include <linux/wait.h>
  24#include <linux/slab.h>
  25
  26#include "vfio_pci_private.h"
  27
  28/*
  29 * INTx
  30 */
  31static void vfio_send_intx_eventfd(void *opaque, void *unused)
  32{
  33        struct vfio_pci_device *vdev = opaque;
  34
  35        if (likely(is_intx(vdev) && !vdev->virq_disabled))
  36                eventfd_signal(vdev->ctx[0].trigger, 1);
  37}
  38
  39void vfio_pci_intx_mask(struct vfio_pci_device *vdev)
  40{
  41        struct pci_dev *pdev = vdev->pdev;
  42        unsigned long flags;
  43
  44        spin_lock_irqsave(&vdev->irqlock, flags);
  45
  46        /*
  47         * Masking can come from interrupt, ioctl, or config space
  48         * via INTx disable.  The latter means this can get called
  49         * even when not using intx delivery.  In this case, just
  50         * try to have the physical bit follow the virtual bit.
  51         */
  52        if (unlikely(!is_intx(vdev))) {
  53                if (vdev->pci_2_3)
  54                        pci_intx(pdev, 0);
  55        } else if (!vdev->ctx[0].masked) {
  56                /*
  57                 * Can't use check_and_mask here because we always want to
  58                 * mask, not just when something is pending.
  59                 */
  60                if (vdev->pci_2_3)
  61                        pci_intx(pdev, 0);
  62                else
  63                        disable_irq_nosync(pdev->irq);
  64
  65                vdev->ctx[0].masked = true;
  66        }
  67
  68        spin_unlock_irqrestore(&vdev->irqlock, flags);
  69}
  70
  71/*
  72 * If this is triggered by an eventfd, we can't call eventfd_signal
  73 * or else we'll deadlock on the eventfd wait queue.  Return >0 when
  74 * a signal is necessary, which can then be handled via a work queue
  75 * or directly depending on the caller.
  76 */
  77static int vfio_pci_intx_unmask_handler(void *opaque, void *unused)
  78{
  79        struct vfio_pci_device *vdev = opaque;
  80        struct pci_dev *pdev = vdev->pdev;
  81        unsigned long flags;
  82        int ret = 0;
  83
  84        spin_lock_irqsave(&vdev->irqlock, flags);
  85
  86        /*
  87         * Unmasking comes from ioctl or config, so again, have the
  88         * physical bit follow the virtual even when not using INTx.
  89         */
  90        if (unlikely(!is_intx(vdev))) {
  91                if (vdev->pci_2_3)
  92                        pci_intx(pdev, 1);
  93        } else if (vdev->ctx[0].masked && !vdev->virq_disabled) {
  94                /*
  95                 * A pending interrupt here would immediately trigger,
  96                 * but we can avoid that overhead by just re-sending
  97                 * the interrupt to the user.
  98                 */
  99                if (vdev->pci_2_3) {
 100                        if (!pci_check_and_unmask_intx(pdev))
 101                                ret = 1;
 102                } else
 103                        enable_irq(pdev->irq);
 104
 105                vdev->ctx[0].masked = (ret > 0);
 106        }
 107
 108        spin_unlock_irqrestore(&vdev->irqlock, flags);
 109
 110        return ret;
 111}
 112
 113void vfio_pci_intx_unmask(struct vfio_pci_device *vdev)
 114{
 115        if (vfio_pci_intx_unmask_handler(vdev, NULL) > 0)
 116                vfio_send_intx_eventfd(vdev, NULL);
 117}
 118
 119static irqreturn_t vfio_intx_handler(int irq, void *dev_id)
 120{
 121        struct vfio_pci_device *vdev = dev_id;
 122        unsigned long flags;
 123        int ret = IRQ_NONE;
 124
 125        spin_lock_irqsave(&vdev->irqlock, flags);
 126
 127        if (!vdev->pci_2_3) {
 128                disable_irq_nosync(vdev->pdev->irq);
 129                vdev->ctx[0].masked = true;
 130                ret = IRQ_HANDLED;
 131        } else if (!vdev->ctx[0].masked &&  /* may be shared */
 132                   pci_check_and_mask_intx(vdev->pdev)) {
 133                vdev->ctx[0].masked = true;
 134                ret = IRQ_HANDLED;
 135        }
 136
 137        spin_unlock_irqrestore(&vdev->irqlock, flags);
 138
 139        if (ret == IRQ_HANDLED)
 140                vfio_send_intx_eventfd(vdev, NULL);
 141
 142        return ret;
 143}
 144
 145static int vfio_intx_enable(struct vfio_pci_device *vdev)
 146{
 147        if (!is_irq_none(vdev))
 148                return -EINVAL;
 149
 150        if (!vdev->pdev->irq)
 151                return -ENODEV;
 152
 153        vdev->ctx = kzalloc(sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
 154        if (!vdev->ctx)
 155                return -ENOMEM;
 156
 157        vdev->num_ctx = 1;
 158
 159        /*
 160         * If the virtual interrupt is masked, restore it.  Devices
 161         * supporting DisINTx can be masked at the hardware level
 162         * here, non-PCI-2.3 devices will have to wait until the
 163         * interrupt is enabled.
 164         */
 165        vdev->ctx[0].masked = vdev->virq_disabled;
 166        if (vdev->pci_2_3)
 167                pci_intx(vdev->pdev, !vdev->ctx[0].masked);
 168
 169        vdev->irq_type = VFIO_PCI_INTX_IRQ_INDEX;
 170
 171        return 0;
 172}
 173
 174static int vfio_intx_set_signal(struct vfio_pci_device *vdev, int fd)
 175{
 176        struct pci_dev *pdev = vdev->pdev;
 177        unsigned long irqflags = IRQF_SHARED;
 178        struct eventfd_ctx *trigger;
 179        unsigned long flags;
 180        int ret;
 181
 182        if (vdev->ctx[0].trigger) {
 183                free_irq(pdev->irq, vdev);
 184                kfree(vdev->ctx[0].name);
 185                eventfd_ctx_put(vdev->ctx[0].trigger);
 186                vdev->ctx[0].trigger = NULL;
 187        }
 188
 189        if (fd < 0) /* Disable only */
 190                return 0;
 191
 192        vdev->ctx[0].name = kasprintf(GFP_KERNEL, "vfio-intx(%s)",
 193                                      pci_name(pdev));
 194        if (!vdev->ctx[0].name)
 195                return -ENOMEM;
 196
 197        trigger = eventfd_ctx_fdget(fd);
 198        if (IS_ERR(trigger)) {
 199                kfree(vdev->ctx[0].name);
 200                return PTR_ERR(trigger);
 201        }
 202
 203        vdev->ctx[0].trigger = trigger;
 204
 205        if (!vdev->pci_2_3)
 206                irqflags = 0;
 207
 208        ret = request_irq(pdev->irq, vfio_intx_handler,
 209                          irqflags, vdev->ctx[0].name, vdev);
 210        if (ret) {
 211                vdev->ctx[0].trigger = NULL;
 212                kfree(vdev->ctx[0].name);
 213                eventfd_ctx_put(trigger);
 214                return ret;
 215        }
 216
 217        /*
 218         * INTx disable will stick across the new irq setup,
 219         * disable_irq won't.
 220         */
 221        spin_lock_irqsave(&vdev->irqlock, flags);
 222        if (!vdev->pci_2_3 && vdev->ctx[0].masked)
 223                disable_irq_nosync(pdev->irq);
 224        spin_unlock_irqrestore(&vdev->irqlock, flags);
 225
 226        return 0;
 227}
 228
 229static void vfio_intx_disable(struct vfio_pci_device *vdev)
 230{
 231        vfio_intx_set_signal(vdev, -1);
 232        vfio_virqfd_disable(&vdev->ctx[0].unmask);
 233        vfio_virqfd_disable(&vdev->ctx[0].mask);
 234        vdev->irq_type = VFIO_PCI_NUM_IRQS;
 235        vdev->num_ctx = 0;
 236        kfree(vdev->ctx);
 237}
 238
 239/*
 240 * MSI/MSI-X
 241 */
 242static irqreturn_t vfio_msihandler(int irq, void *arg)
 243{
 244        struct eventfd_ctx *trigger = arg;
 245
 246        eventfd_signal(trigger, 1);
 247        return IRQ_HANDLED;
 248}
 249
 250static int vfio_msi_enable(struct vfio_pci_device *vdev, int nvec, bool msix)
 251{
 252        struct pci_dev *pdev = vdev->pdev;
 253        int ret;
 254
 255        if (!is_irq_none(vdev))
 256                return -EINVAL;
 257
 258        vdev->ctx = kzalloc(nvec * sizeof(struct vfio_pci_irq_ctx), GFP_KERNEL);
 259        if (!vdev->ctx)
 260                return -ENOMEM;
 261
 262        if (msix) {
 263                int i;
 264
 265                vdev->msix = kzalloc(nvec * sizeof(struct msix_entry),
 266                                     GFP_KERNEL);
 267                if (!vdev->msix) {
 268                        kfree(vdev->ctx);
 269                        return -ENOMEM;
 270                }
 271
 272                for (i = 0; i < nvec; i++)
 273                        vdev->msix[i].entry = i;
 274
 275                ret = pci_enable_msix_range(pdev, vdev->msix, 1, nvec);
 276                if (ret < nvec) {
 277                        if (ret > 0)
 278                                pci_disable_msix(pdev);
 279                        kfree(vdev->msix);
 280                        kfree(vdev->ctx);
 281                        return ret;
 282                }
 283        } else {
 284                ret = pci_enable_msi_range(pdev, 1, nvec);
 285                if (ret < nvec) {
 286                        if (ret > 0)
 287                                pci_disable_msi(pdev);
 288                        kfree(vdev->ctx);
 289                        return ret;
 290                }
 291        }
 292
 293        vdev->num_ctx = nvec;
 294        vdev->irq_type = msix ? VFIO_PCI_MSIX_IRQ_INDEX :
 295                                VFIO_PCI_MSI_IRQ_INDEX;
 296
 297        if (!msix) {
 298                /*
 299                 * Compute the virtual hardware field for max msi vectors -
 300                 * it is the log base 2 of the number of vectors.
 301                 */
 302                vdev->msi_qmax = fls(nvec * 2 - 1) - 1;
 303        }
 304
 305        return 0;
 306}
 307
 308static int vfio_msi_set_vector_signal(struct vfio_pci_device *vdev,
 309                                      int vector, int fd, bool msix)
 310{
 311        struct pci_dev *pdev = vdev->pdev;
 312        struct eventfd_ctx *trigger;
 313        int irq, ret;
 314
 315        if (vector < 0 || vector >= vdev->num_ctx)
 316                return -EINVAL;
 317
 318        irq = msix ? vdev->msix[vector].vector : pdev->irq + vector;
 319
 320        if (vdev->ctx[vector].trigger) {
 321                free_irq(irq, vdev->ctx[vector].trigger);
 322                irq_bypass_unregister_producer(&vdev->ctx[vector].producer);
 323                kfree(vdev->ctx[vector].name);
 324                eventfd_ctx_put(vdev->ctx[vector].trigger);
 325                vdev->ctx[vector].trigger = NULL;
 326        }
 327
 328        if (fd < 0)
 329                return 0;
 330
 331        vdev->ctx[vector].name = kasprintf(GFP_KERNEL, "vfio-msi%s[%d](%s)",
 332                                           msix ? "x" : "", vector,
 333                                           pci_name(pdev));
 334        if (!vdev->ctx[vector].name)
 335                return -ENOMEM;
 336
 337        trigger = eventfd_ctx_fdget(fd);
 338        if (IS_ERR(trigger)) {
 339                kfree(vdev->ctx[vector].name);
 340                return PTR_ERR(trigger);
 341        }
 342
 343        /*
 344         * The MSIx vector table resides in device memory which may be cleared
 345         * via backdoor resets. We don't allow direct access to the vector
 346         * table so even if a userspace driver attempts to save/restore around
 347         * such a reset it would be unsuccessful. To avoid this, restore the
 348         * cached value of the message prior to enabling.
 349         */
 350        if (msix) {
 351                struct msi_msg msg;
 352
 353                get_cached_msi_msg(irq, &msg);
 354                pci_write_msi_msg(irq, &msg);
 355        }
 356
 357        ret = request_irq(irq, vfio_msihandler, 0,
 358                          vdev->ctx[vector].name, trigger);
 359        if (ret) {
 360                kfree(vdev->ctx[vector].name);
 361                eventfd_ctx_put(trigger);
 362                return ret;
 363        }
 364
 365        vdev->ctx[vector].producer.token = trigger;
 366        vdev->ctx[vector].producer.irq = irq;
 367        ret = irq_bypass_register_producer(&vdev->ctx[vector].producer);
 368        if (unlikely(ret))
 369                dev_info(&pdev->dev,
 370                "irq bypass producer (token %p) registration fails: %d\n",
 371                vdev->ctx[vector].producer.token, ret);
 372
 373        vdev->ctx[vector].trigger = trigger;
 374
 375        return 0;
 376}
 377
 378static int vfio_msi_set_block(struct vfio_pci_device *vdev, unsigned start,
 379                              unsigned count, int32_t *fds, bool msix)
 380{
 381        int i, j, ret = 0;
 382
 383        if (start >= vdev->num_ctx || start + count > vdev->num_ctx)
 384                return -EINVAL;
 385
 386        for (i = 0, j = start; i < count && !ret; i++, j++) {
 387                int fd = fds ? fds[i] : -1;
 388                ret = vfio_msi_set_vector_signal(vdev, j, fd, msix);
 389        }
 390
 391        if (ret) {
 392                for (--j; j >= (int)start; j--)
 393                        vfio_msi_set_vector_signal(vdev, j, -1, msix);
 394        }
 395
 396        return ret;
 397}
 398
 399static void vfio_msi_disable(struct vfio_pci_device *vdev, bool msix)
 400{
 401        struct pci_dev *pdev = vdev->pdev;
 402        int i;
 403
 404        vfio_msi_set_block(vdev, 0, vdev->num_ctx, NULL, msix);
 405
 406        for (i = 0; i < vdev->num_ctx; i++) {
 407                vfio_virqfd_disable(&vdev->ctx[i].unmask);
 408                vfio_virqfd_disable(&vdev->ctx[i].mask);
 409        }
 410
 411        if (msix) {
 412                pci_disable_msix(vdev->pdev);
 413                kfree(vdev->msix);
 414        } else
 415                pci_disable_msi(pdev);
 416
 417        vdev->irq_type = VFIO_PCI_NUM_IRQS;
 418        vdev->num_ctx = 0;
 419        kfree(vdev->ctx);
 420}
 421
 422/*
 423 * IOCTL support
 424 */
 425static int vfio_pci_set_intx_unmask(struct vfio_pci_device *vdev,
 426                                    unsigned index, unsigned start,
 427                                    unsigned count, uint32_t flags, void *data)
 428{
 429        if (!is_intx(vdev) || start != 0 || count != 1)
 430                return -EINVAL;
 431
 432        if (flags & VFIO_IRQ_SET_DATA_NONE) {
 433                vfio_pci_intx_unmask(vdev);
 434        } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 435                uint8_t unmask = *(uint8_t *)data;
 436                if (unmask)
 437                        vfio_pci_intx_unmask(vdev);
 438        } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
 439                int32_t fd = *(int32_t *)data;
 440                if (fd >= 0)
 441                        return vfio_virqfd_enable((void *) vdev,
 442                                                  vfio_pci_intx_unmask_handler,
 443                                                  vfio_send_intx_eventfd, NULL,
 444                                                  &vdev->ctx[0].unmask, fd);
 445
 446                vfio_virqfd_disable(&vdev->ctx[0].unmask);
 447        }
 448
 449        return 0;
 450}
 451
 452static int vfio_pci_set_intx_mask(struct vfio_pci_device *vdev,
 453                                  unsigned index, unsigned start,
 454                                  unsigned count, uint32_t flags, void *data)
 455{
 456        if (!is_intx(vdev) || start != 0 || count != 1)
 457                return -EINVAL;
 458
 459        if (flags & VFIO_IRQ_SET_DATA_NONE) {
 460                vfio_pci_intx_mask(vdev);
 461        } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 462                uint8_t mask = *(uint8_t *)data;
 463                if (mask)
 464                        vfio_pci_intx_mask(vdev);
 465        } else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
 466                return -ENOTTY; /* XXX implement me */
 467        }
 468
 469        return 0;
 470}
 471
 472static int vfio_pci_set_intx_trigger(struct vfio_pci_device *vdev,
 473                                     unsigned index, unsigned start,
 474                                     unsigned count, uint32_t flags, void *data)
 475{
 476        if (is_intx(vdev) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
 477                vfio_intx_disable(vdev);
 478                return 0;
 479        }
 480
 481        if (!(is_intx(vdev) || is_irq_none(vdev)) || start != 0 || count != 1)
 482                return -EINVAL;
 483
 484        if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
 485                int32_t fd = *(int32_t *)data;
 486                int ret;
 487
 488                if (is_intx(vdev))
 489                        return vfio_intx_set_signal(vdev, fd);
 490
 491                ret = vfio_intx_enable(vdev);
 492                if (ret)
 493                        return ret;
 494
 495                ret = vfio_intx_set_signal(vdev, fd);
 496                if (ret)
 497                        vfio_intx_disable(vdev);
 498
 499                return ret;
 500        }
 501
 502        if (!is_intx(vdev))
 503                return -EINVAL;
 504
 505        if (flags & VFIO_IRQ_SET_DATA_NONE) {
 506                vfio_send_intx_eventfd(vdev, NULL);
 507        } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 508                uint8_t trigger = *(uint8_t *)data;
 509                if (trigger)
 510                        vfio_send_intx_eventfd(vdev, NULL);
 511        }
 512        return 0;
 513}
 514
 515static int vfio_pci_set_msi_trigger(struct vfio_pci_device *vdev,
 516                                    unsigned index, unsigned start,
 517                                    unsigned count, uint32_t flags, void *data)
 518{
 519        int i;
 520        bool msix = (index == VFIO_PCI_MSIX_IRQ_INDEX) ? true : false;
 521
 522        if (irq_is(vdev, index) && !count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
 523                vfio_msi_disable(vdev, msix);
 524                return 0;
 525        }
 526
 527        if (!(irq_is(vdev, index) || is_irq_none(vdev)))
 528                return -EINVAL;
 529
 530        if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
 531                int32_t *fds = data;
 532                int ret;
 533
 534                if (vdev->irq_type == index)
 535                        return vfio_msi_set_block(vdev, start, count,
 536                                                  fds, msix);
 537
 538                ret = vfio_msi_enable(vdev, start + count, msix);
 539                if (ret)
 540                        return ret;
 541
 542                ret = vfio_msi_set_block(vdev, start, count, fds, msix);
 543                if (ret)
 544                        vfio_msi_disable(vdev, msix);
 545
 546                return ret;
 547        }
 548
 549        if (!irq_is(vdev, index) || start + count > vdev->num_ctx)
 550                return -EINVAL;
 551
 552        for (i = start; i < start + count; i++) {
 553                if (!vdev->ctx[i].trigger)
 554                        continue;
 555                if (flags & VFIO_IRQ_SET_DATA_NONE) {
 556                        eventfd_signal(vdev->ctx[i].trigger, 1);
 557                } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 558                        uint8_t *bools = data;
 559                        if (bools[i - start])
 560                                eventfd_signal(vdev->ctx[i].trigger, 1);
 561                }
 562        }
 563        return 0;
 564}
 565
 566static int vfio_pci_set_ctx_trigger_single(struct eventfd_ctx **ctx,
 567                                           uint32_t flags, void *data)
 568{
 569        int32_t fd = *(int32_t *)data;
 570
 571        if (!(flags & VFIO_IRQ_SET_DATA_TYPE_MASK))
 572                return -EINVAL;
 573
 574        /* DATA_NONE/DATA_BOOL enables loopback testing */
 575        if (flags & VFIO_IRQ_SET_DATA_NONE) {
 576                if (*ctx)
 577                        eventfd_signal(*ctx, 1);
 578                return 0;
 579        } else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
 580                uint8_t trigger = *(uint8_t *)data;
 581                if (trigger && *ctx)
 582                        eventfd_signal(*ctx, 1);
 583                return 0;
 584        }
 585
 586        /* Handle SET_DATA_EVENTFD */
 587        if (fd == -1) {
 588                if (*ctx)
 589                        eventfd_ctx_put(*ctx);
 590                *ctx = NULL;
 591                return 0;
 592        } else if (fd >= 0) {
 593                struct eventfd_ctx *efdctx;
 594                efdctx = eventfd_ctx_fdget(fd);
 595                if (IS_ERR(efdctx))
 596                        return PTR_ERR(efdctx);
 597                if (*ctx)
 598                        eventfd_ctx_put(*ctx);
 599                *ctx = efdctx;
 600                return 0;
 601        } else
 602                return -EINVAL;
 603}
 604
 605static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
 606                                    unsigned index, unsigned start,
 607                                    unsigned count, uint32_t flags, void *data)
 608{
 609        if (index != VFIO_PCI_ERR_IRQ_INDEX)
 610                return -EINVAL;
 611
 612        /*
 613         * We should sanitize start & count, but that wasn't caught
 614         * originally, so this IRQ index must forever ignore them :-(
 615         */
 616
 617        return vfio_pci_set_ctx_trigger_single(&vdev->err_trigger, flags, data);
 618}
 619
 620static int vfio_pci_set_req_trigger(struct vfio_pci_device *vdev,
 621                                    unsigned index, unsigned start,
 622                                    unsigned count, uint32_t flags, void *data)
 623{
 624        if (index != VFIO_PCI_REQ_IRQ_INDEX || start != 0 || count != 1)
 625                return -EINVAL;
 626
 627        return vfio_pci_set_ctx_trigger_single(&vdev->req_trigger, flags, data);
 628}
 629
 630int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
 631                            unsigned index, unsigned start, unsigned count,
 632                            void *data)
 633{
 634        int (*func)(struct vfio_pci_device *vdev, unsigned index,
 635                    unsigned start, unsigned count, uint32_t flags,
 636                    void *data) = NULL;
 637
 638        switch (index) {
 639        case VFIO_PCI_INTX_IRQ_INDEX:
 640                switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
 641                case VFIO_IRQ_SET_ACTION_MASK:
 642                        func = vfio_pci_set_intx_mask;
 643                        break;
 644                case VFIO_IRQ_SET_ACTION_UNMASK:
 645                        func = vfio_pci_set_intx_unmask;
 646                        break;
 647                case VFIO_IRQ_SET_ACTION_TRIGGER:
 648                        func = vfio_pci_set_intx_trigger;
 649                        break;
 650                }
 651                break;
 652        case VFIO_PCI_MSI_IRQ_INDEX:
 653        case VFIO_PCI_MSIX_IRQ_INDEX:
 654                switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
 655                case VFIO_IRQ_SET_ACTION_MASK:
 656                case VFIO_IRQ_SET_ACTION_UNMASK:
 657                        /* XXX Need masking support exported */
 658                        break;
 659                case VFIO_IRQ_SET_ACTION_TRIGGER:
 660                        func = vfio_pci_set_msi_trigger;
 661                        break;
 662                }
 663                break;
 664        case VFIO_PCI_ERR_IRQ_INDEX:
 665                switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
 666                case VFIO_IRQ_SET_ACTION_TRIGGER:
 667                        if (pci_is_pcie(vdev->pdev))
 668                                func = vfio_pci_set_err_trigger;
 669                        break;
 670                }
 671                break;
 672        case VFIO_PCI_REQ_IRQ_INDEX:
 673                switch (flags & VFIO_IRQ_SET_ACTION_TYPE_MASK) {
 674                case VFIO_IRQ_SET_ACTION_TRIGGER:
 675                        func = vfio_pci_set_req_trigger;
 676                        break;
 677                }
 678                break;
 679        }
 680
 681        if (!func)
 682                return -ENOTTY;
 683
 684        return func(vdev, index, start, count, flags, data);
 685}
 686