LXR linux/drivers/virtio/virtio_pci

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Virtio PCI driver - common functionality for all device versions
   4 *
   5 * This module allows virtio devices to be used over a virtual PCI device.
   6 * This can be used with QEMU based VMMs like KVM or Xen.
   7 *
   8 * Copyright IBM Corp. 2007
   9 * Copyright Red Hat, Inc. 2014
  10 *
  11 * Authors:
  12 *  Anthony Liguori  <aliguori@us.ibm.com>
  13 *  Rusty Russell <rusty@rustcorp.com.au>
  14 *  Michael S. Tsirkin <mst@redhat.com>
  15 */
  16
  17#include "virtio_pci_common.h"
  18
  19static bool force_legacy = false;
  20
  21#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
  22module_param(force_legacy, bool, 0444);
  23MODULE_PARM_DESC(force_legacy,
  24                 "Force legacy mode for transitional virtio 1 devices");
  25#endif
  26
  27/* wait for pending irq handlers */
  28void vp_synchronize_vectors(struct virtio_device *vdev)
  29{
  30        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
  31        int i;
  32
  33        if (vp_dev->intx_enabled)
  34                synchronize_irq(vp_dev->pci_dev->irq);
  35
  36        for (i = 0; i < vp_dev->msix_vectors; ++i)
  37                synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i));
  38}
  39
  40/* the notify function used when creating a virt queue */
  41bool vp_notify(struct virtqueue *vq)
  42{
  43        /* we write the queue's selector into the notification register to
  44         * signal the other end */
  45        iowrite16(vq->index, (void __iomem *)vq->priv);
  46        return true;
  47}
  48
  49/* Handle a configuration change: Tell driver if it wants to know. */
  50static irqreturn_t vp_config_changed(int irq, void *opaque)
  51{
  52        struct virtio_pci_device *vp_dev = opaque;
  53
  54        virtio_config_changed(&vp_dev->vdev);
  55        return IRQ_HANDLED;
  56}
  57
  58/* Notify all virtqueues on an interrupt. */
  59static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
  60{
  61        struct virtio_pci_device *vp_dev = opaque;
  62        struct virtio_pci_vq_info *info;
  63        irqreturn_t ret = IRQ_NONE;
  64        unsigned long flags;
  65
  66        spin_lock_irqsave(&vp_dev->lock, flags);
  67        list_for_each_entry(info, &vp_dev->virtqueues, node) {
  68                if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
  69                        ret = IRQ_HANDLED;
  70        }
  71        spin_unlock_irqrestore(&vp_dev->lock, flags);
  72
  73        return ret;
  74}
  75
  76/* A small wrapper to also acknowledge the interrupt when it's handled.
  77 * I really need an EIO hook for the vring so I can ack the interrupt once we
  78 * know that we'll be handling the IRQ but before we invoke the callback since
  79 * the callback may notify the host which results in the host attempting to
  80 * raise an interrupt that we would then mask once we acknowledged the
  81 * interrupt. */
  82static irqreturn_t vp_interrupt(int irq, void *opaque)
  83{
  84        struct virtio_pci_device *vp_dev = opaque;
  85        u8 isr;
  86
  87        /* reading the ISR has the effect of also clearing it so it's very
  88         * important to save off the value. */
  89        isr = ioread8(vp_dev->isr);
  90
  91        /* It's definitely not us if the ISR was not high */
  92        if (!isr)
  93                return IRQ_NONE;
  94
  95        /* Configuration change?  Tell driver if it wants to know. */
  96        if (isr & VIRTIO_PCI_ISR_CONFIG)
  97                vp_config_changed(irq, opaque);
  98
  99        return vp_vring_interrupt(irq, opaque);
 100}
 101
 102static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
 103                                   bool per_vq_vectors, struct irq_affinity *desc)
 104{
 105        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 106        const char *name = dev_name(&vp_dev->vdev.dev);
 107        unsigned flags = PCI_IRQ_MSIX;
 108        unsigned i, v;
 109        int err = -ENOMEM;
 110
 111        vp_dev->msix_vectors = nvectors;
 112
 113        vp_dev->msix_names = kmalloc_array(nvectors,
 114                                           sizeof(*vp_dev->msix_names),
 115                                           GFP_KERNEL);
 116        if (!vp_dev->msix_names)
 117                goto error;
 118        vp_dev->msix_affinity_masks
 119                = kcalloc(nvectors, sizeof(*vp_dev->msix_affinity_masks),
 120                          GFP_KERNEL);
 121        if (!vp_dev->msix_affinity_masks)
 122                goto error;
 123        for (i = 0; i < nvectors; ++i)
 124                if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
 125                                        GFP_KERNEL))
 126                        goto error;
 127
 128        if (desc) {
 129                flags |= PCI_IRQ_AFFINITY;
 130                desc->pre_vectors++; /* virtio config vector */
 131        }
 132
 133        err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
 134                                             nvectors, flags, desc);
 135        if (err < 0)
 136                goto error;
 137        vp_dev->msix_enabled = 1;
 138
 139        /* Set the vector used for configuration */
 140        v = vp_dev->msix_used_vectors;
 141        snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 142                 "%s-config", name);
 143        err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
 144                          vp_config_changed, 0, vp_dev->msix_names[v],
 145                          vp_dev);
 146        if (err)
 147                goto error;
 148        ++vp_dev->msix_used_vectors;
 149
 150        v = vp_dev->config_vector(vp_dev, v);
 151        /* Verify we had enough resources to assign the vector */
 152        if (v == VIRTIO_MSI_NO_VECTOR) {
 153                err = -EBUSY;
 154                goto error;
 155        }
 156
 157        if (!per_vq_vectors) {
 158                /* Shared vector for all VQs */
 159                v = vp_dev->msix_used_vectors;
 160                snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
 161                         "%s-virtqueues", name);
 162                err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
 163                                  vp_vring_interrupt, 0, vp_dev->msix_names[v],
 164                                  vp_dev);
 165                if (err)
 166                        goto error;
 167                ++vp_dev->msix_used_vectors;
 168        }
 169        return 0;
 170error:
 171        return err;
 172}
 173
 174static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
 175                                     void (*callback)(struct virtqueue *vq),
 176                                     const char *name,
 177                                     bool ctx,
 178                                     u16 msix_vec)
 179{
 180        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 181        struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
 182        struct virtqueue *vq;
 183        unsigned long flags;
 184
 185        /* fill out our structure that represents an active queue */
 186        if (!info)
 187                return ERR_PTR(-ENOMEM);
 188
 189        vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
 190                              msix_vec);
 191        if (IS_ERR(vq))
 192                goto out_info;
 193
 194        info->vq = vq;
 195        if (callback) {
 196                spin_lock_irqsave(&vp_dev->lock, flags);
 197                list_add(&info->node, &vp_dev->virtqueues);
 198                spin_unlock_irqrestore(&vp_dev->lock, flags);
 199        } else {
 200                INIT_LIST_HEAD(&info->node);
 201        }
 202
 203        vp_dev->vqs[index] = info;
 204        return vq;
 205
 206out_info:
 207        kfree(info);
 208        return vq;
 209}
 210
 211static void vp_del_vq(struct virtqueue *vq)
 212{
 213        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 214        struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
 215        unsigned long flags;
 216
 217        spin_lock_irqsave(&vp_dev->lock, flags);
 218        list_del(&info->node);
 219        spin_unlock_irqrestore(&vp_dev->lock, flags);
 220
 221        vp_dev->del_vq(info);
 222        kfree(info);
 223}
 224
 225/* the config->del_vqs() implementation */
 226void vp_del_vqs(struct virtio_device *vdev)
 227{
 228        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 229        struct virtqueue *vq, *n;
 230        int i;
 231
 232        list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 233                if (vp_dev->per_vq_vectors) {
 234                        int v = vp_dev->vqs[vq->index]->msix_vector;
 235
 236                        if (v != VIRTIO_MSI_NO_VECTOR) {
 237                                int irq = pci_irq_vector(vp_dev->pci_dev, v);
 238
 239                                irq_set_affinity_hint(irq, NULL);
 240                                free_irq(irq, vq);
 241                        }
 242                }
 243                vp_del_vq(vq);
 244        }
 245        vp_dev->per_vq_vectors = false;
 246
 247        if (vp_dev->intx_enabled) {
 248                free_irq(vp_dev->pci_dev->irq, vp_dev);
 249                vp_dev->intx_enabled = 0;
 250        }
 251
 252        for (i = 0; i < vp_dev->msix_used_vectors; ++i)
 253                free_irq(pci_irq_vector(vp_dev->pci_dev, i), vp_dev);
 254
 255        if (vp_dev->msix_affinity_masks) {
 256                for (i = 0; i < vp_dev->msix_vectors; i++)
 257                        if (vp_dev->msix_affinity_masks[i])
 258                                free_cpumask_var(vp_dev->msix_affinity_masks[i]);
 259        }
 260
 261        if (vp_dev->msix_enabled) {
 262                /* Disable the vector used for configuration */
 263                vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
 264
 265                pci_free_irq_vectors(vp_dev->pci_dev);
 266                vp_dev->msix_enabled = 0;
 267        }
 268
 269        vp_dev->msix_vectors = 0;
 270        vp_dev->msix_used_vectors = 0;
 271        kfree(vp_dev->msix_names);
 272        vp_dev->msix_names = NULL;
 273        kfree(vp_dev->msix_affinity_masks);
 274        vp_dev->msix_affinity_masks = NULL;
 275        kfree(vp_dev->vqs);
 276        vp_dev->vqs = NULL;
 277}
 278
 279static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
 280                struct virtqueue *vqs[], vq_callback_t *callbacks[],
 281                const char * const names[], bool per_vq_vectors,
 282                const bool *ctx,
 283                struct irq_affinity *desc)
 284{
 285        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 286        u16 msix_vec;
 287        int i, err, nvectors, allocated_vectors, queue_idx = 0;
 288
 289        vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
 290        if (!vp_dev->vqs)
 291                return -ENOMEM;
 292
 293        if (per_vq_vectors) {
 294                /* Best option: one for change interrupt, one per vq. */
 295                nvectors = 1;
 296                for (i = 0; i < nvqs; ++i)
 297                        if (names[i] && callbacks[i])
 298                                ++nvectors;
 299        } else {
 300                /* Second best: one for change, shared for all vqs. */
 301                nvectors = 2;
 302        }
 303
 304        err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors,
 305                                      per_vq_vectors ? desc : NULL);
 306        if (err)
 307                goto error_find;
 308
 309        vp_dev->per_vq_vectors = per_vq_vectors;
 310        allocated_vectors = vp_dev->msix_used_vectors;
 311        for (i = 0; i < nvqs; ++i) {
 312                if (!names[i]) {
 313                        vqs[i] = NULL;
 314                        continue;
 315                }
 316
 317                if (!callbacks[i])
 318                        msix_vec = VIRTIO_MSI_NO_VECTOR;
 319                else if (vp_dev->per_vq_vectors)
 320                        msix_vec = allocated_vectors++;
 321                else
 322                        msix_vec = VP_MSIX_VQ_VECTOR;
 323                vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
 324                                     ctx ? ctx[i] : false,
 325                                     msix_vec);
 326                if (IS_ERR(vqs[i])) {
 327                        err = PTR_ERR(vqs[i]);
 328                        goto error_find;
 329                }
 330
 331                if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
 332                        continue;
 333
 334                /* allocate per-vq irq if available and necessary */
 335                snprintf(vp_dev->msix_names[msix_vec],
 336                         sizeof *vp_dev->msix_names,
 337                         "%s-%s",
 338                         dev_name(&vp_dev->vdev.dev), names[i]);
 339                err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
 340                                  vring_interrupt, 0,
 341                                  vp_dev->msix_names[msix_vec],
 342                                  vqs[i]);
 343                if (err)
 344                        goto error_find;
 345        }
 346        return 0;
 347
 348error_find:
 349        vp_del_vqs(vdev);
 350        return err;
 351}
 352
 353static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
 354                struct virtqueue *vqs[], vq_callback_t *callbacks[],
 355                const char * const names[], const bool *ctx)
 356{
 357        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 358        int i, err, queue_idx = 0;
 359
 360        vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
 361        if (!vp_dev->vqs)
 362                return -ENOMEM;
 363
 364        err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
 365                        dev_name(&vdev->dev), vp_dev);
 366        if (err)
 367                goto out_del_vqs;
 368
 369        vp_dev->intx_enabled = 1;
 370        vp_dev->per_vq_vectors = false;
 371        for (i = 0; i < nvqs; ++i) {
 372                if (!names[i]) {
 373                        vqs[i] = NULL;
 374                        continue;
 375                }
 376                vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
 377                                     ctx ? ctx[i] : false,
 378                                     VIRTIO_MSI_NO_VECTOR);
 379                if (IS_ERR(vqs[i])) {
 380                        err = PTR_ERR(vqs[i]);
 381                        goto out_del_vqs;
 382                }
 383        }
 384
 385        return 0;
 386out_del_vqs:
 387        vp_del_vqs(vdev);
 388        return err;
 389}
 390
 391/* the config->find_vqs() implementation */
 392int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 393                struct virtqueue *vqs[], vq_callback_t *callbacks[],
 394                const char * const names[], const bool *ctx,
 395                struct irq_affinity *desc)
 396{
 397        int err;
 398
 399        /* Try MSI-X with one vector per queue. */
 400        err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, true, ctx, desc);
 401        if (!err)
 402                return 0;
 403        /* Fallback: MSI-X with one vector for config, one shared for queues. */
 404        err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc);
 405        if (!err)
 406                return 0;
 407        /* Finally fall back to regular interrupts. */
 408        return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
 409}
 410
 411const char *vp_bus_name(struct virtio_device *vdev)
 412{
 413        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 414
 415        return pci_name(vp_dev->pci_dev);
 416}
 417
 418/* Setup the affinity for a virtqueue:
 419 * - force the affinity for per vq vector
 420 * - OR over all affinities for shared MSI
 421 * - ignore the affinity request if we're using INTX
 422 */
 423int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
 424{
 425        struct virtio_device *vdev = vq->vdev;
 426        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 427        struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
 428        struct cpumask *mask;
 429        unsigned int irq;
 430
 431        if (!vq->callback)
 432                return -EINVAL;
 433
 434        if (vp_dev->msix_enabled) {
 435                mask = vp_dev->msix_affinity_masks[info->msix_vector];
 436                irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector);
 437                if (!cpu_mask)
 438                        irq_set_affinity_hint(irq, NULL);
 439                else {
 440                        cpumask_copy(mask, cpu_mask);
 441                        irq_set_affinity_hint(irq, mask);
 442                }
 443        }
 444        return 0;
 445}
 446
 447const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index)
 448{
 449        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 450
 451        if (!vp_dev->per_vq_vectors ||
 452            vp_dev->vqs[index]->msix_vector == VIRTIO_MSI_NO_VECTOR)
 453                return NULL;
 454
 455        return pci_irq_get_affinity(vp_dev->pci_dev,
 456                                    vp_dev->vqs[index]->msix_vector);
 457}
 458
 459#ifdef CONFIG_PM_SLEEP
 460static int virtio_pci_freeze(struct device *dev)
 461{
 462        struct pci_dev *pci_dev = to_pci_dev(dev);
 463        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 464        int ret;
 465
 466        ret = virtio_device_freeze(&vp_dev->vdev);
 467
 468        if (!ret)
 469                pci_disable_device(pci_dev);
 470        return ret;
 471}
 472
 473static int virtio_pci_restore(struct device *dev)
 474{
 475        struct pci_dev *pci_dev = to_pci_dev(dev);
 476        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 477        int ret;
 478
 479        ret = pci_enable_device(pci_dev);
 480        if (ret)
 481                return ret;
 482
 483        pci_set_master(pci_dev);
 484        return virtio_device_restore(&vp_dev->vdev);
 485}
 486
 487static const struct dev_pm_ops virtio_pci_pm_ops = {
 488        SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
 489};
 490#endif
 491
 492
 493/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
 494static const struct pci_device_id virtio_pci_id_table[] = {
 495        { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
 496        { 0 }
 497};
 498
 499MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
 500
 501static void virtio_pci_release_dev(struct device *_d)
 502{
 503        struct virtio_device *vdev = dev_to_virtio(_d);
 504        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 505
 506        /* As struct device is a kobject, it's not safe to
 507         * free the memory (including the reference counter itself)
 508         * until it's release callback. */
 509        kfree(vp_dev);
 510}
 511
 512static int virtio_pci_probe(struct pci_dev *pci_dev,
 513                            const struct pci_device_id *id)
 514{
 515        struct virtio_pci_device *vp_dev, *reg_dev = NULL;
 516        int rc;
 517
 518        /* allocate our structure and fill it out */
 519        vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
 520        if (!vp_dev)
 521                return -ENOMEM;
 522
 523        pci_set_drvdata(pci_dev, vp_dev);
 524        vp_dev->vdev.dev.parent = &pci_dev->dev;
 525        vp_dev->vdev.dev.release = virtio_pci_release_dev;
 526        vp_dev->pci_dev = pci_dev;
 527        INIT_LIST_HEAD(&vp_dev->virtqueues);
 528        spin_lock_init(&vp_dev->lock);
 529
 530        /* enable the device */
 531        rc = pci_enable_device(pci_dev);
 532        if (rc)
 533                goto err_enable_device;
 534
 535        if (force_legacy) {
 536                rc = virtio_pci_legacy_probe(vp_dev);
 537                /* Also try modern mode if we can't map BAR0 (no IO space). */
 538                if (rc == -ENODEV || rc == -ENOMEM)
 539                        rc = virtio_pci_modern_probe(vp_dev);
 540                if (rc)
 541                        goto err_probe;
 542        } else {
 543                rc = virtio_pci_modern_probe(vp_dev);
 544                if (rc == -ENODEV)
 545                        rc = virtio_pci_legacy_probe(vp_dev);
 546                if (rc)
 547                        goto err_probe;
 548        }
 549
 550        pci_set_master(pci_dev);
 551
 552        rc = register_virtio_device(&vp_dev->vdev);
 553        reg_dev = vp_dev;
 554        if (rc)
 555                goto err_register;
 556
 557        return 0;
 558
 559err_register:
 560        if (vp_dev->ioaddr)
 561             virtio_pci_legacy_remove(vp_dev);
 562        else
 563             virtio_pci_modern_remove(vp_dev);
 564err_probe:
 565        pci_disable_device(pci_dev);
 566err_enable_device:
 567        if (reg_dev)
 568                put_device(&vp_dev->vdev.dev);
 569        else
 570                kfree(vp_dev);
 571        return rc;
 572}
 573
 574static void virtio_pci_remove(struct pci_dev *pci_dev)
 575{
 576        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 577        struct device *dev = get_device(&vp_dev->vdev.dev);
 578
 579        pci_disable_sriov(pci_dev);
 580
 581        unregister_virtio_device(&vp_dev->vdev);
 582
 583        if (vp_dev->ioaddr)
 584                virtio_pci_legacy_remove(vp_dev);
 585        else
 586                virtio_pci_modern_remove(vp_dev);
 587
 588        pci_disable_device(pci_dev);
 589        put_device(dev);
 590}
 591
 592static int virtio_pci_sriov_configure(struct pci_dev *pci_dev, int num_vfs)
 593{
 594        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
 595        struct virtio_device *vdev = &vp_dev->vdev;
 596        int ret;
 597
 598        if (!(vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_DRIVER_OK))
 599                return -EBUSY;
 600
 601        if (!__virtio_test_bit(vdev, VIRTIO_F_SR_IOV))
 602                return -EINVAL;
 603
 604        if (pci_vfs_assigned(pci_dev))
 605                return -EPERM;
 606
 607        if (num_vfs == 0) {
 608                pci_disable_sriov(pci_dev);
 609                return 0;
 610        }
 611
 612        ret = pci_enable_sriov(pci_dev, num_vfs);
 613        if (ret < 0)
 614                return ret;
 615
 616        return num_vfs;
 617}
 618
 619static struct pci_driver virtio_pci_driver = {
 620        .name           = "virtio-pci",
 621        .id_table       = virtio_pci_id_table,
 622        .probe          = virtio_pci_probe,
 623        .remove         = virtio_pci_remove,
 624#ifdef CONFIG_PM_SLEEP
 625        .driver.pm      = &virtio_pci_pm_ops,
 626#endif
 627        .sriov_configure = virtio_pci_sriov_configure,
 628};
 629
 630module_pci_driver(virtio_pci_driver);
 631
 632MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
 633MODULE_DESCRIPTION("virtio-pci");
 634MODULE_LICENSE("GPL");
 635MODULE_VERSION("1");
 636