1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Virtio PCI driver - common functionality for all device versions
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.
8 * Copyright IBM Corp. 2007
9 * Copyright Red Hat, Inc. 2014
12 * Anthony Liguori <aliguori@us.ibm.com>
13 * Rusty Russell <rusty@rustcorp.com.au>
14 * Michael S. Tsirkin <mst@redhat.com>
17 #include "virtio_pci_common.h"
19 static bool force_legacy = false;
21 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
22 module_param(force_legacy, bool, 0444);
23 MODULE_PARM_DESC(force_legacy,
24 "Force legacy mode for transitional virtio 1 devices");
27 /* wait for pending irq handlers */
28 void vp_synchronize_vectors(struct virtio_device *vdev)
30 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
33 if (vp_dev->intx_enabled)
34 synchronize_irq(vp_dev->pci_dev->irq);
36 for (i = 0; i < vp_dev->msix_vectors; ++i)
37 synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i));
40 /* the notify function used when creating a virt queue */
41 bool vp_notify(struct virtqueue *vq)
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);
49 /* Handle a configuration change: Tell driver if it wants to know. */
50 static irqreturn_t vp_config_changed(int irq, void *opaque)
52 struct virtio_pci_device *vp_dev = opaque;
54 virtio_config_changed(&vp_dev->vdev);
58 /* Notify all virtqueues on an interrupt. */
59 static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
61 struct virtio_pci_device *vp_dev = opaque;
62 struct virtio_pci_vq_info *info;
63 irqreturn_t ret = IRQ_NONE;
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)
71 spin_unlock_irqrestore(&vp_dev->lock, flags);
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
82 static irqreturn_t vp_interrupt(int irq, void *opaque)
84 struct virtio_pci_device *vp_dev = opaque;
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);
91 /* It's definitely not us if the ISR was not high */
95 /* Configuration change? Tell driver if it wants to know. */
96 if (isr & VIRTIO_PCI_ISR_CONFIG)
97 vp_config_changed(irq, opaque);
99 return vp_vring_interrupt(irq, opaque);
102 static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
103 bool per_vq_vectors, struct irq_affinity *desc)
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;
111 vp_dev->msix_vectors = nvectors;
113 vp_dev->msix_names = kmalloc_array(nvectors,
114 sizeof(*vp_dev->msix_names),
116 if (!vp_dev->msix_names)
118 vp_dev->msix_affinity_masks
119 = kcalloc(nvectors, sizeof(*vp_dev->msix_affinity_masks),
121 if (!vp_dev->msix_affinity_masks)
123 for (i = 0; i < nvectors; ++i)
124 if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
129 flags |= PCI_IRQ_AFFINITY;
130 desc->pre_vectors++; /* virtio config vector */
133 err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
134 nvectors, flags, desc);
137 vp_dev->msix_enabled = 1;
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,
143 err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
144 vp_config_changed, 0, vp_dev->msix_names[v],
148 ++vp_dev->msix_used_vectors;
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) {
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],
167 ++vp_dev->msix_used_vectors;
174 static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
175 void (*callback)(struct virtqueue *vq),
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;
185 /* fill out our structure that represents an active queue */
187 return ERR_PTR(-ENOMEM);
189 vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
196 spin_lock_irqsave(&vp_dev->lock, flags);
197 list_add(&info->node, &vp_dev->virtqueues);
198 spin_unlock_irqrestore(&vp_dev->lock, flags);
200 INIT_LIST_HEAD(&info->node);
203 vp_dev->vqs[index] = info;
211 static void vp_del_vq(struct virtqueue *vq)
213 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
214 struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
217 spin_lock_irqsave(&vp_dev->lock, flags);
218 list_del(&info->node);
219 spin_unlock_irqrestore(&vp_dev->lock, flags);
221 vp_dev->del_vq(info);
225 /* the config->del_vqs() implementation */
226 void vp_del_vqs(struct virtio_device *vdev)
228 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
229 struct virtqueue *vq, *n;
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;
236 if (v != VIRTIO_MSI_NO_VECTOR) {
237 int irq = pci_irq_vector(vp_dev->pci_dev, v);
239 irq_set_affinity_hint(irq, NULL);
245 vp_dev->per_vq_vectors = false;
247 if (vp_dev->intx_enabled) {
248 free_irq(vp_dev->pci_dev->irq, vp_dev);
249 vp_dev->intx_enabled = 0;
252 for (i = 0; i < vp_dev->msix_used_vectors; ++i)
253 free_irq(pci_irq_vector(vp_dev->pci_dev, i), vp_dev);
255 if (vp_dev->msix_affinity_masks) {
256 for (i = 0; i < vp_dev->msix_vectors; i++)
257 free_cpumask_var(vp_dev->msix_affinity_masks[i]);
260 if (vp_dev->msix_enabled) {
261 /* Disable the vector used for configuration */
262 vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
264 pci_free_irq_vectors(vp_dev->pci_dev);
265 vp_dev->msix_enabled = 0;
268 vp_dev->msix_vectors = 0;
269 vp_dev->msix_used_vectors = 0;
270 kfree(vp_dev->msix_names);
271 vp_dev->msix_names = NULL;
272 kfree(vp_dev->msix_affinity_masks);
273 vp_dev->msix_affinity_masks = NULL;
278 static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
279 struct virtqueue *vqs[], vq_callback_t *callbacks[],
280 const char * const names[], bool per_vq_vectors,
282 struct irq_affinity *desc)
284 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
286 int i, err, nvectors, allocated_vectors, queue_idx = 0;
288 vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
292 if (per_vq_vectors) {
293 /* Best option: one for change interrupt, one per vq. */
295 for (i = 0; i < nvqs; ++i)
296 if (names[i] && callbacks[i])
299 /* Second best: one for change, shared for all vqs. */
303 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors,
304 per_vq_vectors ? desc : NULL);
308 vp_dev->per_vq_vectors = per_vq_vectors;
309 allocated_vectors = vp_dev->msix_used_vectors;
310 for (i = 0; i < nvqs; ++i) {
317 msix_vec = VIRTIO_MSI_NO_VECTOR;
318 else if (vp_dev->per_vq_vectors)
319 msix_vec = allocated_vectors++;
321 msix_vec = VP_MSIX_VQ_VECTOR;
322 vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
323 ctx ? ctx[i] : false,
325 if (IS_ERR(vqs[i])) {
326 err = PTR_ERR(vqs[i]);
330 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
333 /* allocate per-vq irq if available and necessary */
334 snprintf(vp_dev->msix_names[msix_vec],
335 sizeof *vp_dev->msix_names,
337 dev_name(&vp_dev->vdev.dev), names[i]);
338 err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
340 vp_dev->msix_names[msix_vec],
352 static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
353 struct virtqueue *vqs[], vq_callback_t *callbacks[],
354 const char * const names[], const bool *ctx)
356 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
357 int i, err, queue_idx = 0;
359 vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
363 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
364 dev_name(&vdev->dev), vp_dev);
368 vp_dev->intx_enabled = 1;
369 vp_dev->per_vq_vectors = false;
370 for (i = 0; i < nvqs; ++i) {
375 vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
376 ctx ? ctx[i] : false,
377 VIRTIO_MSI_NO_VECTOR);
378 if (IS_ERR(vqs[i])) {
379 err = PTR_ERR(vqs[i]);
390 /* the config->find_vqs() implementation */
391 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
392 struct virtqueue *vqs[], vq_callback_t *callbacks[],
393 const char * const names[], const bool *ctx,
394 struct irq_affinity *desc)
398 /* Try MSI-X with one vector per queue. */
399 err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, true, ctx, desc);
402 /* Fallback: MSI-X with one vector for config, one shared for queues. */
403 err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc);
406 /* Finally fall back to regular interrupts. */
407 return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
410 const char *vp_bus_name(struct virtio_device *vdev)
412 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
414 return pci_name(vp_dev->pci_dev);
417 /* Setup the affinity for a virtqueue:
418 * - force the affinity for per vq vector
419 * - OR over all affinities for shared MSI
420 * - ignore the affinity request if we're using INTX
422 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
424 struct virtio_device *vdev = vq->vdev;
425 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
426 struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
427 struct cpumask *mask;
433 if (vp_dev->msix_enabled) {
434 mask = vp_dev->msix_affinity_masks[info->msix_vector];
435 irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector);
437 irq_set_affinity_hint(irq, NULL);
439 cpumask_copy(mask, cpu_mask);
440 irq_set_affinity_hint(irq, mask);
446 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index)
448 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
450 if (!vp_dev->per_vq_vectors ||
451 vp_dev->vqs[index]->msix_vector == VIRTIO_MSI_NO_VECTOR)
454 return pci_irq_get_affinity(vp_dev->pci_dev,
455 vp_dev->vqs[index]->msix_vector);
458 #ifdef CONFIG_PM_SLEEP
459 static int virtio_pci_freeze(struct device *dev)
461 struct pci_dev *pci_dev = to_pci_dev(dev);
462 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
465 ret = virtio_device_freeze(&vp_dev->vdev);
468 pci_disable_device(pci_dev);
472 static int virtio_pci_restore(struct device *dev)
474 struct pci_dev *pci_dev = to_pci_dev(dev);
475 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
478 ret = pci_enable_device(pci_dev);
482 pci_set_master(pci_dev);
483 return virtio_device_restore(&vp_dev->vdev);
486 static const struct dev_pm_ops virtio_pci_pm_ops = {
487 SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
492 /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
493 static const struct pci_device_id virtio_pci_id_table[] = {
494 { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
498 MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
500 static void virtio_pci_release_dev(struct device *_d)
502 struct virtio_device *vdev = dev_to_virtio(_d);
503 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
505 /* As struct device is a kobject, it's not safe to
506 * free the memory (including the reference counter itself)
507 * until it's release callback. */
511 static int virtio_pci_probe(struct pci_dev *pci_dev,
512 const struct pci_device_id *id)
514 struct virtio_pci_device *vp_dev, *reg_dev = NULL;
517 /* allocate our structure and fill it out */
518 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
522 pci_set_drvdata(pci_dev, vp_dev);
523 vp_dev->vdev.dev.parent = &pci_dev->dev;
524 vp_dev->vdev.dev.release = virtio_pci_release_dev;
525 vp_dev->pci_dev = pci_dev;
526 INIT_LIST_HEAD(&vp_dev->virtqueues);
527 spin_lock_init(&vp_dev->lock);
529 /* enable the device */
530 rc = pci_enable_device(pci_dev);
532 goto err_enable_device;
535 rc = virtio_pci_legacy_probe(vp_dev);
536 /* Also try modern mode if we can't map BAR0 (no IO space). */
537 if (rc == -ENODEV || rc == -ENOMEM)
538 rc = virtio_pci_modern_probe(vp_dev);
542 rc = virtio_pci_modern_probe(vp_dev);
544 rc = virtio_pci_legacy_probe(vp_dev);
549 pci_set_master(pci_dev);
551 rc = register_virtio_device(&vp_dev->vdev);
560 virtio_pci_legacy_remove(vp_dev);
562 virtio_pci_modern_remove(vp_dev);
564 pci_disable_device(pci_dev);
567 put_device(&vp_dev->vdev.dev);
573 static void virtio_pci_remove(struct pci_dev *pci_dev)
575 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
576 struct device *dev = get_device(&vp_dev->vdev.dev);
579 * Device is marked broken on surprise removal so that virtio upper
580 * layers can abort any ongoing operation.
582 if (!pci_device_is_present(pci_dev))
583 virtio_break_device(&vp_dev->vdev);
585 pci_disable_sriov(pci_dev);
587 unregister_virtio_device(&vp_dev->vdev);
590 virtio_pci_legacy_remove(vp_dev);
592 virtio_pci_modern_remove(vp_dev);
594 pci_disable_device(pci_dev);
598 static int virtio_pci_sriov_configure(struct pci_dev *pci_dev, int num_vfs)
600 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
601 struct virtio_device *vdev = &vp_dev->vdev;
604 if (!(vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_DRIVER_OK))
607 if (!__virtio_test_bit(vdev, VIRTIO_F_SR_IOV))
610 if (pci_vfs_assigned(pci_dev))
614 pci_disable_sriov(pci_dev);
618 ret = pci_enable_sriov(pci_dev, num_vfs);
625 static struct pci_driver virtio_pci_driver = {
626 .name = "virtio-pci",
627 .id_table = virtio_pci_id_table,
628 .probe = virtio_pci_probe,
629 .remove = virtio_pci_remove,
630 #ifdef CONFIG_PM_SLEEP
631 .driver.pm = &virtio_pci_pm_ops,
633 .sriov_configure = virtio_pci_sriov_configure,
636 module_pci_driver(virtio_pci_driver);
638 MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
639 MODULE_DESCRIPTION("virtio-pci");
640 MODULE_LICENSE("GPL");