2 * Virtio PCI driver - common functionality for all device versions
4 * This module allows virtio devices to be used over a virtual PCI device.
5 * This can be used with QEMU based VMMs like KVM or Xen.
7 * Copyright IBM Corp. 2007
8 * Copyright Red Hat, Inc. 2014
11 * Anthony Liguori <aliguori@us.ibm.com>
12 * Rusty Russell <rusty@rustcorp.com.au>
13 * Michael S. Tsirkin <mst@redhat.com>
15 * This work is licensed under the terms of the GNU GPL, version 2 or later.
16 * See the COPYING file in the top-level directory.
20 #include "virtio_pci_common.h"
22 static bool force_legacy = false;
24 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
25 module_param(force_legacy, bool, 0444);
26 MODULE_PARM_DESC(force_legacy,
27 "Force legacy mode for transitional virtio 1 devices");
30 /* wait for pending irq handlers */
31 void vp_synchronize_vectors(struct virtio_device *vdev)
33 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
36 if (vp_dev->intx_enabled)
37 synchronize_irq(vp_dev->pci_dev->irq);
39 for (i = 0; i < vp_dev->msix_vectors; ++i)
40 synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i));
43 /* the notify function used when creating a virt queue */
44 bool vp_notify(struct virtqueue *vq)
46 /* we write the queue's selector into the notification register to
47 * signal the other end */
48 iowrite16(vq->index, (void __iomem *)vq->priv);
52 /* Handle a configuration change: Tell driver if it wants to know. */
53 static irqreturn_t vp_config_changed(int irq, void *opaque)
55 struct virtio_pci_device *vp_dev = opaque;
57 virtio_config_changed(&vp_dev->vdev);
61 /* Notify all virtqueues on an interrupt. */
62 static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
64 struct virtio_pci_device *vp_dev = opaque;
65 struct virtio_pci_vq_info *info;
66 irqreturn_t ret = IRQ_NONE;
69 spin_lock_irqsave(&vp_dev->lock, flags);
70 list_for_each_entry(info, &vp_dev->virtqueues, node) {
71 if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
74 spin_unlock_irqrestore(&vp_dev->lock, flags);
79 /* A small wrapper to also acknowledge the interrupt when it's handled.
80 * I really need an EIO hook for the vring so I can ack the interrupt once we
81 * know that we'll be handling the IRQ but before we invoke the callback since
82 * the callback may notify the host which results in the host attempting to
83 * raise an interrupt that we would then mask once we acknowledged the
85 static irqreturn_t vp_interrupt(int irq, void *opaque)
87 struct virtio_pci_device *vp_dev = opaque;
90 /* reading the ISR has the effect of also clearing it so it's very
91 * important to save off the value. */
92 isr = ioread8(vp_dev->isr);
94 /* It's definitely not us if the ISR was not high */
98 /* Configuration change? Tell driver if it wants to know. */
99 if (isr & VIRTIO_PCI_ISR_CONFIG)
100 vp_config_changed(irq, opaque);
102 return vp_vring_interrupt(irq, opaque);
105 static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
106 bool per_vq_vectors, struct irq_affinity *desc)
108 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
109 const char *name = dev_name(&vp_dev->vdev.dev);
113 vp_dev->msix_vectors = nvectors;
115 vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
117 if (!vp_dev->msix_names)
119 vp_dev->msix_affinity_masks
120 = kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks,
122 if (!vp_dev->msix_affinity_masks)
124 for (i = 0; i < nvectors; ++i)
125 if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
129 err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
130 nvectors, PCI_IRQ_MSIX |
131 (desc ? PCI_IRQ_AFFINITY : 0),
135 vp_dev->msix_enabled = 1;
137 /* Set the vector used for configuration */
138 v = vp_dev->msix_used_vectors;
139 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
141 err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
142 vp_config_changed, 0, vp_dev->msix_names[v],
146 ++vp_dev->msix_used_vectors;
148 v = vp_dev->config_vector(vp_dev, v);
149 /* Verify we had enough resources to assign the vector */
150 if (v == VIRTIO_MSI_NO_VECTOR) {
155 if (!per_vq_vectors) {
156 /* Shared vector for all VQs */
157 v = vp_dev->msix_used_vectors;
158 snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
159 "%s-virtqueues", name);
160 err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
161 vp_vring_interrupt, 0, vp_dev->msix_names[v],
165 ++vp_dev->msix_used_vectors;
172 static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
173 void (*callback)(struct virtqueue *vq),
178 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
179 struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
180 struct virtqueue *vq;
183 /* fill out our structure that represents an active queue */
185 return ERR_PTR(-ENOMEM);
187 vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
194 spin_lock_irqsave(&vp_dev->lock, flags);
195 list_add(&info->node, &vp_dev->virtqueues);
196 spin_unlock_irqrestore(&vp_dev->lock, flags);
198 INIT_LIST_HEAD(&info->node);
201 vp_dev->vqs[index] = info;
209 static void vp_del_vq(struct virtqueue *vq)
211 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
212 struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
215 spin_lock_irqsave(&vp_dev->lock, flags);
216 list_del(&info->node);
217 spin_unlock_irqrestore(&vp_dev->lock, flags);
219 vp_dev->del_vq(info);
223 /* the config->del_vqs() implementation */
224 void vp_del_vqs(struct virtio_device *vdev)
226 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
227 struct virtqueue *vq, *n;
230 list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
231 if (vp_dev->per_vq_vectors) {
232 int v = vp_dev->vqs[vq->index]->msix_vector;
234 if (v != VIRTIO_MSI_NO_VECTOR) {
235 int irq = pci_irq_vector(vp_dev->pci_dev, v);
237 irq_set_affinity_hint(irq, NULL);
243 vp_dev->per_vq_vectors = false;
245 if (vp_dev->intx_enabled) {
246 free_irq(vp_dev->pci_dev->irq, vp_dev);
247 vp_dev->intx_enabled = 0;
250 for (i = 0; i < vp_dev->msix_used_vectors; ++i)
251 free_irq(pci_irq_vector(vp_dev->pci_dev, i), vp_dev);
253 for (i = 0; i < vp_dev->msix_vectors; i++)
254 if (vp_dev->msix_affinity_masks[i])
255 free_cpumask_var(vp_dev->msix_affinity_masks[i]);
257 if (vp_dev->msix_enabled) {
258 /* Disable the vector used for configuration */
259 vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
261 pci_free_irq_vectors(vp_dev->pci_dev);
262 vp_dev->msix_enabled = 0;
265 vp_dev->msix_vectors = 0;
266 vp_dev->msix_used_vectors = 0;
267 kfree(vp_dev->msix_names);
268 vp_dev->msix_names = NULL;
269 kfree(vp_dev->msix_affinity_masks);
270 vp_dev->msix_affinity_masks = NULL;
275 static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
276 struct virtqueue *vqs[], vq_callback_t *callbacks[],
277 const char * const names[], bool per_vq_vectors,
279 struct irq_affinity *desc)
281 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
283 int i, err, nvectors, allocated_vectors;
285 vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
289 if (per_vq_vectors) {
290 /* Best option: one for change interrupt, one per vq. */
292 for (i = 0; i < nvqs; ++i)
296 /* Second best: one for change, shared for all vqs. */
300 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors,
301 per_vq_vectors ? desc : NULL);
305 vp_dev->per_vq_vectors = per_vq_vectors;
306 allocated_vectors = vp_dev->msix_used_vectors;
307 for (i = 0; i < nvqs; ++i) {
314 msix_vec = VIRTIO_MSI_NO_VECTOR;
315 else if (vp_dev->per_vq_vectors)
316 msix_vec = allocated_vectors++;
318 msix_vec = VP_MSIX_VQ_VECTOR;
319 vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i],
320 ctx ? ctx[i] : false,
322 if (IS_ERR(vqs[i])) {
323 err = PTR_ERR(vqs[i]);
327 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
330 /* allocate per-vq irq if available and necessary */
331 snprintf(vp_dev->msix_names[msix_vec],
332 sizeof *vp_dev->msix_names,
334 dev_name(&vp_dev->vdev.dev), names[i]);
335 err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
337 vp_dev->msix_names[msix_vec],
349 static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
350 struct virtqueue *vqs[], vq_callback_t *callbacks[],
351 const char * const names[], const bool *ctx)
353 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
356 vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
360 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
361 dev_name(&vdev->dev), vp_dev);
365 vp_dev->intx_enabled = 1;
366 vp_dev->per_vq_vectors = false;
367 for (i = 0; i < nvqs; ++i) {
372 vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i],
373 ctx ? ctx[i] : false,
374 VIRTIO_MSI_NO_VECTOR);
375 if (IS_ERR(vqs[i])) {
376 err = PTR_ERR(vqs[i]);
387 /* the config->find_vqs() implementation */
388 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
389 struct virtqueue *vqs[], vq_callback_t *callbacks[],
390 const char * const names[], const bool *ctx,
391 struct irq_affinity *desc)
395 /* Try MSI-X with one vector per queue. */
396 err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, true, ctx, desc);
399 /* Fallback: MSI-X with one vector for config, one shared for queues. */
400 err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc);
403 /* Finally fall back to regular interrupts. */
404 return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
407 const char *vp_bus_name(struct virtio_device *vdev)
409 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
411 return pci_name(vp_dev->pci_dev);
414 /* Setup the affinity for a virtqueue:
415 * - force the affinity for per vq vector
416 * - OR over all affinities for shared MSI
417 * - ignore the affinity request if we're using INTX
419 int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
421 struct virtio_device *vdev = vq->vdev;
422 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
423 struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
424 struct cpumask *mask;
430 if (vp_dev->msix_enabled) {
431 mask = vp_dev->msix_affinity_masks[info->msix_vector];
432 irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector);
434 irq_set_affinity_hint(irq, NULL);
437 cpumask_set_cpu(cpu, mask);
438 irq_set_affinity_hint(irq, mask);
444 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index)
446 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
448 if (!vp_dev->per_vq_vectors ||
449 vp_dev->vqs[index]->msix_vector == VIRTIO_MSI_NO_VECTOR)
452 return pci_irq_get_affinity(vp_dev->pci_dev,
453 vp_dev->vqs[index]->msix_vector);
456 #ifdef CONFIG_PM_SLEEP
457 static int virtio_pci_freeze(struct device *dev)
459 struct pci_dev *pci_dev = to_pci_dev(dev);
460 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
463 ret = virtio_device_freeze(&vp_dev->vdev);
466 pci_disable_device(pci_dev);
470 static int virtio_pci_restore(struct device *dev)
472 struct pci_dev *pci_dev = to_pci_dev(dev);
473 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
476 ret = pci_enable_device(pci_dev);
480 pci_set_master(pci_dev);
481 return virtio_device_restore(&vp_dev->vdev);
484 static const struct dev_pm_ops virtio_pci_pm_ops = {
485 SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
490 /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
491 static const struct pci_device_id virtio_pci_id_table[] = {
492 { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
496 MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
498 static void virtio_pci_release_dev(struct device *_d)
500 struct virtio_device *vdev = dev_to_virtio(_d);
501 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
503 /* As struct device is a kobject, it's not safe to
504 * free the memory (including the reference counter itself)
505 * until it's release callback. */
509 static int virtio_pci_probe(struct pci_dev *pci_dev,
510 const struct pci_device_id *id)
512 struct virtio_pci_device *vp_dev;
515 /* allocate our structure and fill it out */
516 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
520 pci_set_drvdata(pci_dev, vp_dev);
521 vp_dev->vdev.dev.parent = &pci_dev->dev;
522 vp_dev->vdev.dev.release = virtio_pci_release_dev;
523 vp_dev->pci_dev = pci_dev;
524 INIT_LIST_HEAD(&vp_dev->virtqueues);
525 spin_lock_init(&vp_dev->lock);
527 /* enable the device */
528 rc = pci_enable_device(pci_dev);
530 goto err_enable_device;
533 rc = virtio_pci_legacy_probe(vp_dev);
534 /* Also try modern mode if we can't map BAR0 (no IO space). */
535 if (rc == -ENODEV || rc == -ENOMEM)
536 rc = virtio_pci_modern_probe(vp_dev);
540 rc = virtio_pci_modern_probe(vp_dev);
542 rc = virtio_pci_legacy_probe(vp_dev);
547 pci_set_master(pci_dev);
549 rc = register_virtio_device(&vp_dev->vdev);
557 virtio_pci_legacy_remove(vp_dev);
559 virtio_pci_modern_remove(vp_dev);
561 pci_disable_device(pci_dev);
567 static void virtio_pci_remove(struct pci_dev *pci_dev)
569 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
570 struct device *dev = get_device(&vp_dev->vdev.dev);
572 unregister_virtio_device(&vp_dev->vdev);
575 virtio_pci_legacy_remove(vp_dev);
577 virtio_pci_modern_remove(vp_dev);
579 pci_disable_device(pci_dev);
583 static struct pci_driver virtio_pci_driver = {
584 .name = "virtio-pci",
585 .id_table = virtio_pci_id_table,
586 .probe = virtio_pci_probe,
587 .remove = virtio_pci_remove,
588 #ifdef CONFIG_PM_SLEEP
589 .driver.pm = &virtio_pci_pm_ops,
593 module_pci_driver(virtio_pci_driver);
595 MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
596 MODULE_DESCRIPTION("virtio-pci");
597 MODULE_LICENSE("GPL");