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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 int flags = PCI_IRQ_MSIX;
108 unsigned int 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 int 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 /*
218 * If it fails during re-enable reset vq. This way we won't rejoin
219 * info->node to the queue. Prevent unexpected irqs.
220 */
221 if (!vq->reset) {
222 spin_lock_irqsave(&vp_dev->lock, flags);
223 list_del(&info->node);
224 spin_unlock_irqrestore(&vp_dev->lock, flags);
225 }
226
227 vp_dev->del_vq(info);
228 kfree(info);
229}
230
231/* the config->del_vqs() implementation */
232void vp_del_vqs(struct virtio_device *vdev)
233{
234 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
235 struct virtqueue *vq, *n;
236 int i;
237
238 list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
239 if (vp_dev->per_vq_vectors) {
240 int v = vp_dev->vqs[vq->index]->msix_vector;
241
242 if (v != VIRTIO_MSI_NO_VECTOR) {
243 int irq = pci_irq_vector(vp_dev->pci_dev, v);
244
245 irq_set_affinity_hint(irq, NULL);
246 free_irq(irq, vq);
247 }
248 }
249 vp_del_vq(vq);
250 }
251 vp_dev->per_vq_vectors = false;
252
253 if (vp_dev->intx_enabled) {
254 free_irq(vp_dev->pci_dev->irq, vp_dev);
255 vp_dev->intx_enabled = 0;
256 }
257
258 for (i = 0; i < vp_dev->msix_used_vectors; ++i)
259 free_irq(pci_irq_vector(vp_dev->pci_dev, i), vp_dev);
260
261 if (vp_dev->msix_affinity_masks) {
262 for (i = 0; i < vp_dev->msix_vectors; i++)
263 free_cpumask_var(vp_dev->msix_affinity_masks[i]);
264 }
265
266 if (vp_dev->msix_enabled) {
267 /* Disable the vector used for configuration */
268 vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
269
270 pci_free_irq_vectors(vp_dev->pci_dev);
271 vp_dev->msix_enabled = 0;
272 }
273
274 vp_dev->msix_vectors = 0;
275 vp_dev->msix_used_vectors = 0;
276 kfree(vp_dev->msix_names);
277 vp_dev->msix_names = NULL;
278 kfree(vp_dev->msix_affinity_masks);
279 vp_dev->msix_affinity_masks = NULL;
280 kfree(vp_dev->vqs);
281 vp_dev->vqs = NULL;
282}
283
284static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs,
285 struct virtqueue *vqs[], vq_callback_t *callbacks[],
286 const char * const names[], bool per_vq_vectors,
287 const bool *ctx,
288 struct irq_affinity *desc)
289{
290 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
291 u16 msix_vec;
292 int i, err, nvectors, allocated_vectors, queue_idx = 0;
293
294 vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
295 if (!vp_dev->vqs)
296 return -ENOMEM;
297
298 if (per_vq_vectors) {
299 /* Best option: one for change interrupt, one per vq. */
300 nvectors = 1;
301 for (i = 0; i < nvqs; ++i)
302 if (names[i] && callbacks[i])
303 ++nvectors;
304 } else {
305 /* Second best: one for change, shared for all vqs. */
306 nvectors = 2;
307 }
308
309 err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors,
310 per_vq_vectors ? desc : NULL);
311 if (err)
312 goto error_find;
313
314 vp_dev->per_vq_vectors = per_vq_vectors;
315 allocated_vectors = vp_dev->msix_used_vectors;
316 for (i = 0; i < nvqs; ++i) {
317 if (!names[i]) {
318 vqs[i] = NULL;
319 continue;
320 }
321
322 if (!callbacks[i])
323 msix_vec = VIRTIO_MSI_NO_VECTOR;
324 else if (vp_dev->per_vq_vectors)
325 msix_vec = allocated_vectors++;
326 else
327 msix_vec = VP_MSIX_VQ_VECTOR;
328 vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
329 ctx ? ctx[i] : false,
330 msix_vec);
331 if (IS_ERR(vqs[i])) {
332 err = PTR_ERR(vqs[i]);
333 goto error_find;
334 }
335
336 if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
337 continue;
338
339 /* allocate per-vq irq if available and necessary */
340 snprintf(vp_dev->msix_names[msix_vec],
341 sizeof *vp_dev->msix_names,
342 "%s-%s",
343 dev_name(&vp_dev->vdev.dev), names[i]);
344 err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
345 vring_interrupt, 0,
346 vp_dev->msix_names[msix_vec],
347 vqs[i]);
348 if (err)
349 goto error_find;
350 }
351 return 0;
352
353error_find:
354 vp_del_vqs(vdev);
355 return err;
356}
357
358static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs,
359 struct virtqueue *vqs[], vq_callback_t *callbacks[],
360 const char * const names[], const bool *ctx)
361{
362 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
363 int i, err, queue_idx = 0;
364
365 vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
366 if (!vp_dev->vqs)
367 return -ENOMEM;
368
369 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
370 dev_name(&vdev->dev), vp_dev);
371 if (err)
372 goto out_del_vqs;
373
374 vp_dev->intx_enabled = 1;
375 vp_dev->per_vq_vectors = false;
376 for (i = 0; i < nvqs; ++i) {
377 if (!names[i]) {
378 vqs[i] = NULL;
379 continue;
380 }
381 vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
382 ctx ? ctx[i] : false,
383 VIRTIO_MSI_NO_VECTOR);
384 if (IS_ERR(vqs[i])) {
385 err = PTR_ERR(vqs[i]);
386 goto out_del_vqs;
387 }
388 }
389
390 return 0;
391out_del_vqs:
392 vp_del_vqs(vdev);
393 return err;
394}
395
396/* the config->find_vqs() implementation */
397int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
398 struct virtqueue *vqs[], vq_callback_t *callbacks[],
399 const char * const names[], const bool *ctx,
400 struct irq_affinity *desc)
401{
402 int err;
403
404 /* Try MSI-X with one vector per queue. */
405 err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, true, ctx, desc);
406 if (!err)
407 return 0;
408 /* Fallback: MSI-X with one vector for config, one shared for queues. */
409 err = vp_find_vqs_msix(vdev, nvqs, vqs, callbacks, names, false, ctx, desc);
410 if (!err)
411 return 0;
412 /* Is there an interrupt? If not give up. */
413 if (!(to_vp_device(vdev)->pci_dev->irq))
414 return err;
415 /* Finally fall back to regular interrupts. */
416 return vp_find_vqs_intx(vdev, nvqs, vqs, callbacks, names, ctx);
417}
418
419const char *vp_bus_name(struct virtio_device *vdev)
420{
421 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
422
423 return pci_name(vp_dev->pci_dev);
424}
425
426/* Setup the affinity for a virtqueue:
427 * - force the affinity for per vq vector
428 * - OR over all affinities for shared MSI
429 * - ignore the affinity request if we're using INTX
430 */
431int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask)
432{
433 struct virtio_device *vdev = vq->vdev;
434 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
435 struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
436 struct cpumask *mask;
437 unsigned int irq;
438
439 if (!vq->callback)
440 return -EINVAL;
441
442 if (vp_dev->msix_enabled) {
443 mask = vp_dev->msix_affinity_masks[info->msix_vector];
444 irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector);
445 if (!cpu_mask)
446 irq_set_affinity_hint(irq, NULL);
447 else {
448 cpumask_copy(mask, cpu_mask);
449 irq_set_affinity_hint(irq, mask);
450 }
451 }
452 return 0;
453}
454
455const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index)
456{
457 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
458
459 if (!vp_dev->per_vq_vectors ||
460 vp_dev->vqs[index]->msix_vector == VIRTIO_MSI_NO_VECTOR)
461 return NULL;
462
463 return pci_irq_get_affinity(vp_dev->pci_dev,
464 vp_dev->vqs[index]->msix_vector);
465}
466
467#ifdef CONFIG_PM_SLEEP
468static int virtio_pci_freeze(struct device *dev)
469{
470 struct pci_dev *pci_dev = to_pci_dev(dev);
471 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
472 int ret;
473
474 ret = virtio_device_freeze(&vp_dev->vdev);
475
476 if (!ret)
477 pci_disable_device(pci_dev);
478 return ret;
479}
480
481static int virtio_pci_restore(struct device *dev)
482{
483 struct pci_dev *pci_dev = to_pci_dev(dev);
484 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
485 int ret;
486
487 ret = pci_enable_device(pci_dev);
488 if (ret)
489 return ret;
490
491 pci_set_master(pci_dev);
492 return virtio_device_restore(&vp_dev->vdev);
493}
494
495static const struct dev_pm_ops virtio_pci_pm_ops = {
496 SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore)
497};
498#endif
499
500
501/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
502static const struct pci_device_id virtio_pci_id_table[] = {
503 { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) },
504 { 0 }
505};
506
507MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
508
509static void virtio_pci_release_dev(struct device *_d)
510{
511 struct virtio_device *vdev = dev_to_virtio(_d);
512 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
513
514 /* As struct device is a kobject, it's not safe to
515 * free the memory (including the reference counter itself)
516 * until it's release callback. */
517 kfree(vp_dev);
518}
519
520static int virtio_pci_probe(struct pci_dev *pci_dev,
521 const struct pci_device_id *id)
522{
523 struct virtio_pci_device *vp_dev, *reg_dev = NULL;
524 int rc;
525
526 /* allocate our structure and fill it out */
527 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
528 if (!vp_dev)
529 return -ENOMEM;
530
531 pci_set_drvdata(pci_dev, vp_dev);
532 vp_dev->vdev.dev.parent = &pci_dev->dev;
533 vp_dev->vdev.dev.release = virtio_pci_release_dev;
534 vp_dev->pci_dev = pci_dev;
535 INIT_LIST_HEAD(&vp_dev->virtqueues);
536 spin_lock_init(&vp_dev->lock);
537
538 /* enable the device */
539 rc = pci_enable_device(pci_dev);
540 if (rc)
541 goto err_enable_device;
542
543 if (force_legacy) {
544 rc = virtio_pci_legacy_probe(vp_dev);
545 /* Also try modern mode if we can't map BAR0 (no IO space). */
546 if (rc == -ENODEV || rc == -ENOMEM)
547 rc = virtio_pci_modern_probe(vp_dev);
548 if (rc)
549 goto err_probe;
550 } else {
551 rc = virtio_pci_modern_probe(vp_dev);
552 if (rc == -ENODEV)
553 rc = virtio_pci_legacy_probe(vp_dev);
554 if (rc)
555 goto err_probe;
556 }
557
558 pci_set_master(pci_dev);
559
560 vp_dev->is_legacy = vp_dev->ldev.ioaddr ? true : false;
561
562 rc = register_virtio_device(&vp_dev->vdev);
563 reg_dev = vp_dev;
564 if (rc)
565 goto err_register;
566
567 return 0;
568
569err_register:
570 if (vp_dev->is_legacy)
571 virtio_pci_legacy_remove(vp_dev);
572 else
573 virtio_pci_modern_remove(vp_dev);
574err_probe:
575 pci_disable_device(pci_dev);
576err_enable_device:
577 if (reg_dev)
578 put_device(&vp_dev->vdev.dev);
579 else
580 kfree(vp_dev);
581 return rc;
582}
583
584static void virtio_pci_remove(struct pci_dev *pci_dev)
585{
586 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
587 struct device *dev = get_device(&vp_dev->vdev.dev);
588
589 /*
590 * Device is marked broken on surprise removal so that virtio upper
591 * layers can abort any ongoing operation.
592 */
593 if (!pci_device_is_present(pci_dev))
594 virtio_break_device(&vp_dev->vdev);
595
596 pci_disable_sriov(pci_dev);
597
598 unregister_virtio_device(&vp_dev->vdev);
599
600 if (vp_dev->is_legacy)
601 virtio_pci_legacy_remove(vp_dev);
602 else
603 virtio_pci_modern_remove(vp_dev);
604
605 pci_disable_device(pci_dev);
606 put_device(dev);
607}
608
609static int virtio_pci_sriov_configure(struct pci_dev *pci_dev, int num_vfs)
610{
611 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
612 struct virtio_device *vdev = &vp_dev->vdev;
613 int ret;
614
615 if (!(vdev->config->get_status(vdev) & VIRTIO_CONFIG_S_DRIVER_OK))
616 return -EBUSY;
617
618 if (!__virtio_test_bit(vdev, VIRTIO_F_SR_IOV))
619 return -EINVAL;
620
621 if (pci_vfs_assigned(pci_dev))
622 return -EPERM;
623
624 if (num_vfs == 0) {
625 pci_disable_sriov(pci_dev);
626 return 0;
627 }
628
629 ret = pci_enable_sriov(pci_dev, num_vfs);
630 if (ret < 0)
631 return ret;
632
633 return num_vfs;
634}
635
636static struct pci_driver virtio_pci_driver = {
637 .name = "virtio-pci",
638 .id_table = virtio_pci_id_table,
639 .probe = virtio_pci_probe,
640 .remove = virtio_pci_remove,
641#ifdef CONFIG_PM_SLEEP
642 .driver.pm = &virtio_pci_pm_ops,
643#endif
644 .sriov_configure = virtio_pci_sriov_configure,
645};
646
647module_pci_driver(virtio_pci_driver);
648
649MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
650MODULE_DESCRIPTION("virtio-pci");
651MODULE_LICENSE("GPL");
652MODULE_VERSION("1");