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