1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Virtio PCI driver - modern (virtio 1.0) device support
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 <linux/delay.h>
18#define VIRTIO_PCI_NO_LEGACY
19#define VIRTIO_RING_NO_LEGACY
20#include "virtio_pci_common.h"
21
22#define VIRTIO_AVQ_SGS_MAX 4
23
24static u64 vp_get_features(struct virtio_device *vdev)
25{
26 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
27
28 return vp_modern_get_features(mdev: &vp_dev->mdev);
29}
30
31static bool vp_is_avq(struct virtio_device *vdev, unsigned int index)
32{
33 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
34
35 if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
36 return false;
37
38 return index == vp_dev->admin_vq.vq_index;
39}
40
41static int virtqueue_exec_admin_cmd(struct virtio_pci_admin_vq *admin_vq,
42 u16 opcode,
43 struct scatterlist **sgs,
44 unsigned int out_num,
45 unsigned int in_num,
46 void *data)
47{
48 struct virtqueue *vq;
49 int ret, len;
50
51 vq = admin_vq->info.vq;
52 if (!vq)
53 return -EIO;
54
55 if (opcode != VIRTIO_ADMIN_CMD_LIST_QUERY &&
56 opcode != VIRTIO_ADMIN_CMD_LIST_USE &&
57 !((1ULL << opcode) & admin_vq->supported_cmds))
58 return -EOPNOTSUPP;
59
60 ret = virtqueue_add_sgs(vq, sgs, out_sgs: out_num, in_sgs: in_num, data, GFP_KERNEL);
61 if (ret < 0)
62 return -EIO;
63
64 if (unlikely(!virtqueue_kick(vq)))
65 return -EIO;
66
67 while (!virtqueue_get_buf(vq, len: &len) &&
68 !virtqueue_is_broken(vq))
69 cpu_relax();
70
71 if (virtqueue_is_broken(vq))
72 return -EIO;
73
74 return 0;
75}
76
77int vp_modern_admin_cmd_exec(struct virtio_device *vdev,
78 struct virtio_admin_cmd *cmd)
79{
80 struct scatterlist *sgs[VIRTIO_AVQ_SGS_MAX], hdr, stat;
81 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
82 struct virtio_admin_cmd_status *va_status;
83 unsigned int out_num = 0, in_num = 0;
84 struct virtio_admin_cmd_hdr *va_hdr;
85 u16 status;
86 int ret;
87
88 if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
89 return -EOPNOTSUPP;
90
91 va_status = kzalloc(size: sizeof(*va_status), GFP_KERNEL);
92 if (!va_status)
93 return -ENOMEM;
94
95 va_hdr = kzalloc(size: sizeof(*va_hdr), GFP_KERNEL);
96 if (!va_hdr) {
97 ret = -ENOMEM;
98 goto err_alloc;
99 }
100
101 va_hdr->opcode = cmd->opcode;
102 va_hdr->group_type = cmd->group_type;
103 va_hdr->group_member_id = cmd->group_member_id;
104
105 /* Add header */
106 sg_init_one(&hdr, va_hdr, sizeof(*va_hdr));
107 sgs[out_num] = &hdr;
108 out_num++;
109
110 if (cmd->data_sg) {
111 sgs[out_num] = cmd->data_sg;
112 out_num++;
113 }
114
115 /* Add return status */
116 sg_init_one(&stat, va_status, sizeof(*va_status));
117 sgs[out_num + in_num] = &stat;
118 in_num++;
119
120 if (cmd->result_sg) {
121 sgs[out_num + in_num] = cmd->result_sg;
122 in_num++;
123 }
124
125 mutex_lock(&vp_dev->admin_vq.cmd_lock);
126 ret = virtqueue_exec_admin_cmd(admin_vq: &vp_dev->admin_vq,
127 le16_to_cpu(cmd->opcode),
128 sgs, out_num, in_num, data: sgs);
129 mutex_unlock(lock: &vp_dev->admin_vq.cmd_lock);
130
131 if (ret) {
132 dev_err(&vdev->dev,
133 "Failed to execute command on admin vq: %d\n.", ret);
134 goto err_cmd_exec;
135 }
136
137 status = le16_to_cpu(va_status->status);
138 if (status != VIRTIO_ADMIN_STATUS_OK) {
139 dev_err(&vdev->dev,
140 "admin command error: status(%#x) qualifier(%#x)\n",
141 status, le16_to_cpu(va_status->status_qualifier));
142 ret = -status;
143 }
144
145err_cmd_exec:
146 kfree(objp: va_hdr);
147err_alloc:
148 kfree(objp: va_status);
149 return ret;
150}
151
152static void virtio_pci_admin_cmd_list_init(struct virtio_device *virtio_dev)
153{
154 struct virtio_pci_device *vp_dev = to_vp_device(vdev: virtio_dev);
155 struct virtio_admin_cmd cmd = {};
156 struct scatterlist result_sg;
157 struct scatterlist data_sg;
158 __le64 *data;
159 int ret;
160
161 data = kzalloc(size: sizeof(*data), GFP_KERNEL);
162 if (!data)
163 return;
164
165 sg_init_one(&result_sg, data, sizeof(*data));
166 cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_LIST_QUERY);
167 cmd.group_type = cpu_to_le16(VIRTIO_ADMIN_GROUP_TYPE_SRIOV);
168 cmd.result_sg = &result_sg;
169
170 ret = vp_modern_admin_cmd_exec(vdev: virtio_dev, cmd: &cmd);
171 if (ret)
172 goto end;
173
174 *data &= cpu_to_le64(VIRTIO_ADMIN_CMD_BITMAP);
175 sg_init_one(&data_sg, data, sizeof(*data));
176 cmd.opcode = cpu_to_le16(VIRTIO_ADMIN_CMD_LIST_USE);
177 cmd.data_sg = &data_sg;
178 cmd.result_sg = NULL;
179
180 ret = vp_modern_admin_cmd_exec(vdev: virtio_dev, cmd: &cmd);
181 if (ret)
182 goto end;
183
184 vp_dev->admin_vq.supported_cmds = le64_to_cpu(*data);
185end:
186 kfree(objp: data);
187}
188
189static void vp_modern_avq_activate(struct virtio_device *vdev)
190{
191 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
192 struct virtio_pci_admin_vq *admin_vq = &vp_dev->admin_vq;
193
194 if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
195 return;
196
197 __virtqueue_unbreak(vq: admin_vq->info.vq);
198 virtio_pci_admin_cmd_list_init(virtio_dev: vdev);
199}
200
201static void vp_modern_avq_deactivate(struct virtio_device *vdev)
202{
203 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
204 struct virtio_pci_admin_vq *admin_vq = &vp_dev->admin_vq;
205
206 if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
207 return;
208
209 __virtqueue_break(vq: admin_vq->info.vq);
210}
211
212static void vp_transport_features(struct virtio_device *vdev, u64 features)
213{
214 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
215 struct pci_dev *pci_dev = vp_dev->pci_dev;
216
217 if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
218 pci_find_ext_capability(dev: pci_dev, PCI_EXT_CAP_ID_SRIOV))
219 __virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
220
221 if (features & BIT_ULL(VIRTIO_F_RING_RESET))
222 __virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
223
224 if (features & BIT_ULL(VIRTIO_F_ADMIN_VQ))
225 __virtio_set_bit(vdev, VIRTIO_F_ADMIN_VQ);
226}
227
228static int __vp_check_common_size_one_feature(struct virtio_device *vdev, u32 fbit,
229 u32 offset, const char *fname)
230{
231 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
232
233 if (!__virtio_test_bit(vdev, fbit))
234 return 0;
235
236 if (likely(vp_dev->mdev.common_len >= offset))
237 return 0;
238
239 dev_err(&vdev->dev,
240 "virtio: common cfg size(%zu) does not match the feature %s\n",
241 vp_dev->mdev.common_len, fname);
242
243 return -EINVAL;
244}
245
246#define vp_check_common_size_one_feature(vdev, fbit, field) \
247 __vp_check_common_size_one_feature(vdev, fbit, \
248 offsetofend(struct virtio_pci_modern_common_cfg, field), #fbit)
249
250static int vp_check_common_size(struct virtio_device *vdev)
251{
252 if (vp_check_common_size_one_feature(vdev, VIRTIO_F_NOTIF_CONFIG_DATA, queue_notify_data))
253 return -EINVAL;
254
255 if (vp_check_common_size_one_feature(vdev, VIRTIO_F_RING_RESET, queue_reset))
256 return -EINVAL;
257
258 if (vp_check_common_size_one_feature(vdev, VIRTIO_F_ADMIN_VQ, admin_queue_num))
259 return -EINVAL;
260
261 return 0;
262}
263
264/* virtio config->finalize_features() implementation */
265static int vp_finalize_features(struct virtio_device *vdev)
266{
267 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
268 u64 features = vdev->features;
269
270 /* Give virtio_ring a chance to accept features. */
271 vring_transport_features(vdev);
272
273 /* Give virtio_pci a chance to accept features. */
274 vp_transport_features(vdev, features);
275
276 if (!__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
277 dev_err(&vdev->dev, "virtio: device uses modern interface "
278 "but does not have VIRTIO_F_VERSION_1\n");
279 return -EINVAL;
280 }
281
282 if (vp_check_common_size(vdev))
283 return -EINVAL;
284
285 vp_modern_set_features(mdev: &vp_dev->mdev, features: vdev->features);
286
287 return 0;
288}
289
290/* virtio config->get() implementation */
291static void vp_get(struct virtio_device *vdev, unsigned int offset,
292 void *buf, unsigned int len)
293{
294 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
295 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
296 void __iomem *device = mdev->device;
297 u8 b;
298 __le16 w;
299 __le32 l;
300
301 BUG_ON(offset + len > mdev->device_len);
302
303 switch (len) {
304 case 1:
305 b = ioread8(device + offset);
306 memcpy(buf, &b, sizeof b);
307 break;
308 case 2:
309 w = cpu_to_le16(ioread16(device + offset));
310 memcpy(buf, &w, sizeof w);
311 break;
312 case 4:
313 l = cpu_to_le32(ioread32(device + offset));
314 memcpy(buf, &l, sizeof l);
315 break;
316 case 8:
317 l = cpu_to_le32(ioread32(device + offset));
318 memcpy(buf, &l, sizeof l);
319 l = cpu_to_le32(ioread32(device + offset + sizeof l));
320 memcpy(buf + sizeof l, &l, sizeof l);
321 break;
322 default:
323 BUG();
324 }
325}
326
327/* the config->set() implementation. it's symmetric to the config->get()
328 * implementation */
329static void vp_set(struct virtio_device *vdev, unsigned int offset,
330 const void *buf, unsigned int len)
331{
332 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
333 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
334 void __iomem *device = mdev->device;
335 u8 b;
336 __le16 w;
337 __le32 l;
338
339 BUG_ON(offset + len > mdev->device_len);
340
341 switch (len) {
342 case 1:
343 memcpy(&b, buf, sizeof b);
344 iowrite8(b, device + offset);
345 break;
346 case 2:
347 memcpy(&w, buf, sizeof w);
348 iowrite16(le16_to_cpu(w), device + offset);
349 break;
350 case 4:
351 memcpy(&l, buf, sizeof l);
352 iowrite32(le32_to_cpu(l), device + offset);
353 break;
354 case 8:
355 memcpy(&l, buf, sizeof l);
356 iowrite32(le32_to_cpu(l), device + offset);
357 memcpy(&l, buf + sizeof l, sizeof l);
358 iowrite32(le32_to_cpu(l), device + offset + sizeof l);
359 break;
360 default:
361 BUG();
362 }
363}
364
365static u32 vp_generation(struct virtio_device *vdev)
366{
367 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
368
369 return vp_modern_generation(mdev: &vp_dev->mdev);
370}
371
372/* config->{get,set}_status() implementations */
373static u8 vp_get_status(struct virtio_device *vdev)
374{
375 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
376
377 return vp_modern_get_status(mdev: &vp_dev->mdev);
378}
379
380static void vp_set_status(struct virtio_device *vdev, u8 status)
381{
382 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
383
384 /* We should never be setting status to 0. */
385 BUG_ON(status == 0);
386 vp_modern_set_status(mdev: &vp_dev->mdev, status);
387 if (status & VIRTIO_CONFIG_S_DRIVER_OK)
388 vp_modern_avq_activate(vdev);
389}
390
391static void vp_reset(struct virtio_device *vdev)
392{
393 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
394 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
395
396 /* 0 status means a reset. */
397 vp_modern_set_status(mdev, status: 0);
398 /* After writing 0 to device_status, the driver MUST wait for a read of
399 * device_status to return 0 before reinitializing the device.
400 * This will flush out the status write, and flush in device writes,
401 * including MSI-X interrupts, if any.
402 */
403 while (vp_modern_get_status(mdev))
404 msleep(msecs: 1);
405
406 vp_modern_avq_deactivate(vdev);
407
408 /* Flush pending VQ/configuration callbacks. */
409 vp_synchronize_vectors(vdev);
410}
411
412static int vp_active_vq(struct virtqueue *vq, u16 msix_vec)
413{
414 struct virtio_pci_device *vp_dev = to_vp_device(vdev: vq->vdev);
415 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
416 unsigned long index;
417
418 index = vq->index;
419
420 /* activate the queue */
421 vp_modern_set_queue_size(mdev, idx: index, size: virtqueue_get_vring_size(vq));
422 vp_modern_queue_address(mdev, index, desc_addr: virtqueue_get_desc_addr(vq),
423 driver_addr: virtqueue_get_avail_addr(vq),
424 device_addr: virtqueue_get_used_addr(vq));
425
426 if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
427 msix_vec = vp_modern_queue_vector(mdev, idx: index, vector: msix_vec);
428 if (msix_vec == VIRTIO_MSI_NO_VECTOR)
429 return -EBUSY;
430 }
431
432 return 0;
433}
434
435static int vp_modern_disable_vq_and_reset(struct virtqueue *vq)
436{
437 struct virtio_pci_device *vp_dev = to_vp_device(vdev: vq->vdev);
438 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
439 struct virtio_pci_vq_info *info;
440 unsigned long flags;
441
442 if (!virtio_has_feature(vdev: vq->vdev, VIRTIO_F_RING_RESET))
443 return -ENOENT;
444
445 vp_modern_set_queue_reset(mdev, index: vq->index);
446
447 info = vp_dev->vqs[vq->index];
448
449 /* delete vq from irq handler */
450 spin_lock_irqsave(&vp_dev->lock, flags);
451 list_del(entry: &info->node);
452 spin_unlock_irqrestore(lock: &vp_dev->lock, flags);
453
454 INIT_LIST_HEAD(list: &info->node);
455
456#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
457 __virtqueue_break(vq);
458#endif
459
460 /* For the case where vq has an exclusive irq, call synchronize_irq() to
461 * wait for completion.
462 *
463 * note: We can't use disable_irq() since it conflicts with the affinity
464 * managed IRQ that is used by some drivers.
465 */
466 if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR)
467 synchronize_irq(irq: pci_irq_vector(dev: vp_dev->pci_dev, nr: info->msix_vector));
468
469 vq->reset = true;
470
471 return 0;
472}
473
474static int vp_modern_enable_vq_after_reset(struct virtqueue *vq)
475{
476 struct virtio_pci_device *vp_dev = to_vp_device(vdev: vq->vdev);
477 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
478 struct virtio_pci_vq_info *info;
479 unsigned long flags, index;
480 int err;
481
482 if (!vq->reset)
483 return -EBUSY;
484
485 index = vq->index;
486 info = vp_dev->vqs[index];
487
488 if (vp_modern_get_queue_reset(mdev, index))
489 return -EBUSY;
490
491 if (vp_modern_get_queue_enable(mdev, idx: index))
492 return -EBUSY;
493
494 err = vp_active_vq(vq, msix_vec: info->msix_vector);
495 if (err)
496 return err;
497
498 if (vq->callback) {
499 spin_lock_irqsave(&vp_dev->lock, flags);
500 list_add(new: &info->node, head: &vp_dev->virtqueues);
501 spin_unlock_irqrestore(lock: &vp_dev->lock, flags);
502 } else {
503 INIT_LIST_HEAD(list: &info->node);
504 }
505
506#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION
507 __virtqueue_unbreak(vq);
508#endif
509
510 vp_modern_set_queue_enable(mdev: &vp_dev->mdev, idx: index, enable: true);
511 vq->reset = false;
512
513 return 0;
514}
515
516static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
517{
518 return vp_modern_config_vector(mdev: &vp_dev->mdev, vector);
519}
520
521static bool vp_notify_with_data(struct virtqueue *vq)
522{
523 u32 data = vring_notification_data(vq: vq);
524
525 iowrite32(data, (void __iomem *)vq->priv);
526
527 return true;
528}
529
530static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
531 struct virtio_pci_vq_info *info,
532 unsigned int index,
533 void (*callback)(struct virtqueue *vq),
534 const char *name,
535 bool ctx,
536 u16 msix_vec)
537{
538
539 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
540 bool (*notify)(struct virtqueue *vq);
541 struct virtqueue *vq;
542 bool is_avq;
543 u16 num;
544 int err;
545
546 if (__virtio_test_bit(vdev: &vp_dev->vdev, VIRTIO_F_NOTIFICATION_DATA))
547 notify = vp_notify_with_data;
548 else
549 notify = vp_notify;
550
551 is_avq = vp_is_avq(vdev: &vp_dev->vdev, index);
552 if (index >= vp_modern_get_num_queues(mdev) && !is_avq)
553 return ERR_PTR(error: -EINVAL);
554
555 num = is_avq ?
556 VIRTIO_AVQ_SGS_MAX : vp_modern_get_queue_size(mdev, idx: index);
557 /* Check if queue is either not available or already active. */
558 if (!num || vp_modern_get_queue_enable(mdev, idx: index))
559 return ERR_PTR(error: -ENOENT);
560
561 info->msix_vector = msix_vec;
562
563 /* create the vring */
564 vq = vring_create_virtqueue(index, num,
565 SMP_CACHE_BYTES, vdev: &vp_dev->vdev,
566 weak_barriers: true, may_reduce_num: true, ctx,
567 notify, callback, name);
568 if (!vq)
569 return ERR_PTR(error: -ENOMEM);
570
571 vq->num_max = num;
572
573 err = vp_active_vq(vq, msix_vec);
574 if (err)
575 goto err;
576
577 vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index, NULL);
578 if (!vq->priv) {
579 err = -ENOMEM;
580 goto err;
581 }
582
583 if (is_avq) {
584 mutex_lock(&vp_dev->admin_vq.cmd_lock);
585 vp_dev->admin_vq.info.vq = vq;
586 mutex_unlock(lock: &vp_dev->admin_vq.cmd_lock);
587 }
588
589 return vq;
590
591err:
592 vring_del_virtqueue(vq);
593 return ERR_PTR(error: err);
594}
595
596static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
597 struct virtqueue *vqs[],
598 vq_callback_t *callbacks[],
599 const char * const names[], const bool *ctx,
600 struct irq_affinity *desc)
601{
602 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
603 struct virtqueue *vq;
604 int rc = vp_find_vqs(vdev, nvqs, vqs, callbacks, names, ctx, desc);
605
606 if (rc)
607 return rc;
608
609 /* Select and activate all queues. Has to be done last: once we do
610 * this, there's no way to go back except reset.
611 */
612 list_for_each_entry(vq, &vdev->vqs, list)
613 vp_modern_set_queue_enable(mdev: &vp_dev->mdev, idx: vq->index, enable: true);
614
615 return 0;
616}
617
618static void del_vq(struct virtio_pci_vq_info *info)
619{
620 struct virtqueue *vq = info->vq;
621 struct virtio_pci_device *vp_dev = to_vp_device(vdev: vq->vdev);
622 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
623
624 if (vp_is_avq(vdev: &vp_dev->vdev, index: vq->index)) {
625 mutex_lock(&vp_dev->admin_vq.cmd_lock);
626 vp_dev->admin_vq.info.vq = NULL;
627 mutex_unlock(lock: &vp_dev->admin_vq.cmd_lock);
628 }
629
630 if (vp_dev->msix_enabled)
631 vp_modern_queue_vector(mdev, idx: vq->index,
632 VIRTIO_MSI_NO_VECTOR);
633
634 if (!mdev->notify_base)
635 pci_iounmap(dev: mdev->pci_dev, (void __force __iomem *)vq->priv);
636
637 vring_del_virtqueue(vq);
638}
639
640static int virtio_pci_find_shm_cap(struct pci_dev *dev, u8 required_id,
641 u8 *bar, u64 *offset, u64 *len)
642{
643 int pos;
644
645 for (pos = pci_find_capability(dev, PCI_CAP_ID_VNDR); pos > 0;
646 pos = pci_find_next_capability(dev, pos, PCI_CAP_ID_VNDR)) {
647 u8 type, cap_len, id, res_bar;
648 u32 tmp32;
649 u64 res_offset, res_length;
650
651 pci_read_config_byte(dev, where: pos + offsetof(struct virtio_pci_cap,
652 cfg_type), val: &type);
653 if (type != VIRTIO_PCI_CAP_SHARED_MEMORY_CFG)
654 continue;
655
656 pci_read_config_byte(dev, where: pos + offsetof(struct virtio_pci_cap,
657 cap_len), val: &cap_len);
658 if (cap_len != sizeof(struct virtio_pci_cap64)) {
659 dev_err(&dev->dev, "%s: shm cap with bad size offset:"
660 " %d size: %d\n", __func__, pos, cap_len);
661 continue;
662 }
663
664 pci_read_config_byte(dev, where: pos + offsetof(struct virtio_pci_cap,
665 id), val: &id);
666 if (id != required_id)
667 continue;
668
669 pci_read_config_byte(dev, where: pos + offsetof(struct virtio_pci_cap,
670 bar), val: &res_bar);
671 if (res_bar >= PCI_STD_NUM_BARS)
672 continue;
673
674 /* Type and ID match, and the BAR value isn't reserved.
675 * Looks good.
676 */
677
678 /* Read the lower 32bit of length and offset */
679 pci_read_config_dword(dev, where: pos + offsetof(struct virtio_pci_cap,
680 offset), val: &tmp32);
681 res_offset = tmp32;
682 pci_read_config_dword(dev, where: pos + offsetof(struct virtio_pci_cap,
683 length), val: &tmp32);
684 res_length = tmp32;
685
686 /* and now the top half */
687 pci_read_config_dword(dev,
688 where: pos + offsetof(struct virtio_pci_cap64,
689 offset_hi), val: &tmp32);
690 res_offset |= ((u64)tmp32) << 32;
691 pci_read_config_dword(dev,
692 where: pos + offsetof(struct virtio_pci_cap64,
693 length_hi), val: &tmp32);
694 res_length |= ((u64)tmp32) << 32;
695
696 *bar = res_bar;
697 *offset = res_offset;
698 *len = res_length;
699
700 return pos;
701 }
702 return 0;
703}
704
705static bool vp_get_shm_region(struct virtio_device *vdev,
706 struct virtio_shm_region *region, u8 id)
707{
708 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
709 struct pci_dev *pci_dev = vp_dev->pci_dev;
710 u8 bar;
711 u64 offset, len;
712 phys_addr_t phys_addr;
713 size_t bar_len;
714
715 if (!virtio_pci_find_shm_cap(dev: pci_dev, required_id: id, bar: &bar, offset: &offset, len: &len))
716 return false;
717
718 phys_addr = pci_resource_start(pci_dev, bar);
719 bar_len = pci_resource_len(pci_dev, bar);
720
721 if ((offset + len) < offset) {
722 dev_err(&pci_dev->dev, "%s: cap offset+len overflow detected\n",
723 __func__);
724 return false;
725 }
726
727 if (offset + len > bar_len) {
728 dev_err(&pci_dev->dev, "%s: bar shorter than cap offset+len\n",
729 __func__);
730 return false;
731 }
732
733 region->len = len;
734 region->addr = (u64) phys_addr + offset;
735
736 return true;
737}
738
739static int vp_modern_create_avq(struct virtio_device *vdev)
740{
741 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
742 struct virtio_pci_admin_vq *avq;
743 struct virtqueue *vq;
744 u16 admin_q_num;
745
746 if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
747 return 0;
748
749 admin_q_num = vp_modern_avq_num(mdev: &vp_dev->mdev);
750 if (!admin_q_num)
751 return -EINVAL;
752
753 avq = &vp_dev->admin_vq;
754 avq->vq_index = vp_modern_avq_index(mdev: &vp_dev->mdev);
755 sprintf(buf: avq->name, fmt: "avq.%u", avq->vq_index);
756 vq = vp_dev->setup_vq(vp_dev, &vp_dev->admin_vq.info, avq->vq_index, NULL,
757 avq->name, NULL, VIRTIO_MSI_NO_VECTOR);
758 if (IS_ERR(ptr: vq)) {
759 dev_err(&vdev->dev, "failed to setup admin virtqueue, err=%ld",
760 PTR_ERR(vq));
761 return PTR_ERR(ptr: vq);
762 }
763
764 vp_modern_set_queue_enable(mdev: &vp_dev->mdev, idx: avq->info.vq->index, enable: true);
765 return 0;
766}
767
768static void vp_modern_destroy_avq(struct virtio_device *vdev)
769{
770 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
771
772 if (!virtio_has_feature(vdev, VIRTIO_F_ADMIN_VQ))
773 return;
774
775 vp_dev->del_vq(&vp_dev->admin_vq.info);
776}
777
778static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
779 .get = NULL,
780 .set = NULL,
781 .generation = vp_generation,
782 .get_status = vp_get_status,
783 .set_status = vp_set_status,
784 .reset = vp_reset,
785 .find_vqs = vp_modern_find_vqs,
786 .del_vqs = vp_del_vqs,
787 .synchronize_cbs = vp_synchronize_vectors,
788 .get_features = vp_get_features,
789 .finalize_features = vp_finalize_features,
790 .bus_name = vp_bus_name,
791 .set_vq_affinity = vp_set_vq_affinity,
792 .get_vq_affinity = vp_get_vq_affinity,
793 .get_shm_region = vp_get_shm_region,
794 .disable_vq_and_reset = vp_modern_disable_vq_and_reset,
795 .enable_vq_after_reset = vp_modern_enable_vq_after_reset,
796 .create_avq = vp_modern_create_avq,
797 .destroy_avq = vp_modern_destroy_avq,
798};
799
800static const struct virtio_config_ops virtio_pci_config_ops = {
801 .get = vp_get,
802 .set = vp_set,
803 .generation = vp_generation,
804 .get_status = vp_get_status,
805 .set_status = vp_set_status,
806 .reset = vp_reset,
807 .find_vqs = vp_modern_find_vqs,
808 .del_vqs = vp_del_vqs,
809 .synchronize_cbs = vp_synchronize_vectors,
810 .get_features = vp_get_features,
811 .finalize_features = vp_finalize_features,
812 .bus_name = vp_bus_name,
813 .set_vq_affinity = vp_set_vq_affinity,
814 .get_vq_affinity = vp_get_vq_affinity,
815 .get_shm_region = vp_get_shm_region,
816 .disable_vq_and_reset = vp_modern_disable_vq_and_reset,
817 .enable_vq_after_reset = vp_modern_enable_vq_after_reset,
818 .create_avq = vp_modern_create_avq,
819 .destroy_avq = vp_modern_destroy_avq,
820};
821
822/* the PCI probing function */
823int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
824{
825 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
826 struct pci_dev *pci_dev = vp_dev->pci_dev;
827 int err;
828
829 mdev->pci_dev = pci_dev;
830
831 err = vp_modern_probe(mdev);
832 if (err)
833 return err;
834
835 if (mdev->device)
836 vp_dev->vdev.config = &virtio_pci_config_ops;
837 else
838 vp_dev->vdev.config = &virtio_pci_config_nodev_ops;
839
840 vp_dev->config_vector = vp_config_vector;
841 vp_dev->setup_vq = setup_vq;
842 vp_dev->del_vq = del_vq;
843 vp_dev->is_avq = vp_is_avq;
844 vp_dev->isr = mdev->isr;
845 vp_dev->vdev.id = mdev->id;
846
847 mutex_init(&vp_dev->admin_vq.cmd_lock);
848 return 0;
849}
850
851void virtio_pci_modern_remove(struct virtio_pci_device *vp_dev)
852{
853 struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
854
855 mutex_destroy(lock: &vp_dev->admin_vq.cmd_lock);
856 vp_modern_remove(mdev);
857}
858

source code of linux/drivers/virtio/virtio_pci_modern.c