1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2018-2020 Intel Corporation.
4 * Copyright (C) 2020 Red Hat, Inc.
5 *
6 * Author: Tiwei Bie <tiwei.bie@intel.com>
7 * Jason Wang <jasowang@redhat.com>
8 *
9 * Thanks Michael S. Tsirkin for the valuable comments and
10 * suggestions. And thanks to Cunming Liang and Zhihong Wang for all
11 * their supports.
12 */
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/cdev.h>
17 #include <linux/device.h>
18 #include <linux/mm.h>
19 #include <linux/iommu.h>
20 #include <linux/uuid.h>
21 #include <linux/vdpa.h>
22 #include <linux/nospec.h>
23 #include <linux/vhost.h>
24 #include <linux/virtio_net.h>
25
26 #include "vhost.h"
27
28 enum {
29 VHOST_VDPA_BACKEND_FEATURES =
30 (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) |
31 (1ULL << VHOST_BACKEND_F_IOTLB_BATCH),
32 };
33
34 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
35
36 struct vhost_vdpa {
37 struct vhost_dev vdev;
38 struct iommu_domain *domain;
39 struct vhost_virtqueue *vqs;
40 struct completion completion;
41 struct vdpa_device *vdpa;
42 struct device dev;
43 struct cdev cdev;
44 atomic_t opened;
45 int nvqs;
46 int virtio_id;
47 int minor;
48 struct eventfd_ctx *config_ctx;
49 int in_batch;
50 struct vdpa_iova_range range;
51 };
52
53 static DEFINE_IDA(vhost_vdpa_ida);
54
55 static dev_t vhost_vdpa_major;
56
handle_vq_kick(struct vhost_work * work)57 static void handle_vq_kick(struct vhost_work *work)
58 {
59 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
60 poll.work);
61 struct vhost_vdpa *v = container_of(vq->dev, struct vhost_vdpa, vdev);
62 const struct vdpa_config_ops *ops = v->vdpa->config;
63
64 ops->kick_vq(v->vdpa, vq - v->vqs);
65 }
66
vhost_vdpa_virtqueue_cb(void * private)67 static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
68 {
69 struct vhost_virtqueue *vq = private;
70 struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
71
72 if (call_ctx)
73 eventfd_signal(call_ctx, 1);
74
75 return IRQ_HANDLED;
76 }
77
vhost_vdpa_config_cb(void * private)78 static irqreturn_t vhost_vdpa_config_cb(void *private)
79 {
80 struct vhost_vdpa *v = private;
81 struct eventfd_ctx *config_ctx = v->config_ctx;
82
83 if (config_ctx)
84 eventfd_signal(config_ctx, 1);
85
86 return IRQ_HANDLED;
87 }
88
vhost_vdpa_setup_vq_irq(struct vhost_vdpa * v,u16 qid)89 static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
90 {
91 struct vhost_virtqueue *vq = &v->vqs[qid];
92 const struct vdpa_config_ops *ops = v->vdpa->config;
93 struct vdpa_device *vdpa = v->vdpa;
94 int ret, irq;
95
96 if (!ops->get_vq_irq)
97 return;
98
99 irq = ops->get_vq_irq(vdpa, qid);
100 if (irq < 0)
101 return;
102
103 irq_bypass_unregister_producer(&vq->call_ctx.producer);
104 if (!vq->call_ctx.ctx)
105 return;
106
107 vq->call_ctx.producer.token = vq->call_ctx.ctx;
108 vq->call_ctx.producer.irq = irq;
109 ret = irq_bypass_register_producer(&vq->call_ctx.producer);
110 if (unlikely(ret))
111 dev_info(&v->dev, "vq %u, irq bypass producer (token %p) registration fails, ret = %d\n",
112 qid, vq->call_ctx.producer.token, ret);
113 }
114
vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa * v,u16 qid)115 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
116 {
117 struct vhost_virtqueue *vq = &v->vqs[qid];
118
119 irq_bypass_unregister_producer(&vq->call_ctx.producer);
120 }
121
vhost_vdpa_reset(struct vhost_vdpa * v)122 static void vhost_vdpa_reset(struct vhost_vdpa *v)
123 {
124 struct vdpa_device *vdpa = v->vdpa;
125
126 vdpa_reset(vdpa);
127 v->in_batch = 0;
128 }
129
vhost_vdpa_get_device_id(struct vhost_vdpa * v,u8 __user * argp)130 static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
131 {
132 struct vdpa_device *vdpa = v->vdpa;
133 const struct vdpa_config_ops *ops = vdpa->config;
134 u32 device_id;
135
136 device_id = ops->get_device_id(vdpa);
137
138 if (copy_to_user(argp, &device_id, sizeof(device_id)))
139 return -EFAULT;
140
141 return 0;
142 }
143
vhost_vdpa_get_status(struct vhost_vdpa * v,u8 __user * statusp)144 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
145 {
146 struct vdpa_device *vdpa = v->vdpa;
147 const struct vdpa_config_ops *ops = vdpa->config;
148 u8 status;
149
150 status = ops->get_status(vdpa);
151
152 if (copy_to_user(statusp, &status, sizeof(status)))
153 return -EFAULT;
154
155 return 0;
156 }
157
vhost_vdpa_set_status(struct vhost_vdpa * v,u8 __user * statusp)158 static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
159 {
160 struct vdpa_device *vdpa = v->vdpa;
161 const struct vdpa_config_ops *ops = vdpa->config;
162 u8 status, status_old;
163 int nvqs = v->nvqs;
164 u16 i;
165
166 if (copy_from_user(&status, statusp, sizeof(status)))
167 return -EFAULT;
168
169 status_old = ops->get_status(vdpa);
170
171 /*
172 * Userspace shouldn't remove status bits unless reset the
173 * status to 0.
174 */
175 if (status != 0 && (ops->get_status(vdpa) & ~status) != 0)
176 return -EINVAL;
177
178 ops->set_status(vdpa, status);
179
180 if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
181 for (i = 0; i < nvqs; i++)
182 vhost_vdpa_setup_vq_irq(v, i);
183
184 if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
185 for (i = 0; i < nvqs; i++)
186 vhost_vdpa_unsetup_vq_irq(v, i);
187
188 return 0;
189 }
190
vhost_vdpa_config_validate(struct vhost_vdpa * v,struct vhost_vdpa_config * c)191 static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
192 struct vhost_vdpa_config *c)
193 {
194 long size = 0;
195
196 switch (v->virtio_id) {
197 case VIRTIO_ID_NET:
198 size = sizeof(struct virtio_net_config);
199 break;
200 }
201
202 if (c->len == 0 || c->off > size)
203 return -EINVAL;
204
205 if (c->len > size - c->off)
206 return -E2BIG;
207
208 return 0;
209 }
210
vhost_vdpa_get_config(struct vhost_vdpa * v,struct vhost_vdpa_config __user * c)211 static long vhost_vdpa_get_config(struct vhost_vdpa *v,
212 struct vhost_vdpa_config __user *c)
213 {
214 struct vdpa_device *vdpa = v->vdpa;
215 struct vhost_vdpa_config config;
216 unsigned long size = offsetof(struct vhost_vdpa_config, buf);
217 u8 *buf;
218
219 if (copy_from_user(&config, c, size))
220 return -EFAULT;
221 if (vhost_vdpa_config_validate(v, &config))
222 return -EINVAL;
223 buf = kvzalloc(config.len, GFP_KERNEL);
224 if (!buf)
225 return -ENOMEM;
226
227 vdpa_get_config(vdpa, config.off, buf, config.len);
228
229 if (copy_to_user(c->buf, buf, config.len)) {
230 kvfree(buf);
231 return -EFAULT;
232 }
233
234 kvfree(buf);
235 return 0;
236 }
237
vhost_vdpa_set_config(struct vhost_vdpa * v,struct vhost_vdpa_config __user * c)238 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
239 struct vhost_vdpa_config __user *c)
240 {
241 struct vdpa_device *vdpa = v->vdpa;
242 const struct vdpa_config_ops *ops = vdpa->config;
243 struct vhost_vdpa_config config;
244 unsigned long size = offsetof(struct vhost_vdpa_config, buf);
245 u8 *buf;
246
247 if (copy_from_user(&config, c, size))
248 return -EFAULT;
249 if (vhost_vdpa_config_validate(v, &config))
250 return -EINVAL;
251 buf = kvzalloc(config.len, GFP_KERNEL);
252 if (!buf)
253 return -ENOMEM;
254
255 if (copy_from_user(buf, c->buf, config.len)) {
256 kvfree(buf);
257 return -EFAULT;
258 }
259
260 ops->set_config(vdpa, config.off, buf, config.len);
261
262 kvfree(buf);
263 return 0;
264 }
265
vhost_vdpa_get_features(struct vhost_vdpa * v,u64 __user * featurep)266 static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
267 {
268 struct vdpa_device *vdpa = v->vdpa;
269 const struct vdpa_config_ops *ops = vdpa->config;
270 u64 features;
271
272 features = ops->get_features(vdpa);
273
274 if (copy_to_user(featurep, &features, sizeof(features)))
275 return -EFAULT;
276
277 return 0;
278 }
279
vhost_vdpa_set_features(struct vhost_vdpa * v,u64 __user * featurep)280 static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
281 {
282 struct vdpa_device *vdpa = v->vdpa;
283 const struct vdpa_config_ops *ops = vdpa->config;
284 u64 features;
285
286 /*
287 * It's not allowed to change the features after they have
288 * been negotiated.
289 */
290 if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK)
291 return -EBUSY;
292
293 if (copy_from_user(&features, featurep, sizeof(features)))
294 return -EFAULT;
295
296 if (vdpa_set_features(vdpa, features))
297 return -EINVAL;
298
299 return 0;
300 }
301
vhost_vdpa_get_vring_num(struct vhost_vdpa * v,u16 __user * argp)302 static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
303 {
304 struct vdpa_device *vdpa = v->vdpa;
305 const struct vdpa_config_ops *ops = vdpa->config;
306 u16 num;
307
308 num = ops->get_vq_num_max(vdpa);
309
310 if (copy_to_user(argp, &num, sizeof(num)))
311 return -EFAULT;
312
313 return 0;
314 }
315
vhost_vdpa_config_put(struct vhost_vdpa * v)316 static void vhost_vdpa_config_put(struct vhost_vdpa *v)
317 {
318 if (v->config_ctx) {
319 eventfd_ctx_put(v->config_ctx);
320 v->config_ctx = NULL;
321 }
322 }
323
vhost_vdpa_set_config_call(struct vhost_vdpa * v,u32 __user * argp)324 static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
325 {
326 struct vdpa_callback cb;
327 int fd;
328 struct eventfd_ctx *ctx;
329
330 cb.callback = vhost_vdpa_config_cb;
331 cb.private = v;
332 if (copy_from_user(&fd, argp, sizeof(fd)))
333 return -EFAULT;
334
335 ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
336 swap(ctx, v->config_ctx);
337
338 if (!IS_ERR_OR_NULL(ctx))
339 eventfd_ctx_put(ctx);
340
341 if (IS_ERR(v->config_ctx)) {
342 long ret = PTR_ERR(v->config_ctx);
343
344 v->config_ctx = NULL;
345 return ret;
346 }
347
348 v->vdpa->config->set_config_cb(v->vdpa, &cb);
349
350 return 0;
351 }
352
vhost_vdpa_get_iova_range(struct vhost_vdpa * v,u32 __user * argp)353 static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
354 {
355 struct vhost_vdpa_iova_range range = {
356 .first = v->range.first,
357 .last = v->range.last,
358 };
359
360 if (copy_to_user(argp, &range, sizeof(range)))
361 return -EFAULT;
362 return 0;
363 }
364
vhost_vdpa_vring_ioctl(struct vhost_vdpa * v,unsigned int cmd,void __user * argp)365 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
366 void __user *argp)
367 {
368 struct vdpa_device *vdpa = v->vdpa;
369 const struct vdpa_config_ops *ops = vdpa->config;
370 struct vdpa_vq_state vq_state;
371 struct vdpa_callback cb;
372 struct vhost_virtqueue *vq;
373 struct vhost_vring_state s;
374 u32 idx;
375 long r;
376
377 r = get_user(idx, (u32 __user *)argp);
378 if (r < 0)
379 return r;
380
381 if (idx >= v->nvqs)
382 return -ENOBUFS;
383
384 idx = array_index_nospec(idx, v->nvqs);
385 vq = &v->vqs[idx];
386
387 switch (cmd) {
388 case VHOST_VDPA_SET_VRING_ENABLE:
389 if (copy_from_user(&s, argp, sizeof(s)))
390 return -EFAULT;
391 ops->set_vq_ready(vdpa, idx, s.num);
392 return 0;
393 case VHOST_GET_VRING_BASE:
394 r = ops->get_vq_state(v->vdpa, idx, &vq_state);
395 if (r)
396 return r;
397
398 vq->last_avail_idx = vq_state.avail_index;
399 break;
400 }
401
402 r = vhost_vring_ioctl(&v->vdev, cmd, argp);
403 if (r)
404 return r;
405
406 switch (cmd) {
407 case VHOST_SET_VRING_ADDR:
408 if (ops->set_vq_address(vdpa, idx,
409 (u64)(uintptr_t)vq->desc,
410 (u64)(uintptr_t)vq->avail,
411 (u64)(uintptr_t)vq->used))
412 r = -EINVAL;
413 break;
414
415 case VHOST_SET_VRING_BASE:
416 vq_state.avail_index = vq->last_avail_idx;
417 if (ops->set_vq_state(vdpa, idx, &vq_state))
418 r = -EINVAL;
419 break;
420
421 case VHOST_SET_VRING_CALL:
422 if (vq->call_ctx.ctx) {
423 cb.callback = vhost_vdpa_virtqueue_cb;
424 cb.private = vq;
425 } else {
426 cb.callback = NULL;
427 cb.private = NULL;
428 }
429 ops->set_vq_cb(vdpa, idx, &cb);
430 vhost_vdpa_setup_vq_irq(v, idx);
431 break;
432
433 case VHOST_SET_VRING_NUM:
434 ops->set_vq_num(vdpa, idx, vq->num);
435 break;
436 }
437
438 return r;
439 }
440
vhost_vdpa_unlocked_ioctl(struct file * filep,unsigned int cmd,unsigned long arg)441 static long vhost_vdpa_unlocked_ioctl(struct file *filep,
442 unsigned int cmd, unsigned long arg)
443 {
444 struct vhost_vdpa *v = filep->private_data;
445 struct vhost_dev *d = &v->vdev;
446 void __user *argp = (void __user *)arg;
447 u64 __user *featurep = argp;
448 u64 features;
449 long r = 0;
450
451 if (cmd == VHOST_SET_BACKEND_FEATURES) {
452 if (copy_from_user(&features, featurep, sizeof(features)))
453 return -EFAULT;
454 if (features & ~VHOST_VDPA_BACKEND_FEATURES)
455 return -EOPNOTSUPP;
456 vhost_set_backend_features(&v->vdev, features);
457 return 0;
458 }
459
460 mutex_lock(&d->mutex);
461
462 switch (cmd) {
463 case VHOST_VDPA_GET_DEVICE_ID:
464 r = vhost_vdpa_get_device_id(v, argp);
465 break;
466 case VHOST_VDPA_GET_STATUS:
467 r = vhost_vdpa_get_status(v, argp);
468 break;
469 case VHOST_VDPA_SET_STATUS:
470 r = vhost_vdpa_set_status(v, argp);
471 break;
472 case VHOST_VDPA_GET_CONFIG:
473 r = vhost_vdpa_get_config(v, argp);
474 break;
475 case VHOST_VDPA_SET_CONFIG:
476 r = vhost_vdpa_set_config(v, argp);
477 break;
478 case VHOST_GET_FEATURES:
479 r = vhost_vdpa_get_features(v, argp);
480 break;
481 case VHOST_SET_FEATURES:
482 r = vhost_vdpa_set_features(v, argp);
483 break;
484 case VHOST_VDPA_GET_VRING_NUM:
485 r = vhost_vdpa_get_vring_num(v, argp);
486 break;
487 case VHOST_SET_LOG_BASE:
488 case VHOST_SET_LOG_FD:
489 r = -ENOIOCTLCMD;
490 break;
491 case VHOST_VDPA_SET_CONFIG_CALL:
492 r = vhost_vdpa_set_config_call(v, argp);
493 break;
494 case VHOST_GET_BACKEND_FEATURES:
495 features = VHOST_VDPA_BACKEND_FEATURES;
496 if (copy_to_user(featurep, &features, sizeof(features)))
497 r = -EFAULT;
498 break;
499 case VHOST_VDPA_GET_IOVA_RANGE:
500 r = vhost_vdpa_get_iova_range(v, argp);
501 break;
502 default:
503 r = vhost_dev_ioctl(&v->vdev, cmd, argp);
504 if (r == -ENOIOCTLCMD)
505 r = vhost_vdpa_vring_ioctl(v, cmd, argp);
506 break;
507 }
508
509 mutex_unlock(&d->mutex);
510 return r;
511 }
512
vhost_vdpa_iotlb_unmap(struct vhost_vdpa * v,u64 start,u64 last)513 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v, u64 start, u64 last)
514 {
515 struct vhost_dev *dev = &v->vdev;
516 struct vhost_iotlb *iotlb = dev->iotlb;
517 struct vhost_iotlb_map *map;
518 struct page *page;
519 unsigned long pfn, pinned;
520
521 while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
522 pinned = map->size >> PAGE_SHIFT;
523 for (pfn = map->addr >> PAGE_SHIFT;
524 pinned > 0; pfn++, pinned--) {
525 page = pfn_to_page(pfn);
526 if (map->perm & VHOST_ACCESS_WO)
527 set_page_dirty_lock(page);
528 unpin_user_page(page);
529 }
530 atomic64_sub(map->size >> PAGE_SHIFT, &dev->mm->pinned_vm);
531 vhost_iotlb_map_free(iotlb, map);
532 }
533 }
534
vhost_vdpa_iotlb_free(struct vhost_vdpa * v)535 static void vhost_vdpa_iotlb_free(struct vhost_vdpa *v)
536 {
537 struct vhost_dev *dev = &v->vdev;
538
539 vhost_vdpa_iotlb_unmap(v, 0ULL, 0ULL - 1);
540 kfree(dev->iotlb);
541 dev->iotlb = NULL;
542 }
543
perm_to_iommu_flags(u32 perm)544 static int perm_to_iommu_flags(u32 perm)
545 {
546 int flags = 0;
547
548 switch (perm) {
549 case VHOST_ACCESS_WO:
550 flags |= IOMMU_WRITE;
551 break;
552 case VHOST_ACCESS_RO:
553 flags |= IOMMU_READ;
554 break;
555 case VHOST_ACCESS_RW:
556 flags |= (IOMMU_WRITE | IOMMU_READ);
557 break;
558 default:
559 WARN(1, "invalidate vhost IOTLB permission\n");
560 break;
561 }
562
563 return flags | IOMMU_CACHE;
564 }
565
vhost_vdpa_map(struct vhost_vdpa * v,u64 iova,u64 size,u64 pa,u32 perm)566 static int vhost_vdpa_map(struct vhost_vdpa *v,
567 u64 iova, u64 size, u64 pa, u32 perm)
568 {
569 struct vhost_dev *dev = &v->vdev;
570 struct vdpa_device *vdpa = v->vdpa;
571 const struct vdpa_config_ops *ops = vdpa->config;
572 int r = 0;
573
574 r = vhost_iotlb_add_range(dev->iotlb, iova, iova + size - 1,
575 pa, perm);
576 if (r)
577 return r;
578
579 if (ops->dma_map) {
580 r = ops->dma_map(vdpa, iova, size, pa, perm);
581 } else if (ops->set_map) {
582 if (!v->in_batch)
583 r = ops->set_map(vdpa, dev->iotlb);
584 } else {
585 r = iommu_map(v->domain, iova, pa, size,
586 perm_to_iommu_flags(perm));
587 }
588
589 if (r)
590 vhost_iotlb_del_range(dev->iotlb, iova, iova + size - 1);
591 else
592 atomic64_add(size >> PAGE_SHIFT, &dev->mm->pinned_vm);
593
594 return r;
595 }
596
vhost_vdpa_unmap(struct vhost_vdpa * v,u64 iova,u64 size)597 static void vhost_vdpa_unmap(struct vhost_vdpa *v, u64 iova, u64 size)
598 {
599 struct vhost_dev *dev = &v->vdev;
600 struct vdpa_device *vdpa = v->vdpa;
601 const struct vdpa_config_ops *ops = vdpa->config;
602
603 vhost_vdpa_iotlb_unmap(v, iova, iova + size - 1);
604
605 if (ops->dma_map) {
606 ops->dma_unmap(vdpa, iova, size);
607 } else if (ops->set_map) {
608 if (!v->in_batch)
609 ops->set_map(vdpa, dev->iotlb);
610 } else {
611 iommu_unmap(v->domain, iova, size);
612 }
613 }
614
vhost_vdpa_process_iotlb_update(struct vhost_vdpa * v,struct vhost_iotlb_msg * msg)615 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
616 struct vhost_iotlb_msg *msg)
617 {
618 struct vhost_dev *dev = &v->vdev;
619 struct vhost_iotlb *iotlb = dev->iotlb;
620 struct page **page_list;
621 unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
622 unsigned int gup_flags = FOLL_LONGTERM;
623 unsigned long npages, cur_base, map_pfn, last_pfn = 0;
624 unsigned long lock_limit, sz2pin, nchunks, i;
625 u64 iova = msg->iova;
626 long pinned;
627 int ret = 0;
628
629 if (msg->iova < v->range.first || !msg->size ||
630 msg->iova > U64_MAX - msg->size + 1 ||
631 msg->iova + msg->size - 1 > v->range.last)
632 return -EINVAL;
633
634 if (vhost_iotlb_itree_first(iotlb, msg->iova,
635 msg->iova + msg->size - 1))
636 return -EEXIST;
637
638 /* Limit the use of memory for bookkeeping */
639 page_list = (struct page **) __get_free_page(GFP_KERNEL);
640 if (!page_list)
641 return -ENOMEM;
642
643 if (msg->perm & VHOST_ACCESS_WO)
644 gup_flags |= FOLL_WRITE;
645
646 npages = PAGE_ALIGN(msg->size + (iova & ~PAGE_MASK)) >> PAGE_SHIFT;
647 if (!npages) {
648 ret = -EINVAL;
649 goto free;
650 }
651
652 mmap_read_lock(dev->mm);
653
654 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
655 if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
656 ret = -ENOMEM;
657 goto unlock;
658 }
659
660 cur_base = msg->uaddr & PAGE_MASK;
661 iova &= PAGE_MASK;
662 nchunks = 0;
663
664 while (npages) {
665 sz2pin = min_t(unsigned long, npages, list_size);
666 pinned = pin_user_pages(cur_base, sz2pin,
667 gup_flags, page_list, NULL);
668 if (sz2pin != pinned) {
669 if (pinned < 0) {
670 ret = pinned;
671 } else {
672 unpin_user_pages(page_list, pinned);
673 ret = -ENOMEM;
674 }
675 goto out;
676 }
677 nchunks++;
678
679 if (!last_pfn)
680 map_pfn = page_to_pfn(page_list[0]);
681
682 for (i = 0; i < pinned; i++) {
683 unsigned long this_pfn = page_to_pfn(page_list[i]);
684 u64 csize;
685
686 if (last_pfn && (this_pfn != last_pfn + 1)) {
687 /* Pin a contiguous chunk of memory */
688 csize = (last_pfn - map_pfn + 1) << PAGE_SHIFT;
689 ret = vhost_vdpa_map(v, iova, csize,
690 map_pfn << PAGE_SHIFT,
691 msg->perm);
692 if (ret) {
693 /*
694 * Unpin the pages that are left unmapped
695 * from this point on in the current
696 * page_list. The remaining outstanding
697 * ones which may stride across several
698 * chunks will be covered in the common
699 * error path subsequently.
700 */
701 unpin_user_pages(&page_list[i],
702 pinned - i);
703 goto out;
704 }
705
706 map_pfn = this_pfn;
707 iova += csize;
708 nchunks = 0;
709 }
710
711 last_pfn = this_pfn;
712 }
713
714 cur_base += pinned << PAGE_SHIFT;
715 npages -= pinned;
716 }
717
718 /* Pin the rest chunk */
719 ret = vhost_vdpa_map(v, iova, (last_pfn - map_pfn + 1) << PAGE_SHIFT,
720 map_pfn << PAGE_SHIFT, msg->perm);
721 out:
722 if (ret) {
723 if (nchunks) {
724 unsigned long pfn;
725
726 /*
727 * Unpin the outstanding pages which are yet to be
728 * mapped but haven't due to vdpa_map() or
729 * pin_user_pages() failure.
730 *
731 * Mapped pages are accounted in vdpa_map(), hence
732 * the corresponding unpinning will be handled by
733 * vdpa_unmap().
734 */
735 WARN_ON(!last_pfn);
736 for (pfn = map_pfn; pfn <= last_pfn; pfn++)
737 unpin_user_page(pfn_to_page(pfn));
738 }
739 vhost_vdpa_unmap(v, msg->iova, msg->size);
740 }
741 unlock:
742 mmap_read_unlock(dev->mm);
743 free:
744 free_page((unsigned long)page_list);
745 return ret;
746 }
747
vhost_vdpa_process_iotlb_msg(struct vhost_dev * dev,struct vhost_iotlb_msg * msg)748 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev,
749 struct vhost_iotlb_msg *msg)
750 {
751 struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
752 struct vdpa_device *vdpa = v->vdpa;
753 const struct vdpa_config_ops *ops = vdpa->config;
754 int r = 0;
755
756 mutex_lock(&dev->mutex);
757
758 r = vhost_dev_check_owner(dev);
759 if (r)
760 goto unlock;
761
762 switch (msg->type) {
763 case VHOST_IOTLB_UPDATE:
764 r = vhost_vdpa_process_iotlb_update(v, msg);
765 break;
766 case VHOST_IOTLB_INVALIDATE:
767 vhost_vdpa_unmap(v, msg->iova, msg->size);
768 break;
769 case VHOST_IOTLB_BATCH_BEGIN:
770 v->in_batch = true;
771 break;
772 case VHOST_IOTLB_BATCH_END:
773 if (v->in_batch && ops->set_map)
774 ops->set_map(vdpa, dev->iotlb);
775 v->in_batch = false;
776 break;
777 default:
778 r = -EINVAL;
779 break;
780 }
781 unlock:
782 mutex_unlock(&dev->mutex);
783
784 return r;
785 }
786
vhost_vdpa_chr_write_iter(struct kiocb * iocb,struct iov_iter * from)787 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
788 struct iov_iter *from)
789 {
790 struct file *file = iocb->ki_filp;
791 struct vhost_vdpa *v = file->private_data;
792 struct vhost_dev *dev = &v->vdev;
793
794 return vhost_chr_write_iter(dev, from);
795 }
796
vhost_vdpa_alloc_domain(struct vhost_vdpa * v)797 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
798 {
799 struct vdpa_device *vdpa = v->vdpa;
800 const struct vdpa_config_ops *ops = vdpa->config;
801 struct device *dma_dev = vdpa_get_dma_dev(vdpa);
802 struct bus_type *bus;
803 int ret;
804
805 /* Device want to do DMA by itself */
806 if (ops->set_map || ops->dma_map)
807 return 0;
808
809 bus = dma_dev->bus;
810 if (!bus)
811 return -EFAULT;
812
813 if (!iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
814 return -ENOTSUPP;
815
816 v->domain = iommu_domain_alloc(bus);
817 if (!v->domain)
818 return -EIO;
819
820 ret = iommu_attach_device(v->domain, dma_dev);
821 if (ret)
822 goto err_attach;
823
824 return 0;
825
826 err_attach:
827 iommu_domain_free(v->domain);
828 return ret;
829 }
830
vhost_vdpa_free_domain(struct vhost_vdpa * v)831 static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
832 {
833 struct vdpa_device *vdpa = v->vdpa;
834 struct device *dma_dev = vdpa_get_dma_dev(vdpa);
835
836 if (v->domain) {
837 iommu_detach_device(v->domain, dma_dev);
838 iommu_domain_free(v->domain);
839 }
840
841 v->domain = NULL;
842 }
843
vhost_vdpa_set_iova_range(struct vhost_vdpa * v)844 static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
845 {
846 struct vdpa_iova_range *range = &v->range;
847 struct iommu_domain_geometry geo;
848 struct vdpa_device *vdpa = v->vdpa;
849 const struct vdpa_config_ops *ops = vdpa->config;
850
851 if (ops->get_iova_range) {
852 *range = ops->get_iova_range(vdpa);
853 } else if (v->domain &&
854 !iommu_domain_get_attr(v->domain,
855 DOMAIN_ATTR_GEOMETRY, &geo) &&
856 geo.force_aperture) {
857 range->first = geo.aperture_start;
858 range->last = geo.aperture_end;
859 } else {
860 range->first = 0;
861 range->last = ULLONG_MAX;
862 }
863 }
864
vhost_vdpa_open(struct inode * inode,struct file * filep)865 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
866 {
867 struct vhost_vdpa *v;
868 struct vhost_dev *dev;
869 struct vhost_virtqueue **vqs;
870 int nvqs, i, r, opened;
871
872 v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
873
874 opened = atomic_cmpxchg(&v->opened, 0, 1);
875 if (opened)
876 return -EBUSY;
877
878 nvqs = v->nvqs;
879 vhost_vdpa_reset(v);
880
881 vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
882 if (!vqs) {
883 r = -ENOMEM;
884 goto err;
885 }
886
887 dev = &v->vdev;
888 for (i = 0; i < nvqs; i++) {
889 vqs[i] = &v->vqs[i];
890 vqs[i]->handle_kick = handle_vq_kick;
891 }
892 vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
893 vhost_vdpa_process_iotlb_msg);
894
895 dev->iotlb = vhost_iotlb_alloc(0, 0);
896 if (!dev->iotlb) {
897 r = -ENOMEM;
898 goto err_init_iotlb;
899 }
900
901 r = vhost_vdpa_alloc_domain(v);
902 if (r)
903 goto err_init_iotlb;
904
905 vhost_vdpa_set_iova_range(v);
906
907 filep->private_data = v;
908
909 return 0;
910
911 err_init_iotlb:
912 vhost_dev_cleanup(&v->vdev);
913 kfree(vqs);
914 err:
915 atomic_dec(&v->opened);
916 return r;
917 }
918
vhost_vdpa_clean_irq(struct vhost_vdpa * v)919 static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
920 {
921 int i;
922
923 for (i = 0; i < v->nvqs; i++)
924 vhost_vdpa_unsetup_vq_irq(v, i);
925 }
926
vhost_vdpa_release(struct inode * inode,struct file * filep)927 static int vhost_vdpa_release(struct inode *inode, struct file *filep)
928 {
929 struct vhost_vdpa *v = filep->private_data;
930 struct vhost_dev *d = &v->vdev;
931
932 mutex_lock(&d->mutex);
933 filep->private_data = NULL;
934 vhost_vdpa_reset(v);
935 vhost_dev_stop(&v->vdev);
936 vhost_vdpa_iotlb_free(v);
937 vhost_vdpa_free_domain(v);
938 vhost_vdpa_config_put(v);
939 vhost_vdpa_clean_irq(v);
940 vhost_dev_cleanup(&v->vdev);
941 kfree(v->vdev.vqs);
942 mutex_unlock(&d->mutex);
943
944 atomic_dec(&v->opened);
945 complete(&v->completion);
946
947 return 0;
948 }
949
950 #ifdef CONFIG_MMU
vhost_vdpa_fault(struct vm_fault * vmf)951 static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf)
952 {
953 struct vhost_vdpa *v = vmf->vma->vm_file->private_data;
954 struct vdpa_device *vdpa = v->vdpa;
955 const struct vdpa_config_ops *ops = vdpa->config;
956 struct vdpa_notification_area notify;
957 struct vm_area_struct *vma = vmf->vma;
958 u16 index = vma->vm_pgoff;
959
960 notify = ops->get_vq_notification(vdpa, index);
961
962 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
963 if (remap_pfn_range(vma, vmf->address & PAGE_MASK,
964 notify.addr >> PAGE_SHIFT, PAGE_SIZE,
965 vma->vm_page_prot))
966 return VM_FAULT_SIGBUS;
967
968 return VM_FAULT_NOPAGE;
969 }
970
971 static const struct vm_operations_struct vhost_vdpa_vm_ops = {
972 .fault = vhost_vdpa_fault,
973 };
974
vhost_vdpa_mmap(struct file * file,struct vm_area_struct * vma)975 static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma)
976 {
977 struct vhost_vdpa *v = vma->vm_file->private_data;
978 struct vdpa_device *vdpa = v->vdpa;
979 const struct vdpa_config_ops *ops = vdpa->config;
980 struct vdpa_notification_area notify;
981 unsigned long index = vma->vm_pgoff;
982
983 if (vma->vm_end - vma->vm_start != PAGE_SIZE)
984 return -EINVAL;
985 if ((vma->vm_flags & VM_SHARED) == 0)
986 return -EINVAL;
987 if (vma->vm_flags & VM_READ)
988 return -EINVAL;
989 if (index > 65535)
990 return -EINVAL;
991 if (!ops->get_vq_notification)
992 return -ENOTSUPP;
993
994 /* To be safe and easily modelled by userspace, We only
995 * support the doorbell which sits on the page boundary and
996 * does not share the page with other registers.
997 */
998 notify = ops->get_vq_notification(vdpa, index);
999 if (notify.addr & (PAGE_SIZE - 1))
1000 return -EINVAL;
1001 if (vma->vm_end - vma->vm_start != notify.size)
1002 return -ENOTSUPP;
1003
1004 vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
1005 vma->vm_ops = &vhost_vdpa_vm_ops;
1006 return 0;
1007 }
1008 #endif /* CONFIG_MMU */
1009
1010 static const struct file_operations vhost_vdpa_fops = {
1011 .owner = THIS_MODULE,
1012 .open = vhost_vdpa_open,
1013 .release = vhost_vdpa_release,
1014 .write_iter = vhost_vdpa_chr_write_iter,
1015 .unlocked_ioctl = vhost_vdpa_unlocked_ioctl,
1016 #ifdef CONFIG_MMU
1017 .mmap = vhost_vdpa_mmap,
1018 #endif /* CONFIG_MMU */
1019 .compat_ioctl = compat_ptr_ioctl,
1020 };
1021
vhost_vdpa_release_dev(struct device * device)1022 static void vhost_vdpa_release_dev(struct device *device)
1023 {
1024 struct vhost_vdpa *v =
1025 container_of(device, struct vhost_vdpa, dev);
1026
1027 ida_simple_remove(&vhost_vdpa_ida, v->minor);
1028 kfree(v->vqs);
1029 kfree(v);
1030 }
1031
vhost_vdpa_probe(struct vdpa_device * vdpa)1032 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
1033 {
1034 const struct vdpa_config_ops *ops = vdpa->config;
1035 struct vhost_vdpa *v;
1036 int minor;
1037 int r;
1038
1039 /* Currently, we only accept the network devices. */
1040 if (ops->get_device_id(vdpa) != VIRTIO_ID_NET)
1041 return -ENOTSUPP;
1042
1043 v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1044 if (!v)
1045 return -ENOMEM;
1046
1047 minor = ida_simple_get(&vhost_vdpa_ida, 0,
1048 VHOST_VDPA_DEV_MAX, GFP_KERNEL);
1049 if (minor < 0) {
1050 kfree(v);
1051 return minor;
1052 }
1053
1054 atomic_set(&v->opened, 0);
1055 v->minor = minor;
1056 v->vdpa = vdpa;
1057 v->nvqs = vdpa->nvqs;
1058 v->virtio_id = ops->get_device_id(vdpa);
1059
1060 device_initialize(&v->dev);
1061 v->dev.release = vhost_vdpa_release_dev;
1062 v->dev.parent = &vdpa->dev;
1063 v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
1064 v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
1065 GFP_KERNEL);
1066 if (!v->vqs) {
1067 r = -ENOMEM;
1068 goto err;
1069 }
1070
1071 r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
1072 if (r)
1073 goto err;
1074
1075 cdev_init(&v->cdev, &vhost_vdpa_fops);
1076 v->cdev.owner = THIS_MODULE;
1077
1078 r = cdev_device_add(&v->cdev, &v->dev);
1079 if (r)
1080 goto err;
1081
1082 init_completion(&v->completion);
1083 vdpa_set_drvdata(vdpa, v);
1084
1085 return 0;
1086
1087 err:
1088 put_device(&v->dev);
1089 return r;
1090 }
1091
vhost_vdpa_remove(struct vdpa_device * vdpa)1092 static void vhost_vdpa_remove(struct vdpa_device *vdpa)
1093 {
1094 struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
1095 int opened;
1096
1097 cdev_device_del(&v->cdev, &v->dev);
1098
1099 do {
1100 opened = atomic_cmpxchg(&v->opened, 0, 1);
1101 if (!opened)
1102 break;
1103 wait_for_completion(&v->completion);
1104 } while (1);
1105
1106 put_device(&v->dev);
1107 }
1108
1109 static struct vdpa_driver vhost_vdpa_driver = {
1110 .driver = {
1111 .name = "vhost_vdpa",
1112 },
1113 .probe = vhost_vdpa_probe,
1114 .remove = vhost_vdpa_remove,
1115 };
1116
vhost_vdpa_init(void)1117 static int __init vhost_vdpa_init(void)
1118 {
1119 int r;
1120
1121 r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
1122 "vhost-vdpa");
1123 if (r)
1124 goto err_alloc_chrdev;
1125
1126 r = vdpa_register_driver(&vhost_vdpa_driver);
1127 if (r)
1128 goto err_vdpa_register_driver;
1129
1130 return 0;
1131
1132 err_vdpa_register_driver:
1133 unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1134 err_alloc_chrdev:
1135 return r;
1136 }
1137 module_init(vhost_vdpa_init);
1138
vhost_vdpa_exit(void)1139 static void __exit vhost_vdpa_exit(void)
1140 {
1141 vdpa_unregister_driver(&vhost_vdpa_driver);
1142 unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1143 }
1144 module_exit(vhost_vdpa_exit);
1145
1146 MODULE_VERSION("0.0.1");
1147 MODULE_LICENSE("GPL v2");
1148 MODULE_AUTHOR("Intel Corporation");
1149 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");
1150