xref: /openbmc/linux/drivers/vhost/vdpa.c (revision adb19164) 
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/slab.h>
20 #include <linux/iommu.h>
21 #include <linux/uuid.h>
22 #include <linux/vdpa.h>
23 #include <linux/nospec.h>
24 #include <linux/vhost.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 	(1ULL << VHOST_BACKEND_F_IOTLB_ASID),
33 };
34 
35 #define VHOST_VDPA_DEV_MAX (1U << MINORBITS)
36 
37 #define VHOST_VDPA_IOTLB_BUCKETS 16
38 
39 struct vhost_vdpa_as {
40 	struct hlist_node hash_link;
41 	struct vhost_iotlb iotlb;
42 	u32 id;
43 };
44 
45 struct vhost_vdpa {
46 	struct vhost_dev vdev;
47 	struct iommu_domain *domain;
48 	struct vhost_virtqueue *vqs;
49 	struct completion completion;
50 	struct vdpa_device *vdpa;
51 	struct hlist_head as[VHOST_VDPA_IOTLB_BUCKETS];
52 	struct device dev;
53 	struct cdev cdev;
54 	atomic_t opened;
55 	u32 nvqs;
56 	int virtio_id;
57 	int minor;
58 	struct eventfd_ctx *config_ctx;
59 	int in_batch;
60 	struct vdpa_iova_range range;
61 	u32 batch_asid;
62 };
63 
64 static DEFINE_IDA(vhost_vdpa_ida);
65 
66 static dev_t vhost_vdpa_major;
67 
68 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
69 				   struct vhost_iotlb *iotlb, u64 start,
70 				   u64 last, u32 asid);
71 
72 static inline u32 iotlb_to_asid(struct vhost_iotlb *iotlb)
73 {
74 	struct vhost_vdpa_as *as = container_of(iotlb, struct
75 						vhost_vdpa_as, iotlb);
76 	return as->id;
77 }
78 
79 static struct vhost_vdpa_as *asid_to_as(struct vhost_vdpa *v, u32 asid)
80 {
81 	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
82 	struct vhost_vdpa_as *as;
83 
84 	hlist_for_each_entry(as, head, hash_link)
85 		if (as->id == asid)
86 			return as;
87 
88 	return NULL;
89 }
90 
91 static struct vhost_iotlb *asid_to_iotlb(struct vhost_vdpa *v, u32 asid)
92 {
93 	struct vhost_vdpa_as *as = asid_to_as(v, asid);
94 
95 	if (!as)
96 		return NULL;
97 
98 	return &as->iotlb;
99 }
100 
101 static struct vhost_vdpa_as *vhost_vdpa_alloc_as(struct vhost_vdpa *v, u32 asid)
102 {
103 	struct hlist_head *head = &v->as[asid % VHOST_VDPA_IOTLB_BUCKETS];
104 	struct vhost_vdpa_as *as;
105 
106 	if (asid_to_as(v, asid))
107 		return NULL;
108 
109 	if (asid >= v->vdpa->nas)
110 		return NULL;
111 
112 	as = kmalloc(sizeof(*as), GFP_KERNEL);
113 	if (!as)
114 		return NULL;
115 
116 	vhost_iotlb_init(&as->iotlb, 0, 0);
117 	as->id = asid;
118 	hlist_add_head(&as->hash_link, head);
119 
120 	return as;
121 }
122 
123 static struct vhost_vdpa_as *vhost_vdpa_find_alloc_as(struct vhost_vdpa *v,
124 						      u32 asid)
125 {
126 	struct vhost_vdpa_as *as = asid_to_as(v, asid);
127 
128 	if (as)
129 		return as;
130 
131 	return vhost_vdpa_alloc_as(v, asid);
132 }
133 
134 static int vhost_vdpa_remove_as(struct vhost_vdpa *v, u32 asid)
135 {
136 	struct vhost_vdpa_as *as = asid_to_as(v, asid);
137 
138 	if (!as)
139 		return -EINVAL;
140 
141 	hlist_del(&as->hash_link);
142 	vhost_vdpa_iotlb_unmap(v, &as->iotlb, 0ULL, 0ULL - 1, asid);
143 	kfree(as);
144 
145 	return 0;
146 }
147 
148 static void handle_vq_kick(struct vhost_work *work)
149 {
150 	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
151 						  poll.work);
152 	struct vhost_vdpa *v = container_of(vq->dev, struct vhost_vdpa, vdev);
153 	const struct vdpa_config_ops *ops = v->vdpa->config;
154 
155 	ops->kick_vq(v->vdpa, vq - v->vqs);
156 }
157 
158 static irqreturn_t vhost_vdpa_virtqueue_cb(void *private)
159 {
160 	struct vhost_virtqueue *vq = private;
161 	struct eventfd_ctx *call_ctx = vq->call_ctx.ctx;
162 
163 	if (call_ctx)
164 		eventfd_signal(call_ctx, 1);
165 
166 	return IRQ_HANDLED;
167 }
168 
169 static irqreturn_t vhost_vdpa_config_cb(void *private)
170 {
171 	struct vhost_vdpa *v = private;
172 	struct eventfd_ctx *config_ctx = v->config_ctx;
173 
174 	if (config_ctx)
175 		eventfd_signal(config_ctx, 1);
176 
177 	return IRQ_HANDLED;
178 }
179 
180 static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
181 {
182 	struct vhost_virtqueue *vq = &v->vqs[qid];
183 	const struct vdpa_config_ops *ops = v->vdpa->config;
184 	struct vdpa_device *vdpa = v->vdpa;
185 	int ret, irq;
186 
187 	if (!ops->get_vq_irq)
188 		return;
189 
190 	irq = ops->get_vq_irq(vdpa, qid);
191 	if (irq < 0)
192 		return;
193 
194 	irq_bypass_unregister_producer(&vq->call_ctx.producer);
195 	if (!vq->call_ctx.ctx)
196 		return;
197 
198 	vq->call_ctx.producer.token = vq->call_ctx.ctx;
199 	vq->call_ctx.producer.irq = irq;
200 	ret = irq_bypass_register_producer(&vq->call_ctx.producer);
201 	if (unlikely(ret))
202 		dev_info(&v->dev, "vq %u, irq bypass producer (token %p) registration fails, ret =  %d\n",
203 			 qid, vq->call_ctx.producer.token, ret);
204 }
205 
206 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)
207 {
208 	struct vhost_virtqueue *vq = &v->vqs[qid];
209 
210 	irq_bypass_unregister_producer(&vq->call_ctx.producer);
211 }
212 
213 static int vhost_vdpa_reset(struct vhost_vdpa *v)
214 {
215 	struct vdpa_device *vdpa = v->vdpa;
216 
217 	v->in_batch = 0;
218 
219 	return vdpa_reset(vdpa);
220 }
221 
222 static long vhost_vdpa_bind_mm(struct vhost_vdpa *v)
223 {
224 	struct vdpa_device *vdpa = v->vdpa;
225 	const struct vdpa_config_ops *ops = vdpa->config;
226 
227 	if (!vdpa->use_va || !ops->bind_mm)
228 		return 0;
229 
230 	return ops->bind_mm(vdpa, v->vdev.mm);
231 }
232 
233 static void vhost_vdpa_unbind_mm(struct vhost_vdpa *v)
234 {
235 	struct vdpa_device *vdpa = v->vdpa;
236 	const struct vdpa_config_ops *ops = vdpa->config;
237 
238 	if (!vdpa->use_va || !ops->unbind_mm)
239 		return;
240 
241 	ops->unbind_mm(vdpa);
242 }
243 
244 static long vhost_vdpa_get_device_id(struct vhost_vdpa *v, u8 __user *argp)
245 {
246 	struct vdpa_device *vdpa = v->vdpa;
247 	const struct vdpa_config_ops *ops = vdpa->config;
248 	u32 device_id;
249 
250 	device_id = ops->get_device_id(vdpa);
251 
252 	if (copy_to_user(argp, &device_id, sizeof(device_id)))
253 		return -EFAULT;
254 
255 	return 0;
256 }
257 
258 static long vhost_vdpa_get_status(struct vhost_vdpa *v, u8 __user *statusp)
259 {
260 	struct vdpa_device *vdpa = v->vdpa;
261 	const struct vdpa_config_ops *ops = vdpa->config;
262 	u8 status;
263 
264 	status = ops->get_status(vdpa);
265 
266 	if (copy_to_user(statusp, &status, sizeof(status)))
267 		return -EFAULT;
268 
269 	return 0;
270 }
271 
272 static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp)
273 {
274 	struct vdpa_device *vdpa = v->vdpa;
275 	const struct vdpa_config_ops *ops = vdpa->config;
276 	u8 status, status_old;
277 	u32 nvqs = v->nvqs;
278 	int ret;
279 	u16 i;
280 
281 	if (copy_from_user(&status, statusp, sizeof(status)))
282 		return -EFAULT;
283 
284 	status_old = ops->get_status(vdpa);
285 
286 	/*
287 	 * Userspace shouldn't remove status bits unless reset the
288 	 * status to 0.
289 	 */
290 	if (status != 0 && (status_old & ~status) != 0)
291 		return -EINVAL;
292 
293 	if ((status_old & VIRTIO_CONFIG_S_DRIVER_OK) && !(status & VIRTIO_CONFIG_S_DRIVER_OK))
294 		for (i = 0; i < nvqs; i++)
295 			vhost_vdpa_unsetup_vq_irq(v, i);
296 
297 	if (status == 0) {
298 		ret = vdpa_reset(vdpa);
299 		if (ret)
300 			return ret;
301 	} else
302 		vdpa_set_status(vdpa, status);
303 
304 	if ((status & VIRTIO_CONFIG_S_DRIVER_OK) && !(status_old & VIRTIO_CONFIG_S_DRIVER_OK))
305 		for (i = 0; i < nvqs; i++)
306 			vhost_vdpa_setup_vq_irq(v, i);
307 
308 	return 0;
309 }
310 
311 static int vhost_vdpa_config_validate(struct vhost_vdpa *v,
312 				      struct vhost_vdpa_config *c)
313 {
314 	struct vdpa_device *vdpa = v->vdpa;
315 	size_t size = vdpa->config->get_config_size(vdpa);
316 
317 	if (c->len == 0 || c->off > size)
318 		return -EINVAL;
319 
320 	if (c->len > size - c->off)
321 		return -E2BIG;
322 
323 	return 0;
324 }
325 
326 static long vhost_vdpa_get_config(struct vhost_vdpa *v,
327 				  struct vhost_vdpa_config __user *c)
328 {
329 	struct vdpa_device *vdpa = v->vdpa;
330 	struct vhost_vdpa_config config;
331 	unsigned long size = offsetof(struct vhost_vdpa_config, buf);
332 	u8 *buf;
333 
334 	if (copy_from_user(&config, c, size))
335 		return -EFAULT;
336 	if (vhost_vdpa_config_validate(v, &config))
337 		return -EINVAL;
338 	buf = kvzalloc(config.len, GFP_KERNEL);
339 	if (!buf)
340 		return -ENOMEM;
341 
342 	vdpa_get_config(vdpa, config.off, buf, config.len);
343 
344 	if (copy_to_user(c->buf, buf, config.len)) {
345 		kvfree(buf);
346 		return -EFAULT;
347 	}
348 
349 	kvfree(buf);
350 	return 0;
351 }
352 
353 static long vhost_vdpa_set_config(struct vhost_vdpa *v,
354 				  struct vhost_vdpa_config __user *c)
355 {
356 	struct vdpa_device *vdpa = v->vdpa;
357 	struct vhost_vdpa_config config;
358 	unsigned long size = offsetof(struct vhost_vdpa_config, buf);
359 	u8 *buf;
360 
361 	if (copy_from_user(&config, c, size))
362 		return -EFAULT;
363 	if (vhost_vdpa_config_validate(v, &config))
364 		return -EINVAL;
365 
366 	buf = vmemdup_user(c->buf, config.len);
367 	if (IS_ERR(buf))
368 		return PTR_ERR(buf);
369 
370 	vdpa_set_config(vdpa, config.off, buf, config.len);
371 
372 	kvfree(buf);
373 	return 0;
374 }
375 
376 static bool vhost_vdpa_can_suspend(const struct vhost_vdpa *v)
377 {
378 	struct vdpa_device *vdpa = v->vdpa;
379 	const struct vdpa_config_ops *ops = vdpa->config;
380 
381 	return ops->suspend;
382 }
383 
384 static bool vhost_vdpa_can_resume(const struct vhost_vdpa *v)
385 {
386 	struct vdpa_device *vdpa = v->vdpa;
387 	const struct vdpa_config_ops *ops = vdpa->config;
388 
389 	return ops->resume;
390 }
391 
392 static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep)
393 {
394 	struct vdpa_device *vdpa = v->vdpa;
395 	const struct vdpa_config_ops *ops = vdpa->config;
396 	u64 features;
397 
398 	features = ops->get_device_features(vdpa);
399 
400 	if (copy_to_user(featurep, &features, sizeof(features)))
401 		return -EFAULT;
402 
403 	return 0;
404 }
405 
406 static u64 vhost_vdpa_get_backend_features(const struct vhost_vdpa *v)
407 {
408 	struct vdpa_device *vdpa = v->vdpa;
409 	const struct vdpa_config_ops *ops = vdpa->config;
410 
411 	if (!ops->get_backend_features)
412 		return 0;
413 	else
414 		return ops->get_backend_features(vdpa);
415 }
416 
417 static long vhost_vdpa_set_features(struct vhost_vdpa *v, u64 __user *featurep)
418 {
419 	struct vdpa_device *vdpa = v->vdpa;
420 	const struct vdpa_config_ops *ops = vdpa->config;
421 	struct vhost_dev *d = &v->vdev;
422 	u64 actual_features;
423 	u64 features;
424 	int i;
425 
426 	/*
427 	 * It's not allowed to change the features after they have
428 	 * been negotiated.
429 	 */
430 	if (ops->get_status(vdpa) & VIRTIO_CONFIG_S_FEATURES_OK)
431 		return -EBUSY;
432 
433 	if (copy_from_user(&features, featurep, sizeof(features)))
434 		return -EFAULT;
435 
436 	if (vdpa_set_features(vdpa, features))
437 		return -EINVAL;
438 
439 	/* let the vqs know what has been configured */
440 	actual_features = ops->get_driver_features(vdpa);
441 	for (i = 0; i < d->nvqs; ++i) {
442 		struct vhost_virtqueue *vq = d->vqs[i];
443 
444 		mutex_lock(&vq->mutex);
445 		vq->acked_features = actual_features;
446 		mutex_unlock(&vq->mutex);
447 	}
448 
449 	return 0;
450 }
451 
452 static long vhost_vdpa_get_vring_num(struct vhost_vdpa *v, u16 __user *argp)
453 {
454 	struct vdpa_device *vdpa = v->vdpa;
455 	const struct vdpa_config_ops *ops = vdpa->config;
456 	u16 num;
457 
458 	num = ops->get_vq_num_max(vdpa);
459 
460 	if (copy_to_user(argp, &num, sizeof(num)))
461 		return -EFAULT;
462 
463 	return 0;
464 }
465 
466 static void vhost_vdpa_config_put(struct vhost_vdpa *v)
467 {
468 	if (v->config_ctx) {
469 		eventfd_ctx_put(v->config_ctx);
470 		v->config_ctx = NULL;
471 	}
472 }
473 
474 static long vhost_vdpa_set_config_call(struct vhost_vdpa *v, u32 __user *argp)
475 {
476 	struct vdpa_callback cb;
477 	int fd;
478 	struct eventfd_ctx *ctx;
479 
480 	cb.callback = vhost_vdpa_config_cb;
481 	cb.private = v;
482 	if (copy_from_user(&fd, argp, sizeof(fd)))
483 		return  -EFAULT;
484 
485 	ctx = fd == VHOST_FILE_UNBIND ? NULL : eventfd_ctx_fdget(fd);
486 	swap(ctx, v->config_ctx);
487 
488 	if (!IS_ERR_OR_NULL(ctx))
489 		eventfd_ctx_put(ctx);
490 
491 	if (IS_ERR(v->config_ctx)) {
492 		long ret = PTR_ERR(v->config_ctx);
493 
494 		v->config_ctx = NULL;
495 		return ret;
496 	}
497 
498 	v->vdpa->config->set_config_cb(v->vdpa, &cb);
499 
500 	return 0;
501 }
502 
503 static long vhost_vdpa_get_iova_range(struct vhost_vdpa *v, u32 __user *argp)
504 {
505 	struct vhost_vdpa_iova_range range = {
506 		.first = v->range.first,
507 		.last = v->range.last,
508 	};
509 
510 	if (copy_to_user(argp, &range, sizeof(range)))
511 		return -EFAULT;
512 	return 0;
513 }
514 
515 static long vhost_vdpa_get_config_size(struct vhost_vdpa *v, u32 __user *argp)
516 {
517 	struct vdpa_device *vdpa = v->vdpa;
518 	const struct vdpa_config_ops *ops = vdpa->config;
519 	u32 size;
520 
521 	size = ops->get_config_size(vdpa);
522 
523 	if (copy_to_user(argp, &size, sizeof(size)))
524 		return -EFAULT;
525 
526 	return 0;
527 }
528 
529 static long vhost_vdpa_get_vqs_count(struct vhost_vdpa *v, u32 __user *argp)
530 {
531 	struct vdpa_device *vdpa = v->vdpa;
532 
533 	if (copy_to_user(argp, &vdpa->nvqs, sizeof(vdpa->nvqs)))
534 		return -EFAULT;
535 
536 	return 0;
537 }
538 
539 /* After a successful return of ioctl the device must not process more
540  * virtqueue descriptors. The device can answer to read or writes of config
541  * fields as if it were not suspended. In particular, writing to "queue_enable"
542  * with a value of 1 will not make the device start processing buffers.
543  */
544 static long vhost_vdpa_suspend(struct vhost_vdpa *v)
545 {
546 	struct vdpa_device *vdpa = v->vdpa;
547 	const struct vdpa_config_ops *ops = vdpa->config;
548 
549 	if (!ops->suspend)
550 		return -EOPNOTSUPP;
551 
552 	return ops->suspend(vdpa);
553 }
554 
555 /* After a successful return of this ioctl the device resumes processing
556  * virtqueue descriptors. The device becomes fully operational the same way it
557  * was before it was suspended.
558  */
559 static long vhost_vdpa_resume(struct vhost_vdpa *v)
560 {
561 	struct vdpa_device *vdpa = v->vdpa;
562 	const struct vdpa_config_ops *ops = vdpa->config;
563 
564 	if (!ops->resume)
565 		return -EOPNOTSUPP;
566 
567 	return ops->resume(vdpa);
568 }
569 
570 static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
571 				   void __user *argp)
572 {
573 	struct vdpa_device *vdpa = v->vdpa;
574 	const struct vdpa_config_ops *ops = vdpa->config;
575 	struct vdpa_vq_state vq_state;
576 	struct vdpa_callback cb;
577 	struct vhost_virtqueue *vq;
578 	struct vhost_vring_state s;
579 	u32 idx;
580 	long r;
581 
582 	r = get_user(idx, (u32 __user *)argp);
583 	if (r < 0)
584 		return r;
585 
586 	if (idx >= v->nvqs)
587 		return -ENOBUFS;
588 
589 	idx = array_index_nospec(idx, v->nvqs);
590 	vq = &v->vqs[idx];
591 
592 	switch (cmd) {
593 	case VHOST_VDPA_SET_VRING_ENABLE:
594 		if (copy_from_user(&s, argp, sizeof(s)))
595 			return -EFAULT;
596 		ops->set_vq_ready(vdpa, idx, s.num);
597 		return 0;
598 	case VHOST_VDPA_GET_VRING_GROUP:
599 		if (!ops->get_vq_group)
600 			return -EOPNOTSUPP;
601 		s.index = idx;
602 		s.num = ops->get_vq_group(vdpa, idx);
603 		if (s.num >= vdpa->ngroups)
604 			return -EIO;
605 		else if (copy_to_user(argp, &s, sizeof(s)))
606 			return -EFAULT;
607 		return 0;
608 	case VHOST_VDPA_SET_GROUP_ASID:
609 		if (copy_from_user(&s, argp, sizeof(s)))
610 			return -EFAULT;
611 		if (s.num >= vdpa->nas)
612 			return -EINVAL;
613 		if (!ops->set_group_asid)
614 			return -EOPNOTSUPP;
615 		return ops->set_group_asid(vdpa, idx, s.num);
616 	case VHOST_GET_VRING_BASE:
617 		r = ops->get_vq_state(v->vdpa, idx, &vq_state);
618 		if (r)
619 			return r;
620 
621 		if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
622 			vq->last_avail_idx = vq_state.packed.last_avail_idx |
623 					     (vq_state.packed.last_avail_counter << 15);
624 			vq->last_used_idx = vq_state.packed.last_used_idx |
625 					    (vq_state.packed.last_used_counter << 15);
626 		} else {
627 			vq->last_avail_idx = vq_state.split.avail_index;
628 		}
629 		break;
630 	}
631 
632 	r = vhost_vring_ioctl(&v->vdev, cmd, argp);
633 	if (r)
634 		return r;
635 
636 	switch (cmd) {
637 	case VHOST_SET_VRING_ADDR:
638 		if (ops->set_vq_address(vdpa, idx,
639 					(u64)(uintptr_t)vq->desc,
640 					(u64)(uintptr_t)vq->avail,
641 					(u64)(uintptr_t)vq->used))
642 			r = -EINVAL;
643 		break;
644 
645 	case VHOST_SET_VRING_BASE:
646 		if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) {
647 			vq_state.packed.last_avail_idx = vq->last_avail_idx & 0x7fff;
648 			vq_state.packed.last_avail_counter = !!(vq->last_avail_idx & 0x8000);
649 			vq_state.packed.last_used_idx = vq->last_used_idx & 0x7fff;
650 			vq_state.packed.last_used_counter = !!(vq->last_used_idx & 0x8000);
651 		} else {
652 			vq_state.split.avail_index = vq->last_avail_idx;
653 		}
654 		r = ops->set_vq_state(vdpa, idx, &vq_state);
655 		break;
656 
657 	case VHOST_SET_VRING_CALL:
658 		if (vq->call_ctx.ctx) {
659 			cb.callback = vhost_vdpa_virtqueue_cb;
660 			cb.private = vq;
661 			cb.trigger = vq->call_ctx.ctx;
662 		} else {
663 			cb.callback = NULL;
664 			cb.private = NULL;
665 			cb.trigger = NULL;
666 		}
667 		ops->set_vq_cb(vdpa, idx, &cb);
668 		vhost_vdpa_setup_vq_irq(v, idx);
669 		break;
670 
671 	case VHOST_SET_VRING_NUM:
672 		ops->set_vq_num(vdpa, idx, vq->num);
673 		break;
674 	}
675 
676 	return r;
677 }
678 
679 static long vhost_vdpa_unlocked_ioctl(struct file *filep,
680 				      unsigned int cmd, unsigned long arg)
681 {
682 	struct vhost_vdpa *v = filep->private_data;
683 	struct vhost_dev *d = &v->vdev;
684 	void __user *argp = (void __user *)arg;
685 	u64 __user *featurep = argp;
686 	u64 features;
687 	long r = 0;
688 
689 	if (cmd == VHOST_SET_BACKEND_FEATURES) {
690 		if (copy_from_user(&features, featurep, sizeof(features)))
691 			return -EFAULT;
692 		if (features & ~(VHOST_VDPA_BACKEND_FEATURES |
693 				 BIT_ULL(VHOST_BACKEND_F_SUSPEND) |
694 				 BIT_ULL(VHOST_BACKEND_F_RESUME) |
695 				 BIT_ULL(VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK)))
696 			return -EOPNOTSUPP;
697 		if ((features & BIT_ULL(VHOST_BACKEND_F_SUSPEND)) &&
698 		     !vhost_vdpa_can_suspend(v))
699 			return -EOPNOTSUPP;
700 		if ((features & BIT_ULL(VHOST_BACKEND_F_RESUME)) &&
701 		     !vhost_vdpa_can_resume(v))
702 			return -EOPNOTSUPP;
703 		vhost_set_backend_features(&v->vdev, features);
704 		return 0;
705 	}
706 
707 	mutex_lock(&d->mutex);
708 
709 	switch (cmd) {
710 	case VHOST_VDPA_GET_DEVICE_ID:
711 		r = vhost_vdpa_get_device_id(v, argp);
712 		break;
713 	case VHOST_VDPA_GET_STATUS:
714 		r = vhost_vdpa_get_status(v, argp);
715 		break;
716 	case VHOST_VDPA_SET_STATUS:
717 		r = vhost_vdpa_set_status(v, argp);
718 		break;
719 	case VHOST_VDPA_GET_CONFIG:
720 		r = vhost_vdpa_get_config(v, argp);
721 		break;
722 	case VHOST_VDPA_SET_CONFIG:
723 		r = vhost_vdpa_set_config(v, argp);
724 		break;
725 	case VHOST_GET_FEATURES:
726 		r = vhost_vdpa_get_features(v, argp);
727 		break;
728 	case VHOST_SET_FEATURES:
729 		r = vhost_vdpa_set_features(v, argp);
730 		break;
731 	case VHOST_VDPA_GET_VRING_NUM:
732 		r = vhost_vdpa_get_vring_num(v, argp);
733 		break;
734 	case VHOST_VDPA_GET_GROUP_NUM:
735 		if (copy_to_user(argp, &v->vdpa->ngroups,
736 				 sizeof(v->vdpa->ngroups)))
737 			r = -EFAULT;
738 		break;
739 	case VHOST_VDPA_GET_AS_NUM:
740 		if (copy_to_user(argp, &v->vdpa->nas, sizeof(v->vdpa->nas)))
741 			r = -EFAULT;
742 		break;
743 	case VHOST_SET_LOG_BASE:
744 	case VHOST_SET_LOG_FD:
745 		r = -ENOIOCTLCMD;
746 		break;
747 	case VHOST_VDPA_SET_CONFIG_CALL:
748 		r = vhost_vdpa_set_config_call(v, argp);
749 		break;
750 	case VHOST_GET_BACKEND_FEATURES:
751 		features = VHOST_VDPA_BACKEND_FEATURES;
752 		if (vhost_vdpa_can_suspend(v))
753 			features |= BIT_ULL(VHOST_BACKEND_F_SUSPEND);
754 		if (vhost_vdpa_can_resume(v))
755 			features |= BIT_ULL(VHOST_BACKEND_F_RESUME);
756 		features |= vhost_vdpa_get_backend_features(v);
757 		if (copy_to_user(featurep, &features, sizeof(features)))
758 			r = -EFAULT;
759 		break;
760 	case VHOST_VDPA_GET_IOVA_RANGE:
761 		r = vhost_vdpa_get_iova_range(v, argp);
762 		break;
763 	case VHOST_VDPA_GET_CONFIG_SIZE:
764 		r = vhost_vdpa_get_config_size(v, argp);
765 		break;
766 	case VHOST_VDPA_GET_VQS_COUNT:
767 		r = vhost_vdpa_get_vqs_count(v, argp);
768 		break;
769 	case VHOST_VDPA_SUSPEND:
770 		r = vhost_vdpa_suspend(v);
771 		break;
772 	case VHOST_VDPA_RESUME:
773 		r = vhost_vdpa_resume(v);
774 		break;
775 	default:
776 		r = vhost_dev_ioctl(&v->vdev, cmd, argp);
777 		if (r == -ENOIOCTLCMD)
778 			r = vhost_vdpa_vring_ioctl(v, cmd, argp);
779 		break;
780 	}
781 
782 	if (r)
783 		goto out;
784 
785 	switch (cmd) {
786 	case VHOST_SET_OWNER:
787 		r = vhost_vdpa_bind_mm(v);
788 		if (r)
789 			vhost_dev_reset_owner(d, NULL);
790 		break;
791 	}
792 out:
793 	mutex_unlock(&d->mutex);
794 	return r;
795 }
796 static void vhost_vdpa_general_unmap(struct vhost_vdpa *v,
797 				     struct vhost_iotlb_map *map, u32 asid)
798 {
799 	struct vdpa_device *vdpa = v->vdpa;
800 	const struct vdpa_config_ops *ops = vdpa->config;
801 	if (ops->dma_map) {
802 		ops->dma_unmap(vdpa, asid, map->start, map->size);
803 	} else if (ops->set_map == NULL) {
804 		iommu_unmap(v->domain, map->start, map->size);
805 	}
806 }
807 
808 static void vhost_vdpa_pa_unmap(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
809 				u64 start, u64 last, u32 asid)
810 {
811 	struct vhost_dev *dev = &v->vdev;
812 	struct vhost_iotlb_map *map;
813 	struct page *page;
814 	unsigned long pfn, pinned;
815 
816 	while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
817 		pinned = PFN_DOWN(map->size);
818 		for (pfn = PFN_DOWN(map->addr);
819 		     pinned > 0; pfn++, pinned--) {
820 			page = pfn_to_page(pfn);
821 			if (map->perm & VHOST_ACCESS_WO)
822 				set_page_dirty_lock(page);
823 			unpin_user_page(page);
824 		}
825 		atomic64_sub(PFN_DOWN(map->size), &dev->mm->pinned_vm);
826 		vhost_vdpa_general_unmap(v, map, asid);
827 		vhost_iotlb_map_free(iotlb, map);
828 	}
829 }
830 
831 static void vhost_vdpa_va_unmap(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
832 				u64 start, u64 last, u32 asid)
833 {
834 	struct vhost_iotlb_map *map;
835 	struct vdpa_map_file *map_file;
836 
837 	while ((map = vhost_iotlb_itree_first(iotlb, start, last)) != NULL) {
838 		map_file = (struct vdpa_map_file *)map->opaque;
839 		fput(map_file->file);
840 		kfree(map_file);
841 		vhost_vdpa_general_unmap(v, map, asid);
842 		vhost_iotlb_map_free(iotlb, map);
843 	}
844 }
845 
846 static void vhost_vdpa_iotlb_unmap(struct vhost_vdpa *v,
847 				   struct vhost_iotlb *iotlb, u64 start,
848 				   u64 last, u32 asid)
849 {
850 	struct vdpa_device *vdpa = v->vdpa;
851 
852 	if (vdpa->use_va)
853 		return vhost_vdpa_va_unmap(v, iotlb, start, last, asid);
854 
855 	return vhost_vdpa_pa_unmap(v, iotlb, start, last, asid);
856 }
857 
858 static int perm_to_iommu_flags(u32 perm)
859 {
860 	int flags = 0;
861 
862 	switch (perm) {
863 	case VHOST_ACCESS_WO:
864 		flags |= IOMMU_WRITE;
865 		break;
866 	case VHOST_ACCESS_RO:
867 		flags |= IOMMU_READ;
868 		break;
869 	case VHOST_ACCESS_RW:
870 		flags |= (IOMMU_WRITE | IOMMU_READ);
871 		break;
872 	default:
873 		WARN(1, "invalidate vhost IOTLB permission\n");
874 		break;
875 	}
876 
877 	return flags | IOMMU_CACHE;
878 }
879 
880 static int vhost_vdpa_map(struct vhost_vdpa *v, struct vhost_iotlb *iotlb,
881 			  u64 iova, u64 size, u64 pa, u32 perm, void *opaque)
882 {
883 	struct vhost_dev *dev = &v->vdev;
884 	struct vdpa_device *vdpa = v->vdpa;
885 	const struct vdpa_config_ops *ops = vdpa->config;
886 	u32 asid = iotlb_to_asid(iotlb);
887 	int r = 0;
888 
889 	r = vhost_iotlb_add_range_ctx(iotlb, iova, iova + size - 1,
890 				      pa, perm, opaque);
891 	if (r)
892 		return r;
893 
894 	if (ops->dma_map) {
895 		r = ops->dma_map(vdpa, asid, iova, size, pa, perm, opaque);
896 	} else if (ops->set_map) {
897 		if (!v->in_batch)
898 			r = ops->set_map(vdpa, asid, iotlb);
899 	} else {
900 		r = iommu_map(v->domain, iova, pa, size,
901 			      perm_to_iommu_flags(perm), GFP_KERNEL);
902 	}
903 	if (r) {
904 		vhost_iotlb_del_range(iotlb, iova, iova + size - 1);
905 		return r;
906 	}
907 
908 	if (!vdpa->use_va)
909 		atomic64_add(PFN_DOWN(size), &dev->mm->pinned_vm);
910 
911 	return 0;
912 }
913 
914 static void vhost_vdpa_unmap(struct vhost_vdpa *v,
915 			     struct vhost_iotlb *iotlb,
916 			     u64 iova, u64 size)
917 {
918 	struct vdpa_device *vdpa = v->vdpa;
919 	const struct vdpa_config_ops *ops = vdpa->config;
920 	u32 asid = iotlb_to_asid(iotlb);
921 
922 	vhost_vdpa_iotlb_unmap(v, iotlb, iova, iova + size - 1, asid);
923 
924 	if (ops->set_map) {
925 		if (!v->in_batch)
926 			ops->set_map(vdpa, asid, iotlb);
927 	}
928 
929 }
930 
931 static int vhost_vdpa_va_map(struct vhost_vdpa *v,
932 			     struct vhost_iotlb *iotlb,
933 			     u64 iova, u64 size, u64 uaddr, u32 perm)
934 {
935 	struct vhost_dev *dev = &v->vdev;
936 	u64 offset, map_size, map_iova = iova;
937 	struct vdpa_map_file *map_file;
938 	struct vm_area_struct *vma;
939 	int ret = 0;
940 
941 	mmap_read_lock(dev->mm);
942 
943 	while (size) {
944 		vma = find_vma(dev->mm, uaddr);
945 		if (!vma) {
946 			ret = -EINVAL;
947 			break;
948 		}
949 		map_size = min(size, vma->vm_end - uaddr);
950 		if (!(vma->vm_file && (vma->vm_flags & VM_SHARED) &&
951 			!(vma->vm_flags & (VM_IO | VM_PFNMAP))))
952 			goto next;
953 
954 		map_file = kzalloc(sizeof(*map_file), GFP_KERNEL);
955 		if (!map_file) {
956 			ret = -ENOMEM;
957 			break;
958 		}
959 		offset = (vma->vm_pgoff << PAGE_SHIFT) + uaddr - vma->vm_start;
960 		map_file->offset = offset;
961 		map_file->file = get_file(vma->vm_file);
962 		ret = vhost_vdpa_map(v, iotlb, map_iova, map_size, uaddr,
963 				     perm, map_file);
964 		if (ret) {
965 			fput(map_file->file);
966 			kfree(map_file);
967 			break;
968 		}
969 next:
970 		size -= map_size;
971 		uaddr += map_size;
972 		map_iova += map_size;
973 	}
974 	if (ret)
975 		vhost_vdpa_unmap(v, iotlb, iova, map_iova - iova);
976 
977 	mmap_read_unlock(dev->mm);
978 
979 	return ret;
980 }
981 
982 static int vhost_vdpa_pa_map(struct vhost_vdpa *v,
983 			     struct vhost_iotlb *iotlb,
984 			     u64 iova, u64 size, u64 uaddr, u32 perm)
985 {
986 	struct vhost_dev *dev = &v->vdev;
987 	struct page **page_list;
988 	unsigned long list_size = PAGE_SIZE / sizeof(struct page *);
989 	unsigned int gup_flags = FOLL_LONGTERM;
990 	unsigned long npages, cur_base, map_pfn, last_pfn = 0;
991 	unsigned long lock_limit, sz2pin, nchunks, i;
992 	u64 start = iova;
993 	long pinned;
994 	int ret = 0;
995 
996 	/* Limit the use of memory for bookkeeping */
997 	page_list = (struct page **) __get_free_page(GFP_KERNEL);
998 	if (!page_list)
999 		return -ENOMEM;
1000 
1001 	if (perm & VHOST_ACCESS_WO)
1002 		gup_flags |= FOLL_WRITE;
1003 
1004 	npages = PFN_UP(size + (iova & ~PAGE_MASK));
1005 	if (!npages) {
1006 		ret = -EINVAL;
1007 		goto free;
1008 	}
1009 
1010 	mmap_read_lock(dev->mm);
1011 
1012 	lock_limit = PFN_DOWN(rlimit(RLIMIT_MEMLOCK));
1013 	if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) {
1014 		ret = -ENOMEM;
1015 		goto unlock;
1016 	}
1017 
1018 	cur_base = uaddr & PAGE_MASK;
1019 	iova &= PAGE_MASK;
1020 	nchunks = 0;
1021 
1022 	while (npages) {
1023 		sz2pin = min_t(unsigned long, npages, list_size);
1024 		pinned = pin_user_pages(cur_base, sz2pin,
1025 					gup_flags, page_list);
1026 		if (sz2pin != pinned) {
1027 			if (pinned < 0) {
1028 				ret = pinned;
1029 			} else {
1030 				unpin_user_pages(page_list, pinned);
1031 				ret = -ENOMEM;
1032 			}
1033 			goto out;
1034 		}
1035 		nchunks++;
1036 
1037 		if (!last_pfn)
1038 			map_pfn = page_to_pfn(page_list[0]);
1039 
1040 		for (i = 0; i < pinned; i++) {
1041 			unsigned long this_pfn = page_to_pfn(page_list[i]);
1042 			u64 csize;
1043 
1044 			if (last_pfn && (this_pfn != last_pfn + 1)) {
1045 				/* Pin a contiguous chunk of memory */
1046 				csize = PFN_PHYS(last_pfn - map_pfn + 1);
1047 				ret = vhost_vdpa_map(v, iotlb, iova, csize,
1048 						     PFN_PHYS(map_pfn),
1049 						     perm, NULL);
1050 				if (ret) {
1051 					/*
1052 					 * Unpin the pages that are left unmapped
1053 					 * from this point on in the current
1054 					 * page_list. The remaining outstanding
1055 					 * ones which may stride across several
1056 					 * chunks will be covered in the common
1057 					 * error path subsequently.
1058 					 */
1059 					unpin_user_pages(&page_list[i],
1060 							 pinned - i);
1061 					goto out;
1062 				}
1063 
1064 				map_pfn = this_pfn;
1065 				iova += csize;
1066 				nchunks = 0;
1067 			}
1068 
1069 			last_pfn = this_pfn;
1070 		}
1071 
1072 		cur_base += PFN_PHYS(pinned);
1073 		npages -= pinned;
1074 	}
1075 
1076 	/* Pin the rest chunk */
1077 	ret = vhost_vdpa_map(v, iotlb, iova, PFN_PHYS(last_pfn - map_pfn + 1),
1078 			     PFN_PHYS(map_pfn), perm, NULL);
1079 out:
1080 	if (ret) {
1081 		if (nchunks) {
1082 			unsigned long pfn;
1083 
1084 			/*
1085 			 * Unpin the outstanding pages which are yet to be
1086 			 * mapped but haven't due to vdpa_map() or
1087 			 * pin_user_pages() failure.
1088 			 *
1089 			 * Mapped pages are accounted in vdpa_map(), hence
1090 			 * the corresponding unpinning will be handled by
1091 			 * vdpa_unmap().
1092 			 */
1093 			WARN_ON(!last_pfn);
1094 			for (pfn = map_pfn; pfn <= last_pfn; pfn++)
1095 				unpin_user_page(pfn_to_page(pfn));
1096 		}
1097 		vhost_vdpa_unmap(v, iotlb, start, size);
1098 	}
1099 unlock:
1100 	mmap_read_unlock(dev->mm);
1101 free:
1102 	free_page((unsigned long)page_list);
1103 	return ret;
1104 
1105 }
1106 
1107 static int vhost_vdpa_process_iotlb_update(struct vhost_vdpa *v,
1108 					   struct vhost_iotlb *iotlb,
1109 					   struct vhost_iotlb_msg *msg)
1110 {
1111 	struct vdpa_device *vdpa = v->vdpa;
1112 
1113 	if (msg->iova < v->range.first || !msg->size ||
1114 	    msg->iova > U64_MAX - msg->size + 1 ||
1115 	    msg->iova + msg->size - 1 > v->range.last)
1116 		return -EINVAL;
1117 
1118 	if (vhost_iotlb_itree_first(iotlb, msg->iova,
1119 				    msg->iova + msg->size - 1))
1120 		return -EEXIST;
1121 
1122 	if (vdpa->use_va)
1123 		return vhost_vdpa_va_map(v, iotlb, msg->iova, msg->size,
1124 					 msg->uaddr, msg->perm);
1125 
1126 	return vhost_vdpa_pa_map(v, iotlb, msg->iova, msg->size, msg->uaddr,
1127 				 msg->perm);
1128 }
1129 
1130 static int vhost_vdpa_process_iotlb_msg(struct vhost_dev *dev, u32 asid,
1131 					struct vhost_iotlb_msg *msg)
1132 {
1133 	struct vhost_vdpa *v = container_of(dev, struct vhost_vdpa, vdev);
1134 	struct vdpa_device *vdpa = v->vdpa;
1135 	const struct vdpa_config_ops *ops = vdpa->config;
1136 	struct vhost_iotlb *iotlb = NULL;
1137 	struct vhost_vdpa_as *as = NULL;
1138 	int r = 0;
1139 
1140 	mutex_lock(&dev->mutex);
1141 
1142 	r = vhost_dev_check_owner(dev);
1143 	if (r)
1144 		goto unlock;
1145 
1146 	if (msg->type == VHOST_IOTLB_UPDATE ||
1147 	    msg->type == VHOST_IOTLB_BATCH_BEGIN) {
1148 		as = vhost_vdpa_find_alloc_as(v, asid);
1149 		if (!as) {
1150 			dev_err(&v->dev, "can't find and alloc asid %d\n",
1151 				asid);
1152 			r = -EINVAL;
1153 			goto unlock;
1154 		}
1155 		iotlb = &as->iotlb;
1156 	} else
1157 		iotlb = asid_to_iotlb(v, asid);
1158 
1159 	if ((v->in_batch && v->batch_asid != asid) || !iotlb) {
1160 		if (v->in_batch && v->batch_asid != asid) {
1161 			dev_info(&v->dev, "batch id %d asid %d\n",
1162 				 v->batch_asid, asid);
1163 		}
1164 		if (!iotlb)
1165 			dev_err(&v->dev, "no iotlb for asid %d\n", asid);
1166 		r = -EINVAL;
1167 		goto unlock;
1168 	}
1169 
1170 	switch (msg->type) {
1171 	case VHOST_IOTLB_UPDATE:
1172 		r = vhost_vdpa_process_iotlb_update(v, iotlb, msg);
1173 		break;
1174 	case VHOST_IOTLB_INVALIDATE:
1175 		vhost_vdpa_unmap(v, iotlb, msg->iova, msg->size);
1176 		break;
1177 	case VHOST_IOTLB_BATCH_BEGIN:
1178 		v->batch_asid = asid;
1179 		v->in_batch = true;
1180 		break;
1181 	case VHOST_IOTLB_BATCH_END:
1182 		if (v->in_batch && ops->set_map)
1183 			ops->set_map(vdpa, asid, iotlb);
1184 		v->in_batch = false;
1185 		break;
1186 	default:
1187 		r = -EINVAL;
1188 		break;
1189 	}
1190 unlock:
1191 	mutex_unlock(&dev->mutex);
1192 
1193 	return r;
1194 }
1195 
1196 static ssize_t vhost_vdpa_chr_write_iter(struct kiocb *iocb,
1197 					 struct iov_iter *from)
1198 {
1199 	struct file *file = iocb->ki_filp;
1200 	struct vhost_vdpa *v = file->private_data;
1201 	struct vhost_dev *dev = &v->vdev;
1202 
1203 	return vhost_chr_write_iter(dev, from);
1204 }
1205 
1206 static int vhost_vdpa_alloc_domain(struct vhost_vdpa *v)
1207 {
1208 	struct vdpa_device *vdpa = v->vdpa;
1209 	const struct vdpa_config_ops *ops = vdpa->config;
1210 	struct device *dma_dev = vdpa_get_dma_dev(vdpa);
1211 	const struct bus_type *bus;
1212 	int ret;
1213 
1214 	/* Device want to do DMA by itself */
1215 	if (ops->set_map || ops->dma_map)
1216 		return 0;
1217 
1218 	bus = dma_dev->bus;
1219 	if (!bus)
1220 		return -EFAULT;
1221 
1222 	if (!device_iommu_capable(dma_dev, IOMMU_CAP_CACHE_COHERENCY)) {
1223 		dev_warn_once(&v->dev,
1224 			      "Failed to allocate domain, device is not IOMMU cache coherent capable\n");
1225 		return -ENOTSUPP;
1226 	}
1227 
1228 	v->domain = iommu_domain_alloc(bus);
1229 	if (!v->domain)
1230 		return -EIO;
1231 
1232 	ret = iommu_attach_device(v->domain, dma_dev);
1233 	if (ret)
1234 		goto err_attach;
1235 
1236 	return 0;
1237 
1238 err_attach:
1239 	iommu_domain_free(v->domain);
1240 	v->domain = NULL;
1241 	return ret;
1242 }
1243 
1244 static void vhost_vdpa_free_domain(struct vhost_vdpa *v)
1245 {
1246 	struct vdpa_device *vdpa = v->vdpa;
1247 	struct device *dma_dev = vdpa_get_dma_dev(vdpa);
1248 
1249 	if (v->domain) {
1250 		iommu_detach_device(v->domain, dma_dev);
1251 		iommu_domain_free(v->domain);
1252 	}
1253 
1254 	v->domain = NULL;
1255 }
1256 
1257 static void vhost_vdpa_set_iova_range(struct vhost_vdpa *v)
1258 {
1259 	struct vdpa_iova_range *range = &v->range;
1260 	struct vdpa_device *vdpa = v->vdpa;
1261 	const struct vdpa_config_ops *ops = vdpa->config;
1262 
1263 	if (ops->get_iova_range) {
1264 		*range = ops->get_iova_range(vdpa);
1265 	} else if (v->domain && v->domain->geometry.force_aperture) {
1266 		range->first = v->domain->geometry.aperture_start;
1267 		range->last = v->domain->geometry.aperture_end;
1268 	} else {
1269 		range->first = 0;
1270 		range->last = ULLONG_MAX;
1271 	}
1272 }
1273 
1274 static void vhost_vdpa_cleanup(struct vhost_vdpa *v)
1275 {
1276 	struct vhost_vdpa_as *as;
1277 	u32 asid;
1278 
1279 	for (asid = 0; asid < v->vdpa->nas; asid++) {
1280 		as = asid_to_as(v, asid);
1281 		if (as)
1282 			vhost_vdpa_remove_as(v, asid);
1283 	}
1284 
1285 	vhost_vdpa_free_domain(v);
1286 	vhost_dev_cleanup(&v->vdev);
1287 	kfree(v->vdev.vqs);
1288 }
1289 
1290 static int vhost_vdpa_open(struct inode *inode, struct file *filep)
1291 {
1292 	struct vhost_vdpa *v;
1293 	struct vhost_dev *dev;
1294 	struct vhost_virtqueue **vqs;
1295 	int r, opened;
1296 	u32 i, nvqs;
1297 
1298 	v = container_of(inode->i_cdev, struct vhost_vdpa, cdev);
1299 
1300 	opened = atomic_cmpxchg(&v->opened, 0, 1);
1301 	if (opened)
1302 		return -EBUSY;
1303 
1304 	nvqs = v->nvqs;
1305 	r = vhost_vdpa_reset(v);
1306 	if (r)
1307 		goto err;
1308 
1309 	vqs = kmalloc_array(nvqs, sizeof(*vqs), GFP_KERNEL);
1310 	if (!vqs) {
1311 		r = -ENOMEM;
1312 		goto err;
1313 	}
1314 
1315 	dev = &v->vdev;
1316 	for (i = 0; i < nvqs; i++) {
1317 		vqs[i] = &v->vqs[i];
1318 		vqs[i]->handle_kick = handle_vq_kick;
1319 	}
1320 	vhost_dev_init(dev, vqs, nvqs, 0, 0, 0, false,
1321 		       vhost_vdpa_process_iotlb_msg);
1322 
1323 	r = vhost_vdpa_alloc_domain(v);
1324 	if (r)
1325 		goto err_alloc_domain;
1326 
1327 	vhost_vdpa_set_iova_range(v);
1328 
1329 	filep->private_data = v;
1330 
1331 	return 0;
1332 
1333 err_alloc_domain:
1334 	vhost_vdpa_cleanup(v);
1335 err:
1336 	atomic_dec(&v->opened);
1337 	return r;
1338 }
1339 
1340 static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
1341 {
1342 	u32 i;
1343 
1344 	for (i = 0; i < v->nvqs; i++)
1345 		vhost_vdpa_unsetup_vq_irq(v, i);
1346 }
1347 
1348 static int vhost_vdpa_release(struct inode *inode, struct file *filep)
1349 {
1350 	struct vhost_vdpa *v = filep->private_data;
1351 	struct vhost_dev *d = &v->vdev;
1352 
1353 	mutex_lock(&d->mutex);
1354 	filep->private_data = NULL;
1355 	vhost_vdpa_clean_irq(v);
1356 	vhost_vdpa_reset(v);
1357 	vhost_dev_stop(&v->vdev);
1358 	vhost_vdpa_unbind_mm(v);
1359 	vhost_vdpa_config_put(v);
1360 	vhost_vdpa_cleanup(v);
1361 	mutex_unlock(&d->mutex);
1362 
1363 	atomic_dec(&v->opened);
1364 	complete(&v->completion);
1365 
1366 	return 0;
1367 }
1368 
1369 #ifdef CONFIG_MMU
1370 static vm_fault_t vhost_vdpa_fault(struct vm_fault *vmf)
1371 {
1372 	struct vhost_vdpa *v = vmf->vma->vm_file->private_data;
1373 	struct vdpa_device *vdpa = v->vdpa;
1374 	const struct vdpa_config_ops *ops = vdpa->config;
1375 	struct vdpa_notification_area notify;
1376 	struct vm_area_struct *vma = vmf->vma;
1377 	u16 index = vma->vm_pgoff;
1378 
1379 	notify = ops->get_vq_notification(vdpa, index);
1380 
1381 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1382 	if (remap_pfn_range(vma, vmf->address & PAGE_MASK,
1383 			    PFN_DOWN(notify.addr), PAGE_SIZE,
1384 			    vma->vm_page_prot))
1385 		return VM_FAULT_SIGBUS;
1386 
1387 	return VM_FAULT_NOPAGE;
1388 }
1389 
1390 static const struct vm_operations_struct vhost_vdpa_vm_ops = {
1391 	.fault = vhost_vdpa_fault,
1392 };
1393 
1394 static int vhost_vdpa_mmap(struct file *file, struct vm_area_struct *vma)
1395 {
1396 	struct vhost_vdpa *v = vma->vm_file->private_data;
1397 	struct vdpa_device *vdpa = v->vdpa;
1398 	const struct vdpa_config_ops *ops = vdpa->config;
1399 	struct vdpa_notification_area notify;
1400 	unsigned long index = vma->vm_pgoff;
1401 
1402 	if (vma->vm_end - vma->vm_start != PAGE_SIZE)
1403 		return -EINVAL;
1404 	if ((vma->vm_flags & VM_SHARED) == 0)
1405 		return -EINVAL;
1406 	if (vma->vm_flags & VM_READ)
1407 		return -EINVAL;
1408 	if (index > 65535)
1409 		return -EINVAL;
1410 	if (!ops->get_vq_notification)
1411 		return -ENOTSUPP;
1412 
1413 	/* To be safe and easily modelled by userspace, We only
1414 	 * support the doorbell which sits on the page boundary and
1415 	 * does not share the page with other registers.
1416 	 */
1417 	notify = ops->get_vq_notification(vdpa, index);
1418 	if (notify.addr & (PAGE_SIZE - 1))
1419 		return -EINVAL;
1420 	if (vma->vm_end - vma->vm_start != notify.size)
1421 		return -ENOTSUPP;
1422 
1423 	vm_flags_set(vma, VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP);
1424 	vma->vm_ops = &vhost_vdpa_vm_ops;
1425 	return 0;
1426 }
1427 #endif /* CONFIG_MMU */
1428 
1429 static const struct file_operations vhost_vdpa_fops = {
1430 	.owner		= THIS_MODULE,
1431 	.open		= vhost_vdpa_open,
1432 	.release	= vhost_vdpa_release,
1433 	.write_iter	= vhost_vdpa_chr_write_iter,
1434 	.unlocked_ioctl	= vhost_vdpa_unlocked_ioctl,
1435 #ifdef CONFIG_MMU
1436 	.mmap		= vhost_vdpa_mmap,
1437 #endif /* CONFIG_MMU */
1438 	.compat_ioctl	= compat_ptr_ioctl,
1439 };
1440 
1441 static void vhost_vdpa_release_dev(struct device *device)
1442 {
1443 	struct vhost_vdpa *v =
1444 	       container_of(device, struct vhost_vdpa, dev);
1445 
1446 	ida_simple_remove(&vhost_vdpa_ida, v->minor);
1447 	kfree(v->vqs);
1448 	kfree(v);
1449 }
1450 
1451 static int vhost_vdpa_probe(struct vdpa_device *vdpa)
1452 {
1453 	const struct vdpa_config_ops *ops = vdpa->config;
1454 	struct vhost_vdpa *v;
1455 	int minor;
1456 	int i, r;
1457 
1458 	/* We can't support platform IOMMU device with more than 1
1459 	 * group or as
1460 	 */
1461 	if (!ops->set_map && !ops->dma_map &&
1462 	    (vdpa->ngroups > 1 || vdpa->nas > 1))
1463 		return -EOPNOTSUPP;
1464 
1465 	v = kzalloc(sizeof(*v), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1466 	if (!v)
1467 		return -ENOMEM;
1468 
1469 	minor = ida_simple_get(&vhost_vdpa_ida, 0,
1470 			       VHOST_VDPA_DEV_MAX, GFP_KERNEL);
1471 	if (minor < 0) {
1472 		kfree(v);
1473 		return minor;
1474 	}
1475 
1476 	atomic_set(&v->opened, 0);
1477 	v->minor = minor;
1478 	v->vdpa = vdpa;
1479 	v->nvqs = vdpa->nvqs;
1480 	v->virtio_id = ops->get_device_id(vdpa);
1481 
1482 	device_initialize(&v->dev);
1483 	v->dev.release = vhost_vdpa_release_dev;
1484 	v->dev.parent = &vdpa->dev;
1485 	v->dev.devt = MKDEV(MAJOR(vhost_vdpa_major), minor);
1486 	v->vqs = kmalloc_array(v->nvqs, sizeof(struct vhost_virtqueue),
1487 			       GFP_KERNEL);
1488 	if (!v->vqs) {
1489 		r = -ENOMEM;
1490 		goto err;
1491 	}
1492 
1493 	r = dev_set_name(&v->dev, "vhost-vdpa-%u", minor);
1494 	if (r)
1495 		goto err;
1496 
1497 	cdev_init(&v->cdev, &vhost_vdpa_fops);
1498 	v->cdev.owner = THIS_MODULE;
1499 
1500 	r = cdev_device_add(&v->cdev, &v->dev);
1501 	if (r)
1502 		goto err;
1503 
1504 	init_completion(&v->completion);
1505 	vdpa_set_drvdata(vdpa, v);
1506 
1507 	for (i = 0; i < VHOST_VDPA_IOTLB_BUCKETS; i++)
1508 		INIT_HLIST_HEAD(&v->as[i]);
1509 
1510 	return 0;
1511 
1512 err:
1513 	put_device(&v->dev);
1514 	return r;
1515 }
1516 
1517 static void vhost_vdpa_remove(struct vdpa_device *vdpa)
1518 {
1519 	struct vhost_vdpa *v = vdpa_get_drvdata(vdpa);
1520 	int opened;
1521 
1522 	cdev_device_del(&v->cdev, &v->dev);
1523 
1524 	do {
1525 		opened = atomic_cmpxchg(&v->opened, 0, 1);
1526 		if (!opened)
1527 			break;
1528 		wait_for_completion(&v->completion);
1529 	} while (1);
1530 
1531 	put_device(&v->dev);
1532 }
1533 
1534 static struct vdpa_driver vhost_vdpa_driver = {
1535 	.driver = {
1536 		.name	= "vhost_vdpa",
1537 	},
1538 	.probe	= vhost_vdpa_probe,
1539 	.remove	= vhost_vdpa_remove,
1540 };
1541 
1542 static int __init vhost_vdpa_init(void)
1543 {
1544 	int r;
1545 
1546 	r = alloc_chrdev_region(&vhost_vdpa_major, 0, VHOST_VDPA_DEV_MAX,
1547 				"vhost-vdpa");
1548 	if (r)
1549 		goto err_alloc_chrdev;
1550 
1551 	r = vdpa_register_driver(&vhost_vdpa_driver);
1552 	if (r)
1553 		goto err_vdpa_register_driver;
1554 
1555 	return 0;
1556 
1557 err_vdpa_register_driver:
1558 	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1559 err_alloc_chrdev:
1560 	return r;
1561 }
1562 module_init(vhost_vdpa_init);
1563 
1564 static void __exit vhost_vdpa_exit(void)
1565 {
1566 	vdpa_unregister_driver(&vhost_vdpa_driver);
1567 	unregister_chrdev_region(vhost_vdpa_major, VHOST_VDPA_DEV_MAX);
1568 }
1569 module_exit(vhost_vdpa_exit);
1570 
1571 MODULE_VERSION("0.0.1");
1572 MODULE_LICENSE("GPL v2");
1573 MODULE_AUTHOR("Intel Corporation");
1574 MODULE_DESCRIPTION("vDPA-based vhost backend for virtio");
1575