summaryrefslogtreecommitdiffstats
path: root/drivers/vdpa/vdpa_sim/vdpa_sim.c
blob: 01c456f7c1f7bda2df1c592c6056b54585b40ba6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
// SPDX-License-Identifier: GPL-2.0-only
/*
 * VDPA networking device simulator.
 *
 * Copyright (c) 2020, Red Hat Inc. All rights reserved.
 *     Author: Jason Wang <jasowang@redhat.com>
 *
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/uuid.h>
#include <linux/iommu.h>
#include <linux/dma-mapping.h>
#include <linux/sysfs.h>
#include <linux/file.h>
#include <linux/etherdevice.h>
#include <linux/vringh.h>
#include <linux/vdpa.h>
#include <linux/vhost_iotlb.h>
#include <uapi/linux/virtio_config.h>
#include <uapi/linux/virtio_net.h>

#define DRV_VERSION  "0.1"
#define DRV_AUTHOR   "Jason Wang <jasowang@redhat.com>"
#define DRV_DESC     "vDPA Device Simulator"
#define DRV_LICENSE  "GPL v2"

struct vdpasim_virtqueue {
	struct vringh vring;
	struct vringh_kiov iov;
	unsigned short head;
	bool ready;
	u64 desc_addr;
	u64 device_addr;
	u64 driver_addr;
	u32 num;
	void *private;
	irqreturn_t (*cb)(void *data);
};

#define VDPASIM_QUEUE_ALIGN PAGE_SIZE
#define VDPASIM_QUEUE_MAX 256
#define VDPASIM_DEVICE_ID 0x1
#define VDPASIM_VENDOR_ID 0
#define VDPASIM_VQ_NUM 0x2
#define VDPASIM_NAME "vdpasim-netdev"

static u64 vdpasim_features = (1ULL << VIRTIO_F_ANY_LAYOUT) |
			      (1ULL << VIRTIO_F_VERSION_1)  |
			      (1ULL << VIRTIO_F_IOMMU_PLATFORM);

/* State of each vdpasim device */
struct vdpasim {
	struct vdpa_device vdpa;
	struct vdpasim_virtqueue vqs[2];
	struct work_struct work;
	/* spinlock to synchronize virtqueue state */
	spinlock_t lock;
	struct virtio_net_config config;
	struct vhost_iotlb *iommu;
	void *buffer;
	u32 status;
	u32 generation;
	u64 features;
};

static struct vdpasim *vdpasim_dev;

static struct vdpasim *vdpa_to_sim(struct vdpa_device *vdpa)
{
	return container_of(vdpa, struct vdpasim, vdpa);
}

static struct vdpasim *dev_to_sim(struct device *dev)
{
	struct vdpa_device *vdpa = dev_to_vdpa(dev);

	return vdpa_to_sim(vdpa);
}

static void vdpasim_queue_ready(struct vdpasim *vdpasim, unsigned int idx)
{
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	vringh_init_iotlb(&vq->vring, vdpasim_features,
			  VDPASIM_QUEUE_MAX, false,
			  (struct vring_desc *)(uintptr_t)vq->desc_addr,
			  (struct vring_avail *)
			  (uintptr_t)vq->driver_addr,
			  (struct vring_used *)
			  (uintptr_t)vq->device_addr);
}

static void vdpasim_vq_reset(struct vdpasim_virtqueue *vq)
{
	vq->ready = 0;
	vq->desc_addr = 0;
	vq->driver_addr = 0;
	vq->device_addr = 0;
	vq->cb = NULL;
	vq->private = NULL;
	vringh_init_iotlb(&vq->vring, vdpasim_features, VDPASIM_QUEUE_MAX,
			  false, NULL, NULL, NULL);
}

static void vdpasim_reset(struct vdpasim *vdpasim)
{
	int i;

	for (i = 0; i < VDPASIM_VQ_NUM; i++)
		vdpasim_vq_reset(&vdpasim->vqs[i]);

	vhost_iotlb_reset(vdpasim->iommu);

	vdpasim->features = 0;
	vdpasim->status = 0;
	++vdpasim->generation;
}

static void vdpasim_work(struct work_struct *work)
{
	struct vdpasim *vdpasim = container_of(work, struct
						 vdpasim, work);
	struct vdpasim_virtqueue *txq = &vdpasim->vqs[1];
	struct vdpasim_virtqueue *rxq = &vdpasim->vqs[0];
	size_t read, write, total_write;
	int err;
	int pkts = 0;

	spin_lock(&vdpasim->lock);

	if (!(vdpasim->status & VIRTIO_CONFIG_S_DRIVER_OK))
		goto out;

	if (!txq->ready || !rxq->ready)
		goto out;

	while (true) {
		total_write = 0;
		err = vringh_getdesc_iotlb(&txq->vring, &txq->iov, NULL,
					   &txq->head, GFP_ATOMIC);
		if (err <= 0)
			break;

		err = vringh_getdesc_iotlb(&rxq->vring, NULL, &rxq->iov,
					   &rxq->head, GFP_ATOMIC);
		if (err <= 0) {
			vringh_complete_iotlb(&txq->vring, txq->head, 0);
			break;
		}

		while (true) {
			read = vringh_iov_pull_iotlb(&txq->vring, &txq->iov,
						     vdpasim->buffer,
						     PAGE_SIZE);
			if (read <= 0)
				break;

			write = vringh_iov_push_iotlb(&rxq->vring, &rxq->iov,
						      vdpasim->buffer, read);
			if (write <= 0)
				break;

			total_write += write;
		}

		/* Make sure data is wrote before advancing index */
		smp_wmb();

		vringh_complete_iotlb(&txq->vring, txq->head, 0);
		vringh_complete_iotlb(&rxq->vring, rxq->head, total_write);

		/* Make sure used is visible before rasing the interrupt. */
		smp_wmb();

		local_bh_disable();
		if (txq->cb)
			txq->cb(txq->private);
		if (rxq->cb)
			rxq->cb(rxq->private);
		local_bh_enable();

		if (++pkts > 4) {
			schedule_work(&vdpasim->work);
			goto out;
		}
	}

out:
	spin_unlock(&vdpasim->lock);
}

static int dir_to_perm(enum dma_data_direction dir)
{
	int perm = -EFAULT;

	switch (dir) {
	case DMA_FROM_DEVICE:
		perm = VHOST_MAP_WO;
		break;
	case DMA_TO_DEVICE:
		perm = VHOST_MAP_RO;
		break;
	case DMA_BIDIRECTIONAL:
		perm = VHOST_MAP_RW;
		break;
	default:
		break;
	}

	return perm;
}

static dma_addr_t vdpasim_map_page(struct device *dev, struct page *page,
				   unsigned long offset, size_t size,
				   enum dma_data_direction dir,
				   unsigned long attrs)
{
	struct vdpasim *vdpasim = dev_to_sim(dev);
	struct vhost_iotlb *iommu = vdpasim->iommu;
	u64 pa = (page_to_pfn(page) << PAGE_SHIFT) + offset;
	int ret, perm = dir_to_perm(dir);

	if (perm < 0)
		return DMA_MAPPING_ERROR;

	/* For simplicity, use identical mapping to avoid e.g iova
	 * allocator.
	 */
	ret = vhost_iotlb_add_range(iommu, pa, pa + size - 1,
				    pa, dir_to_perm(dir));
	if (ret)
		return DMA_MAPPING_ERROR;

	return (dma_addr_t)(pa);
}

static void vdpasim_unmap_page(struct device *dev, dma_addr_t dma_addr,
			       size_t size, enum dma_data_direction dir,
			       unsigned long attrs)
{
	struct vdpasim *vdpasim = dev_to_sim(dev);
	struct vhost_iotlb *iommu = vdpasim->iommu;

	vhost_iotlb_del_range(iommu, (u64)dma_addr,
			      (u64)dma_addr + size - 1);
}

static void *vdpasim_alloc_coherent(struct device *dev, size_t size,
				    dma_addr_t *dma_addr, gfp_t flag,
				    unsigned long attrs)
{
	struct vdpasim *vdpasim = dev_to_sim(dev);
	struct vhost_iotlb *iommu = vdpasim->iommu;
	void *addr = kmalloc(size, flag);
	int ret;

	if (!addr)
		*dma_addr = DMA_MAPPING_ERROR;
	else {
		u64 pa = virt_to_phys(addr);

		ret = vhost_iotlb_add_range(iommu, (u64)pa,
					    (u64)pa + size - 1,
					    pa, VHOST_MAP_RW);
		if (ret) {
			*dma_addr = DMA_MAPPING_ERROR;
			kfree(addr);
			addr = NULL;
		} else
			*dma_addr = (dma_addr_t)pa;
	}

	return addr;
}

static void vdpasim_free_coherent(struct device *dev, size_t size,
				  void *vaddr, dma_addr_t dma_addr,
				  unsigned long attrs)
{
	struct vdpasim *vdpasim = dev_to_sim(dev);
	struct vhost_iotlb *iommu = vdpasim->iommu;

	vhost_iotlb_del_range(iommu, (u64)dma_addr,
			      (u64)dma_addr + size - 1);
	kfree(phys_to_virt((uintptr_t)dma_addr));
}

static const struct dma_map_ops vdpasim_dma_ops = {
	.map_page = vdpasim_map_page,
	.unmap_page = vdpasim_unmap_page,
	.alloc = vdpasim_alloc_coherent,
	.free = vdpasim_free_coherent,
};

static const struct vdpa_config_ops vdpasim_net_config_ops;

static struct vdpasim *vdpasim_create(void)
{
	struct virtio_net_config *config;
	struct vdpasim *vdpasim;
	struct device *dev;
	int ret = -ENOMEM;

	vdpasim = vdpa_alloc_device(struct vdpasim, vdpa, NULL,
				    &vdpasim_net_config_ops);
	if (!vdpasim)
		goto err_alloc;

	INIT_WORK(&vdpasim->work, vdpasim_work);
	spin_lock_init(&vdpasim->lock);

	dev = &vdpasim->vdpa.dev;
	dev->coherent_dma_mask = DMA_BIT_MASK(64);
	set_dma_ops(dev, &vdpasim_dma_ops);

	vdpasim->iommu = vhost_iotlb_alloc(2048, 0);
	if (!vdpasim->iommu)
		goto err_iommu;

	vdpasim->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!vdpasim->buffer)
		goto err_iommu;

	config = &vdpasim->config;
	config->mtu = 1500;
	config->status = VIRTIO_NET_S_LINK_UP;
	eth_random_addr(config->mac);

	vringh_set_iotlb(&vdpasim->vqs[0].vring, vdpasim->iommu);
	vringh_set_iotlb(&vdpasim->vqs[1].vring, vdpasim->iommu);

	vdpasim->vdpa.dma_dev = dev;
	ret = vdpa_register_device(&vdpasim->vdpa);
	if (ret)
		goto err_iommu;

	return vdpasim;

err_iommu:
	put_device(dev);
err_alloc:
	return ERR_PTR(ret);
}

static int vdpasim_set_vq_address(struct vdpa_device *vdpa, u16 idx,
				  u64 desc_area, u64 driver_area,
				  u64 device_area)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	vq->desc_addr = desc_area;
	vq->driver_addr = driver_area;
	vq->device_addr = device_area;

	return 0;
}

static void vdpasim_set_vq_num(struct vdpa_device *vdpa, u16 idx, u32 num)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	vq->num = num;
}

static void vdpasim_kick_vq(struct vdpa_device *vdpa, u16 idx)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	if (vq->ready)
		schedule_work(&vdpasim->work);
}

static void vdpasim_set_vq_cb(struct vdpa_device *vdpa, u16 idx,
			      struct vdpa_callback *cb)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	vq->cb = cb->callback;
	vq->private = cb->private;
}

static void vdpasim_set_vq_ready(struct vdpa_device *vdpa, u16 idx, bool ready)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	spin_lock(&vdpasim->lock);
	vq->ready = ready;
	if (vq->ready)
		vdpasim_queue_ready(vdpasim, idx);
	spin_unlock(&vdpasim->lock);
}

static bool vdpasim_get_vq_ready(struct vdpa_device *vdpa, u16 idx)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];

	return vq->ready;
}

static int vdpasim_set_vq_state(struct vdpa_device *vdpa, u16 idx, u64 state)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
	struct vringh *vrh = &vq->vring;

	spin_lock(&vdpasim->lock);
	vrh->last_avail_idx = state;
	spin_unlock(&vdpasim->lock);

	return 0;
}

static u64 vdpasim_get_vq_state(struct vdpa_device *vdpa, u16 idx)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vdpasim_virtqueue *vq = &vdpasim->vqs[idx];
	struct vringh *vrh = &vq->vring;

	return vrh->last_avail_idx;
}

static u32 vdpasim_get_vq_align(struct vdpa_device *vdpa)
{
	return VDPASIM_QUEUE_ALIGN;
}

static u64 vdpasim_get_features(struct vdpa_device *vdpa)
{
	return vdpasim_features;
}

static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	/* DMA mapping must be done by driver */
	if (!(features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)))
		return -EINVAL;

	vdpasim->features = features & vdpasim_features;

	return 0;
}

static void vdpasim_set_config_cb(struct vdpa_device *vdpa,
				  struct vdpa_callback *cb)
{
	/* We don't support config interrupt */
}

static u16 vdpasim_get_vq_num_max(struct vdpa_device *vdpa)
{
	return VDPASIM_QUEUE_MAX;
}

static u32 vdpasim_get_device_id(struct vdpa_device *vdpa)
{
	return VDPASIM_DEVICE_ID;
}

static u32 vdpasim_get_vendor_id(struct vdpa_device *vdpa)
{
	return VDPASIM_VENDOR_ID;
}

static u8 vdpasim_get_status(struct vdpa_device *vdpa)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	u8 status;

	spin_lock(&vdpasim->lock);
	status = vdpasim->status;
	spin_unlock(&vdpasim->lock);

	return status;
}

static void vdpasim_set_status(struct vdpa_device *vdpa, u8 status)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	spin_lock(&vdpasim->lock);
	vdpasim->status = status;
	if (status == 0)
		vdpasim_reset(vdpasim);
	spin_unlock(&vdpasim->lock);
}

static void vdpasim_get_config(struct vdpa_device *vdpa, unsigned int offset,
			     void *buf, unsigned int len)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	if (offset + len < sizeof(struct virtio_net_config))
		memcpy(buf, &vdpasim->config + offset, len);
}

static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,
			     const void *buf, unsigned int len)
{
	/* No writable config supportted by vdpasim */
}

static u32 vdpasim_get_generation(struct vdpa_device *vdpa)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	return vdpasim->generation;
}

static int vdpasim_set_map(struct vdpa_device *vdpa,
			   struct vhost_iotlb *iotlb)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
	struct vhost_iotlb_map *map;
	u64 start = 0ULL, last = 0ULL - 1;
	int ret;

	vhost_iotlb_reset(vdpasim->iommu);

	for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
	     map = vhost_iotlb_itree_next(map, start, last)) {
		ret = vhost_iotlb_add_range(vdpasim->iommu, map->start,
					    map->last, map->addr, map->perm);
		if (ret)
			goto err;
	}
	return 0;

err:
	vhost_iotlb_reset(vdpasim->iommu);
	return ret;
}

static int vdpasim_dma_map(struct vdpa_device *vdpa, u64 iova, u64 size,
			   u64 pa, u32 perm)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	return vhost_iotlb_add_range(vdpasim->iommu, iova,
				     iova + size - 1, pa, perm);
}

static int vdpasim_dma_unmap(struct vdpa_device *vdpa, u64 iova, u64 size)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	vhost_iotlb_del_range(vdpasim->iommu, iova, iova + size - 1);

	return 0;
}

static void vdpasim_free(struct vdpa_device *vdpa)
{
	struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

	cancel_work_sync(&vdpasim->work);
	kfree(vdpasim->buffer);
	if (vdpasim->iommu)
		vhost_iotlb_free(vdpasim->iommu);
}

static const struct vdpa_config_ops vdpasim_net_config_ops = {
	.set_vq_address         = vdpasim_set_vq_address,
	.set_vq_num             = vdpasim_set_vq_num,
	.kick_vq                = vdpasim_kick_vq,
	.set_vq_cb              = vdpasim_set_vq_cb,
	.set_vq_ready           = vdpasim_set_vq_ready,
	.get_vq_ready           = vdpasim_get_vq_ready,
	.set_vq_state           = vdpasim_set_vq_state,
	.get_vq_state           = vdpasim_get_vq_state,
	.get_vq_align           = vdpasim_get_vq_align,
	.get_features           = vdpasim_get_features,
	.set_features           = vdpasim_set_features,
	.set_config_cb          = vdpasim_set_config_cb,
	.get_vq_num_max         = vdpasim_get_vq_num_max,
	.get_device_id          = vdpasim_get_device_id,
	.get_vendor_id          = vdpasim_get_vendor_id,
	.get_status             = vdpasim_get_status,
	.set_status             = vdpasim_set_status,
	.get_config             = vdpasim_get_config,
	.set_config             = vdpasim_set_config,
	.get_generation         = vdpasim_get_generation,
	.set_map                = vdpasim_set_map,
	.dma_map                = vdpasim_dma_map,
	.dma_unmap              = vdpasim_dma_unmap,
	.free                   = vdpasim_free,
};

static int __init vdpasim_dev_init(void)
{
	vdpasim_dev = vdpasim_create();

	if (!IS_ERR(vdpasim_dev))
		return 0;

	return PTR_ERR(vdpasim_dev);
}

static void __exit vdpasim_dev_exit(void)
{
	struct vdpa_device *vdpa = &vdpasim_dev->vdpa;

	vdpa_unregister_device(vdpa);
}

module_init(vdpasim_dev_init)
module_exit(vdpasim_dev_exit)

MODULE_VERSION(DRV_VERSION);
MODULE_LICENSE(DRV_LICENSE);
MODULE_AUTHOR(DRV_AUTHOR);
MODULE_DESCRIPTION(DRV_DESC);