summaryrefslogtreecommitdiff
path: root/examples/vhost_scsi/vhost_scsi.c
blob: 3cb4383e9c051468380fab1bac248a2fe55c189d (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
/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2017 Intel Corporation
 */

#include <stdint.h>
#include <unistd.h>
#include <stdbool.h>
#include <signal.h>
#include <assert.h>
#include <semaphore.h>
#include <linux/virtio_scsi.h>
#include <linux/virtio_ring.h>

#include <rte_atomic.h>
#include <rte_cycles.h>
#include <rte_log.h>
#include <rte_malloc.h>
#include <rte_vhost.h>

#include "vhost_scsi.h"
#include "scsi_spec.h"

#define VIRTIO_SCSI_FEATURES ((1 << VIRTIO_F_NOTIFY_ON_EMPTY) |\
			      (1 << VIRTIO_SCSI_F_INOUT) |\
			      (1 << VIRTIO_SCSI_F_CHANGE))

/* Path to folder where character device will be created. Can be set by user. */
static char dev_pathname[PATH_MAX] = "";

static struct vhost_scsi_ctrlr *g_vhost_ctrlr;
static int g_should_stop;
static sem_t exit_sem;

static struct vhost_scsi_ctrlr *
vhost_scsi_ctrlr_find(__rte_unused const char *ctrlr_name)
{
	/* currently we only support 1 socket file fd */
	return g_vhost_ctrlr;
}

static uint64_t gpa_to_vva(int vid, uint64_t gpa)
{
	char path[PATH_MAX];
	struct vhost_scsi_ctrlr *ctrlr;
	int ret = 0;

	ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
	if (ret) {
		fprintf(stderr, "Cannot get socket name\n");
		assert(ret != 0);
	}

	ctrlr = vhost_scsi_ctrlr_find(path);
	if (!ctrlr) {
		fprintf(stderr, "Controller is not ready\n");
		assert(ctrlr != NULL);
	}

	assert(ctrlr->mem != NULL);

	return rte_vhost_gpa_to_vva(ctrlr->mem, gpa);
}

static struct vring_desc *
descriptor_get_next(struct vring_desc *vq_desc, struct vring_desc *cur_desc)
{
	return &vq_desc[cur_desc->next];
}

static bool
descriptor_has_next(struct vring_desc *cur_desc)
{
	return !!(cur_desc->flags & VRING_DESC_F_NEXT);
}

static bool
descriptor_is_wr(struct vring_desc *cur_desc)
{
	return !!(cur_desc->flags & VRING_DESC_F_WRITE);
}

static void
submit_completion(struct vhost_scsi_task *task, uint32_t q_idx)
{
	struct rte_vhost_vring *vq;
	struct vring_used *used;

	vq = task->vq;
	used = vq->used;
	/* Fill out the next entry in the "used" ring.  id = the
	 * index of the descriptor that contained the SCSI request.
	 * len = the total amount of data transferred for the SCSI
	 * request. We must report the correct len, for variable
	 * length SCSI CDBs, where we may return less data than
	 * allocated by the guest VM.
	 */
	used->ring[used->idx & (vq->size - 1)].id = task->req_idx;
	used->ring[used->idx & (vq->size - 1)].len = task->data_len;
	used->idx++;

	/* Send an interrupt back to the guest VM so that it knows
	 * a completion is ready to be processed.
	 */
	rte_vhost_vring_call(task->bdev->vid, q_idx);
}

static void
vhost_process_read_payload_chain(struct vhost_scsi_task *task)
{
	void *data;

	task->iovs_cnt = 0;
	task->resp = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
						   task->desc->addr);

	while (descriptor_has_next(task->desc)) {
		task->desc = descriptor_get_next(task->vq->desc, task->desc);
		data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
						     task->desc->addr);
		task->iovs[task->iovs_cnt].iov_base = data;
		task->iovs[task->iovs_cnt].iov_len = task->desc->len;
		task->data_len += task->desc->len;
		task->iovs_cnt++;
	}
}

static void
vhost_process_write_payload_chain(struct vhost_scsi_task *task)
{
	void *data;

	task->iovs_cnt = 0;

	do {
		data = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
						     task->desc->addr);
		task->iovs[task->iovs_cnt].iov_base = data;
		task->iovs[task->iovs_cnt].iov_len = task->desc->len;
		task->data_len += task->desc->len;
		task->iovs_cnt++;
		task->desc = descriptor_get_next(task->vq->desc, task->desc);
	} while (descriptor_has_next(task->desc));

	task->resp = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
						   task->desc->addr);
}

static struct vhost_block_dev *
vhost_scsi_bdev_construct(const char *bdev_name, const char *bdev_serial,
			  uint32_t blk_size, uint64_t blk_cnt,
			  bool wce_enable)
{
	struct vhost_block_dev *bdev;

	bdev = rte_zmalloc(NULL, sizeof(*bdev), RTE_CACHE_LINE_SIZE);
	if (!bdev)
		return NULL;

	strncpy(bdev->name, bdev_name, sizeof(bdev->name));
	strncpy(bdev->product_name, bdev_serial, sizeof(bdev->product_name));
	bdev->blocklen = blk_size;
	bdev->blockcnt = blk_cnt;
	bdev->write_cache = wce_enable;

	/* use memory as disk storage space */
	bdev->data = rte_zmalloc(NULL, blk_cnt * blk_size, 0);
	if (!bdev->data) {
		fprintf(stderr, "no enough reseverd huge memory for disk\n");
		return NULL;
	}

	return bdev;
}

static void
process_requestq(struct vhost_scsi_ctrlr *ctrlr, uint32_t q_idx)
{
	int ret;
	struct vhost_scsi_queue *scsi_vq;
	struct rte_vhost_vring *vq;

	scsi_vq = &ctrlr->bdev->queues[q_idx];
	vq = &scsi_vq->vq;
	ret = rte_vhost_get_vhost_vring(ctrlr->bdev->vid, q_idx, vq);
	assert(ret == 0);

	while (vq->avail->idx != scsi_vq->last_used_idx) {
		int req_idx;
		uint16_t last_idx;
		struct vhost_scsi_task *task;

		last_idx = scsi_vq->last_used_idx & (vq->size - 1);
		req_idx = vq->avail->ring[last_idx];

		task = rte_zmalloc(NULL, sizeof(*task), 0);
		assert(task != NULL);

		task->ctrlr = ctrlr;
		task->bdev = ctrlr->bdev;
		task->vq = vq;
		task->req_idx = req_idx;
		task->desc = &task->vq->desc[task->req_idx];

		/* does not support indirect descriptors */
		assert((task->desc->flags & VRING_DESC_F_INDIRECT) == 0);
		scsi_vq->last_used_idx++;

		task->req = (void *)(uintptr_t)gpa_to_vva(task->bdev->vid,
							  task->desc->addr);

		task->desc = descriptor_get_next(task->vq->desc, task->desc);
		if (!descriptor_has_next(task->desc)) {
			task->dxfer_dir = SCSI_DIR_NONE;
			task->resp = (void *)(uintptr_t)
					      gpa_to_vva(task->bdev->vid,
							 task->desc->addr);

		} else if (!descriptor_is_wr(task->desc)) {
			task->dxfer_dir = SCSI_DIR_TO_DEV;
			vhost_process_write_payload_chain(task);
		} else {
			task->dxfer_dir = SCSI_DIR_FROM_DEV;
			vhost_process_read_payload_chain(task);
		}

		ret = vhost_bdev_process_scsi_commands(ctrlr->bdev, task);
		if (ret) {
			/* invalid response */
			task->resp->response = VIRTIO_SCSI_S_BAD_TARGET;
		} else {
			/* successfully */
			task->resp->response = VIRTIO_SCSI_S_OK;
			task->resp->status = 0;
			task->resp->resid = 0;
		}
		submit_completion(task, q_idx);
		rte_free(task);
	}
}

/* Main framework for processing IOs */
static void *
ctrlr_worker(void *arg)
{
	uint32_t idx, num;
	struct vhost_scsi_ctrlr *ctrlr = (struct vhost_scsi_ctrlr *)arg;
	cpu_set_t cpuset;
	pthread_t thread;

	thread = pthread_self();
	CPU_ZERO(&cpuset);
	CPU_SET(0, &cpuset);
	pthread_setaffinity_np(thread, sizeof(cpu_set_t), &cpuset);

	num =  rte_vhost_get_vring_num(ctrlr->bdev->vid);
	fprintf(stdout, "Ctrlr Worker Thread Started with %u Vring\n", num);

	if (num != NUM_OF_SCSI_QUEUES) {
		fprintf(stderr, "Only 1 IO queue are supported\n");
		exit(0);
	}

	while (!g_should_stop && ctrlr->bdev != NULL) {
		/* At least 3 vrings, currently only can support 1 IO queue
		 * Queue 2 for IO queue, does not support TMF and hotplug
		 * for the example application now
		 */
		for (idx = 2; idx < num; idx++)
			process_requestq(ctrlr, idx);
	}

	fprintf(stdout, "Ctrlr Worker Thread Exiting\n");
	sem_post(&exit_sem);
	return NULL;
}

static int
new_device(int vid)
{
	char path[PATH_MAX];
	struct vhost_scsi_ctrlr *ctrlr;
	struct vhost_scsi_queue *scsi_vq;
	struct rte_vhost_vring *vq;
	pthread_t tid;
	int i, ret;

	ret = rte_vhost_get_ifname(vid, path, PATH_MAX);
	if (ret) {
		fprintf(stderr, "Cannot get socket name\n");
		return -1;
	}

	ctrlr = vhost_scsi_ctrlr_find(path);
	if (!ctrlr) {
		fprintf(stderr, "Controller is not ready\n");
		return -1;
	}

	ret = rte_vhost_get_mem_table(vid, &ctrlr->mem);
	if (ret) {
		fprintf(stderr, "Get Controller memory region failed\n");
		return -1;
	}
	assert(ctrlr->mem != NULL);

	/* hardcoded block device information with 128MiB */
	ctrlr->bdev = vhost_scsi_bdev_construct("malloc0", "vhost_scsi_malloc0",
						4096, 32768, 0);
	if (!ctrlr->bdev)
		return -1;

	ctrlr->bdev->vid = vid;

	/* Disable Notifications */
	for (i = 0; i < NUM_OF_SCSI_QUEUES; i++) {
		rte_vhost_enable_guest_notification(vid, i, 0);
		/* restore used index */
		scsi_vq = &ctrlr->bdev->queues[i];
		vq = &scsi_vq->vq;
		ret = rte_vhost_get_vhost_vring(ctrlr->bdev->vid, i, vq);
		assert(ret == 0);
		scsi_vq->last_used_idx = vq->used->idx;
		scsi_vq->last_avail_idx = vq->used->idx;
	}

	g_should_stop = 0;
	fprintf(stdout, "New Device %s, Device ID %d\n", path, vid);
	if (pthread_create(&tid, NULL, &ctrlr_worker, ctrlr) < 0) {
		fprintf(stderr, "Worker Thread Started Failed\n");
		return -1;
	}
	pthread_detach(tid);
	return 0;
}

static void
destroy_device(int vid)
{
	char path[PATH_MAX];
	struct vhost_scsi_ctrlr *ctrlr;

	rte_vhost_get_ifname(vid, path, PATH_MAX);
	fprintf(stdout, "Destroy %s Device ID %d\n", path, vid);
	ctrlr = vhost_scsi_ctrlr_find(path);
	if (!ctrlr) {
		fprintf(stderr, "Destroy Ctrlr Failed\n");
		return;
	}
	ctrlr->bdev = NULL;
	g_should_stop = 1;

	sem_wait(&exit_sem);
}

static const struct vhost_device_ops vhost_scsi_device_ops = {
	.new_device =  new_device,
	.destroy_device = destroy_device,
};

static struct vhost_scsi_ctrlr *
vhost_scsi_ctrlr_construct(const char *ctrlr_name)
{
	int ret;
	struct vhost_scsi_ctrlr *ctrlr;
	char *path;
	char cwd[PATH_MAX];

	/* always use current directory */
	path = getcwd(cwd, PATH_MAX);
	if (!path) {
		fprintf(stderr, "Cannot get current working directory\n");
		return NULL;
	}
	snprintf(dev_pathname, sizeof(dev_pathname), "%s/%s", path, ctrlr_name);

	if (access(dev_pathname, F_OK) != -1) {
		if (unlink(dev_pathname) != 0)
			rte_exit(EXIT_FAILURE, "Cannot remove %s.\n",
				 dev_pathname);
	}

	if (rte_vhost_driver_register(dev_pathname, 0) != 0) {
		fprintf(stderr, "socket %s already exists\n", dev_pathname);
		return NULL;
	}

	fprintf(stdout, "socket file: %s created\n", dev_pathname);

	ret = rte_vhost_driver_set_features(dev_pathname, VIRTIO_SCSI_FEATURES);
	if (ret != 0) {
		fprintf(stderr, "Set vhost driver features failed\n");
		return NULL;
	}

	ctrlr = rte_zmalloc(NULL, sizeof(*ctrlr), RTE_CACHE_LINE_SIZE);
	if (!ctrlr)
		return NULL;

	rte_vhost_driver_callback_register(dev_pathname,
					   &vhost_scsi_device_ops);

	return ctrlr;
}

static void
signal_handler(__rte_unused int signum)
{

	if (access(dev_pathname, F_OK) == 0)
		unlink(dev_pathname);
	exit(0);
}

int main(int argc, char *argv[])
{
	int ret;

	signal(SIGINT, signal_handler);

	/* init EAL */
	ret = rte_eal_init(argc, argv);
	if (ret < 0)
		rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");

	g_vhost_ctrlr = vhost_scsi_ctrlr_construct("vhost.socket");
	if (g_vhost_ctrlr == NULL) {
		fprintf(stderr, "Construct vhost scsi controller failed\n");
		return 0;
	}

	if (sem_init(&exit_sem, 0, 0) < 0) {
		fprintf(stderr, "Error init exit_sem\n");
		return -1;
	}

	rte_vhost_driver_start(dev_pathname);

	/* loop for exit the application */
	while (1)
		sleep(1);

	return 0;
}