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18#include "qemu/osdep.h"
19#include "standard-headers/linux/virtio_blk.h"
20#include "contrib/libvhost-user/libvhost-user-glib.h"
21#include "contrib/libvhost-user/libvhost-user.h"
22
23#if defined(__linux__)
24#include <linux/fs.h>
25#include <sys/ioctl.h>
26#endif
27
28enum {
29 VHOST_USER_BLK_MAX_QUEUES = 8,
30};
31
32struct virtio_blk_inhdr {
33 unsigned char status;
34};
35
36
37typedef struct VubDev {
38 VugDev parent;
39 int blk_fd;
40 struct virtio_blk_config blkcfg;
41 bool enable_ro;
42 char *blk_name;
43 GMainLoop *loop;
44} VubDev;
45
46typedef struct VubReq {
47 VuVirtqElement *elem;
48 int64_t sector_num;
49 size_t size;
50 struct virtio_blk_inhdr *in;
51 struct virtio_blk_outhdr *out;
52 VubDev *vdev_blk;
53 struct VuVirtq *vq;
54} VubReq;
55
56
57static size_t vub_iov_size(const struct iovec *iov,
58 const unsigned int iov_cnt)
59{
60 size_t len;
61 unsigned int i;
62
63 len = 0;
64 for (i = 0; i < iov_cnt; i++) {
65 len += iov[i].iov_len;
66 }
67 return len;
68}
69
70static size_t vub_iov_to_buf(const struct iovec *iov,
71 const unsigned int iov_cnt, void *buf)
72{
73 size_t len;
74 unsigned int i;
75
76 len = 0;
77 for (i = 0; i < iov_cnt; i++) {
78 memcpy(buf + len, iov[i].iov_base, iov[i].iov_len);
79 len += iov[i].iov_len;
80 }
81 return len;
82}
83
84static void vub_panic_cb(VuDev *vu_dev, const char *buf)
85{
86 VugDev *gdev;
87 VubDev *vdev_blk;
88
89 assert(vu_dev);
90
91 gdev = container_of(vu_dev, VugDev, parent);
92 vdev_blk = container_of(gdev, VubDev, parent);
93 if (buf) {
94 g_warning("vu_panic: %s", buf);
95 }
96
97 g_main_loop_quit(vdev_blk->loop);
98}
99
100static void vub_req_complete(VubReq *req)
101{
102 VugDev *gdev = &req->vdev_blk->parent;
103 VuDev *vu_dev = &gdev->parent;
104
105
106 vu_queue_push(vu_dev, req->vq, req->elem,
107 req->size + 1);
108 vu_queue_notify(vu_dev, req->vq);
109
110 if (req->elem) {
111 free(req->elem);
112 }
113
114 g_free(req);
115}
116
117static int vub_open(const char *file_name, bool wce)
118{
119 int fd;
120 int flags = O_RDWR;
121
122 if (!wce) {
123 flags |= O_DIRECT;
124 }
125
126 fd = open(file_name, flags);
127 if (fd < 0) {
128 fprintf(stderr, "Cannot open file %s, %s\n", file_name,
129 strerror(errno));
130 return -1;
131 }
132
133 return fd;
134}
135
136static ssize_t
137vub_readv(VubReq *req, struct iovec *iov, uint32_t iovcnt)
138{
139 VubDev *vdev_blk = req->vdev_blk;
140 ssize_t rc;
141
142 if (!iovcnt) {
143 fprintf(stderr, "Invalid Read IOV count\n");
144 return -1;
145 }
146
147 req->size = vub_iov_size(iov, iovcnt);
148 rc = preadv(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512);
149 if (rc < 0) {
150 fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n",
151 vdev_blk->blk_name, req->sector_num, req->size,
152 strerror(errno));
153 return -1;
154 }
155
156 return rc;
157}
158
159static ssize_t
160vub_writev(VubReq *req, struct iovec *iov, uint32_t iovcnt)
161{
162 VubDev *vdev_blk = req->vdev_blk;
163 ssize_t rc;
164
165 if (!iovcnt) {
166 fprintf(stderr, "Invalid Write IOV count\n");
167 return -1;
168 }
169
170 req->size = vub_iov_size(iov, iovcnt);
171 rc = pwritev(vdev_blk->blk_fd, iov, iovcnt, req->sector_num * 512);
172 if (rc < 0) {
173 fprintf(stderr, "%s, Sector %"PRIu64", Size %lu failed with %s\n",
174 vdev_blk->blk_name, req->sector_num, req->size,
175 strerror(errno));
176 return -1;
177 }
178
179 return rc;
180}
181
182static int
183vub_discard_write_zeroes(VubReq *req, struct iovec *iov, uint32_t iovcnt,
184 uint32_t type)
185{
186 struct virtio_blk_discard_write_zeroes *desc;
187 ssize_t size;
188 void *buf;
189
190 size = vub_iov_size(iov, iovcnt);
191 if (size != sizeof(*desc)) {
192 fprintf(stderr, "Invalid size %ld, expect %ld\n", size, sizeof(*desc));
193 return -1;
194 }
195 buf = g_new0(char, size);
196 vub_iov_to_buf(iov, iovcnt, buf);
197
198 #if defined(__linux__) && defined(BLKDISCARD) && defined(BLKZEROOUT)
199 VubDev *vdev_blk = req->vdev_blk;
200 desc = (struct virtio_blk_discard_write_zeroes *)buf;
201 uint64_t range[2] = { le64toh(desc->sector) << 9,
202 le32toh(desc->num_sectors) << 9 };
203 if (type == VIRTIO_BLK_T_DISCARD) {
204 if (ioctl(vdev_blk->blk_fd, BLKDISCARD, range) == 0) {
205 g_free(buf);
206 return 0;
207 }
208 } else if (type == VIRTIO_BLK_T_WRITE_ZEROES) {
209 if (ioctl(vdev_blk->blk_fd, BLKZEROOUT, range) == 0) {
210 g_free(buf);
211 return 0;
212 }
213 }
214 #endif
215
216 g_free(buf);
217 return -1;
218}
219
220static void
221vub_flush(VubReq *req)
222{
223 VubDev *vdev_blk = req->vdev_blk;
224
225 fdatasync(vdev_blk->blk_fd);
226}
227
228static int vub_virtio_process_req(VubDev *vdev_blk,
229 VuVirtq *vq)
230{
231 VugDev *gdev = &vdev_blk->parent;
232 VuDev *vu_dev = &gdev->parent;
233 VuVirtqElement *elem;
234 uint32_t type;
235 unsigned in_num;
236 unsigned out_num;
237 VubReq *req;
238
239 elem = vu_queue_pop(vu_dev, vq, sizeof(VuVirtqElement) + sizeof(VubReq));
240 if (!elem) {
241 return -1;
242 }
243
244
245 if (elem->out_num < 1 || elem->in_num < 1) {
246 fprintf(stderr, "virtio-blk request missing headers\n");
247 free(elem);
248 return -1;
249 }
250
251 req = g_new0(VubReq, 1);
252 req->vdev_blk = vdev_blk;
253 req->vq = vq;
254 req->elem = elem;
255
256 in_num = elem->in_num;
257 out_num = elem->out_num;
258
259
260 if (elem->out_sg[0].iov_len < sizeof(struct virtio_blk_outhdr)) {
261 fprintf(stderr, "Invalid outhdr size\n");
262 goto err;
263 }
264 req->out = (struct virtio_blk_outhdr *)elem->out_sg[0].iov_base;
265 out_num--;
266
267 if (elem->in_sg[in_num - 1].iov_len < sizeof(struct virtio_blk_inhdr)) {
268 fprintf(stderr, "Invalid inhdr size\n");
269 goto err;
270 }
271 req->in = (struct virtio_blk_inhdr *)elem->in_sg[in_num - 1].iov_base;
272 in_num--;
273
274 type = le32toh(req->out->type);
275 switch (type & ~VIRTIO_BLK_T_BARRIER) {
276 case VIRTIO_BLK_T_IN:
277 case VIRTIO_BLK_T_OUT: {
278 ssize_t ret = 0;
279 bool is_write = type & VIRTIO_BLK_T_OUT;
280 req->sector_num = le64toh(req->out->sector);
281 if (is_write) {
282 ret = vub_writev(req, &elem->out_sg[1], out_num);
283 } else {
284 ret = vub_readv(req, &elem->in_sg[0], in_num);
285 }
286 if (ret >= 0) {
287 req->in->status = VIRTIO_BLK_S_OK;
288 } else {
289 req->in->status = VIRTIO_BLK_S_IOERR;
290 }
291 vub_req_complete(req);
292 break;
293 }
294 case VIRTIO_BLK_T_FLUSH:
295 vub_flush(req);
296 req->in->status = VIRTIO_BLK_S_OK;
297 vub_req_complete(req);
298 break;
299 case VIRTIO_BLK_T_GET_ID: {
300 size_t size = MIN(vub_iov_size(&elem->in_sg[0], in_num),
301 VIRTIO_BLK_ID_BYTES);
302 snprintf(elem->in_sg[0].iov_base, size, "%s", "vhost_user_blk");
303 req->in->status = VIRTIO_BLK_S_OK;
304 req->size = elem->in_sg[0].iov_len;
305 vub_req_complete(req);
306 break;
307 }
308 case VIRTIO_BLK_T_DISCARD:
309 case VIRTIO_BLK_T_WRITE_ZEROES: {
310 int rc;
311 rc = vub_discard_write_zeroes(req, &elem->out_sg[1], out_num, type);
312 if (rc == 0) {
313 req->in->status = VIRTIO_BLK_S_OK;
314 } else {
315 req->in->status = VIRTIO_BLK_S_IOERR;
316 }
317 vub_req_complete(req);
318 break;
319 }
320 default:
321 req->in->status = VIRTIO_BLK_S_UNSUPP;
322 vub_req_complete(req);
323 break;
324 }
325
326 return 0;
327
328err:
329 free(elem);
330 g_free(req);
331 return -1;
332}
333
334static void vub_process_vq(VuDev *vu_dev, int idx)
335{
336 VugDev *gdev;
337 VubDev *vdev_blk;
338 VuVirtq *vq;
339 int ret;
340
341 gdev = container_of(vu_dev, VugDev, parent);
342 vdev_blk = container_of(gdev, VubDev, parent);
343 assert(vdev_blk);
344
345 vq = vu_get_queue(vu_dev, idx);
346 assert(vq);
347
348 while (1) {
349 ret = vub_virtio_process_req(vdev_blk, vq);
350 if (ret) {
351 break;
352 }
353 }
354}
355
356static void vub_queue_set_started(VuDev *vu_dev, int idx, bool started)
357{
358 VuVirtq *vq;
359
360 assert(vu_dev);
361
362 vq = vu_get_queue(vu_dev, idx);
363 vu_set_queue_handler(vu_dev, vq, started ? vub_process_vq : NULL);
364}
365
366static uint64_t
367vub_get_features(VuDev *dev)
368{
369 uint64_t features;
370 VugDev *gdev;
371 VubDev *vdev_blk;
372
373 gdev = container_of(dev, VugDev, parent);
374 vdev_blk = container_of(gdev, VubDev, parent);
375
376 features = 1ull << VIRTIO_BLK_F_SIZE_MAX |
377 1ull << VIRTIO_BLK_F_SEG_MAX |
378 1ull << VIRTIO_BLK_F_TOPOLOGY |
379 1ull << VIRTIO_BLK_F_BLK_SIZE |
380 1ull << VIRTIO_BLK_F_FLUSH |
381 #if defined(__linux__) && defined(BLKDISCARD) && defined(BLKZEROOUT)
382 1ull << VIRTIO_BLK_F_DISCARD |
383 1ull << VIRTIO_BLK_F_WRITE_ZEROES |
384 #endif
385 1ull << VIRTIO_BLK_F_CONFIG_WCE |
386 1ull << VIRTIO_F_VERSION_1 |
387 1ull << VHOST_USER_F_PROTOCOL_FEATURES;
388
389 if (vdev_blk->enable_ro) {
390 features |= 1ull << VIRTIO_BLK_F_RO;
391 }
392
393 return features;
394}
395
396static uint64_t
397vub_get_protocol_features(VuDev *dev)
398{
399 return 1ull << VHOST_USER_PROTOCOL_F_CONFIG |
400 1ull << VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD;
401}
402
403static int
404vub_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
405{
406 VugDev *gdev;
407 VubDev *vdev_blk;
408
409 gdev = container_of(vu_dev, VugDev, parent);
410 vdev_blk = container_of(gdev, VubDev, parent);
411 memcpy(config, &vdev_blk->blkcfg, len);
412
413 return 0;
414}
415
416static int
417vub_set_config(VuDev *vu_dev, const uint8_t *data,
418 uint32_t offset, uint32_t size, uint32_t flags)
419{
420 VugDev *gdev;
421 VubDev *vdev_blk;
422 uint8_t wce;
423 int fd;
424
425
426 if (flags != VHOST_SET_CONFIG_TYPE_MASTER) {
427 return -1;
428 }
429
430 gdev = container_of(vu_dev, VugDev, parent);
431 vdev_blk = container_of(gdev, VubDev, parent);
432
433 if (offset != offsetof(struct virtio_blk_config, wce) ||
434 size != 1) {
435 return -1;
436 }
437
438 wce = *data;
439 if (wce == vdev_blk->blkcfg.wce) {
440
441 return 0;
442 }
443
444 vdev_blk->blkcfg.wce = wce;
445 fprintf(stdout, "Write Cache Policy Changed\n");
446 if (vdev_blk->blk_fd >= 0) {
447 close(vdev_blk->blk_fd);
448 vdev_blk->blk_fd = -1;
449 }
450
451 fd = vub_open(vdev_blk->blk_name, wce);
452 if (fd < 0) {
453 fprintf(stderr, "Error to open block device %s\n", vdev_blk->blk_name);
454 vdev_blk->blk_fd = -1;
455 return -1;
456 }
457 vdev_blk->blk_fd = fd;
458
459 return 0;
460}
461
462static const VuDevIface vub_iface = {
463 .get_features = vub_get_features,
464 .queue_set_started = vub_queue_set_started,
465 .get_protocol_features = vub_get_protocol_features,
466 .get_config = vub_get_config,
467 .set_config = vub_set_config,
468};
469
470static int unix_sock_new(char *unix_fn)
471{
472 int sock;
473 struct sockaddr_un un;
474 size_t len;
475
476 assert(unix_fn);
477
478 sock = socket(AF_UNIX, SOCK_STREAM, 0);
479 if (sock <= 0) {
480 perror("socket");
481 return -1;
482 }
483
484 un.sun_family = AF_UNIX;
485 (void)snprintf(un.sun_path, sizeof(un.sun_path), "%s", unix_fn);
486 len = sizeof(un.sun_family) + strlen(un.sun_path);
487
488 (void)unlink(unix_fn);
489 if (bind(sock, (struct sockaddr *)&un, len) < 0) {
490 perror("bind");
491 goto fail;
492 }
493
494 if (listen(sock, 1) < 0) {
495 perror("listen");
496 goto fail;
497 }
498
499 return sock;
500
501fail:
502 (void)close(sock);
503
504 return -1;
505}
506
507static void vub_free(struct VubDev *vdev_blk)
508{
509 if (!vdev_blk) {
510 return;
511 }
512
513 g_main_loop_unref(vdev_blk->loop);
514 if (vdev_blk->blk_fd >= 0) {
515 close(vdev_blk->blk_fd);
516 }
517 g_free(vdev_blk);
518}
519
520static uint32_t
521vub_get_blocksize(int fd)
522{
523 uint32_t blocksize = 512;
524
525#if defined(__linux__) && defined(BLKSSZGET)
526 if (ioctl(fd, BLKSSZGET, &blocksize) == 0) {
527 return blocksize;
528 }
529#endif
530
531 return blocksize;
532}
533
534static void
535vub_initialize_config(int fd, struct virtio_blk_config *config)
536{
537 off64_t capacity;
538
539 capacity = lseek64(fd, 0, SEEK_END);
540 config->capacity = capacity >> 9;
541 config->blk_size = vub_get_blocksize(fd);
542 config->size_max = 65536;
543 config->seg_max = 128 - 2;
544 config->min_io_size = 1;
545 config->opt_io_size = 1;
546 config->num_queues = 1;
547 #if defined(__linux__) && defined(BLKDISCARD) && defined(BLKZEROOUT)
548 config->max_discard_sectors = 32768;
549 config->max_discard_seg = 1;
550 config->discard_sector_alignment = config->blk_size >> 9;
551 config->max_write_zeroes_sectors = 32768;
552 config->max_write_zeroes_seg = 1;
553 #endif
554}
555
556static VubDev *
557vub_new(char *blk_file)
558{
559 VubDev *vdev_blk;
560
561 vdev_blk = g_new0(VubDev, 1);
562 vdev_blk->loop = g_main_loop_new(NULL, FALSE);
563 vdev_blk->blk_fd = vub_open(blk_file, 0);
564 if (vdev_blk->blk_fd < 0) {
565 fprintf(stderr, "Error to open block device %s\n", blk_file);
566 vub_free(vdev_blk);
567 return NULL;
568 }
569 vdev_blk->enable_ro = false;
570 vdev_blk->blkcfg.wce = 0;
571 vdev_blk->blk_name = blk_file;
572
573
574 vub_initialize_config(vdev_blk->blk_fd, &vdev_blk->blkcfg);
575
576 return vdev_blk;
577}
578
579int main(int argc, char **argv)
580{
581 int opt;
582 char *unix_socket = NULL;
583 char *blk_file = NULL;
584 bool enable_ro = false;
585 int lsock = -1, csock = -1;
586 VubDev *vdev_blk = NULL;
587
588 while ((opt = getopt(argc, argv, "b:rs:h")) != -1) {
589 switch (opt) {
590 case 'b':
591 blk_file = g_strdup(optarg);
592 break;
593 case 's':
594 unix_socket = g_strdup(optarg);
595 break;
596 case 'r':
597 enable_ro = true;
598 break;
599 case 'h':
600 default:
601 printf("Usage: %s [ -b block device or file, -s UNIX domain socket"
602 " | -r Enable read-only ] | [ -h ]\n", argv[0]);
603 return 0;
604 }
605 }
606
607 if (!unix_socket || !blk_file) {
608 printf("Usage: %s [ -b block device or file, -s UNIX domain socket"
609 " | -r Enable read-only ] | [ -h ]\n", argv[0]);
610 return -1;
611 }
612
613 lsock = unix_sock_new(unix_socket);
614 if (lsock < 0) {
615 goto err;
616 }
617
618 csock = accept(lsock, (void *)0, (void *)0);
619 if (csock < 0) {
620 fprintf(stderr, "Accept error %s\n", strerror(errno));
621 goto err;
622 }
623
624 vdev_blk = vub_new(blk_file);
625 if (!vdev_blk) {
626 goto err;
627 }
628 if (enable_ro) {
629 vdev_blk->enable_ro = true;
630 }
631
632 if (!vug_init(&vdev_blk->parent, VHOST_USER_BLK_MAX_QUEUES, csock,
633 vub_panic_cb, &vub_iface)) {
634 fprintf(stderr, "Failed to initialized libvhost-user-glib\n");
635 goto err;
636 }
637
638 g_main_loop_run(vdev_blk->loop);
639
640 vug_deinit(&vdev_blk->parent);
641
642err:
643 vub_free(vdev_blk);
644 if (csock >= 0) {
645 close(csock);
646 }
647 if (lsock >= 0) {
648 close(lsock);
649 }
650 g_free(unix_socket);
651 g_free(blk_file);
652
653 return 0;
654}
655