1 // SPDX-License-Identifier: GPL-2.0
2 /* Simple test of virtio code, entirely in userpsace. */
3 #define _GNU_SOURCE
4 #include <sched.h>
5 #include <err.h>
6 #include <linux/kernel.h>
7 #include <linux/err.h>
8 #include <linux/virtio.h>
9 #include <linux/vringh.h>
10 #include <linux/virtio_ring.h>
11 #include <linux/virtio_config.h>
12 #include <linux/uaccess.h>
13 #include <sys/types.h>
14 #include <sys/stat.h>
15 #include <sys/mman.h>
16 #include <sys/wait.h>
17 #include <fcntl.h>
18
19 #define USER_MEM (1024*1024)
20 void *__user_addr_min, *__user_addr_max;
21 void *__kmalloc_fake, *__kfree_ignore_start, *__kfree_ignore_end;
22 static u64 user_addr_offset;
23
24 #define RINGSIZE 256
25 #define ALIGN 4096
26
27 static bool never_notify_host(struct virtqueue *vq)
28 {
29 abort();
30 }
31
32 static void never_callback_guest(struct virtqueue *vq)
33 {
34 abort();
35 }
36
37 static bool getrange_iov(struct vringh *vrh, u64 addr, struct vringh_range *r)
38 {
39 if (addr < (u64)(unsigned long)__user_addr_min - user_addr_offset)
40 return false;
41 if (addr >= (u64)(unsigned long)__user_addr_max - user_addr_offset)
42 return false;
43
44 r->start = (u64)(unsigned long)__user_addr_min - user_addr_offset;
45 r->end_incl = (u64)(unsigned long)__user_addr_max - 1 - user_addr_offset;
46 r->offset = user_addr_offset;
47 return true;
48 }
49
50 /* We return single byte ranges. */
51 static bool getrange_slow(struct vringh *vrh, u64 addr, struct vringh_range *r)
52 {
53 if (addr < (u64)(unsigned long)__user_addr_min - user_addr_offset)
54 return false;
55 if (addr >= (u64)(unsigned long)__user_addr_max - user_addr_offset)
56 return false;
57
58 r->start = addr;
59 r->end_incl = r->start;
60 r->offset = user_addr_offset;
61 return true;
62 }
63
64 struct guest_virtio_device {
65 struct virtio_device vdev;
66 int to_host_fd;
67 unsigned long notifies;
68 };
69
70 static bool parallel_notify_host(struct virtqueue *vq)
71 {
72 int rc;
73 struct guest_virtio_device *gvdev;
74
75 gvdev = container_of(vq->vdev, struct guest_virtio_device, vdev);
76 rc = write(gvdev->to_host_fd, "", 1);
77 if (rc < 0)
78 return false;
79 gvdev->notifies++;
80 return true;
81 }
82
83 static bool no_notify_host(struct virtqueue *vq)
84 {
85 return true;
86 }
87
88 #define NUM_XFERS (10000000)
89
90 /* We aim for two "distant" cpus. */
91 static void find_cpus(unsigned int *first, unsigned int *last)
92 {
93 unsigned int i;
94
95 *first = -1U;
96 *last = 0;
97 for (i = 0; i < 4096; i++) {
98 cpu_set_t set;
99 CPU_ZERO(&set);
100 CPU_SET(i, &set);
101 if (sched_setaffinity(getpid(), sizeof(set), &set) == 0) {
102 if (i < *first)
103 *first = i;
104 if (i > *last)
105 *last = i;
106 }
107 }
108 }
109
110 /* Opencoded version for fast mode */
111 static inline int vringh_get_head(struct vringh *vrh, u16 *head)
112 {
113 u16 avail_idx, i;
114 int err;
115
116 err = get_user(avail_idx, &vrh->vring.avail->idx);
117 if (err)
118 return err;
119
120 if (vrh->last_avail_idx == avail_idx)
121 return 0;
122
123 /* Only get avail ring entries after they have been exposed by guest. */
124 virtio_rmb(vrh->weak_barriers);
125
126 i = vrh->last_avail_idx & (vrh->vring.num - 1);
127
128 err = get_user(*head, &vrh->vring.avail->ring[i]);
129 if (err)
130 return err;
131
132 vrh->last_avail_idx++;
133 return 1;
134 }
135
136 static int parallel_test(u64 features,
137 bool (*getrange)(struct vringh *vrh,
138 u64 addr, struct vringh_range *r),
139 bool fast_vringh)
140 {
141 void *host_map, *guest_map;
142 int fd, mapsize, to_guest[2], to_host[2];
143 unsigned long xfers = 0, notifies = 0, receives = 0;
144 unsigned int first_cpu, last_cpu;
145 cpu_set_t cpu_set;
146 char buf[128];
147
148 /* Create real file to mmap. */
149 fd = open("/tmp/vringh_test-file", O_RDWR|O_CREAT|O_TRUNC, 0600);
150 if (fd < 0)
151 err(1, "Opening /tmp/vringh_test-file");
152
153 /* Extra room at the end for some data, and indirects */
154 mapsize = vring_size(RINGSIZE, ALIGN)
155 + RINGSIZE * 2 * sizeof(int)
156 + RINGSIZE * 6 * sizeof(struct vring_desc);
157 mapsize = (mapsize + getpagesize() - 1) & ~(getpagesize() - 1);
158 ftruncate(fd, mapsize);
159
160 /* Parent and child use separate addresses, to check our mapping logic! */
161 host_map = mmap(NULL, mapsize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
162 guest_map = mmap(NULL, mapsize, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
163
164 pipe(to_guest);
165 pipe(to_host);
166
167 CPU_ZERO(&cpu_set);
168 find_cpus(&first_cpu, &last_cpu);
169 printf("Using CPUS %u and %u\n", first_cpu, last_cpu);
170 fflush(stdout);
171
172 if (fork() != 0) {
173 struct vringh vrh;
174 int status, err, rlen = 0;
175 char rbuf[5];
176
177 /* We are the host: never access guest addresses! */
178 munmap(guest_map, mapsize);
179
180 __user_addr_min = host_map;
181 __user_addr_max = __user_addr_min + mapsize;
182 user_addr_offset = host_map - guest_map;
183 assert(user_addr_offset);
184
185 close(to_guest[0]);
186 close(to_host[1]);
187
188 vring_init(&vrh.vring, RINGSIZE, host_map, ALIGN);
189 vringh_init_user(&vrh, features, RINGSIZE, true,
190 vrh.vring.desc, vrh.vring.avail, vrh.vring.used);
191 CPU_SET(first_cpu, &cpu_set);
192 if (sched_setaffinity(getpid(), sizeof(cpu_set), &cpu_set))
193 errx(1, "Could not set affinity to cpu %u", first_cpu);
194
195 while (xfers < NUM_XFERS) {
196 struct iovec host_riov[2], host_wiov[2];
197 struct vringh_iov riov, wiov;
198 u16 head, written;
199
200 if (fast_vringh) {
201 for (;;) {
202 err = vringh_get_head(&vrh, &head);
203 if (err != 0)
204 break;
205 err = vringh_need_notify_user(&vrh);
206 if (err < 0)
207 errx(1, "vringh_need_notify_user: %i",
208 err);
209 if (err) {
210 write(to_guest[1], "", 1);
211 notifies++;
212 }
213 }
214 if (err != 1)
215 errx(1, "vringh_get_head");
216 written = 0;
217 goto complete;
218 } else {
219 vringh_iov_init(&riov,
220 host_riov,
221 ARRAY_SIZE(host_riov));
222 vringh_iov_init(&wiov,
223 host_wiov,
224 ARRAY_SIZE(host_wiov));
225
226 err = vringh_getdesc_user(&vrh, &riov, &wiov,
227 getrange, &head);
228 }
229 if (err == 0) {
230 err = vringh_need_notify_user(&vrh);
231 if (err < 0)
232 errx(1, "vringh_need_notify_user: %i",
233 err);
234 if (err) {
235 write(to_guest[1], "", 1);
236 notifies++;
237 }
238
239 if (!vringh_notify_enable_user(&vrh))
240 continue;
241
242 /* Swallow all notifies at once. */
243 if (read(to_host[0], buf, sizeof(buf)) < 1)
244 break;
245
246 vringh_notify_disable_user(&vrh);
247 receives++;
248 continue;
249 }
250 if (err != 1)
251 errx(1, "vringh_getdesc_user: %i", err);
252
253 /* We simply copy bytes. */
254 if (riov.used) {
255 rlen = vringh_iov_pull_user(&riov, rbuf,
256 sizeof(rbuf));
257 if (rlen != 4)
258 errx(1, "vringh_iov_pull_user: %i",
259 rlen);
260 assert(riov.i == riov.used);
261 written = 0;
262 } else {
263 err = vringh_iov_push_user(&wiov, rbuf, rlen);
264 if (err != rlen)
265 errx(1, "vringh_iov_push_user: %i",
266 err);
267 assert(wiov.i == wiov.used);
268 written = err;
269 }
270 complete:
271 xfers++;
272
273 err = vringh_complete_user(&vrh, head, written);
274 if (err != 0)
275 errx(1, "vringh_complete_user: %i", err);
276 }
277
278 err = vringh_need_notify_user(&vrh);
279 if (err < 0)
280 errx(1, "vringh_need_notify_user: %i", err);
281 if (err) {
282 write(to_guest[1], "", 1);
283 notifies++;
284 }
285 wait(&status);
286 if (!WIFEXITED(status))
287 errx(1, "Child died with signal %i?", WTERMSIG(status));
288 if (WEXITSTATUS(status) != 0)
289 errx(1, "Child exited %i?", WEXITSTATUS(status));
290 printf("Host: notified %lu, pinged %lu\n", notifies, receives);
291 return 0;
292 } else {
293 struct guest_virtio_device gvdev;
294 struct virtqueue *vq;
295 unsigned int *data;
296 struct vring_desc *indirects;
297 unsigned int finished = 0;
298
299 /* We pass sg[]s pointing into here, but we need RINGSIZE+1 */
300 data = guest_map + vring_size(RINGSIZE, ALIGN);
301 indirects = (void *)data + (RINGSIZE + 1) * 2 * sizeof(int);
302
303 /* We are the guest. */
304 munmap(host_map, mapsize);
305
306 close(to_guest[1]);
307 close(to_host[0]);
308
309 gvdev.vdev.features = features;
310 gvdev.to_host_fd = to_host[1];
311 gvdev.notifies = 0;
312
313 CPU_SET(first_cpu, &cpu_set);
314 if (sched_setaffinity(getpid(), sizeof(cpu_set), &cpu_set))
315 err(1, "Could not set affinity to cpu %u", first_cpu);
316
317 vq = vring_new_virtqueue(0, RINGSIZE, ALIGN, &gvdev.vdev, true,
318 false, guest_map,
319 fast_vringh ? no_notify_host
320 : parallel_notify_host,
321 never_callback_guest, "guest vq");
322
323 /* Don't kfree indirects. */
324 __kfree_ignore_start = indirects;
325 __kfree_ignore_end = indirects + RINGSIZE * 6;
326
327 while (xfers < NUM_XFERS) {
328 struct scatterlist sg[4];
329 unsigned int num_sg, len;
330 int *dbuf, err;
331 bool output = !(xfers % 2);
332
333 /* Consume bufs. */
334 while ((dbuf = virtqueue_get_buf(vq, &len)) != NULL) {
335 if (len == 4)
336 assert(*dbuf == finished - 1);
337 else if (!fast_vringh)
338 assert(*dbuf == finished);
339 finished++;
340 }
341
342 /* Produce a buffer. */
343 dbuf = data + (xfers % (RINGSIZE + 1));
344
345 if (output)
346 *dbuf = xfers;
347 else
348 *dbuf = -1;
349
350 switch ((xfers / sizeof(*dbuf)) % 4) {
351 case 0:
352 /* Nasty three-element sg list. */
353 sg_init_table(sg, num_sg = 3);
354 sg_set_buf(&sg[0], (void *)dbuf, 1);
355 sg_set_buf(&sg[1], (void *)dbuf + 1, 2);
356 sg_set_buf(&sg[2], (void *)dbuf + 3, 1);
357 break;
358 case 1:
359 sg_init_table(sg, num_sg = 2);
360 sg_set_buf(&sg[0], (void *)dbuf, 1);
361 sg_set_buf(&sg[1], (void *)dbuf + 1, 3);
362 break;
363 case 2:
364 sg_init_table(sg, num_sg = 1);
365 sg_set_buf(&sg[0], (void *)dbuf, 4);
366 break;
367 case 3:
368 sg_init_table(sg, num_sg = 4);
369 sg_set_buf(&sg[0], (void *)dbuf, 1);
370 sg_set_buf(&sg[1], (void *)dbuf + 1, 1);
371 sg_set_buf(&sg[2], (void *)dbuf + 2, 1);
372 sg_set_buf(&sg[3], (void *)dbuf + 3, 1);
373 break;
374 }
375
376 /* May allocate an indirect, so force it to allocate
377 * user addr */
378 __kmalloc_fake = indirects + (xfers % RINGSIZE) * 4;
379 if (output)
380 err = virtqueue_add_outbuf(vq, sg, num_sg, dbuf,
381 GFP_KERNEL);
382 else
383 err = virtqueue_add_inbuf(vq, sg, num_sg,
384 dbuf, GFP_KERNEL);
385
386 if (err == -ENOSPC) {
387 if (!virtqueue_enable_cb_delayed(vq))
388 continue;
389 /* Swallow all notifies at once. */
390 if (read(to_guest[0], buf, sizeof(buf)) < 1)
391 break;
392
393 receives++;
394 virtqueue_disable_cb(vq);
395 continue;
396 }
397
398 if (err)
399 errx(1, "virtqueue_add_in/outbuf: %i", err);
400
401 xfers++;
402 virtqueue_kick(vq);
403 }
404
405 /* Any extra? */
406 while (finished != xfers) {
407 int *dbuf;
408 unsigned int len;
409
410 /* Consume bufs. */
411 dbuf = virtqueue_get_buf(vq, &len);
412 if (dbuf) {
413 if (len == 4)
414 assert(*dbuf == finished - 1);
415 else
416 assert(len == 0);
417 finished++;
418 continue;
419 }
420
421 if (!virtqueue_enable_cb_delayed(vq))
422 continue;
423 if (read(to_guest[0], buf, sizeof(buf)) < 1)
424 break;
425
426 receives++;
427 virtqueue_disable_cb(vq);
428 }
429
430 printf("Guest: notified %lu, pinged %lu\n",
431 gvdev.notifies, receives);
432 vring_del_virtqueue(vq);
433 return 0;
434 }
435 }
436
437 int main(int argc, char *argv[])
438 {
439 struct virtio_device vdev;
440 struct virtqueue *vq;
441 struct vringh vrh;
442 struct scatterlist guest_sg[RINGSIZE], *sgs[2];
443 struct iovec host_riov[2], host_wiov[2];
444 struct vringh_iov riov, wiov;
445 struct vring_used_elem used[RINGSIZE];
446 char buf[28];
447 u16 head;
448 int err;
449 unsigned i;
450 void *ret;
451 bool (*getrange)(struct vringh *vrh, u64 addr, struct vringh_range *r);
452 bool fast_vringh = false, parallel = false;
453
454 getrange = getrange_iov;
455 vdev.features = 0;
456
457 while (argv[1]) {
458 if (strcmp(argv[1], "--indirect") == 0)
459 __virtio_set_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC);
460 else if (strcmp(argv[1], "--eventidx") == 0)
461 __virtio_set_bit(&vdev, VIRTIO_RING_F_EVENT_IDX);
462 else if (strcmp(argv[1], "--virtio-1") == 0)
463 __virtio_set_bit(&vdev, VIRTIO_F_VERSION_1);
464 else if (strcmp(argv[1], "--slow-range") == 0)
465 getrange = getrange_slow;
466 else if (strcmp(argv[1], "--fast-vringh") == 0)
467 fast_vringh = true;
468 else if (strcmp(argv[1], "--parallel") == 0)
469 parallel = true;
470 else
471 errx(1, "Unknown arg %s", argv[1]);
472 argv++;
473 }
474
475 if (parallel)
476 return parallel_test(vdev.features, getrange, fast_vringh);
477
478 if (posix_memalign(&__user_addr_min, PAGE_SIZE, USER_MEM) != 0)
479 abort();
480 __user_addr_max = __user_addr_min + USER_MEM;
481 memset(__user_addr_min, 0, vring_size(RINGSIZE, ALIGN));
482
483 /* Set up guest side. */
484 vq = vring_new_virtqueue(0, RINGSIZE, ALIGN, &vdev, true, false,
485 __user_addr_min,
486 never_notify_host, never_callback_guest,
487 "guest vq");
488
489 /* Set up host side. */
490 vring_init(&vrh.vring, RINGSIZE, __user_addr_min, ALIGN);
491 vringh_init_user(&vrh, vdev.features, RINGSIZE, true,
492 vrh.vring.desc, vrh.vring.avail, vrh.vring.used);
493
494 /* No descriptor to get yet... */
495 err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
496 if (err != 0)
497 errx(1, "vringh_getdesc_user: %i", err);
498
499 /* Guest puts in a descriptor. */
500 memcpy(__user_addr_max - 1, "a", 1);
501 sg_init_table(guest_sg, 1);
502 sg_set_buf(&guest_sg[0], __user_addr_max - 1, 1);
503 sg_init_table(guest_sg+1, 1);
504 sg_set_buf(&guest_sg[1], __user_addr_max - 3, 2);
505 sgs[0] = &guest_sg[0];
506 sgs[1] = &guest_sg[1];
507
508 /* May allocate an indirect, so force it to allocate user addr */
509 __kmalloc_fake = __user_addr_min + vring_size(RINGSIZE, ALIGN);
510 err = virtqueue_add_sgs(vq, sgs, 1, 1, &err, GFP_KERNEL);
511 if (err)
512 errx(1, "virtqueue_add_sgs: %i", err);
513 __kmalloc_fake = NULL;
514
515 /* Host retreives it. */
516 vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
517 vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
518
519 err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
520 if (err != 1)
521 errx(1, "vringh_getdesc_user: %i", err);
522
523 assert(riov.used == 1);
524 assert(riov.iov[0].iov_base == __user_addr_max - 1);
525 assert(riov.iov[0].iov_len == 1);
526 if (getrange != getrange_slow) {
527 assert(wiov.used == 1);
528 assert(wiov.iov[0].iov_base == __user_addr_max - 3);
529 assert(wiov.iov[0].iov_len == 2);
530 } else {
531 assert(wiov.used == 2);
532 assert(wiov.iov[0].iov_base == __user_addr_max - 3);
533 assert(wiov.iov[0].iov_len == 1);
534 assert(wiov.iov[1].iov_base == __user_addr_max - 2);
535 assert(wiov.iov[1].iov_len == 1);
536 }
537
538 err = vringh_iov_pull_user(&riov, buf, 5);
539 if (err != 1)
540 errx(1, "vringh_iov_pull_user: %i", err);
541 assert(buf[0] == 'a');
542 assert(riov.i == 1);
543 assert(vringh_iov_pull_user(&riov, buf, 5) == 0);
544
545 memcpy(buf, "bcdef", 5);
546 err = vringh_iov_push_user(&wiov, buf, 5);
547 if (err != 2)
548 errx(1, "vringh_iov_push_user: %i", err);
549 assert(memcmp(__user_addr_max - 3, "bc", 2) == 0);
550 assert(wiov.i == wiov.used);
551 assert(vringh_iov_push_user(&wiov, buf, 5) == 0);
552
553 /* Host is done. */
554 err = vringh_complete_user(&vrh, head, err);
555 if (err != 0)
556 errx(1, "vringh_complete_user: %i", err);
557
558 /* Guest should see used token now. */
559 __kfree_ignore_start = __user_addr_min + vring_size(RINGSIZE, ALIGN);
560 __kfree_ignore_end = __kfree_ignore_start + 1;
561 ret = virtqueue_get_buf(vq, &i);
562 if (ret != &err)
563 errx(1, "virtqueue_get_buf: %p", ret);
564 assert(i == 2);
565
566 /* Guest puts in a huge descriptor. */
567 sg_init_table(guest_sg, RINGSIZE);
568 for (i = 0; i < RINGSIZE; i++) {
569 sg_set_buf(&guest_sg[i],
570 __user_addr_max - USER_MEM/4, USER_MEM/4);
571 }
572
573 /* Fill contents with recognisable garbage. */
574 for (i = 0; i < USER_MEM/4; i++)
575 ((char *)__user_addr_max - USER_MEM/4)[i] = i;
576
577 /* This will allocate an indirect, so force it to allocate user addr */
578 __kmalloc_fake = __user_addr_min + vring_size(RINGSIZE, ALIGN);
579 err = virtqueue_add_outbuf(vq, guest_sg, RINGSIZE, &err, GFP_KERNEL);
580 if (err)
581 errx(1, "virtqueue_add_outbuf (large): %i", err);
582 __kmalloc_fake = NULL;
583
584 /* Host picks it up (allocates new iov). */
585 vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
586 vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
587
588 err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
589 if (err != 1)
590 errx(1, "vringh_getdesc_user: %i", err);
591
592 assert(riov.max_num & VRINGH_IOV_ALLOCATED);
593 assert(riov.iov != host_riov);
594 if (getrange != getrange_slow)
595 assert(riov.used == RINGSIZE);
596 else
597 assert(riov.used == RINGSIZE * USER_MEM/4);
598
599 assert(!(wiov.max_num & VRINGH_IOV_ALLOCATED));
600 assert(wiov.used == 0);
601
602 /* Pull data back out (in odd chunks), should be as expected. */
603 for (i = 0; i < RINGSIZE * USER_MEM/4; i += 3) {
604 err = vringh_iov_pull_user(&riov, buf, 3);
605 if (err != 3 && i + err != RINGSIZE * USER_MEM/4)
606 errx(1, "vringh_iov_pull_user large: %i", err);
607 assert(buf[0] == (char)i);
608 assert(err < 2 || buf[1] == (char)(i + 1));
609 assert(err < 3 || buf[2] == (char)(i + 2));
610 }
611 assert(riov.i == riov.used);
612 vringh_iov_cleanup(&riov);
613 vringh_iov_cleanup(&wiov);
614
615 /* Complete using multi interface, just because we can. */
616 used[0].id = head;
617 used[0].len = 0;
618 err = vringh_complete_multi_user(&vrh, used, 1);
619 if (err)
620 errx(1, "vringh_complete_multi_user(1): %i", err);
621
622 /* Free up those descriptors. */
623 ret = virtqueue_get_buf(vq, &i);
624 if (ret != &err)
625 errx(1, "virtqueue_get_buf: %p", ret);
626
627 /* Add lots of descriptors. */
628 sg_init_table(guest_sg, 1);
629 sg_set_buf(&guest_sg[0], __user_addr_max - 1, 1);
630 for (i = 0; i < RINGSIZE; i++) {
631 err = virtqueue_add_outbuf(vq, guest_sg, 1, &err, GFP_KERNEL);
632 if (err)
633 errx(1, "virtqueue_add_outbuf (multiple): %i", err);
634 }
635
636 /* Now get many, and consume them all at once. */
637 vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
638 vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
639
640 for (i = 0; i < RINGSIZE; i++) {
641 err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
642 if (err != 1)
643 errx(1, "vringh_getdesc_user: %i", err);
644 used[i].id = head;
645 used[i].len = 0;
646 }
647 /* Make sure it wraps around ring, to test! */
648 assert(vrh.vring.used->idx % RINGSIZE != 0);
649 err = vringh_complete_multi_user(&vrh, used, RINGSIZE);
650 if (err)
651 errx(1, "vringh_complete_multi_user: %i", err);
652
653 /* Free those buffers. */
654 for (i = 0; i < RINGSIZE; i++) {
655 unsigned len;
656 assert(virtqueue_get_buf(vq, &len) != NULL);
657 }
658
659 /* Test weird (but legal!) indirect. */
660 if (__virtio_test_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC)) {
661 char *data = __user_addr_max - USER_MEM/4;
662 struct vring_desc *d = __user_addr_max - USER_MEM/2;
663 struct vring vring;
664
665 /* Force creation of direct, which we modify. */
666 __virtio_clear_bit(&vdev, VIRTIO_RING_F_INDIRECT_DESC);
667 vq = vring_new_virtqueue(0, RINGSIZE, ALIGN, &vdev, true,
668 false, __user_addr_min,
669 never_notify_host,
670 never_callback_guest,
671 "guest vq");
672
673 sg_init_table(guest_sg, 4);
674 sg_set_buf(&guest_sg[0], d, sizeof(*d)*2);
675 sg_set_buf(&guest_sg[1], d + 2, sizeof(*d)*1);
676 sg_set_buf(&guest_sg[2], data + 6, 4);
677 sg_set_buf(&guest_sg[3], d + 3, sizeof(*d)*3);
678
679 err = virtqueue_add_outbuf(vq, guest_sg, 4, &err, GFP_KERNEL);
680 if (err)
681 errx(1, "virtqueue_add_outbuf (indirect): %i", err);
682
683 vring_init(&vring, RINGSIZE, __user_addr_min, ALIGN);
684
685 /* They're used in order, but double-check... */
686 assert(vring.desc[0].addr == (unsigned long)d);
687 assert(vring.desc[1].addr == (unsigned long)(d+2));
688 assert(vring.desc[2].addr == (unsigned long)data + 6);
689 assert(vring.desc[3].addr == (unsigned long)(d+3));
690 vring.desc[0].flags |= VRING_DESC_F_INDIRECT;
691 vring.desc[1].flags |= VRING_DESC_F_INDIRECT;
692 vring.desc[3].flags |= VRING_DESC_F_INDIRECT;
693
694 /* First indirect */
695 d[0].addr = (unsigned long)data;
696 d[0].len = 1;
697 d[0].flags = VRING_DESC_F_NEXT;
698 d[0].next = 1;
699 d[1].addr = (unsigned long)data + 1;
700 d[1].len = 2;
701 d[1].flags = 0;
702
703 /* Second indirect */
704 d[2].addr = (unsigned long)data + 3;
705 d[2].len = 3;
706 d[2].flags = 0;
707
708 /* Third indirect */
709 d[3].addr = (unsigned long)data + 10;
710 d[3].len = 5;
711 d[3].flags = VRING_DESC_F_NEXT;
712 d[3].next = 1;
713 d[4].addr = (unsigned long)data + 15;
714 d[4].len = 6;
715 d[4].flags = VRING_DESC_F_NEXT;
716 d[4].next = 2;
717 d[5].addr = (unsigned long)data + 21;
718 d[5].len = 7;
719 d[5].flags = 0;
720
721 /* Host picks it up (allocates new iov). */
722 vringh_iov_init(&riov, host_riov, ARRAY_SIZE(host_riov));
723 vringh_iov_init(&wiov, host_wiov, ARRAY_SIZE(host_wiov));
724
725 err = vringh_getdesc_user(&vrh, &riov, &wiov, getrange, &head);
726 if (err != 1)
727 errx(1, "vringh_getdesc_user: %i", err);
728
729 if (head != 0)
730 errx(1, "vringh_getdesc_user: head %i not 0", head);
731
732 assert(riov.max_num & VRINGH_IOV_ALLOCATED);
733 if (getrange != getrange_slow)
734 assert(riov.used == 7);
735 else
736 assert(riov.used == 28);
737 err = vringh_iov_pull_user(&riov, buf, 29);
738 assert(err == 28);
739
740 /* Data should be linear. */
741 for (i = 0; i < err; i++)
742 assert(buf[i] == i);
743 vringh_iov_cleanup(&riov);
744 }
745
746 /* Don't leak memory... */
747 vring_del_virtqueue(vq);
748 free(__user_addr_min);
749
750 return 0;
751 }
752
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