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1 /*
2 * VDUSE (vDPA Device in Userspace) library
3 *
4 * Copyright (C) 2022 Bytedance Inc. and/or its affiliates. All rights reserved.
5 * Portions of codes and concepts borrowed from libvhost-user.c, so:
6 * Copyright IBM, Corp. 2007
7 * Copyright (c) 2016 Red Hat, Inc.
8 *
9 * Author:
10 * Xie Yongji <xieyongji@bytedance.com>
11 * Anthony Liguori <aliguori@us.ibm.com>
12 * Marc-André Lureau <mlureau@redhat.com>
13 * Victor Kaplansky <victork@redhat.com>
14 *
15 * This work is licensed under the terms of the GNU GPL, version 2 or
16 * later. See the COPYING file in the top-level directory.
17 */
18
19 #ifndef _GNU_SOURCE
20 #define _GNU_SOURCE
21 #endif
22
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <stdbool.h>
26 #include <stddef.h>
27 #include <errno.h>
28 #include <string.h>
29 #include <assert.h>
30 #include <endian.h>
31 #include <unistd.h>
32 #include <limits.h>
33 #include <fcntl.h>
34 #include <inttypes.h>
35
36 #include <sys/ioctl.h>
37 #include <sys/eventfd.h>
38 #include <sys/mman.h>
39
40 #include "include/atomic.h"
41 #include "linux-headers/linux/virtio_ring.h"
42 #include "linux-headers/linux/virtio_config.h"
43 #include "linux-headers/linux/vduse.h"
44 #include "libvduse.h"
45
46 #define VDUSE_VQ_ALIGN 4096
47 #define MAX_IOVA_REGIONS 256
48
49 #define LOG_ALIGNMENT 64
50
51 /* Round number down to multiple */
52 #define ALIGN_DOWN(n, m) ((n) / (m) * (m))
53
54 /* Round number up to multiple */
55 #define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m))
56
57 #ifndef unlikely
58 #define unlikely(x) __builtin_expect(!!(x), 0)
59 #endif
60
61 typedef struct VduseDescStateSplit {
62 uint8_t inflight;
63 uint8_t padding[5];
64 uint16_t next;
65 uint64_t counter;
66 } VduseDescStateSplit;
67
68 typedef struct VduseVirtqLogInflight {
69 uint64_t features;
70 uint16_t version;
71 uint16_t desc_num;
72 uint16_t last_batch_head;
73 uint16_t used_idx;
74 VduseDescStateSplit desc[];
75 } VduseVirtqLogInflight;
76
77 typedef struct VduseVirtqLog {
78 VduseVirtqLogInflight inflight;
79 } VduseVirtqLog;
80
81 typedef struct VduseVirtqInflightDesc {
82 uint16_t index;
83 uint64_t counter;
84 } VduseVirtqInflightDesc;
85
86 typedef struct VduseRing {
87 unsigned int num;
88 uint64_t desc_addr;
89 uint64_t avail_addr;
90 uint64_t used_addr;
91 struct vring_desc *desc;
92 struct vring_avail *avail;
93 struct vring_used *used;
94 } VduseRing;
95
96 struct VduseVirtq {
97 VduseRing vring;
98 uint16_t last_avail_idx;
99 uint16_t shadow_avail_idx;
100 uint16_t used_idx;
101 uint16_t signalled_used;
102 bool signalled_used_valid;
103 int index;
104 unsigned int inuse;
105 bool ready;
106 int fd;
107 VduseDev *dev;
108 VduseVirtqInflightDesc *resubmit_list;
109 uint16_t resubmit_num;
110 uint64_t counter;
111 VduseVirtqLog *log;
112 };
113
114 typedef struct VduseIovaRegion {
115 uint64_t iova;
116 uint64_t size;
117 uint64_t mmap_offset;
118 uint64_t mmap_addr;
119 } VduseIovaRegion;
120
121 struct VduseDev {
122 VduseVirtq *vqs;
123 VduseIovaRegion regions[MAX_IOVA_REGIONS];
124 int num_regions;
125 char *name;
126 uint32_t device_id;
127 uint32_t vendor_id;
128 uint16_t num_queues;
129 uint16_t queue_size;
130 uint64_t features;
131 const VduseOps *ops;
132 int fd;
133 int ctrl_fd;
134 void *priv;
135 void *log;
136 };
137
138 static inline size_t vduse_vq_log_size(uint16_t queue_size)
139 {
140 return ALIGN_UP(sizeof(VduseDescStateSplit) * queue_size +
141 sizeof(VduseVirtqLogInflight), LOG_ALIGNMENT);
142 }
143
144 static void *vduse_log_get(const char *filename, size_t size)
145 {
146 void *ptr = MAP_FAILED;
147 int fd;
148
149 fd = open(filename, O_RDWR | O_CREAT, 0600);
150 if (fd == -1) {
151 return MAP_FAILED;
152 }
153
154 if (ftruncate(fd, size) == -1) {
155 goto out;
156 }
157
158 ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
159
160 out:
161 close(fd);
162 return ptr;
163 }
164
165 static inline bool has_feature(uint64_t features, unsigned int fbit)
166 {
167 assert(fbit < 64);
168 return !!(features & (1ULL << fbit));
169 }
170
171 static inline bool vduse_dev_has_feature(VduseDev *dev, unsigned int fbit)
172 {
173 return has_feature(dev->features, fbit);
174 }
175
176 uint64_t vduse_get_virtio_features(void)
177 {
178 return (1ULL << VIRTIO_F_IOMMU_PLATFORM) |
179 (1ULL << VIRTIO_F_VERSION_1) |
180 (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) |
181 (1ULL << VIRTIO_RING_F_EVENT_IDX) |
182 (1ULL << VIRTIO_RING_F_INDIRECT_DESC);
183 }
184
185 VduseDev *vduse_queue_get_dev(VduseVirtq *vq)
186 {
187 return vq->dev;
188 }
189
190 int vduse_queue_get_fd(VduseVirtq *vq)
191 {
192 return vq->fd;
193 }
194
195 void *vduse_dev_get_priv(VduseDev *dev)
196 {
197 return dev->priv;
198 }
199
200 VduseVirtq *vduse_dev_get_queue(VduseDev *dev, int index)
201 {
202 return &dev->vqs[index];
203 }
204
205 int vduse_dev_get_fd(VduseDev *dev)
206 {
207 return dev->fd;
208 }
209
210 static int vduse_inject_irq(VduseDev *dev, int index)
211 {
212 return ioctl(dev->fd, VDUSE_VQ_INJECT_IRQ, &index);
213 }
214
215 static int inflight_desc_compare(const void *a, const void *b)
216 {
217 VduseVirtqInflightDesc *desc0 = (VduseVirtqInflightDesc *)a,
218 *desc1 = (VduseVirtqInflightDesc *)b;
219
220 if (desc1->counter > desc0->counter &&
221 (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) {
222 return 1;
223 }
224
225 return -1;
226 }
227
228 static int vduse_queue_check_inflights(VduseVirtq *vq)
229 {
230 int i = 0;
231 VduseDev *dev = vq->dev;
232
233 vq->used_idx = le16toh(vq->vring.used->idx);
234 vq->resubmit_num = 0;
235 vq->resubmit_list = NULL;
236 vq->counter = 0;
237
238 if (unlikely(vq->log->inflight.used_idx != vq->used_idx)) {
239 if (vq->log->inflight.last_batch_head > VIRTQUEUE_MAX_SIZE) {
240 return -1;
241 }
242
243 vq->log->inflight.desc[vq->log->inflight.last_batch_head].inflight = 0;
244
245 barrier();
246
247 vq->log->inflight.used_idx = vq->used_idx;
248 }
249
250 for (i = 0; i < vq->log->inflight.desc_num; i++) {
251 if (vq->log->inflight.desc[i].inflight == 1) {
252 vq->inuse++;
253 }
254 }
255
256 vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx;
257
258 if (vq->inuse) {
259 vq->resubmit_list = calloc(vq->inuse, sizeof(VduseVirtqInflightDesc));
260 if (!vq->resubmit_list) {
261 return -1;
262 }
263
264 for (i = 0; i < vq->log->inflight.desc_num; i++) {
265 if (vq->log->inflight.desc[i].inflight) {
266 vq->resubmit_list[vq->resubmit_num].index = i;
267 vq->resubmit_list[vq->resubmit_num].counter =
268 vq->log->inflight.desc[i].counter;
269 vq->resubmit_num++;
270 }
271 }
272
273 if (vq->resubmit_num > 1) {
274 qsort(vq->resubmit_list, vq->resubmit_num,
275 sizeof(VduseVirtqInflightDesc), inflight_desc_compare);
276 }
277 vq->counter = vq->resubmit_list[0].counter + 1;
278 }
279
280 vduse_inject_irq(dev, vq->index);
281
282 return 0;
283 }
284
285 static int vduse_queue_inflight_get(VduseVirtq *vq, int desc_idx)
286 {
287 vq->log->inflight.desc[desc_idx].counter = vq->counter++;
288
289 barrier();
290
291 vq->log->inflight.desc[desc_idx].inflight = 1;
292
293 return 0;
294 }
295
296 static int vduse_queue_inflight_pre_put(VduseVirtq *vq, int desc_idx)
297 {
298 vq->log->inflight.last_batch_head = desc_idx;
299
300 return 0;
301 }
302
303 static int vduse_queue_inflight_post_put(VduseVirtq *vq, int desc_idx)
304 {
305 vq->log->inflight.desc[desc_idx].inflight = 0;
306
307 barrier();
308
309 vq->log->inflight.used_idx = vq->used_idx;
310
311 return 0;
312 }
313
314 static void vduse_iova_remove_region(VduseDev *dev, uint64_t start,
315 uint64_t last)
316 {
317 int i;
318
319 if (last == start) {
320 return;
321 }
322
323 for (i = 0; i < MAX_IOVA_REGIONS; i++) {
324 if (!dev->regions[i].mmap_addr) {
325 continue;
326 }
327
328 if (start <= dev->regions[i].iova &&
329 last >= (dev->regions[i].iova + dev->regions[i].size - 1)) {
330 munmap((void *)(uintptr_t)dev->regions[i].mmap_addr,
331 dev->regions[i].mmap_offset + dev->regions[i].size);
332 dev->regions[i].mmap_addr = 0;
333 dev->num_regions--;
334 }
335 }
336 }
337
338 static int vduse_iova_add_region(VduseDev *dev, int fd,
339 uint64_t offset, uint64_t start,
340 uint64_t last, int prot)
341 {
342 int i;
343 uint64_t size = last - start + 1;
344 void *mmap_addr = mmap(0, size + offset, prot, MAP_SHARED, fd, 0);
345
346 if (mmap_addr == MAP_FAILED) {
347 close(fd);
348 return -EINVAL;
349 }
350
351 for (i = 0; i < MAX_IOVA_REGIONS; i++) {
352 if (!dev->regions[i].mmap_addr) {
353 dev->regions[i].mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
354 dev->regions[i].mmap_offset = offset;
355 dev->regions[i].iova = start;
356 dev->regions[i].size = size;
357 dev->num_regions++;
358 break;
359 }
360 }
361 assert(i < MAX_IOVA_REGIONS);
362 close(fd);
363
364 return 0;
365 }
366
367 static int perm_to_prot(uint8_t perm)
368 {
369 int prot = 0;
370
371 switch (perm) {
372 case VDUSE_ACCESS_WO:
373 prot |= PROT_WRITE;
374 break;
375 case VDUSE_ACCESS_RO:
376 prot |= PROT_READ;
377 break;
378 case VDUSE_ACCESS_RW:
379 prot |= PROT_READ | PROT_WRITE;
380 break;
381 default:
382 break;
383 }
384
385 return prot;
386 }
387
388 static inline void *iova_to_va(VduseDev *dev, uint64_t *plen, uint64_t iova)
389 {
390 int i, ret;
391 struct vduse_iotlb_entry entry;
392
393 for (i = 0; i < MAX_IOVA_REGIONS; i++) {
394 VduseIovaRegion *r = &dev->regions[i];
395
396 if (!r->mmap_addr) {
397 continue;
398 }
399
400 if ((iova >= r->iova) && (iova < (r->iova + r->size))) {
401 if ((iova + *plen) > (r->iova + r->size)) {
402 *plen = r->iova + r->size - iova;
403 }
404 return (void *)(uintptr_t)(iova - r->iova +
405 r->mmap_addr + r->mmap_offset);
406 }
407 }
408
409 entry.start = iova;
410 entry.last = iova + 1;
411 ret = ioctl(dev->fd, VDUSE_IOTLB_GET_FD, &entry);
412 if (ret < 0) {
413 return NULL;
414 }
415
416 if (!vduse_iova_add_region(dev, ret, entry.offset, entry.start,
417 entry.last, perm_to_prot(entry.perm))) {
418 return iova_to_va(dev, plen, iova);
419 }
420
421 return NULL;
422 }
423
424 static inline uint16_t vring_avail_flags(VduseVirtq *vq)
425 {
426 return le16toh(vq->vring.avail->flags);
427 }
428
429 static inline uint16_t vring_avail_idx(VduseVirtq *vq)
430 {
431 vq->shadow_avail_idx = le16toh(vq->vring.avail->idx);
432
433 return vq->shadow_avail_idx;
434 }
435
436 static inline uint16_t vring_avail_ring(VduseVirtq *vq, int i)
437 {
438 return le16toh(vq->vring.avail->ring[i]);
439 }
440
441 static inline uint16_t vring_get_used_event(VduseVirtq *vq)
442 {
443 return vring_avail_ring(vq, vq->vring.num);
444 }
445
446 static bool vduse_queue_get_head(VduseVirtq *vq, unsigned int idx,
447 unsigned int *head)
448 {
449 /*
450 * Grab the next descriptor number they're advertising, and increment
451 * the index we've seen.
452 */
453 *head = vring_avail_ring(vq, idx % vq->vring.num);
454
455 /* If their number is silly, that's a fatal mistake. */
456 if (*head >= vq->vring.num) {
457 fprintf(stderr, "Guest says index %u is available\n", *head);
458 return false;
459 }
460
461 return true;
462 }
463
464 static int
465 vduse_queue_read_indirect_desc(VduseDev *dev, struct vring_desc *desc,
466 uint64_t addr, size_t len)
467 {
468 char *dst_desc = (char *)desc;
469 uint64_t read_len;
470 void *ori_desc;
471
472 if (len > (VIRTQUEUE_MAX_SIZE * sizeof(struct vring_desc))) {
473 return -1;
474 }
475
476 if (len == 0) {
477 return -1;
478 }
479
480 while (len) {
481 read_len = len;
482 ori_desc = iova_to_va(dev, &read_len, addr);
483 if (!ori_desc) {
484 return -1;
485 }
486
487 memcpy(dst_desc, ori_desc, read_len);
488 len -= read_len;
489 addr += read_len;
490 dst_desc += read_len;
491 }
492
493 return 0;
494 }
495
496 enum {
497 VIRTQUEUE_READ_DESC_ERROR = -1,
498 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */
499 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */
500 };
501
502 static int vduse_queue_read_next_desc(struct vring_desc *desc, int i,
503 unsigned int max, unsigned int *next)
504 {
505 /* If this descriptor says it doesn't chain, we're done. */
506 if (!(le16toh(desc[i].flags) & VRING_DESC_F_NEXT)) {
507 return VIRTQUEUE_READ_DESC_DONE;
508 }
509
510 /* Check they're not leading us off end of descriptors. */
511 *next = desc[i].next;
512 /* Make sure compiler knows to grab that: we don't want it changing! */
513 smp_wmb();
514
515 if (*next >= max) {
516 fprintf(stderr, "Desc next is %u\n", *next);
517 return VIRTQUEUE_READ_DESC_ERROR;
518 }
519
520 return VIRTQUEUE_READ_DESC_MORE;
521 }
522
523 /*
524 * Fetch avail_idx from VQ memory only when we really need to know if
525 * guest has added some buffers.
526 */
527 static bool vduse_queue_empty(VduseVirtq *vq)
528 {
529 if (unlikely(!vq->vring.avail)) {
530 return true;
531 }
532
533 if (vq->shadow_avail_idx != vq->last_avail_idx) {
534 return false;
535 }
536
537 return vring_avail_idx(vq) == vq->last_avail_idx;
538 }
539
540 static bool vduse_queue_should_notify(VduseVirtq *vq)
541 {
542 VduseDev *dev = vq->dev;
543 uint16_t old, new;
544 bool v;
545
546 /* We need to expose used array entries before checking used event. */
547 smp_mb();
548
549 /* Always notify when queue is empty (when feature acknowledge) */
550 if (vduse_dev_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
551 !vq->inuse && vduse_queue_empty(vq)) {
552 return true;
553 }
554
555 if (!vduse_dev_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
556 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT);
557 }
558
559 v = vq->signalled_used_valid;
560 vq->signalled_used_valid = true;
561 old = vq->signalled_used;
562 new = vq->signalled_used = vq->used_idx;
563 return !v || vring_need_event(vring_get_used_event(vq), new, old);
564 }
565
566 void vduse_queue_notify(VduseVirtq *vq)
567 {
568 VduseDev *dev = vq->dev;
569
570 if (unlikely(!vq->vring.avail)) {
571 return;
572 }
573
574 if (!vduse_queue_should_notify(vq)) {
575 return;
576 }
577
578 if (vduse_inject_irq(dev, vq->index) < 0) {
579 fprintf(stderr, "Error inject irq for vq %d: %s\n",
580 vq->index, strerror(errno));
581 }
582 }
583
584 static inline void vring_set_avail_event(VduseVirtq *vq, uint16_t val)
585 {
586 uint16_t val_le = htole16(val);
587 memcpy(&vq->vring.used->ring[vq->vring.num], &val_le, sizeof(uint16_t));
588 }
589
590 static bool vduse_queue_map_single_desc(VduseVirtq *vq, unsigned int *p_num_sg,
591 struct iovec *iov, unsigned int max_num_sg,
592 bool is_write, uint64_t pa, size_t sz)
593 {
594 unsigned num_sg = *p_num_sg;
595 VduseDev *dev = vq->dev;
596
597 assert(num_sg <= max_num_sg);
598
599 if (!sz) {
600 fprintf(stderr, "virtio: zero sized buffers are not allowed\n");
601 return false;
602 }
603
604 while (sz) {
605 uint64_t len = sz;
606
607 if (num_sg == max_num_sg) {
608 fprintf(stderr,
609 "virtio: too many descriptors in indirect table\n");
610 return false;
611 }
612
613 iov[num_sg].iov_base = iova_to_va(dev, &len, pa);
614 if (iov[num_sg].iov_base == NULL) {
615 fprintf(stderr, "virtio: invalid address for buffers\n");
616 return false;
617 }
618 iov[num_sg++].iov_len = len;
619 sz -= len;
620 pa += len;
621 }
622
623 *p_num_sg = num_sg;
624 return true;
625 }
626
627 static void *vduse_queue_alloc_element(size_t sz, unsigned out_num,
628 unsigned in_num)
629 {
630 VduseVirtqElement *elem;
631 size_t in_sg_ofs = ALIGN_UP(sz, __alignof__(elem->in_sg[0]));
632 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]);
633 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]);
634
635 assert(sz >= sizeof(VduseVirtqElement));
636 elem = malloc(out_sg_end);
637 if (!elem) {
638 return NULL;
639 }
640 elem->out_num = out_num;
641 elem->in_num = in_num;
642 elem->in_sg = (void *)elem + in_sg_ofs;
643 elem->out_sg = (void *)elem + out_sg_ofs;
644 return elem;
645 }
646
647 static void *vduse_queue_map_desc(VduseVirtq *vq, unsigned int idx, size_t sz)
648 {
649 struct vring_desc *desc = vq->vring.desc;
650 VduseDev *dev = vq->dev;
651 uint64_t desc_addr, read_len;
652 unsigned int desc_len;
653 unsigned int max = vq->vring.num;
654 unsigned int i = idx;
655 VduseVirtqElement *elem;
656 struct iovec iov[VIRTQUEUE_MAX_SIZE];
657 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE];
658 unsigned int out_num = 0, in_num = 0;
659 int rc;
660
661 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) {
662 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) {
663 fprintf(stderr, "Invalid size for indirect buffer table\n");
664 return NULL;
665 }
666
667 /* loop over the indirect descriptor table */
668 desc_addr = le64toh(desc[i].addr);
669 desc_len = le32toh(desc[i].len);
670 max = desc_len / sizeof(struct vring_desc);
671 read_len = desc_len;
672 desc = iova_to_va(dev, &read_len, desc_addr);
673 if (unlikely(desc && read_len != desc_len)) {
674 /* Failed to use zero copy */
675 desc = NULL;
676 if (!vduse_queue_read_indirect_desc(dev, desc_buf,
677 desc_addr,
678 desc_len)) {
679 desc = desc_buf;
680 }
681 }
682 if (!desc) {
683 fprintf(stderr, "Invalid indirect buffer table\n");
684 return NULL;
685 }
686 i = 0;
687 }
688
689 /* Collect all the descriptors */
690 do {
691 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) {
692 if (!vduse_queue_map_single_desc(vq, &in_num, iov + out_num,
693 VIRTQUEUE_MAX_SIZE - out_num,
694 true, le64toh(desc[i].addr),
695 le32toh(desc[i].len))) {
696 return NULL;
697 }
698 } else {
699 if (in_num) {
700 fprintf(stderr, "Incorrect order for descriptors\n");
701 return NULL;
702 }
703 if (!vduse_queue_map_single_desc(vq, &out_num, iov,
704 VIRTQUEUE_MAX_SIZE, false,
705 le64toh(desc[i].addr),
706 le32toh(desc[i].len))) {
707 return NULL;
708 }
709 }
710
711 /* If we've got too many, that implies a descriptor loop. */
712 if ((in_num + out_num) > max) {
713 fprintf(stderr, "Looped descriptor\n");
714 return NULL;
715 }
716 rc = vduse_queue_read_next_desc(desc, i, max, &i);
717 } while (rc == VIRTQUEUE_READ_DESC_MORE);
718
719 if (rc == VIRTQUEUE_READ_DESC_ERROR) {
720 fprintf(stderr, "read descriptor error\n");
721 return NULL;
722 }
723
724 /* Now copy what we have collected and mapped */
725 elem = vduse_queue_alloc_element(sz, out_num, in_num);
726 if (!elem) {
727 fprintf(stderr, "read descriptor error\n");
728 return NULL;
729 }
730 elem->index = idx;
731 for (i = 0; i < out_num; i++) {
732 elem->out_sg[i] = iov[i];
733 }
734 for (i = 0; i < in_num; i++) {
735 elem->in_sg[i] = iov[out_num + i];
736 }
737
738 return elem;
739 }
740
741 void *vduse_queue_pop(VduseVirtq *vq, size_t sz)
742 {
743 unsigned int head;
744 VduseVirtqElement *elem;
745 VduseDev *dev = vq->dev;
746 int i;
747
748 if (unlikely(!vq->vring.avail)) {
749 return NULL;
750 }
751
752 if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) {
753 i = (--vq->resubmit_num);
754 elem = vduse_queue_map_desc(vq, vq->resubmit_list[i].index, sz);
755
756 if (!vq->resubmit_num) {
757 free(vq->resubmit_list);
758 vq->resubmit_list = NULL;
759 }
760
761 return elem;
762 }
763
764 if (vduse_queue_empty(vq)) {
765 return NULL;
766 }
767 /* Needed after virtio_queue_empty() */
768 smp_rmb();
769
770 if (vq->inuse >= vq->vring.num) {
771 fprintf(stderr, "Virtqueue size exceeded: %d\n", vq->inuse);
772 return NULL;
773 }
774
775 if (!vduse_queue_get_head(vq, vq->last_avail_idx++, &head)) {
776 return NULL;
777 }
778
779 if (vduse_dev_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) {
780 vring_set_avail_event(vq, vq->last_avail_idx);
781 }
782
783 elem = vduse_queue_map_desc(vq, head, sz);
784
785 if (!elem) {
786 return NULL;
787 }
788
789 vq->inuse++;
790
791 vduse_queue_inflight_get(vq, head);
792
793 return elem;
794 }
795
796 static inline void vring_used_write(VduseVirtq *vq,
797 struct vring_used_elem *uelem, int i)
798 {
799 struct vring_used *used = vq->vring.used;
800
801 used->ring[i] = *uelem;
802 }
803
804 static void vduse_queue_fill(VduseVirtq *vq, const VduseVirtqElement *elem,
805 unsigned int len, unsigned int idx)
806 {
807 struct vring_used_elem uelem;
808
809 if (unlikely(!vq->vring.used)) {
810 return;
811 }
812
813 idx = (idx + vq->used_idx) % vq->vring.num;
814
815 uelem.id = htole32(elem->index);
816 uelem.len = htole32(len);
817 vring_used_write(vq, &uelem, idx);
818 }
819
820 static inline void vring_used_idx_set(VduseVirtq *vq, uint16_t val)
821 {
822 vq->vring.used->idx = htole16(val);
823 vq->used_idx = val;
824 }
825
826 static void vduse_queue_flush(VduseVirtq *vq, unsigned int count)
827 {
828 uint16_t old, new;
829
830 if (unlikely(!vq->vring.used)) {
831 return;
832 }
833
834 /* Make sure buffer is written before we update index. */
835 smp_wmb();
836
837 old = vq->used_idx;
838 new = old + count;
839 vring_used_idx_set(vq, new);
840 vq->inuse -= count;
841 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) {
842 vq->signalled_used_valid = false;
843 }
844 }
845
846 void vduse_queue_push(VduseVirtq *vq, const VduseVirtqElement *elem,
847 unsigned int len)
848 {
849 vduse_queue_fill(vq, elem, len, 0);
850 vduse_queue_inflight_pre_put(vq, elem->index);
851 vduse_queue_flush(vq, 1);
852 vduse_queue_inflight_post_put(vq, elem->index);
853 }
854
855 static int vduse_queue_update_vring(VduseVirtq *vq, uint64_t desc_addr,
856 uint64_t avail_addr, uint64_t used_addr)
857 {
858 struct VduseDev *dev = vq->dev;
859 uint64_t len;
860
861 len = sizeof(struct vring_desc);
862 vq->vring.desc = iova_to_va(dev, &len, desc_addr);
863 if (len != sizeof(struct vring_desc)) {
864 return -EINVAL;
865 }
866
867 len = sizeof(struct vring_avail);
868 vq->vring.avail = iova_to_va(dev, &len, avail_addr);
869 if (len != sizeof(struct vring_avail)) {
870 return -EINVAL;
871 }
872
873 len = sizeof(struct vring_used);
874 vq->vring.used = iova_to_va(dev, &len, used_addr);
875 if (len != sizeof(struct vring_used)) {
876 return -EINVAL;
877 }
878
879 if (!vq->vring.desc || !vq->vring.avail || !vq->vring.used) {
880 fprintf(stderr, "Failed to get vq[%d] iova mapping\n", vq->index);
881 return -EINVAL;
882 }
883
884 return 0;
885 }
886
887 static void vduse_queue_enable(VduseVirtq *vq)
888 {
889 struct VduseDev *dev = vq->dev;
890 struct vduse_vq_info vq_info;
891 struct vduse_vq_eventfd vq_eventfd;
892 int fd;
893
894 vq_info.index = vq->index;
895 if (ioctl(dev->fd, VDUSE_VQ_GET_INFO, &vq_info)) {
896 fprintf(stderr, "Failed to get vq[%d] info: %s\n",
897 vq->index, strerror(errno));
898 return;
899 }
900
901 if (!vq_info.ready) {
902 return;
903 }
904
905 if (vq_info.num > VIRTQUEUE_MAX_SIZE) {
906 fprintf(stderr, "vq[%d] vring num %u exceeds max %u\n",
907 vq->index, vq_info.num, VIRTQUEUE_MAX_SIZE);
908 return;
909 }
910 vq->vring.num = vq_info.num;
911 vq->vring.desc_addr = vq_info.desc_addr;
912 vq->vring.avail_addr = vq_info.driver_addr;
913 vq->vring.used_addr = vq_info.device_addr;
914
915 if (vduse_queue_update_vring(vq, vq_info.desc_addr,
916 vq_info.driver_addr, vq_info.device_addr)) {
917 fprintf(stderr, "Failed to update vring for vq[%d]\n", vq->index);
918 return;
919 }
920
921 fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
922 if (fd < 0) {
923 fprintf(stderr, "Failed to init eventfd for vq[%d]\n", vq->index);
924 return;
925 }
926
927 vq_eventfd.index = vq->index;
928 vq_eventfd.fd = fd;
929 if (ioctl(dev->fd, VDUSE_VQ_SETUP_KICKFD, &vq_eventfd)) {
930 fprintf(stderr, "Failed to setup kick fd for vq[%d]\n", vq->index);
931 close(fd);
932 return;
933 }
934
935 vq->fd = fd;
936 vq->signalled_used_valid = false;
937 vq->ready = true;
938
939 if (vduse_queue_check_inflights(vq)) {
940 fprintf(stderr, "Failed to check inflights for vq[%d]\n", vq->index);
941 close(fd);
942 return;
943 }
944
945 dev->ops->enable_queue(dev, vq);
946 }
947
948 static void vduse_queue_disable(VduseVirtq *vq)
949 {
950 struct VduseDev *dev = vq->dev;
951 struct vduse_vq_eventfd eventfd;
952
953 if (!vq->ready) {
954 return;
955 }
956
957 dev->ops->disable_queue(dev, vq);
958
959 eventfd.index = vq->index;
960 eventfd.fd = VDUSE_EVENTFD_DEASSIGN;
961 ioctl(dev->fd, VDUSE_VQ_SETUP_KICKFD, &eventfd);
962 close(vq->fd);
963
964 assert(vq->inuse == 0);
965
966 vq->vring.num = 0;
967 vq->vring.desc_addr = 0;
968 vq->vring.avail_addr = 0;
969 vq->vring.used_addr = 0;
970 vq->vring.desc = 0;
971 vq->vring.avail = 0;
972 vq->vring.used = 0;
973 vq->ready = false;
974 vq->fd = -1;
975 }
976
977 static void vduse_dev_start_dataplane(VduseDev *dev)
978 {
979 int i;
980
981 if (ioctl(dev->fd, VDUSE_DEV_GET_FEATURES, &dev->features)) {
982 fprintf(stderr, "Failed to get features: %s\n", strerror(errno));
983 return;
984 }
985 assert(vduse_dev_has_feature(dev, VIRTIO_F_VERSION_1));
986
987 for (i = 0; i < dev->num_queues; i++) {
988 vduse_queue_enable(&dev->vqs[i]);
989 }
990 }
991
992 static void vduse_dev_stop_dataplane(VduseDev *dev)
993 {
994 size_t log_size = dev->num_queues * vduse_vq_log_size(VIRTQUEUE_MAX_SIZE);
995 int i;
996
997 for (i = 0; i < dev->num_queues; i++) {
998 vduse_queue_disable(&dev->vqs[i]);
999 }
1000 if (dev->log) {
1001 memset(dev->log, 0, log_size);
1002 }
1003 dev->features = 0;
1004 vduse_iova_remove_region(dev, 0, ULONG_MAX);
1005 }
1006
1007 int vduse_dev_handler(VduseDev *dev)
1008 {
1009 struct vduse_dev_request req;
1010 struct vduse_dev_response resp = { 0 };
1011 VduseVirtq *vq;
1012 int i, ret;
1013
1014 ret = read(dev->fd, &req, sizeof(req));
1015 if (ret != sizeof(req)) {
1016 fprintf(stderr, "Read request error [%d]: %s\n",
1017 ret, strerror(errno));
1018 return -errno;
1019 }
1020 resp.request_id = req.request_id;
1021
1022 switch (req.type) {
1023 case VDUSE_GET_VQ_STATE:
1024 vq = &dev->vqs[req.vq_state.index];
1025 resp.vq_state.split.avail_index = vq->last_avail_idx;
1026 resp.result = VDUSE_REQ_RESULT_OK;
1027 break;
1028 case VDUSE_SET_STATUS:
1029 if (req.s.status & VIRTIO_CONFIG_S_DRIVER_OK) {
1030 vduse_dev_start_dataplane(dev);
1031 } else if (req.s.status == 0) {
1032 vduse_dev_stop_dataplane(dev);
1033 }
1034 resp.result = VDUSE_REQ_RESULT_OK;
1035 break;
1036 case VDUSE_UPDATE_IOTLB:
1037 /* The iova will be updated by iova_to_va() later, so just remove it */
1038 vduse_iova_remove_region(dev, req.iova.start, req.iova.last);
1039 for (i = 0; i < dev->num_queues; i++) {
1040 vq = &dev->vqs[i];
1041 if (vq->ready) {
1042 if (vduse_queue_update_vring(vq, vq->vring.desc_addr,
1043 vq->vring.avail_addr,
1044 vq->vring.used_addr)) {
1045 fprintf(stderr, "Failed to update vring for vq[%d]\n",
1046 vq->index);
1047 }
1048 }
1049 }
1050 resp.result = VDUSE_REQ_RESULT_OK;
1051 break;
1052 default:
1053 resp.result = VDUSE_REQ_RESULT_FAILED;
1054 break;
1055 }
1056
1057 ret = write(dev->fd, &resp, sizeof(resp));
1058 if (ret != sizeof(resp)) {
1059 fprintf(stderr, "Write request %d error [%d]: %s\n",
1060 req.type, ret, strerror(errno));
1061 return -errno;
1062 }
1063 return 0;
1064 }
1065
1066 int vduse_dev_update_config(VduseDev *dev, uint32_t size,
1067 uint32_t offset, char *buffer)
1068 {
1069 int ret;
1070 struct vduse_config_data *data;
1071
1072 data = malloc(offsetof(struct vduse_config_data, buffer) + size);
1073 if (!data) {
1074 return -ENOMEM;
1075 }
1076
1077 data->offset = offset;
1078 data->length = size;
1079 memcpy(data->buffer, buffer, size);
1080
1081 ret = ioctl(dev->fd, VDUSE_DEV_SET_CONFIG, data);
1082 free(data);
1083
1084 if (ret) {
1085 return -errno;
1086 }
1087
1088 if (ioctl(dev->fd, VDUSE_DEV_INJECT_CONFIG_IRQ)) {
1089 return -errno;
1090 }
1091
1092 return 0;
1093 }
1094
1095 int vduse_dev_setup_queue(VduseDev *dev, int index, int max_size)
1096 {
1097 VduseVirtq *vq = &dev->vqs[index];
1098 struct vduse_vq_config vq_config = { 0 };
1099
1100 if (max_size > VIRTQUEUE_MAX_SIZE) {
1101 return -EINVAL;
1102 }
1103
1104 vq_config.index = vq->index;
1105 vq_config.max_size = max_size;
1106
1107 if (ioctl(dev->fd, VDUSE_VQ_SETUP, &vq_config)) {
1108 return -errno;
1109 }
1110
1111 vduse_queue_enable(vq);
1112
1113 return 0;
1114 }
1115
1116 int vduse_set_reconnect_log_file(VduseDev *dev, const char *filename)
1117 {
1118
1119 size_t log_size = dev->num_queues * vduse_vq_log_size(VIRTQUEUE_MAX_SIZE);
1120 void *log;
1121 int i;
1122
1123 dev->log = log = vduse_log_get(filename, log_size);
1124 if (log == MAP_FAILED) {
1125 fprintf(stderr, "Failed to get vduse log\n");
1126 return -EINVAL;
1127 }
1128
1129 for (i = 0; i < dev->num_queues; i++) {
1130 dev->vqs[i].log = log;
1131 dev->vqs[i].log->inflight.desc_num = VIRTQUEUE_MAX_SIZE;
1132 log = (void *)((char *)log + vduse_vq_log_size(VIRTQUEUE_MAX_SIZE));
1133 }
1134
1135 return 0;
1136 }
1137
1138 static int vduse_dev_init_vqs(VduseDev *dev, uint16_t num_queues)
1139 {
1140 VduseVirtq *vqs;
1141 int i;
1142
1143 vqs = calloc(sizeof(VduseVirtq), num_queues);
1144 if (!vqs) {
1145 return -ENOMEM;
1146 }
1147
1148 for (i = 0; i < num_queues; i++) {
1149 vqs[i].index = i;
1150 vqs[i].dev = dev;
1151 vqs[i].fd = -1;
1152 }
1153 dev->vqs = vqs;
1154
1155 return 0;
1156 }
1157
1158 static int vduse_dev_init(VduseDev *dev, const char *name,
1159 uint16_t num_queues, const VduseOps *ops,
1160 void *priv)
1161 {
1162 char *dev_path, *dev_name;
1163 int ret, fd;
1164
1165 dev_path = malloc(strlen(name) + strlen("/dev/vduse/") + 1);
1166 if (!dev_path) {
1167 return -ENOMEM;
1168 }
1169 sprintf(dev_path, "/dev/vduse/%s", name);
1170
1171 fd = open(dev_path, O_RDWR);
1172 free(dev_path);
1173 if (fd < 0) {
1174 fprintf(stderr, "Failed to open vduse dev %s: %s\n",
1175 name, strerror(errno));
1176 return -errno;
1177 }
1178
1179 if (ioctl(fd, VDUSE_DEV_GET_FEATURES, &dev->features)) {
1180 fprintf(stderr, "Failed to get features: %s\n", strerror(errno));
1181 close(fd);
1182 return -errno;
1183 }
1184
1185 dev_name = strdup(name);
1186 if (!dev_name) {
1187 close(fd);
1188 return -ENOMEM;
1189 }
1190
1191 ret = vduse_dev_init_vqs(dev, num_queues);
1192 if (ret) {
1193 free(dev_name);
1194 close(fd);
1195 return ret;
1196 }
1197
1198 dev->name = dev_name;
1199 dev->num_queues = num_queues;
1200 dev->fd = fd;
1201 dev->ops = ops;
1202 dev->priv = priv;
1203
1204 return 0;
1205 }
1206
1207 static inline bool vduse_name_is_invalid(const char *name)
1208 {
1209 return strlen(name) >= VDUSE_NAME_MAX || strstr(name, "..");
1210 }
1211
1212 VduseDev *vduse_dev_create_by_fd(int fd, uint16_t num_queues,
1213 const VduseOps *ops, void *priv)
1214 {
1215 VduseDev *dev;
1216 int ret;
1217
1218 if (!ops || !ops->enable_queue || !ops->disable_queue) {
1219 fprintf(stderr, "Invalid parameter for vduse\n");
1220 return NULL;
1221 }
1222
1223 dev = calloc(sizeof(VduseDev), 1);
1224 if (!dev) {
1225 fprintf(stderr, "Failed to allocate vduse device\n");
1226 return NULL;
1227 }
1228
1229 if (ioctl(fd, VDUSE_DEV_GET_FEATURES, &dev->features)) {
1230 fprintf(stderr, "Failed to get features: %s\n", strerror(errno));
1231 free(dev);
1232 return NULL;
1233 }
1234
1235 ret = vduse_dev_init_vqs(dev, num_queues);
1236 if (ret) {
1237 fprintf(stderr, "Failed to init vqs\n");
1238 free(dev);
1239 return NULL;
1240 }
1241
1242 dev->num_queues = num_queues;
1243 dev->fd = fd;
1244 dev->ops = ops;
1245 dev->priv = priv;
1246
1247 return dev;
1248 }
1249
1250 VduseDev *vduse_dev_create_by_name(const char *name, uint16_t num_queues,
1251 const VduseOps *ops, void *priv)
1252 {
1253 VduseDev *dev;
1254 int ret;
1255
1256 if (!name || vduse_name_is_invalid(name) || !ops ||
1257 !ops->enable_queue || !ops->disable_queue) {
1258 fprintf(stderr, "Invalid parameter for vduse\n");
1259 return NULL;
1260 }
1261
1262 dev = calloc(sizeof(VduseDev), 1);
1263 if (!dev) {
1264 fprintf(stderr, "Failed to allocate vduse device\n");
1265 return NULL;
1266 }
1267
1268 ret = vduse_dev_init(dev, name, num_queues, ops, priv);
1269 if (ret < 0) {
1270 fprintf(stderr, "Failed to init vduse device %s: %s\n",
1271 name, strerror(-ret));
1272 free(dev);
1273 return NULL;
1274 }
1275
1276 return dev;
1277 }
1278
1279 VduseDev *vduse_dev_create(const char *name, uint32_t device_id,
1280 uint32_t vendor_id, uint64_t features,
1281 uint16_t num_queues, uint32_t config_size,
1282 char *config, const VduseOps *ops, void *priv)
1283 {
1284 VduseDev *dev;
1285 int ret, ctrl_fd;
1286 uint64_t version;
1287 struct vduse_dev_config *dev_config;
1288 size_t size = offsetof(struct vduse_dev_config, config);
1289
1290 if (!name || vduse_name_is_invalid(name) ||
1291 !has_feature(features, VIRTIO_F_VERSION_1) || !config ||
1292 !config_size || !ops || !ops->enable_queue || !ops->disable_queue) {
1293 fprintf(stderr, "Invalid parameter for vduse\n");
1294 return NULL;
1295 }
1296
1297 dev = calloc(sizeof(VduseDev), 1);
1298 if (!dev) {
1299 fprintf(stderr, "Failed to allocate vduse device\n");
1300 return NULL;
1301 }
1302
1303 ctrl_fd = open("/dev/vduse/control", O_RDWR);
1304 if (ctrl_fd < 0) {
1305 fprintf(stderr, "Failed to open /dev/vduse/control: %s\n",
1306 strerror(errno));
1307 goto err_ctrl;
1308 }
1309
1310 version = VDUSE_API_VERSION;
1311 if (ioctl(ctrl_fd, VDUSE_SET_API_VERSION, &version)) {
1312 fprintf(stderr, "Failed to set api version %" PRIu64 ": %s\n",
1313 version, strerror(errno));
1314 goto err_dev;
1315 }
1316
1317 dev_config = calloc(size + config_size, 1);
1318 if (!dev_config) {
1319 fprintf(stderr, "Failed to allocate config space\n");
1320 goto err_dev;
1321 }
1322
1323 assert(!vduse_name_is_invalid(name));
1324 strcpy(dev_config->name, name);
1325 dev_config->device_id = device_id;
1326 dev_config->vendor_id = vendor_id;
1327 dev_config->features = features;
1328 dev_config->vq_num = num_queues;
1329 dev_config->vq_align = VDUSE_VQ_ALIGN;
1330 dev_config->config_size = config_size;
1331 memcpy(dev_config->config, config, config_size);
1332
1333 ret = ioctl(ctrl_fd, VDUSE_CREATE_DEV, dev_config);
1334 free(dev_config);
1335 if (ret && errno != EEXIST) {
1336 fprintf(stderr, "Failed to create vduse device %s: %s\n",
1337 name, strerror(errno));
1338 goto err_dev;
1339 }
1340 dev->ctrl_fd = ctrl_fd;
1341
1342 ret = vduse_dev_init(dev, name, num_queues, ops, priv);
1343 if (ret < 0) {
1344 fprintf(stderr, "Failed to init vduse device %s: %s\n",
1345 name, strerror(-ret));
1346 goto err;
1347 }
1348
1349 return dev;
1350 err:
1351 ioctl(ctrl_fd, VDUSE_DESTROY_DEV, name);
1352 err_dev:
1353 close(ctrl_fd);
1354 err_ctrl:
1355 free(dev);
1356
1357 return NULL;
1358 }
1359
1360 int vduse_dev_destroy(VduseDev *dev)
1361 {
1362 size_t log_size = dev->num_queues * vduse_vq_log_size(VIRTQUEUE_MAX_SIZE);
1363 int i, ret = 0;
1364
1365 if (dev->log) {
1366 munmap(dev->log, log_size);
1367 }
1368 for (i = 0; i < dev->num_queues; i++) {
1369 free(dev->vqs[i].resubmit_list);
1370 }
1371 free(dev->vqs);
1372 if (dev->fd >= 0) {
1373 close(dev->fd);
1374 dev->fd = -1;
1375 }
1376 if (dev->ctrl_fd >= 0) {
1377 if (ioctl(dev->ctrl_fd, VDUSE_DESTROY_DEV, dev->name)) {
1378 ret = -errno;
1379 }
1380 close(dev->ctrl_fd);
1381 dev->ctrl_fd = -1;
1382 }
1383 free(dev->name);
1384 free(dev);
1385
1386 return ret;
1387 }