libvduse.c (35335B)
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 #include <stdlib.h> 20 #include <stdio.h> 21 #include <stdbool.h> 22 #include <stddef.h> 23 #include <errno.h> 24 #include <string.h> 25 #include <assert.h> 26 #include <endian.h> 27 #include <unistd.h> 28 #include <limits.h> 29 #include <fcntl.h> 30 #include <inttypes.h> 31 32 #include <sys/ioctl.h> 33 #include <sys/eventfd.h> 34 #include <sys/mman.h> 35 36 #include "include/atomic.h" 37 #include "linux-headers/linux/virtio_ring.h" 38 #include "linux-headers/linux/virtio_config.h" 39 #include "linux-headers/linux/vduse.h" 40 #include "libvduse.h" 41 42 #define VDUSE_VQ_ALIGN 4096 43 #define MAX_IOVA_REGIONS 256 44 45 #define LOG_ALIGNMENT 64 46 47 /* Round number down to multiple */ 48 #define ALIGN_DOWN(n, m) ((n) / (m) * (m)) 49 50 /* Round number up to multiple */ 51 #define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m)) 52 53 #ifndef unlikely 54 #define unlikely(x) __builtin_expect(!!(x), 0) 55 #endif 56 57 typedef struct VduseDescStateSplit { 58 uint8_t inflight; 59 uint8_t padding[5]; 60 uint16_t next; 61 uint64_t counter; 62 } VduseDescStateSplit; 63 64 typedef struct VduseVirtqLogInflight { 65 uint64_t features; 66 uint16_t version; 67 uint16_t desc_num; 68 uint16_t last_batch_head; 69 uint16_t used_idx; 70 VduseDescStateSplit desc[]; 71 } VduseVirtqLogInflight; 72 73 typedef struct VduseVirtqLog { 74 VduseVirtqLogInflight inflight; 75 } VduseVirtqLog; 76 77 typedef struct VduseVirtqInflightDesc { 78 uint16_t index; 79 uint64_t counter; 80 } VduseVirtqInflightDesc; 81 82 typedef struct VduseRing { 83 unsigned int num; 84 uint64_t desc_addr; 85 uint64_t avail_addr; 86 uint64_t used_addr; 87 struct vring_desc *desc; 88 struct vring_avail *avail; 89 struct vring_used *used; 90 } VduseRing; 91 92 struct VduseVirtq { 93 VduseRing vring; 94 uint16_t last_avail_idx; 95 uint16_t shadow_avail_idx; 96 uint16_t used_idx; 97 uint16_t signalled_used; 98 bool signalled_used_valid; 99 int index; 100 int inuse; 101 bool ready; 102 int fd; 103 VduseDev *dev; 104 VduseVirtqInflightDesc *resubmit_list; 105 uint16_t resubmit_num; 106 uint64_t counter; 107 VduseVirtqLog *log; 108 }; 109 110 typedef struct VduseIovaRegion { 111 uint64_t iova; 112 uint64_t size; 113 uint64_t mmap_offset; 114 uint64_t mmap_addr; 115 } VduseIovaRegion; 116 117 struct VduseDev { 118 VduseVirtq *vqs; 119 VduseIovaRegion regions[MAX_IOVA_REGIONS]; 120 int num_regions; 121 char *name; 122 uint32_t device_id; 123 uint32_t vendor_id; 124 uint16_t num_queues; 125 uint16_t queue_size; 126 uint64_t features; 127 const VduseOps *ops; 128 int fd; 129 int ctrl_fd; 130 void *priv; 131 void *log; 132 }; 133 134 static inline size_t vduse_vq_log_size(uint16_t queue_size) 135 { 136 return ALIGN_UP(sizeof(VduseDescStateSplit) * queue_size + 137 sizeof(VduseVirtqLogInflight), LOG_ALIGNMENT); 138 } 139 140 static void *vduse_log_get(const char *filename, size_t size) 141 { 142 void *ptr = MAP_FAILED; 143 int fd; 144 145 fd = open(filename, O_RDWR | O_CREAT, 0600); 146 if (fd == -1) { 147 return MAP_FAILED; 148 } 149 150 if (ftruncate(fd, size) == -1) { 151 goto out; 152 } 153 154 ptr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); 155 156 out: 157 close(fd); 158 return ptr; 159 } 160 161 static inline bool has_feature(uint64_t features, unsigned int fbit) 162 { 163 assert(fbit < 64); 164 return !!(features & (1ULL << fbit)); 165 } 166 167 static inline bool vduse_dev_has_feature(VduseDev *dev, unsigned int fbit) 168 { 169 return has_feature(dev->features, fbit); 170 } 171 172 uint64_t vduse_get_virtio_features(void) 173 { 174 return (1ULL << VIRTIO_F_IOMMU_PLATFORM) | 175 (1ULL << VIRTIO_F_VERSION_1) | 176 (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | 177 (1ULL << VIRTIO_RING_F_EVENT_IDX) | 178 (1ULL << VIRTIO_RING_F_INDIRECT_DESC); 179 } 180 181 VduseDev *vduse_queue_get_dev(VduseVirtq *vq) 182 { 183 return vq->dev; 184 } 185 186 int vduse_queue_get_fd(VduseVirtq *vq) 187 { 188 return vq->fd; 189 } 190 191 void *vduse_dev_get_priv(VduseDev *dev) 192 { 193 return dev->priv; 194 } 195 196 VduseVirtq *vduse_dev_get_queue(VduseDev *dev, int index) 197 { 198 return &dev->vqs[index]; 199 } 200 201 int vduse_dev_get_fd(VduseDev *dev) 202 { 203 return dev->fd; 204 } 205 206 static int vduse_inject_irq(VduseDev *dev, int index) 207 { 208 return ioctl(dev->fd, VDUSE_VQ_INJECT_IRQ, &index); 209 } 210 211 static int inflight_desc_compare(const void *a, const void *b) 212 { 213 VduseVirtqInflightDesc *desc0 = (VduseVirtqInflightDesc *)a, 214 *desc1 = (VduseVirtqInflightDesc *)b; 215 216 if (desc1->counter > desc0->counter && 217 (desc1->counter - desc0->counter) < VIRTQUEUE_MAX_SIZE * 2) { 218 return 1; 219 } 220 221 return -1; 222 } 223 224 static int vduse_queue_check_inflights(VduseVirtq *vq) 225 { 226 int i = 0; 227 VduseDev *dev = vq->dev; 228 229 vq->used_idx = le16toh(vq->vring.used->idx); 230 vq->resubmit_num = 0; 231 vq->resubmit_list = NULL; 232 vq->counter = 0; 233 234 if (unlikely(vq->log->inflight.used_idx != vq->used_idx)) { 235 if (vq->log->inflight.last_batch_head > VIRTQUEUE_MAX_SIZE) { 236 return -1; 237 } 238 239 vq->log->inflight.desc[vq->log->inflight.last_batch_head].inflight = 0; 240 241 barrier(); 242 243 vq->log->inflight.used_idx = vq->used_idx; 244 } 245 246 for (i = 0; i < vq->log->inflight.desc_num; i++) { 247 if (vq->log->inflight.desc[i].inflight == 1) { 248 vq->inuse++; 249 } 250 } 251 252 vq->shadow_avail_idx = vq->last_avail_idx = vq->inuse + vq->used_idx; 253 254 if (vq->inuse) { 255 vq->resubmit_list = calloc(vq->inuse, sizeof(VduseVirtqInflightDesc)); 256 if (!vq->resubmit_list) { 257 return -1; 258 } 259 260 for (i = 0; i < vq->log->inflight.desc_num; i++) { 261 if (vq->log->inflight.desc[i].inflight) { 262 vq->resubmit_list[vq->resubmit_num].index = i; 263 vq->resubmit_list[vq->resubmit_num].counter = 264 vq->log->inflight.desc[i].counter; 265 vq->resubmit_num++; 266 } 267 } 268 269 if (vq->resubmit_num > 1) { 270 qsort(vq->resubmit_list, vq->resubmit_num, 271 sizeof(VduseVirtqInflightDesc), inflight_desc_compare); 272 } 273 vq->counter = vq->resubmit_list[0].counter + 1; 274 } 275 276 vduse_inject_irq(dev, vq->index); 277 278 return 0; 279 } 280 281 static int vduse_queue_inflight_get(VduseVirtq *vq, int desc_idx) 282 { 283 vq->log->inflight.desc[desc_idx].counter = vq->counter++; 284 285 barrier(); 286 287 vq->log->inflight.desc[desc_idx].inflight = 1; 288 289 return 0; 290 } 291 292 static int vduse_queue_inflight_pre_put(VduseVirtq *vq, int desc_idx) 293 { 294 vq->log->inflight.last_batch_head = desc_idx; 295 296 return 0; 297 } 298 299 static int vduse_queue_inflight_post_put(VduseVirtq *vq, int desc_idx) 300 { 301 vq->log->inflight.desc[desc_idx].inflight = 0; 302 303 barrier(); 304 305 vq->log->inflight.used_idx = vq->used_idx; 306 307 return 0; 308 } 309 310 static void vduse_iova_remove_region(VduseDev *dev, uint64_t start, 311 uint64_t last) 312 { 313 int i; 314 315 if (last == start) { 316 return; 317 } 318 319 for (i = 0; i < MAX_IOVA_REGIONS; i++) { 320 if (!dev->regions[i].mmap_addr) { 321 continue; 322 } 323 324 if (start <= dev->regions[i].iova && 325 last >= (dev->regions[i].iova + dev->regions[i].size - 1)) { 326 munmap((void *)(uintptr_t)dev->regions[i].mmap_addr, 327 dev->regions[i].mmap_offset + dev->regions[i].size); 328 dev->regions[i].mmap_addr = 0; 329 dev->num_regions--; 330 } 331 } 332 } 333 334 static int vduse_iova_add_region(VduseDev *dev, int fd, 335 uint64_t offset, uint64_t start, 336 uint64_t last, int prot) 337 { 338 int i; 339 uint64_t size = last - start + 1; 340 void *mmap_addr = mmap(0, size + offset, prot, MAP_SHARED, fd, 0); 341 342 if (mmap_addr == MAP_FAILED) { 343 close(fd); 344 return -EINVAL; 345 } 346 347 for (i = 0; i < MAX_IOVA_REGIONS; i++) { 348 if (!dev->regions[i].mmap_addr) { 349 dev->regions[i].mmap_addr = (uint64_t)(uintptr_t)mmap_addr; 350 dev->regions[i].mmap_offset = offset; 351 dev->regions[i].iova = start; 352 dev->regions[i].size = size; 353 dev->num_regions++; 354 break; 355 } 356 } 357 assert(i < MAX_IOVA_REGIONS); 358 close(fd); 359 360 return 0; 361 } 362 363 static int perm_to_prot(uint8_t perm) 364 { 365 int prot = 0; 366 367 switch (perm) { 368 case VDUSE_ACCESS_WO: 369 prot |= PROT_WRITE; 370 break; 371 case VDUSE_ACCESS_RO: 372 prot |= PROT_READ; 373 break; 374 case VDUSE_ACCESS_RW: 375 prot |= PROT_READ | PROT_WRITE; 376 break; 377 default: 378 break; 379 } 380 381 return prot; 382 } 383 384 static inline void *iova_to_va(VduseDev *dev, uint64_t *plen, uint64_t iova) 385 { 386 int i, ret; 387 struct vduse_iotlb_entry entry; 388 389 for (i = 0; i < MAX_IOVA_REGIONS; i++) { 390 VduseIovaRegion *r = &dev->regions[i]; 391 392 if (!r->mmap_addr) { 393 continue; 394 } 395 396 if ((iova >= r->iova) && (iova < (r->iova + r->size))) { 397 if ((iova + *plen) > (r->iova + r->size)) { 398 *plen = r->iova + r->size - iova; 399 } 400 return (void *)(uintptr_t)(iova - r->iova + 401 r->mmap_addr + r->mmap_offset); 402 } 403 } 404 405 entry.start = iova; 406 entry.last = iova + 1; 407 ret = ioctl(dev->fd, VDUSE_IOTLB_GET_FD, &entry); 408 if (ret < 0) { 409 return NULL; 410 } 411 412 if (!vduse_iova_add_region(dev, ret, entry.offset, entry.start, 413 entry.last, perm_to_prot(entry.perm))) { 414 return iova_to_va(dev, plen, iova); 415 } 416 417 return NULL; 418 } 419 420 static inline uint16_t vring_avail_flags(VduseVirtq *vq) 421 { 422 return le16toh(vq->vring.avail->flags); 423 } 424 425 static inline uint16_t vring_avail_idx(VduseVirtq *vq) 426 { 427 vq->shadow_avail_idx = le16toh(vq->vring.avail->idx); 428 429 return vq->shadow_avail_idx; 430 } 431 432 static inline uint16_t vring_avail_ring(VduseVirtq *vq, int i) 433 { 434 return le16toh(vq->vring.avail->ring[i]); 435 } 436 437 static inline uint16_t vring_get_used_event(VduseVirtq *vq) 438 { 439 return vring_avail_ring(vq, vq->vring.num); 440 } 441 442 static bool vduse_queue_get_head(VduseVirtq *vq, unsigned int idx, 443 unsigned int *head) 444 { 445 /* 446 * Grab the next descriptor number they're advertising, and increment 447 * the index we've seen. 448 */ 449 *head = vring_avail_ring(vq, idx % vq->vring.num); 450 451 /* If their number is silly, that's a fatal mistake. */ 452 if (*head >= vq->vring.num) { 453 fprintf(stderr, "Guest says index %u is available\n", *head); 454 return false; 455 } 456 457 return true; 458 } 459 460 static int 461 vduse_queue_read_indirect_desc(VduseDev *dev, struct vring_desc *desc, 462 uint64_t addr, size_t len) 463 { 464 struct vring_desc *ori_desc; 465 uint64_t read_len; 466 467 if (len > (VIRTQUEUE_MAX_SIZE * sizeof(struct vring_desc))) { 468 return -1; 469 } 470 471 if (len == 0) { 472 return -1; 473 } 474 475 while (len) { 476 read_len = len; 477 ori_desc = iova_to_va(dev, &read_len, addr); 478 if (!ori_desc) { 479 return -1; 480 } 481 482 memcpy(desc, ori_desc, read_len); 483 len -= read_len; 484 addr += read_len; 485 desc += read_len; 486 } 487 488 return 0; 489 } 490 491 enum { 492 VIRTQUEUE_READ_DESC_ERROR = -1, 493 VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */ 494 VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */ 495 }; 496 497 static int vduse_queue_read_next_desc(struct vring_desc *desc, int i, 498 unsigned int max, unsigned int *next) 499 { 500 /* If this descriptor says it doesn't chain, we're done. */ 501 if (!(le16toh(desc[i].flags) & VRING_DESC_F_NEXT)) { 502 return VIRTQUEUE_READ_DESC_DONE; 503 } 504 505 /* Check they're not leading us off end of descriptors. */ 506 *next = desc[i].next; 507 /* Make sure compiler knows to grab that: we don't want it changing! */ 508 smp_wmb(); 509 510 if (*next >= max) { 511 fprintf(stderr, "Desc next is %u\n", *next); 512 return VIRTQUEUE_READ_DESC_ERROR; 513 } 514 515 return VIRTQUEUE_READ_DESC_MORE; 516 } 517 518 /* 519 * Fetch avail_idx from VQ memory only when we really need to know if 520 * guest has added some buffers. 521 */ 522 static bool vduse_queue_empty(VduseVirtq *vq) 523 { 524 if (unlikely(!vq->vring.avail)) { 525 return true; 526 } 527 528 if (vq->shadow_avail_idx != vq->last_avail_idx) { 529 return false; 530 } 531 532 return vring_avail_idx(vq) == vq->last_avail_idx; 533 } 534 535 static bool vduse_queue_should_notify(VduseVirtq *vq) 536 { 537 VduseDev *dev = vq->dev; 538 uint16_t old, new; 539 bool v; 540 541 /* We need to expose used array entries before checking used event. */ 542 smp_mb(); 543 544 /* Always notify when queue is empty (when feature acknowledge) */ 545 if (vduse_dev_has_feature(dev, VIRTIO_F_NOTIFY_ON_EMPTY) && 546 !vq->inuse && vduse_queue_empty(vq)) { 547 return true; 548 } 549 550 if (!vduse_dev_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { 551 return !(vring_avail_flags(vq) & VRING_AVAIL_F_NO_INTERRUPT); 552 } 553 554 v = vq->signalled_used_valid; 555 vq->signalled_used_valid = true; 556 old = vq->signalled_used; 557 new = vq->signalled_used = vq->used_idx; 558 return !v || vring_need_event(vring_get_used_event(vq), new, old); 559 } 560 561 void vduse_queue_notify(VduseVirtq *vq) 562 { 563 VduseDev *dev = vq->dev; 564 565 if (unlikely(!vq->vring.avail)) { 566 return; 567 } 568 569 if (!vduse_queue_should_notify(vq)) { 570 return; 571 } 572 573 if (vduse_inject_irq(dev, vq->index) < 0) { 574 fprintf(stderr, "Error inject irq for vq %d: %s\n", 575 vq->index, strerror(errno)); 576 } 577 } 578 579 static inline void vring_set_avail_event(VduseVirtq *vq, uint16_t val) 580 { 581 *((uint16_t *)&vq->vring.used->ring[vq->vring.num]) = htole16(val); 582 } 583 584 static bool vduse_queue_map_single_desc(VduseVirtq *vq, unsigned int *p_num_sg, 585 struct iovec *iov, unsigned int max_num_sg, 586 bool is_write, uint64_t pa, size_t sz) 587 { 588 unsigned num_sg = *p_num_sg; 589 VduseDev *dev = vq->dev; 590 591 assert(num_sg <= max_num_sg); 592 593 if (!sz) { 594 fprintf(stderr, "virtio: zero sized buffers are not allowed\n"); 595 return false; 596 } 597 598 while (sz) { 599 uint64_t len = sz; 600 601 if (num_sg == max_num_sg) { 602 fprintf(stderr, 603 "virtio: too many descriptors in indirect table\n"); 604 return false; 605 } 606 607 iov[num_sg].iov_base = iova_to_va(dev, &len, pa); 608 if (iov[num_sg].iov_base == NULL) { 609 fprintf(stderr, "virtio: invalid address for buffers\n"); 610 return false; 611 } 612 iov[num_sg++].iov_len = len; 613 sz -= len; 614 pa += len; 615 } 616 617 *p_num_sg = num_sg; 618 return true; 619 } 620 621 static void *vduse_queue_alloc_element(size_t sz, unsigned out_num, 622 unsigned in_num) 623 { 624 VduseVirtqElement *elem; 625 size_t in_sg_ofs = ALIGN_UP(sz, __alignof__(elem->in_sg[0])); 626 size_t out_sg_ofs = in_sg_ofs + in_num * sizeof(elem->in_sg[0]); 627 size_t out_sg_end = out_sg_ofs + out_num * sizeof(elem->out_sg[0]); 628 629 assert(sz >= sizeof(VduseVirtqElement)); 630 elem = malloc(out_sg_end); 631 if (!elem) { 632 return NULL; 633 } 634 elem->out_num = out_num; 635 elem->in_num = in_num; 636 elem->in_sg = (void *)elem + in_sg_ofs; 637 elem->out_sg = (void *)elem + out_sg_ofs; 638 return elem; 639 } 640 641 static void *vduse_queue_map_desc(VduseVirtq *vq, unsigned int idx, size_t sz) 642 { 643 struct vring_desc *desc = vq->vring.desc; 644 VduseDev *dev = vq->dev; 645 uint64_t desc_addr, read_len; 646 unsigned int desc_len; 647 unsigned int max = vq->vring.num; 648 unsigned int i = idx; 649 VduseVirtqElement *elem; 650 struct iovec iov[VIRTQUEUE_MAX_SIZE]; 651 struct vring_desc desc_buf[VIRTQUEUE_MAX_SIZE]; 652 unsigned int out_num = 0, in_num = 0; 653 int rc; 654 655 if (le16toh(desc[i].flags) & VRING_DESC_F_INDIRECT) { 656 if (le32toh(desc[i].len) % sizeof(struct vring_desc)) { 657 fprintf(stderr, "Invalid size for indirect buffer table\n"); 658 return NULL; 659 } 660 661 /* loop over the indirect descriptor table */ 662 desc_addr = le64toh(desc[i].addr); 663 desc_len = le32toh(desc[i].len); 664 max = desc_len / sizeof(struct vring_desc); 665 read_len = desc_len; 666 desc = iova_to_va(dev, &read_len, desc_addr); 667 if (unlikely(desc && read_len != desc_len)) { 668 /* Failed to use zero copy */ 669 desc = NULL; 670 if (!vduse_queue_read_indirect_desc(dev, desc_buf, 671 desc_addr, 672 desc_len)) { 673 desc = desc_buf; 674 } 675 } 676 if (!desc) { 677 fprintf(stderr, "Invalid indirect buffer table\n"); 678 return NULL; 679 } 680 i = 0; 681 } 682 683 /* Collect all the descriptors */ 684 do { 685 if (le16toh(desc[i].flags) & VRING_DESC_F_WRITE) { 686 if (!vduse_queue_map_single_desc(vq, &in_num, iov + out_num, 687 VIRTQUEUE_MAX_SIZE - out_num, 688 true, le64toh(desc[i].addr), 689 le32toh(desc[i].len))) { 690 return NULL; 691 } 692 } else { 693 if (in_num) { 694 fprintf(stderr, "Incorrect order for descriptors\n"); 695 return NULL; 696 } 697 if (!vduse_queue_map_single_desc(vq, &out_num, iov, 698 VIRTQUEUE_MAX_SIZE, false, 699 le64toh(desc[i].addr), 700 le32toh(desc[i].len))) { 701 return NULL; 702 } 703 } 704 705 /* If we've got too many, that implies a descriptor loop. */ 706 if ((in_num + out_num) > max) { 707 fprintf(stderr, "Looped descriptor\n"); 708 return NULL; 709 } 710 rc = vduse_queue_read_next_desc(desc, i, max, &i); 711 } while (rc == VIRTQUEUE_READ_DESC_MORE); 712 713 if (rc == VIRTQUEUE_READ_DESC_ERROR) { 714 fprintf(stderr, "read descriptor error\n"); 715 return NULL; 716 } 717 718 /* Now copy what we have collected and mapped */ 719 elem = vduse_queue_alloc_element(sz, out_num, in_num); 720 if (!elem) { 721 fprintf(stderr, "read descriptor error\n"); 722 return NULL; 723 } 724 elem->index = idx; 725 for (i = 0; i < out_num; i++) { 726 elem->out_sg[i] = iov[i]; 727 } 728 for (i = 0; i < in_num; i++) { 729 elem->in_sg[i] = iov[out_num + i]; 730 } 731 732 return elem; 733 } 734 735 void *vduse_queue_pop(VduseVirtq *vq, size_t sz) 736 { 737 unsigned int head; 738 VduseVirtqElement *elem; 739 VduseDev *dev = vq->dev; 740 int i; 741 742 if (unlikely(!vq->vring.avail)) { 743 return NULL; 744 } 745 746 if (unlikely(vq->resubmit_list && vq->resubmit_num > 0)) { 747 i = (--vq->resubmit_num); 748 elem = vduse_queue_map_desc(vq, vq->resubmit_list[i].index, sz); 749 750 if (!vq->resubmit_num) { 751 free(vq->resubmit_list); 752 vq->resubmit_list = NULL; 753 } 754 755 return elem; 756 } 757 758 if (vduse_queue_empty(vq)) { 759 return NULL; 760 } 761 /* Needed after virtio_queue_empty() */ 762 smp_rmb(); 763 764 if (vq->inuse >= vq->vring.num) { 765 fprintf(stderr, "Virtqueue size exceeded: %d\n", vq->inuse); 766 return NULL; 767 } 768 769 if (!vduse_queue_get_head(vq, vq->last_avail_idx++, &head)) { 770 return NULL; 771 } 772 773 if (vduse_dev_has_feature(dev, VIRTIO_RING_F_EVENT_IDX)) { 774 vring_set_avail_event(vq, vq->last_avail_idx); 775 } 776 777 elem = vduse_queue_map_desc(vq, head, sz); 778 779 if (!elem) { 780 return NULL; 781 } 782 783 vq->inuse++; 784 785 vduse_queue_inflight_get(vq, head); 786 787 return elem; 788 } 789 790 static inline void vring_used_write(VduseVirtq *vq, 791 struct vring_used_elem *uelem, int i) 792 { 793 struct vring_used *used = vq->vring.used; 794 795 used->ring[i] = *uelem; 796 } 797 798 static void vduse_queue_fill(VduseVirtq *vq, const VduseVirtqElement *elem, 799 unsigned int len, unsigned int idx) 800 { 801 struct vring_used_elem uelem; 802 803 if (unlikely(!vq->vring.used)) { 804 return; 805 } 806 807 idx = (idx + vq->used_idx) % vq->vring.num; 808 809 uelem.id = htole32(elem->index); 810 uelem.len = htole32(len); 811 vring_used_write(vq, &uelem, idx); 812 } 813 814 static inline void vring_used_idx_set(VduseVirtq *vq, uint16_t val) 815 { 816 vq->vring.used->idx = htole16(val); 817 vq->used_idx = val; 818 } 819 820 static void vduse_queue_flush(VduseVirtq *vq, unsigned int count) 821 { 822 uint16_t old, new; 823 824 if (unlikely(!vq->vring.used)) { 825 return; 826 } 827 828 /* Make sure buffer is written before we update index. */ 829 smp_wmb(); 830 831 old = vq->used_idx; 832 new = old + count; 833 vring_used_idx_set(vq, new); 834 vq->inuse -= count; 835 if (unlikely((int16_t)(new - vq->signalled_used) < (uint16_t)(new - old))) { 836 vq->signalled_used_valid = false; 837 } 838 } 839 840 void vduse_queue_push(VduseVirtq *vq, const VduseVirtqElement *elem, 841 unsigned int len) 842 { 843 vduse_queue_fill(vq, elem, len, 0); 844 vduse_queue_inflight_pre_put(vq, elem->index); 845 vduse_queue_flush(vq, 1); 846 vduse_queue_inflight_post_put(vq, elem->index); 847 } 848 849 static int vduse_queue_update_vring(VduseVirtq *vq, uint64_t desc_addr, 850 uint64_t avail_addr, uint64_t used_addr) 851 { 852 struct VduseDev *dev = vq->dev; 853 uint64_t len; 854 855 len = sizeof(struct vring_desc); 856 vq->vring.desc = iova_to_va(dev, &len, desc_addr); 857 if (len != sizeof(struct vring_desc)) { 858 return -EINVAL; 859 } 860 861 len = sizeof(struct vring_avail); 862 vq->vring.avail = iova_to_va(dev, &len, avail_addr); 863 if (len != sizeof(struct vring_avail)) { 864 return -EINVAL; 865 } 866 867 len = sizeof(struct vring_used); 868 vq->vring.used = iova_to_va(dev, &len, used_addr); 869 if (len != sizeof(struct vring_used)) { 870 return -EINVAL; 871 } 872 873 if (!vq->vring.desc || !vq->vring.avail || !vq->vring.used) { 874 fprintf(stderr, "Failed to get vq[%d] iova mapping\n", vq->index); 875 return -EINVAL; 876 } 877 878 return 0; 879 } 880 881 static void vduse_queue_enable(VduseVirtq *vq) 882 { 883 struct VduseDev *dev = vq->dev; 884 struct vduse_vq_info vq_info; 885 struct vduse_vq_eventfd vq_eventfd; 886 int fd; 887 888 vq_info.index = vq->index; 889 if (ioctl(dev->fd, VDUSE_VQ_GET_INFO, &vq_info)) { 890 fprintf(stderr, "Failed to get vq[%d] info: %s\n", 891 vq->index, strerror(errno)); 892 return; 893 } 894 895 if (!vq_info.ready) { 896 return; 897 } 898 899 vq->vring.num = vq_info.num; 900 vq->vring.desc_addr = vq_info.desc_addr; 901 vq->vring.avail_addr = vq_info.driver_addr; 902 vq->vring.used_addr = vq_info.device_addr; 903 904 if (vduse_queue_update_vring(vq, vq_info.desc_addr, 905 vq_info.driver_addr, vq_info.device_addr)) { 906 fprintf(stderr, "Failed to update vring for vq[%d]\n", vq->index); 907 return; 908 } 909 910 fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC); 911 if (fd < 0) { 912 fprintf(stderr, "Failed to init eventfd for vq[%d]\n", vq->index); 913 return; 914 } 915 916 vq_eventfd.index = vq->index; 917 vq_eventfd.fd = fd; 918 if (ioctl(dev->fd, VDUSE_VQ_SETUP_KICKFD, &vq_eventfd)) { 919 fprintf(stderr, "Failed to setup kick fd for vq[%d]\n", vq->index); 920 close(fd); 921 return; 922 } 923 924 vq->fd = fd; 925 vq->signalled_used_valid = false; 926 vq->ready = true; 927 928 if (vduse_queue_check_inflights(vq)) { 929 fprintf(stderr, "Failed to check inflights for vq[%d]\n", vq->index); 930 close(fd); 931 return; 932 } 933 934 dev->ops->enable_queue(dev, vq); 935 } 936 937 static void vduse_queue_disable(VduseVirtq *vq) 938 { 939 struct VduseDev *dev = vq->dev; 940 struct vduse_vq_eventfd eventfd; 941 942 if (!vq->ready) { 943 return; 944 } 945 946 dev->ops->disable_queue(dev, vq); 947 948 eventfd.index = vq->index; 949 eventfd.fd = VDUSE_EVENTFD_DEASSIGN; 950 ioctl(dev->fd, VDUSE_VQ_SETUP_KICKFD, &eventfd); 951 close(vq->fd); 952 953 assert(vq->inuse == 0); 954 955 vq->vring.num = 0; 956 vq->vring.desc_addr = 0; 957 vq->vring.avail_addr = 0; 958 vq->vring.used_addr = 0; 959 vq->vring.desc = 0; 960 vq->vring.avail = 0; 961 vq->vring.used = 0; 962 vq->ready = false; 963 vq->fd = -1; 964 } 965 966 static void vduse_dev_start_dataplane(VduseDev *dev) 967 { 968 int i; 969 970 if (ioctl(dev->fd, VDUSE_DEV_GET_FEATURES, &dev->features)) { 971 fprintf(stderr, "Failed to get features: %s\n", strerror(errno)); 972 return; 973 } 974 assert(vduse_dev_has_feature(dev, VIRTIO_F_VERSION_1)); 975 976 for (i = 0; i < dev->num_queues; i++) { 977 vduse_queue_enable(&dev->vqs[i]); 978 } 979 } 980 981 static void vduse_dev_stop_dataplane(VduseDev *dev) 982 { 983 size_t log_size = dev->num_queues * vduse_vq_log_size(VIRTQUEUE_MAX_SIZE); 984 int i; 985 986 for (i = 0; i < dev->num_queues; i++) { 987 vduse_queue_disable(&dev->vqs[i]); 988 } 989 if (dev->log) { 990 memset(dev->log, 0, log_size); 991 } 992 dev->features = 0; 993 vduse_iova_remove_region(dev, 0, ULONG_MAX); 994 } 995 996 int vduse_dev_handler(VduseDev *dev) 997 { 998 struct vduse_dev_request req; 999 struct vduse_dev_response resp = { 0 }; 1000 VduseVirtq *vq; 1001 int i, ret; 1002 1003 ret = read(dev->fd, &req, sizeof(req)); 1004 if (ret != sizeof(req)) { 1005 fprintf(stderr, "Read request error [%d]: %s\n", 1006 ret, strerror(errno)); 1007 return -errno; 1008 } 1009 resp.request_id = req.request_id; 1010 1011 switch (req.type) { 1012 case VDUSE_GET_VQ_STATE: 1013 vq = &dev->vqs[req.vq_state.index]; 1014 resp.vq_state.split.avail_index = vq->last_avail_idx; 1015 resp.result = VDUSE_REQ_RESULT_OK; 1016 break; 1017 case VDUSE_SET_STATUS: 1018 if (req.s.status & VIRTIO_CONFIG_S_DRIVER_OK) { 1019 vduse_dev_start_dataplane(dev); 1020 } else if (req.s.status == 0) { 1021 vduse_dev_stop_dataplane(dev); 1022 } 1023 resp.result = VDUSE_REQ_RESULT_OK; 1024 break; 1025 case VDUSE_UPDATE_IOTLB: 1026 /* The iova will be updated by iova_to_va() later, so just remove it */ 1027 vduse_iova_remove_region(dev, req.iova.start, req.iova.last); 1028 for (i = 0; i < dev->num_queues; i++) { 1029 VduseVirtq *vq = &dev->vqs[i]; 1030 if (vq->ready) { 1031 if (vduse_queue_update_vring(vq, vq->vring.desc_addr, 1032 vq->vring.avail_addr, 1033 vq->vring.used_addr)) { 1034 fprintf(stderr, "Failed to update vring for vq[%d]\n", 1035 vq->index); 1036 } 1037 } 1038 } 1039 resp.result = VDUSE_REQ_RESULT_OK; 1040 break; 1041 default: 1042 resp.result = VDUSE_REQ_RESULT_FAILED; 1043 break; 1044 } 1045 1046 ret = write(dev->fd, &resp, sizeof(resp)); 1047 if (ret != sizeof(resp)) { 1048 fprintf(stderr, "Write request %d error [%d]: %s\n", 1049 req.type, ret, strerror(errno)); 1050 return -errno; 1051 } 1052 return 0; 1053 } 1054 1055 int vduse_dev_update_config(VduseDev *dev, uint32_t size, 1056 uint32_t offset, char *buffer) 1057 { 1058 int ret; 1059 struct vduse_config_data *data; 1060 1061 data = malloc(offsetof(struct vduse_config_data, buffer) + size); 1062 if (!data) { 1063 return -ENOMEM; 1064 } 1065 1066 data->offset = offset; 1067 data->length = size; 1068 memcpy(data->buffer, buffer, size); 1069 1070 ret = ioctl(dev->fd, VDUSE_DEV_SET_CONFIG, data); 1071 free(data); 1072 1073 if (ret) { 1074 return -errno; 1075 } 1076 1077 if (ioctl(dev->fd, VDUSE_DEV_INJECT_CONFIG_IRQ)) { 1078 return -errno; 1079 } 1080 1081 return 0; 1082 } 1083 1084 int vduse_dev_setup_queue(VduseDev *dev, int index, int max_size) 1085 { 1086 VduseVirtq *vq = &dev->vqs[index]; 1087 struct vduse_vq_config vq_config = { 0 }; 1088 1089 if (max_size > VIRTQUEUE_MAX_SIZE) { 1090 return -EINVAL; 1091 } 1092 1093 vq_config.index = vq->index; 1094 vq_config.max_size = max_size; 1095 1096 if (ioctl(dev->fd, VDUSE_VQ_SETUP, &vq_config)) { 1097 return -errno; 1098 } 1099 1100 vduse_queue_enable(vq); 1101 1102 return 0; 1103 } 1104 1105 int vduse_set_reconnect_log_file(VduseDev *dev, const char *filename) 1106 { 1107 1108 size_t log_size = dev->num_queues * vduse_vq_log_size(VIRTQUEUE_MAX_SIZE); 1109 void *log; 1110 int i; 1111 1112 dev->log = log = vduse_log_get(filename, log_size); 1113 if (log == MAP_FAILED) { 1114 fprintf(stderr, "Failed to get vduse log\n"); 1115 return -EINVAL; 1116 } 1117 1118 for (i = 0; i < dev->num_queues; i++) { 1119 dev->vqs[i].log = log; 1120 dev->vqs[i].log->inflight.desc_num = VIRTQUEUE_MAX_SIZE; 1121 log = (void *)((char *)log + vduse_vq_log_size(VIRTQUEUE_MAX_SIZE)); 1122 } 1123 1124 return 0; 1125 } 1126 1127 static int vduse_dev_init_vqs(VduseDev *dev, uint16_t num_queues) 1128 { 1129 VduseVirtq *vqs; 1130 int i; 1131 1132 vqs = calloc(sizeof(VduseVirtq), num_queues); 1133 if (!vqs) { 1134 return -ENOMEM; 1135 } 1136 1137 for (i = 0; i < num_queues; i++) { 1138 vqs[i].index = i; 1139 vqs[i].dev = dev; 1140 vqs[i].fd = -1; 1141 } 1142 dev->vqs = vqs; 1143 1144 return 0; 1145 } 1146 1147 static int vduse_dev_init(VduseDev *dev, const char *name, 1148 uint16_t num_queues, const VduseOps *ops, 1149 void *priv) 1150 { 1151 char *dev_path, *dev_name; 1152 int ret, fd; 1153 1154 dev_path = malloc(strlen(name) + strlen("/dev/vduse/") + 1); 1155 if (!dev_path) { 1156 return -ENOMEM; 1157 } 1158 sprintf(dev_path, "/dev/vduse/%s", name); 1159 1160 fd = open(dev_path, O_RDWR); 1161 free(dev_path); 1162 if (fd < 0) { 1163 fprintf(stderr, "Failed to open vduse dev %s: %s\n", 1164 name, strerror(errno)); 1165 return -errno; 1166 } 1167 1168 if (ioctl(fd, VDUSE_DEV_GET_FEATURES, &dev->features)) { 1169 fprintf(stderr, "Failed to get features: %s\n", strerror(errno)); 1170 close(fd); 1171 return -errno; 1172 } 1173 1174 dev_name = strdup(name); 1175 if (!dev_name) { 1176 close(fd); 1177 return -ENOMEM; 1178 } 1179 1180 ret = vduse_dev_init_vqs(dev, num_queues); 1181 if (ret) { 1182 free(dev_name); 1183 close(fd); 1184 return ret; 1185 } 1186 1187 dev->name = dev_name; 1188 dev->num_queues = num_queues; 1189 dev->fd = fd; 1190 dev->ops = ops; 1191 dev->priv = priv; 1192 1193 return 0; 1194 } 1195 1196 static inline bool vduse_name_is_invalid(const char *name) 1197 { 1198 return strlen(name) >= VDUSE_NAME_MAX || strstr(name, ".."); 1199 } 1200 1201 VduseDev *vduse_dev_create_by_fd(int fd, uint16_t num_queues, 1202 const VduseOps *ops, void *priv) 1203 { 1204 VduseDev *dev; 1205 int ret; 1206 1207 if (!ops || !ops->enable_queue || !ops->disable_queue) { 1208 fprintf(stderr, "Invalid parameter for vduse\n"); 1209 return NULL; 1210 } 1211 1212 dev = calloc(sizeof(VduseDev), 1); 1213 if (!dev) { 1214 fprintf(stderr, "Failed to allocate vduse device\n"); 1215 return NULL; 1216 } 1217 1218 if (ioctl(fd, VDUSE_DEV_GET_FEATURES, &dev->features)) { 1219 fprintf(stderr, "Failed to get features: %s\n", strerror(errno)); 1220 free(dev); 1221 return NULL; 1222 } 1223 1224 ret = vduse_dev_init_vqs(dev, num_queues); 1225 if (ret) { 1226 fprintf(stderr, "Failed to init vqs\n"); 1227 free(dev); 1228 return NULL; 1229 } 1230 1231 dev->num_queues = num_queues; 1232 dev->fd = fd; 1233 dev->ops = ops; 1234 dev->priv = priv; 1235 1236 return dev; 1237 } 1238 1239 VduseDev *vduse_dev_create_by_name(const char *name, uint16_t num_queues, 1240 const VduseOps *ops, void *priv) 1241 { 1242 VduseDev *dev; 1243 int ret; 1244 1245 if (!name || vduse_name_is_invalid(name) || !ops || 1246 !ops->enable_queue || !ops->disable_queue) { 1247 fprintf(stderr, "Invalid parameter for vduse\n"); 1248 return NULL; 1249 } 1250 1251 dev = calloc(sizeof(VduseDev), 1); 1252 if (!dev) { 1253 fprintf(stderr, "Failed to allocate vduse device\n"); 1254 return NULL; 1255 } 1256 1257 ret = vduse_dev_init(dev, name, num_queues, ops, priv); 1258 if (ret < 0) { 1259 fprintf(stderr, "Failed to init vduse device %s: %s\n", 1260 name, strerror(-ret)); 1261 free(dev); 1262 return NULL; 1263 } 1264 1265 return dev; 1266 } 1267 1268 VduseDev *vduse_dev_create(const char *name, uint32_t device_id, 1269 uint32_t vendor_id, uint64_t features, 1270 uint16_t num_queues, uint32_t config_size, 1271 char *config, const VduseOps *ops, void *priv) 1272 { 1273 VduseDev *dev; 1274 int ret, ctrl_fd; 1275 uint64_t version; 1276 struct vduse_dev_config *dev_config; 1277 size_t size = offsetof(struct vduse_dev_config, config); 1278 1279 if (!name || vduse_name_is_invalid(name) || 1280 !has_feature(features, VIRTIO_F_VERSION_1) || !config || 1281 !config_size || !ops || !ops->enable_queue || !ops->disable_queue) { 1282 fprintf(stderr, "Invalid parameter for vduse\n"); 1283 return NULL; 1284 } 1285 1286 dev = calloc(sizeof(VduseDev), 1); 1287 if (!dev) { 1288 fprintf(stderr, "Failed to allocate vduse device\n"); 1289 return NULL; 1290 } 1291 1292 ctrl_fd = open("/dev/vduse/control", O_RDWR); 1293 if (ctrl_fd < 0) { 1294 fprintf(stderr, "Failed to open /dev/vduse/control: %s\n", 1295 strerror(errno)); 1296 goto err_ctrl; 1297 } 1298 1299 version = VDUSE_API_VERSION; 1300 if (ioctl(ctrl_fd, VDUSE_SET_API_VERSION, &version)) { 1301 fprintf(stderr, "Failed to set api version %" PRIu64 ": %s\n", 1302 version, strerror(errno)); 1303 goto err_dev; 1304 } 1305 1306 dev_config = calloc(size + config_size, 1); 1307 if (!dev_config) { 1308 fprintf(stderr, "Failed to allocate config space\n"); 1309 goto err_dev; 1310 } 1311 1312 assert(!vduse_name_is_invalid(name)); 1313 strcpy(dev_config->name, name); 1314 dev_config->device_id = device_id; 1315 dev_config->vendor_id = vendor_id; 1316 dev_config->features = features; 1317 dev_config->vq_num = num_queues; 1318 dev_config->vq_align = VDUSE_VQ_ALIGN; 1319 dev_config->config_size = config_size; 1320 memcpy(dev_config->config, config, config_size); 1321 1322 ret = ioctl(ctrl_fd, VDUSE_CREATE_DEV, dev_config); 1323 free(dev_config); 1324 if (ret && errno != EEXIST) { 1325 fprintf(stderr, "Failed to create vduse device %s: %s\n", 1326 name, strerror(errno)); 1327 goto err_dev; 1328 } 1329 dev->ctrl_fd = ctrl_fd; 1330 1331 ret = vduse_dev_init(dev, name, num_queues, ops, priv); 1332 if (ret < 0) { 1333 fprintf(stderr, "Failed to init vduse device %s: %s\n", 1334 name, strerror(-ret)); 1335 goto err; 1336 } 1337 1338 return dev; 1339 err: 1340 ioctl(ctrl_fd, VDUSE_DESTROY_DEV, name); 1341 err_dev: 1342 close(ctrl_fd); 1343 err_ctrl: 1344 free(dev); 1345 1346 return NULL; 1347 } 1348 1349 int vduse_dev_destroy(VduseDev *dev) 1350 { 1351 size_t log_size = dev->num_queues * vduse_vq_log_size(VIRTQUEUE_MAX_SIZE); 1352 int i, ret = 0; 1353 1354 if (dev->log) { 1355 munmap(dev->log, log_size); 1356 } 1357 for (i = 0; i < dev->num_queues; i++) { 1358 free(dev->vqs[i].resubmit_list); 1359 } 1360 free(dev->vqs); 1361 if (dev->fd >= 0) { 1362 close(dev->fd); 1363 dev->fd = -1; 1364 } 1365 if (dev->ctrl_fd >= 0) { 1366 if (ioctl(dev->ctrl_fd, VDUSE_DESTROY_DEV, dev->name)) { 1367 ret = -errno; 1368 } 1369 close(dev->ctrl_fd); 1370 dev->ctrl_fd = -1; 1371 } 1372 free(dev->name); 1373 free(dev); 1374 1375 return ret; 1376 }