1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/kernel.h> 3 #include <linux/errno.h> 4 #include <linux/dma-map-ops.h> 5 #include <linux/mm.h> 6 #include <linux/nospec.h> 7 #include <linux/io_uring.h> 8 #include <linux/netdevice.h> 9 #include <linux/rtnetlink.h> 10 #include <linux/skbuff_ref.h> 11 #include <linux/anon_inodes.h> 12 13 #include <net/page_pool/helpers.h> 14 #include <net/page_pool/memory_provider.h> 15 #include <net/netlink.h> 16 #include <net/netdev_queues.h> 17 #include <net/netdev_rx_queue.h> 18 #include <net/tcp.h> 19 #include <net/rps.h> 20 21 #include <trace/events/page_pool.h> 22 23 #include <uapi/linux/io_uring.h> 24 25 #include "io_uring.h" 26 #include "kbuf.h" 27 #include "memmap.h" 28 #include "zcrx.h" 29 #include "rsrc.h" 30 31 #define IO_ZCRX_AREA_SUPPORTED_FLAGS (IORING_ZCRX_AREA_DMABUF) 32 33 #define IO_DMA_ATTR (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING) 34 35 static inline struct io_zcrx_ifq *io_pp_to_ifq(struct page_pool *pp) 36 { 37 return pp->mp_priv; 38 } 39 40 static inline struct io_zcrx_area *io_zcrx_iov_to_area(const struct net_iov *niov) 41 { 42 struct net_iov_area *owner = net_iov_owner(niov); 43 44 return container_of(owner, struct io_zcrx_area, nia); 45 } 46 47 static inline struct page *io_zcrx_iov_page(const struct net_iov *niov) 48 { 49 struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); 50 unsigned niov_pages_shift; 51 52 lockdep_assert(!area->mem.is_dmabuf); 53 54 niov_pages_shift = area->ifq->niov_shift - PAGE_SHIFT; 55 return area->mem.pages[net_iov_idx(niov) << niov_pages_shift]; 56 } 57 58 static int io_area_max_shift(struct io_zcrx_mem *mem) 59 { 60 struct sg_table *sgt = mem->sgt; 61 struct scatterlist *sg; 62 unsigned shift = -1U; 63 unsigned i; 64 65 for_each_sgtable_dma_sg(sgt, sg, i) 66 shift = min(shift, __ffs(sg_dma_len(sg))); 67 return shift; 68 } 69 70 static int io_populate_area_dma(struct io_zcrx_ifq *ifq, 71 struct io_zcrx_area *area) 72 { 73 unsigned niov_size = 1U << ifq->niov_shift; 74 struct sg_table *sgt = area->mem.sgt; 75 struct scatterlist *sg; 76 unsigned i, niov_idx = 0; 77 78 for_each_sgtable_dma_sg(sgt, sg, i) { 79 dma_addr_t dma = sg_dma_address(sg); 80 unsigned long sg_len = sg_dma_len(sg); 81 82 if (WARN_ON_ONCE(sg_len % niov_size)) 83 return -EINVAL; 84 85 while (sg_len && niov_idx < area->nia.num_niovs) { 86 struct net_iov *niov = &area->nia.niovs[niov_idx]; 87 88 if (net_mp_niov_set_dma_addr(niov, dma)) 89 return -EFAULT; 90 sg_len -= niov_size; 91 dma += niov_size; 92 niov_idx++; 93 } 94 } 95 96 if (WARN_ON_ONCE(niov_idx != area->nia.num_niovs)) 97 return -EFAULT; 98 return 0; 99 } 100 101 static void io_release_dmabuf(struct io_zcrx_mem *mem) 102 { 103 if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) 104 return; 105 106 if (mem->sgt) 107 dma_buf_unmap_attachment_unlocked(mem->attach, mem->sgt, 108 DMA_FROM_DEVICE); 109 if (mem->attach) 110 dma_buf_detach(mem->dmabuf, mem->attach); 111 if (mem->dmabuf) 112 dma_buf_put(mem->dmabuf); 113 114 mem->sgt = NULL; 115 mem->attach = NULL; 116 mem->dmabuf = NULL; 117 } 118 119 static int io_import_dmabuf(struct io_zcrx_ifq *ifq, 120 struct io_zcrx_mem *mem, 121 struct io_uring_zcrx_area_reg *area_reg) 122 { 123 unsigned long off = (unsigned long)area_reg->addr; 124 unsigned long len = (unsigned long)area_reg->len; 125 unsigned long total_size = 0; 126 struct scatterlist *sg; 127 int dmabuf_fd = area_reg->dmabuf_fd; 128 int i, ret; 129 130 if (!ifq->dev) 131 return -EINVAL; 132 if (off) 133 return -EINVAL; 134 if (!IS_ENABLED(CONFIG_DMA_SHARED_BUFFER)) 135 return -EINVAL; 136 137 mem->is_dmabuf = true; 138 mem->dmabuf = dma_buf_get(dmabuf_fd); 139 if (IS_ERR(mem->dmabuf)) { 140 ret = PTR_ERR(mem->dmabuf); 141 mem->dmabuf = NULL; 142 goto err; 143 } 144 145 mem->attach = dma_buf_attach(mem->dmabuf, ifq->dev); 146 if (IS_ERR(mem->attach)) { 147 ret = PTR_ERR(mem->attach); 148 mem->attach = NULL; 149 goto err; 150 } 151 152 mem->sgt = dma_buf_map_attachment_unlocked(mem->attach, DMA_FROM_DEVICE); 153 if (IS_ERR(mem->sgt)) { 154 ret = PTR_ERR(mem->sgt); 155 mem->sgt = NULL; 156 goto err; 157 } 158 159 for_each_sgtable_dma_sg(mem->sgt, sg, i) 160 total_size += sg_dma_len(sg); 161 162 if (total_size != len) { 163 ret = -EINVAL; 164 goto err; 165 } 166 167 mem->size = len; 168 return 0; 169 err: 170 io_release_dmabuf(mem); 171 return ret; 172 } 173 174 static unsigned long io_count_account_pages(struct page **pages, unsigned nr_pages) 175 { 176 struct folio *last_folio = NULL; 177 unsigned long res = 0; 178 int i; 179 180 for (i = 0; i < nr_pages; i++) { 181 struct folio *folio = page_folio(pages[i]); 182 183 if (folio == last_folio) 184 continue; 185 last_folio = folio; 186 res += folio_nr_pages(folio); 187 } 188 return res; 189 } 190 191 static int io_import_umem(struct io_zcrx_ifq *ifq, 192 struct io_zcrx_mem *mem, 193 struct io_uring_zcrx_area_reg *area_reg) 194 { 195 struct page **pages; 196 int nr_pages, ret; 197 bool mapped = false; 198 199 if (area_reg->dmabuf_fd) 200 return -EINVAL; 201 if (!area_reg->addr) 202 return -EFAULT; 203 pages = io_pin_pages((unsigned long)area_reg->addr, area_reg->len, 204 &nr_pages); 205 if (IS_ERR(pages)) 206 return PTR_ERR(pages); 207 208 ret = sg_alloc_table_from_pages(&mem->page_sg_table, pages, nr_pages, 209 0, (unsigned long)nr_pages << PAGE_SHIFT, 210 GFP_KERNEL_ACCOUNT); 211 if (ret) 212 goto out_err; 213 214 if (ifq->dev) { 215 ret = dma_map_sgtable(ifq->dev, &mem->page_sg_table, 216 DMA_FROM_DEVICE, IO_DMA_ATTR); 217 if (ret < 0) 218 goto out_err; 219 mapped = true; 220 } 221 222 mem->account_pages = io_count_account_pages(pages, nr_pages); 223 ret = io_account_mem(ifq->user, ifq->mm_account, mem->account_pages); 224 if (ret < 0) { 225 mem->account_pages = 0; 226 goto out_err; 227 } 228 229 mem->sgt = &mem->page_sg_table; 230 mem->pages = pages; 231 mem->nr_folios = nr_pages; 232 mem->size = area_reg->len; 233 return ret; 234 out_err: 235 if (mapped) 236 dma_unmap_sgtable(ifq->dev, &mem->page_sg_table, 237 DMA_FROM_DEVICE, IO_DMA_ATTR); 238 sg_free_table(&mem->page_sg_table); 239 unpin_user_pages(pages, nr_pages); 240 kvfree(pages); 241 return ret; 242 } 243 244 static void io_release_area_mem(struct io_zcrx_mem *mem) 245 { 246 if (mem->is_dmabuf) { 247 io_release_dmabuf(mem); 248 return; 249 } 250 if (mem->pages) { 251 unpin_user_pages(mem->pages, mem->nr_folios); 252 sg_free_table(mem->sgt); 253 mem->sgt = NULL; 254 kvfree(mem->pages); 255 } 256 } 257 258 static int io_import_area(struct io_zcrx_ifq *ifq, 259 struct io_zcrx_mem *mem, 260 struct io_uring_zcrx_area_reg *area_reg) 261 { 262 int ret; 263 264 if (area_reg->flags & ~IO_ZCRX_AREA_SUPPORTED_FLAGS) 265 return -EINVAL; 266 if (area_reg->rq_area_token) 267 return -EINVAL; 268 if (area_reg->__resv2[0] || area_reg->__resv2[1]) 269 return -EINVAL; 270 271 ret = io_validate_user_buf_range(area_reg->addr, area_reg->len); 272 if (ret) 273 return ret; 274 if (area_reg->addr & ~PAGE_MASK || area_reg->len & ~PAGE_MASK) 275 return -EINVAL; 276 277 if (area_reg->flags & IORING_ZCRX_AREA_DMABUF) 278 return io_import_dmabuf(ifq, mem, area_reg); 279 return io_import_umem(ifq, mem, area_reg); 280 } 281 282 static void io_zcrx_unmap_area(struct io_zcrx_ifq *ifq, 283 struct io_zcrx_area *area) 284 { 285 int i; 286 287 guard(mutex)(&ifq->pp_lock); 288 if (!area->is_mapped) 289 return; 290 area->is_mapped = false; 291 292 if (area->nia.niovs) { 293 for (i = 0; i < area->nia.num_niovs; i++) 294 net_mp_niov_set_dma_addr(&area->nia.niovs[i], 0); 295 } 296 297 if (area->mem.is_dmabuf) { 298 io_release_dmabuf(&area->mem); 299 } else { 300 dma_unmap_sgtable(ifq->dev, &area->mem.page_sg_table, 301 DMA_FROM_DEVICE, IO_DMA_ATTR); 302 } 303 } 304 305 static void zcrx_sync_for_device(struct page_pool *pp, struct io_zcrx_ifq *zcrx, 306 netmem_ref *netmems, unsigned nr) 307 { 308 #if defined(CONFIG_HAS_DMA) && defined(CONFIG_DMA_NEED_SYNC) 309 struct device *dev = pp->p.dev; 310 unsigned i, niov_size; 311 dma_addr_t dma_addr; 312 313 if (!dma_dev_need_sync(dev)) 314 return; 315 niov_size = 1U << zcrx->niov_shift; 316 317 for (i = 0; i < nr; i++) { 318 dma_addr = page_pool_get_dma_addr_netmem(netmems[i]); 319 __dma_sync_single_for_device(dev, dma_addr + pp->p.offset, 320 niov_size, pp->p.dma_dir); 321 } 322 #endif 323 } 324 325 #define IO_RQ_MAX_ENTRIES 32768 326 327 #define IO_SKBS_PER_CALL_LIMIT 20 328 329 struct io_zcrx_args { 330 struct io_kiocb *req; 331 struct io_zcrx_ifq *ifq; 332 struct socket *sock; 333 unsigned nr_skbs; 334 }; 335 336 static const struct memory_provider_ops io_uring_pp_zc_ops; 337 338 static inline atomic_t *io_get_user_counter(struct net_iov *niov) 339 { 340 struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); 341 342 return &area->user_refs[net_iov_idx(niov)]; 343 } 344 345 static bool io_zcrx_put_niov_uref(struct net_iov *niov) 346 { 347 atomic_t *uref = io_get_user_counter(niov); 348 int old; 349 350 old = atomic_read(uref); 351 do { 352 if (unlikely(old == 0)) 353 return false; 354 } while (!atomic_try_cmpxchg(uref, &old, old - 1)); 355 356 return true; 357 } 358 359 static void io_zcrx_get_niov_uref(struct net_iov *niov) 360 { 361 atomic_inc(io_get_user_counter(niov)); 362 } 363 364 static void io_fill_zcrx_offsets(struct io_uring_zcrx_offsets *offsets) 365 { 366 offsets->head = offsetof(struct io_uring, head); 367 offsets->tail = offsetof(struct io_uring, tail); 368 offsets->rqes = ALIGN(sizeof(struct io_uring), L1_CACHE_BYTES); 369 } 370 371 static int io_allocate_rbuf_ring(struct io_ring_ctx *ctx, 372 struct io_zcrx_ifq *ifq, 373 struct io_uring_zcrx_ifq_reg *reg, 374 struct io_uring_region_desc *rd, 375 u32 id) 376 { 377 u64 mmap_offset; 378 size_t off, size; 379 void *ptr; 380 int ret; 381 382 io_fill_zcrx_offsets(®->offsets); 383 off = reg->offsets.rqes; 384 size = off + sizeof(struct io_uring_zcrx_rqe) * reg->rq_entries; 385 if (size > rd->size) 386 return -EINVAL; 387 388 mmap_offset = IORING_MAP_OFF_ZCRX_REGION; 389 mmap_offset += (u64)id << IORING_OFF_ZCRX_SHIFT; 390 391 ret = io_create_region(ctx, &ifq->rq_region, rd, mmap_offset); 392 if (ret < 0) 393 return ret; 394 395 ptr = io_region_get_ptr(&ifq->rq_region); 396 ifq->rq.ring = (struct io_uring *)ptr; 397 ifq->rq.rqes = (struct io_uring_zcrx_rqe *)(ptr + off); 398 399 return 0; 400 } 401 402 static void io_free_rbuf_ring(struct io_zcrx_ifq *ifq) 403 { 404 io_free_region(ifq->user, &ifq->rq_region); 405 ifq->rq.ring = NULL; 406 ifq->rq.rqes = NULL; 407 } 408 409 static void io_zcrx_free_area(struct io_zcrx_ifq *ifq, 410 struct io_zcrx_area *area) 411 { 412 io_zcrx_unmap_area(ifq, area); 413 io_release_area_mem(&area->mem); 414 415 if (area->mem.account_pages) 416 io_unaccount_mem(ifq->user, ifq->mm_account, 417 area->mem.account_pages); 418 419 kvfree(area->freelist); 420 kvfree(area->nia.niovs); 421 kvfree(area->user_refs); 422 kfree(area); 423 } 424 425 static int io_zcrx_append_area(struct io_zcrx_ifq *ifq, 426 struct io_zcrx_area *area) 427 { 428 bool kern_readable = !area->mem.is_dmabuf; 429 430 if (WARN_ON_ONCE(ifq->area)) 431 return -EINVAL; 432 if (WARN_ON_ONCE(ifq->kern_readable != kern_readable)) 433 return -EINVAL; 434 435 ifq->area = area; 436 return 0; 437 } 438 439 static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, 440 struct io_uring_zcrx_area_reg *area_reg, 441 struct io_uring_zcrx_ifq_reg *reg) 442 { 443 int buf_size_shift = PAGE_SHIFT; 444 struct io_zcrx_area *area; 445 unsigned nr_iovs; 446 int i, ret; 447 448 if (reg->rx_buf_len) { 449 if (!is_power_of_2(reg->rx_buf_len) || 450 reg->rx_buf_len < PAGE_SIZE) 451 return -EINVAL; 452 buf_size_shift = ilog2(reg->rx_buf_len); 453 } 454 if (!ifq->dev && buf_size_shift != PAGE_SHIFT) 455 return -EOPNOTSUPP; 456 457 ret = -ENOMEM; 458 area = kzalloc_obj(*area); 459 if (!area) 460 goto err; 461 area->ifq = ifq; 462 463 ret = io_import_area(ifq, &area->mem, area_reg); 464 if (ret) 465 goto err; 466 if (ifq->dev) 467 area->is_mapped = true; 468 469 if (ifq->dev && buf_size_shift > io_area_max_shift(&area->mem)) { 470 ret = -ERANGE; 471 goto err; 472 } 473 474 ifq->niov_shift = buf_size_shift; 475 nr_iovs = area->mem.size >> ifq->niov_shift; 476 area->nia.num_niovs = nr_iovs; 477 478 ret = -ENOMEM; 479 area->nia.niovs = kvmalloc_objs(area->nia.niovs[0], nr_iovs, 480 GFP_KERNEL_ACCOUNT | __GFP_ZERO); 481 if (!area->nia.niovs) 482 goto err; 483 484 area->freelist = kvmalloc_array(nr_iovs, sizeof(area->freelist[0]), 485 GFP_KERNEL_ACCOUNT | __GFP_ZERO); 486 if (!area->freelist) 487 goto err; 488 489 area->user_refs = kvmalloc_objs(area->user_refs[0], nr_iovs, 490 GFP_KERNEL_ACCOUNT | __GFP_ZERO); 491 if (!area->user_refs) 492 goto err; 493 494 for (i = 0; i < nr_iovs; i++) { 495 struct net_iov *niov = &area->nia.niovs[i]; 496 497 niov->owner = &area->nia; 498 area->freelist[i] = i; 499 atomic_set(&area->user_refs[i], 0); 500 niov->type = NET_IOV_IOURING; 501 } 502 503 if (ifq->dev) { 504 ret = io_populate_area_dma(ifq, area); 505 if (ret) 506 goto err; 507 } 508 509 area->free_count = nr_iovs; 510 /* we're only supporting one area per ifq for now */ 511 area->area_id = 0; 512 area_reg->rq_area_token = (u64)area->area_id << IORING_ZCRX_AREA_SHIFT; 513 spin_lock_init(&area->freelist_lock); 514 515 ret = io_zcrx_append_area(ifq, area); 516 if (!ret) 517 return 0; 518 err: 519 if (area) 520 io_zcrx_free_area(ifq, area); 521 return ret; 522 } 523 524 static struct io_zcrx_ifq *io_zcrx_ifq_alloc(struct io_ring_ctx *ctx) 525 { 526 struct io_zcrx_ifq *ifq; 527 528 ifq = kzalloc_obj(*ifq); 529 if (!ifq) 530 return NULL; 531 532 ifq->if_rxq = -1; 533 spin_lock_init(&ifq->rq.lock); 534 mutex_init(&ifq->pp_lock); 535 refcount_set(&ifq->refs, 1); 536 refcount_set(&ifq->user_refs, 1); 537 return ifq; 538 } 539 540 static void io_zcrx_drop_netdev(struct io_zcrx_ifq *ifq) 541 { 542 guard(mutex)(&ifq->pp_lock); 543 544 if (!ifq->netdev) 545 return; 546 netdev_put(ifq->netdev, &ifq->netdev_tracker); 547 ifq->netdev = NULL; 548 } 549 550 static void io_close_queue(struct io_zcrx_ifq *ifq) 551 { 552 struct net_device *netdev; 553 netdevice_tracker netdev_tracker; 554 struct pp_memory_provider_params p = { 555 .mp_ops = &io_uring_pp_zc_ops, 556 .mp_priv = ifq, 557 }; 558 559 scoped_guard(mutex, &ifq->pp_lock) { 560 netdev = ifq->netdev; 561 netdev_tracker = ifq->netdev_tracker; 562 ifq->netdev = NULL; 563 } 564 565 if (netdev) { 566 if (ifq->if_rxq != -1) { 567 netdev_lock(netdev); 568 netif_mp_close_rxq(netdev, ifq->if_rxq, &p); 569 netdev_unlock(netdev); 570 } 571 netdev_put(netdev, &netdev_tracker); 572 } 573 ifq->if_rxq = -1; 574 } 575 576 static void io_zcrx_ifq_free(struct io_zcrx_ifq *ifq) 577 { 578 io_close_queue(ifq); 579 580 if (ifq->area) 581 io_zcrx_free_area(ifq, ifq->area); 582 free_uid(ifq->user); 583 if (ifq->mm_account) 584 mmdrop(ifq->mm_account); 585 if (ifq->dev) 586 put_device(ifq->dev); 587 588 io_free_rbuf_ring(ifq); 589 mutex_destroy(&ifq->pp_lock); 590 kfree(ifq); 591 } 592 593 static void io_put_zcrx_ifq(struct io_zcrx_ifq *ifq) 594 { 595 if (refcount_dec_and_test(&ifq->refs)) 596 io_zcrx_ifq_free(ifq); 597 } 598 599 static void io_zcrx_return_niov_freelist(struct net_iov *niov) 600 { 601 struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); 602 603 guard(spinlock_bh)(&area->freelist_lock); 604 area->freelist[area->free_count++] = net_iov_idx(niov); 605 } 606 607 static struct net_iov *zcrx_get_free_niov(struct io_zcrx_area *area) 608 { 609 unsigned niov_idx; 610 611 lockdep_assert_held(&area->freelist_lock); 612 613 if (unlikely(!area->free_count)) 614 return NULL; 615 616 niov_idx = area->freelist[--area->free_count]; 617 return &area->nia.niovs[niov_idx]; 618 } 619 620 static void io_zcrx_return_niov(struct net_iov *niov) 621 { 622 netmem_ref netmem = net_iov_to_netmem(niov); 623 624 if (!niov->desc.pp) { 625 /* copy fallback allocated niovs */ 626 io_zcrx_return_niov_freelist(niov); 627 return; 628 } 629 page_pool_put_unrefed_netmem(niov->desc.pp, netmem, -1, false); 630 } 631 632 static void io_zcrx_scrub(struct io_zcrx_ifq *ifq) 633 { 634 struct io_zcrx_area *area = ifq->area; 635 int i; 636 637 if (!area) 638 return; 639 640 /* Reclaim back all buffers given to the user space. */ 641 for (i = 0; i < area->nia.num_niovs; i++) { 642 struct net_iov *niov = &area->nia.niovs[i]; 643 int nr; 644 645 if (!atomic_read(io_get_user_counter(niov))) 646 continue; 647 nr = atomic_xchg(io_get_user_counter(niov), 0); 648 if (nr && !page_pool_unref_netmem(net_iov_to_netmem(niov), nr)) 649 io_zcrx_return_niov(niov); 650 } 651 } 652 653 static void zcrx_unregister_user(struct io_zcrx_ifq *ifq) 654 { 655 if (refcount_dec_and_test(&ifq->user_refs)) { 656 io_close_queue(ifq); 657 io_zcrx_scrub(ifq); 658 } 659 } 660 661 static void zcrx_unregister(struct io_zcrx_ifq *ifq) 662 { 663 zcrx_unregister_user(ifq); 664 io_put_zcrx_ifq(ifq); 665 } 666 667 struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx, 668 unsigned int id) 669 { 670 struct io_zcrx_ifq *ifq = xa_load(&ctx->zcrx_ctxs, id); 671 672 lockdep_assert_held(&ctx->mmap_lock); 673 674 return ifq ? &ifq->rq_region : NULL; 675 } 676 677 static int zcrx_box_release(struct inode *inode, struct file *file) 678 { 679 struct io_zcrx_ifq *ifq = file->private_data; 680 681 if (WARN_ON_ONCE(!ifq)) 682 return -EFAULT; 683 zcrx_unregister(ifq); 684 return 0; 685 } 686 687 static const struct file_operations zcrx_box_fops = { 688 .owner = THIS_MODULE, 689 .release = zcrx_box_release, 690 }; 691 692 static int zcrx_export(struct io_ring_ctx *ctx, struct io_zcrx_ifq *ifq, 693 struct zcrx_ctrl *ctrl, void __user *arg) 694 { 695 struct zcrx_ctrl_export *ce = &ctrl->zc_export; 696 struct file *file; 697 int fd = -1; 698 699 if (!mem_is_zero(ce, sizeof(*ce))) 700 return -EINVAL; 701 fd = get_unused_fd_flags(O_CLOEXEC); 702 if (fd < 0) 703 return fd; 704 705 ce->zcrx_fd = fd; 706 if (copy_to_user(arg, ctrl, sizeof(*ctrl))) { 707 put_unused_fd(fd); 708 return -EFAULT; 709 } 710 711 refcount_inc(&ifq->refs); 712 refcount_inc(&ifq->user_refs); 713 714 file = anon_inode_create_getfile("[zcrx]", &zcrx_box_fops, 715 ifq, O_CLOEXEC, NULL); 716 if (IS_ERR(file)) { 717 put_unused_fd(fd); 718 zcrx_unregister(ifq); 719 return PTR_ERR(file); 720 } 721 722 fd_install(fd, file); 723 return 0; 724 } 725 726 static int import_zcrx(struct io_ring_ctx *ctx, 727 struct io_uring_zcrx_ifq_reg __user *arg, 728 struct io_uring_zcrx_ifq_reg *reg) 729 { 730 struct io_zcrx_ifq *ifq; 731 struct file *file; 732 int fd, ret; 733 u32 id; 734 735 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 736 return -EINVAL; 737 if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED))) 738 return -EINVAL; 739 if (reg->if_rxq || reg->rq_entries || reg->area_ptr || reg->region_ptr) 740 return -EINVAL; 741 if (reg->flags & ~ZCRX_REG_IMPORT) 742 return -EINVAL; 743 744 fd = reg->if_idx; 745 CLASS(fd, f)(fd); 746 if (fd_empty(f)) 747 return -EBADF; 748 749 file = fd_file(f); 750 if (file->f_op != &zcrx_box_fops || !file->private_data) 751 return -EBADF; 752 753 ifq = file->private_data; 754 refcount_inc(&ifq->refs); 755 refcount_inc(&ifq->user_refs); 756 757 scoped_guard(mutex, &ctx->mmap_lock) { 758 ret = xa_alloc(&ctx->zcrx_ctxs, &id, NULL, xa_limit_31b, GFP_KERNEL); 759 if (ret) 760 goto err; 761 } 762 763 reg->zcrx_id = id; 764 io_fill_zcrx_offsets(®->offsets); 765 if (copy_to_user(arg, reg, sizeof(*reg))) { 766 ret = -EFAULT; 767 goto err_xa_erase; 768 } 769 770 scoped_guard(mutex, &ctx->mmap_lock) { 771 ret = -ENOMEM; 772 if (xa_store(&ctx->zcrx_ctxs, id, ifq, GFP_KERNEL)) 773 goto err_xa_erase; 774 } 775 776 return 0; 777 err_xa_erase: 778 scoped_guard(mutex, &ctx->mmap_lock) 779 xa_erase(&ctx->zcrx_ctxs, id); 780 err: 781 zcrx_unregister(ifq); 782 return ret; 783 } 784 785 static int zcrx_register_netdev(struct io_zcrx_ifq *ifq, 786 struct io_uring_zcrx_ifq_reg *reg, 787 struct io_uring_zcrx_area_reg *area) 788 { 789 struct pp_memory_provider_params mp_param = {}; 790 unsigned if_rxq = reg->if_rxq; 791 int ret; 792 793 ifq->netdev = netdev_get_by_index_lock(current->nsproxy->net_ns, 794 reg->if_idx); 795 if (!ifq->netdev) 796 return -ENODEV; 797 798 netdev_hold(ifq->netdev, &ifq->netdev_tracker, GFP_KERNEL); 799 800 ifq->dev = netdev_queue_get_dma_dev(ifq->netdev, if_rxq, NETDEV_QUEUE_TYPE_RX); 801 if (!ifq->dev) { 802 ret = -EOPNOTSUPP; 803 goto netdev_put_unlock; 804 } 805 get_device(ifq->dev); 806 807 ret = io_zcrx_create_area(ifq, area, reg); 808 if (ret) 809 goto netdev_put_unlock; 810 811 if (reg->rx_buf_len) 812 mp_param.rx_page_size = 1U << ifq->niov_shift; 813 mp_param.mp_ops = &io_uring_pp_zc_ops; 814 mp_param.mp_priv = ifq; 815 ret = netif_mp_open_rxq(ifq->netdev, if_rxq, &mp_param, NULL); 816 if (ret) 817 goto netdev_put_unlock; 818 819 ifq->if_rxq = if_rxq; 820 ret = 0; 821 netdev_put_unlock: 822 netdev_unlock(ifq->netdev); 823 return ret; 824 } 825 826 int io_register_zcrx(struct io_ring_ctx *ctx, 827 struct io_uring_zcrx_ifq_reg __user *arg) 828 { 829 struct io_uring_zcrx_area_reg area; 830 struct io_uring_zcrx_ifq_reg reg; 831 struct io_uring_region_desc rd; 832 struct io_zcrx_ifq *ifq; 833 int ret; 834 u32 id; 835 836 /* 837 * 1. Interface queue allocation. 838 * 2. It can observe data destined for sockets of other tasks. 839 */ 840 if (!capable(CAP_NET_ADMIN)) 841 return -EPERM; 842 843 /* mandatory io_uring features for zc rx */ 844 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 845 return -EINVAL; 846 if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED))) 847 return -EINVAL; 848 if (copy_from_user(®, arg, sizeof(reg))) 849 return -EFAULT; 850 if (!mem_is_zero(®.__resv, sizeof(reg.__resv)) || reg.zcrx_id) 851 return -EINVAL; 852 if (reg.flags & ~ZCRX_SUPPORTED_REG_FLAGS) 853 return -EINVAL; 854 if (reg.flags & ZCRX_REG_IMPORT) 855 return import_zcrx(ctx, arg, ®); 856 if (copy_from_user(&rd, u64_to_user_ptr(reg.region_ptr), sizeof(rd))) 857 return -EFAULT; 858 if (reg.if_rxq == -1 || !reg.rq_entries) 859 return -EINVAL; 860 if ((reg.if_rxq || reg.if_idx) && (reg.flags & ZCRX_REG_NODEV)) 861 return -EINVAL; 862 if (reg.rq_entries > IO_RQ_MAX_ENTRIES) { 863 if (!(ctx->flags & IORING_SETUP_CLAMP)) 864 return -EINVAL; 865 reg.rq_entries = IO_RQ_MAX_ENTRIES; 866 } 867 reg.rq_entries = roundup_pow_of_two(reg.rq_entries); 868 869 if (copy_from_user(&area, u64_to_user_ptr(reg.area_ptr), sizeof(area))) 870 return -EFAULT; 871 872 ifq = io_zcrx_ifq_alloc(ctx); 873 if (!ifq) 874 return -ENOMEM; 875 876 if (ctx->user) { 877 get_uid(ctx->user); 878 ifq->user = ctx->user; 879 } 880 if (ctx->mm_account) { 881 mmgrab(ctx->mm_account); 882 ifq->mm_account = ctx->mm_account; 883 } 884 ifq->rq.nr_entries = reg.rq_entries; 885 886 scoped_guard(mutex, &ctx->mmap_lock) { 887 /* preallocate id */ 888 ret = xa_alloc(&ctx->zcrx_ctxs, &id, NULL, xa_limit_31b, GFP_KERNEL); 889 if (ret) 890 goto ifq_free; 891 } 892 893 ret = io_allocate_rbuf_ring(ctx, ifq, ®, &rd, id); 894 if (ret) 895 goto err; 896 897 ifq->kern_readable = !(area.flags & IORING_ZCRX_AREA_DMABUF); 898 899 if (!(reg.flags & ZCRX_REG_NODEV)) { 900 ret = zcrx_register_netdev(ifq, ®, &area); 901 if (ret) 902 goto err; 903 } else { 904 ret = io_zcrx_create_area(ifq, &area, ®); 905 if (ret) 906 goto err; 907 } 908 909 reg.zcrx_id = id; 910 911 scoped_guard(mutex, &ctx->mmap_lock) { 912 /* publish ifq */ 913 ret = -ENOMEM; 914 if (xa_store(&ctx->zcrx_ctxs, id, ifq, GFP_KERNEL)) 915 goto err; 916 } 917 918 reg.rx_buf_len = 1U << ifq->niov_shift; 919 920 if (copy_to_user(arg, ®, sizeof(reg)) || 921 copy_to_user(u64_to_user_ptr(reg.region_ptr), &rd, sizeof(rd)) || 922 copy_to_user(u64_to_user_ptr(reg.area_ptr), &area, sizeof(area))) { 923 ret = -EFAULT; 924 goto err; 925 } 926 return 0; 927 err: 928 scoped_guard(mutex, &ctx->mmap_lock) 929 xa_erase(&ctx->zcrx_ctxs, id); 930 ifq_free: 931 zcrx_unregister(ifq); 932 return ret; 933 } 934 935 static inline bool is_zcrx_entry_marked(struct io_ring_ctx *ctx, unsigned long id) 936 { 937 return xa_get_mark(&ctx->zcrx_ctxs, id, XA_MARK_1); 938 } 939 940 static inline void set_zcrx_entry_mark(struct io_ring_ctx *ctx, unsigned long id) 941 { 942 xa_set_mark(&ctx->zcrx_ctxs, id, XA_MARK_1); 943 } 944 945 void io_terminate_zcrx(struct io_ring_ctx *ctx) 946 { 947 struct io_zcrx_ifq *ifq; 948 unsigned long id = 0; 949 950 lockdep_assert_held(&ctx->uring_lock); 951 952 while (1) { 953 scoped_guard(mutex, &ctx->mmap_lock) 954 ifq = xa_find(&ctx->zcrx_ctxs, &id, ULONG_MAX, XA_PRESENT); 955 if (!ifq) 956 break; 957 if (WARN_ON_ONCE(is_zcrx_entry_marked(ctx, id))) 958 break; 959 set_zcrx_entry_mark(ctx, id); 960 id++; 961 zcrx_unregister_user(ifq); 962 } 963 } 964 965 void io_unregister_zcrx(struct io_ring_ctx *ctx) 966 { 967 struct io_zcrx_ifq *ifq; 968 969 lockdep_assert_held(&ctx->uring_lock); 970 971 while (1) { 972 scoped_guard(mutex, &ctx->mmap_lock) { 973 unsigned long id = 0; 974 975 ifq = xa_find(&ctx->zcrx_ctxs, &id, ULONG_MAX, XA_PRESENT); 976 if (ifq) { 977 if (WARN_ON_ONCE(!is_zcrx_entry_marked(ctx, id))) { 978 ifq = NULL; 979 break; 980 } 981 xa_erase(&ctx->zcrx_ctxs, id); 982 } 983 } 984 if (!ifq) 985 break; 986 io_put_zcrx_ifq(ifq); 987 } 988 989 xa_destroy(&ctx->zcrx_ctxs); 990 } 991 992 static inline u32 zcrx_rq_entries(struct zcrx_rq *rq) 993 { 994 u32 entries; 995 996 entries = smp_load_acquire(&rq->ring->tail) - rq->cached_head; 997 return min(entries, rq->nr_entries); 998 } 999 1000 static struct io_uring_zcrx_rqe *zcrx_next_rqe(struct zcrx_rq *rq, unsigned mask) 1001 { 1002 unsigned int idx = rq->cached_head++ & mask; 1003 1004 return &rq->rqes[idx]; 1005 } 1006 1007 static inline bool io_parse_rqe(struct io_uring_zcrx_rqe *rqe, 1008 struct io_zcrx_ifq *ifq, 1009 struct net_iov **ret_niov) 1010 { 1011 __u64 off = READ_ONCE(rqe->off); 1012 unsigned niov_idx, area_idx; 1013 struct io_zcrx_area *area; 1014 1015 area_idx = off >> IORING_ZCRX_AREA_SHIFT; 1016 niov_idx = (off & ~IORING_ZCRX_AREA_MASK) >> ifq->niov_shift; 1017 1018 if (unlikely(rqe->__pad || area_idx)) 1019 return false; 1020 area = ifq->area; 1021 1022 if (unlikely(niov_idx >= area->nia.num_niovs)) 1023 return false; 1024 niov_idx = array_index_nospec(niov_idx, area->nia.num_niovs); 1025 1026 *ret_niov = &area->nia.niovs[niov_idx]; 1027 return true; 1028 } 1029 1030 static unsigned io_zcrx_ring_refill(struct page_pool *pp, 1031 struct io_zcrx_ifq *ifq, 1032 netmem_ref *netmems, unsigned to_alloc) 1033 { 1034 struct zcrx_rq *rq = &ifq->rq; 1035 unsigned int mask = rq->nr_entries - 1; 1036 unsigned int entries; 1037 unsigned allocated = 0; 1038 1039 guard(spinlock_bh)(&rq->lock); 1040 1041 entries = zcrx_rq_entries(rq); 1042 entries = min_t(unsigned, entries, to_alloc); 1043 if (unlikely(!entries)) 1044 return 0; 1045 1046 do { 1047 struct io_uring_zcrx_rqe *rqe = zcrx_next_rqe(rq, mask); 1048 struct net_iov *niov; 1049 netmem_ref netmem; 1050 1051 if (!io_parse_rqe(rqe, ifq, &niov)) 1052 continue; 1053 if (!io_zcrx_put_niov_uref(niov)) 1054 continue; 1055 1056 netmem = net_iov_to_netmem(niov); 1057 if (!page_pool_unref_and_test(netmem)) 1058 continue; 1059 1060 if (unlikely(niov->desc.pp != pp)) { 1061 io_zcrx_return_niov(niov); 1062 continue; 1063 } 1064 1065 netmems[allocated] = netmem; 1066 allocated++; 1067 } while (--entries); 1068 1069 smp_store_release(&rq->ring->head, rq->cached_head); 1070 return allocated; 1071 } 1072 1073 static unsigned io_zcrx_refill_slow(struct page_pool *pp, struct io_zcrx_ifq *ifq, 1074 netmem_ref *netmems, unsigned to_alloc) 1075 { 1076 struct io_zcrx_area *area = ifq->area; 1077 unsigned allocated = 0; 1078 1079 guard(spinlock_bh)(&area->freelist_lock); 1080 1081 for (allocated = 0; allocated < to_alloc; allocated++) { 1082 struct net_iov *niov = zcrx_get_free_niov(area); 1083 1084 if (!niov) 1085 break; 1086 net_mp_niov_set_page_pool(pp, niov); 1087 netmems[allocated] = net_iov_to_netmem(niov); 1088 } 1089 return allocated; 1090 } 1091 1092 static netmem_ref io_pp_zc_alloc_netmems(struct page_pool *pp, gfp_t gfp) 1093 { 1094 struct io_zcrx_ifq *ifq = io_pp_to_ifq(pp); 1095 netmem_ref *netmems = pp->alloc.cache; 1096 unsigned to_alloc = PP_ALLOC_CACHE_REFILL; 1097 unsigned allocated; 1098 1099 /* pp should already be ensuring that */ 1100 if (WARN_ON_ONCE(pp->alloc.count)) 1101 return 0; 1102 1103 allocated = io_zcrx_ring_refill(pp, ifq, netmems, to_alloc); 1104 if (likely(allocated)) 1105 goto out_return; 1106 1107 allocated = io_zcrx_refill_slow(pp, ifq, netmems, to_alloc); 1108 if (!allocated) 1109 return 0; 1110 out_return: 1111 zcrx_sync_for_device(pp, ifq, netmems, allocated); 1112 allocated--; 1113 pp->alloc.count += allocated; 1114 return netmems[allocated]; 1115 } 1116 1117 static bool io_pp_zc_release_netmem(struct page_pool *pp, netmem_ref netmem) 1118 { 1119 struct net_iov *niov; 1120 1121 if (WARN_ON_ONCE(!netmem_is_net_iov(netmem))) 1122 return false; 1123 1124 niov = netmem_to_net_iov(netmem); 1125 net_mp_niov_clear_page_pool(niov); 1126 io_zcrx_return_niov_freelist(niov); 1127 return false; 1128 } 1129 1130 static int io_pp_zc_init(struct page_pool *pp) 1131 { 1132 struct io_zcrx_ifq *ifq = io_pp_to_ifq(pp); 1133 1134 if (WARN_ON_ONCE(!ifq)) 1135 return -EINVAL; 1136 if (WARN_ON_ONCE(ifq->dev != pp->p.dev)) 1137 return -EINVAL; 1138 if (WARN_ON_ONCE(!pp->dma_map)) 1139 return -EOPNOTSUPP; 1140 if (pp->p.order + PAGE_SHIFT != ifq->niov_shift) 1141 return -EINVAL; 1142 if (pp->p.dma_dir != DMA_FROM_DEVICE) 1143 return -EOPNOTSUPP; 1144 1145 refcount_inc(&ifq->refs); 1146 return 0; 1147 } 1148 1149 static void io_pp_zc_destroy(struct page_pool *pp) 1150 { 1151 io_put_zcrx_ifq(io_pp_to_ifq(pp)); 1152 } 1153 1154 static int io_pp_nl_fill(void *mp_priv, struct sk_buff *rsp, 1155 struct netdev_rx_queue *rxq) 1156 { 1157 struct nlattr *nest; 1158 int type; 1159 1160 type = rxq ? NETDEV_A_QUEUE_IO_URING : NETDEV_A_PAGE_POOL_IO_URING; 1161 nest = nla_nest_start(rsp, type); 1162 if (!nest) 1163 return -EMSGSIZE; 1164 nla_nest_end(rsp, nest); 1165 1166 return 0; 1167 } 1168 1169 static void io_pp_uninstall(void *mp_priv, struct netdev_rx_queue *rxq) 1170 { 1171 struct pp_memory_provider_params *p = &rxq->mp_params; 1172 struct io_zcrx_ifq *ifq = mp_priv; 1173 1174 io_zcrx_drop_netdev(ifq); 1175 if (ifq->area) 1176 io_zcrx_unmap_area(ifq, ifq->area); 1177 1178 p->mp_ops = NULL; 1179 p->mp_priv = NULL; 1180 } 1181 1182 static const struct memory_provider_ops io_uring_pp_zc_ops = { 1183 .alloc_netmems = io_pp_zc_alloc_netmems, 1184 .release_netmem = io_pp_zc_release_netmem, 1185 .init = io_pp_zc_init, 1186 .destroy = io_pp_zc_destroy, 1187 .nl_fill = io_pp_nl_fill, 1188 .uninstall = io_pp_uninstall, 1189 }; 1190 1191 static unsigned zcrx_parse_rq(netmem_ref *netmem_array, unsigned nr, 1192 struct io_zcrx_ifq *zcrx, struct zcrx_rq *rq) 1193 { 1194 unsigned int mask = rq->nr_entries - 1; 1195 unsigned int i; 1196 1197 nr = min(nr, zcrx_rq_entries(rq)); 1198 for (i = 0; i < nr; i++) { 1199 struct io_uring_zcrx_rqe *rqe = zcrx_next_rqe(rq, mask); 1200 struct net_iov *niov; 1201 1202 if (!io_parse_rqe(rqe, zcrx, &niov)) 1203 break; 1204 netmem_array[i] = net_iov_to_netmem(niov); 1205 } 1206 1207 smp_store_release(&rq->ring->head, rq->cached_head); 1208 return i; 1209 } 1210 1211 #define ZCRX_FLUSH_BATCH 32 1212 1213 static void zcrx_return_buffers(netmem_ref *netmems, unsigned nr) 1214 { 1215 unsigned i; 1216 1217 for (i = 0; i < nr; i++) { 1218 netmem_ref netmem = netmems[i]; 1219 struct net_iov *niov = netmem_to_net_iov(netmem); 1220 1221 if (!io_zcrx_put_niov_uref(niov)) 1222 continue; 1223 if (!page_pool_unref_and_test(netmem)) 1224 continue; 1225 io_zcrx_return_niov(niov); 1226 } 1227 } 1228 1229 static int zcrx_flush_rq(struct io_ring_ctx *ctx, struct io_zcrx_ifq *zcrx, 1230 struct zcrx_ctrl *ctrl) 1231 { 1232 struct zcrx_ctrl_flush_rq *frq = &ctrl->zc_flush; 1233 netmem_ref netmems[ZCRX_FLUSH_BATCH]; 1234 unsigned total = 0; 1235 unsigned nr; 1236 1237 if (!mem_is_zero(&frq->__resv, sizeof(frq->__resv))) 1238 return -EINVAL; 1239 1240 do { 1241 struct zcrx_rq *rq = &zcrx->rq; 1242 1243 scoped_guard(spinlock_bh, &rq->lock) { 1244 nr = zcrx_parse_rq(netmems, ZCRX_FLUSH_BATCH, zcrx, rq); 1245 zcrx_return_buffers(netmems, nr); 1246 } 1247 1248 total += nr; 1249 1250 if (fatal_signal_pending(current)) 1251 break; 1252 cond_resched(); 1253 } while (nr == ZCRX_FLUSH_BATCH && total < zcrx->rq.nr_entries); 1254 1255 return 0; 1256 } 1257 1258 int io_zcrx_ctrl(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) 1259 { 1260 struct zcrx_ctrl ctrl; 1261 struct io_zcrx_ifq *zcrx; 1262 1263 BUILD_BUG_ON(sizeof(ctrl.zc_export) != sizeof(ctrl.zc_flush)); 1264 1265 if (nr_args) 1266 return -EINVAL; 1267 if (copy_from_user(&ctrl, arg, sizeof(ctrl))) 1268 return -EFAULT; 1269 if (!mem_is_zero(&ctrl.__resv, sizeof(ctrl.__resv))) 1270 return -EFAULT; 1271 1272 zcrx = xa_load(&ctx->zcrx_ctxs, ctrl.zcrx_id); 1273 if (!zcrx) 1274 return -ENXIO; 1275 1276 switch (ctrl.op) { 1277 case ZCRX_CTRL_FLUSH_RQ: 1278 return zcrx_flush_rq(ctx, zcrx, &ctrl); 1279 case ZCRX_CTRL_EXPORT: 1280 return zcrx_export(ctx, zcrx, &ctrl, arg); 1281 } 1282 1283 return -EOPNOTSUPP; 1284 } 1285 1286 static bool io_zcrx_queue_cqe(struct io_kiocb *req, struct net_iov *niov, 1287 struct io_zcrx_ifq *ifq, int off, int len) 1288 { 1289 struct io_ring_ctx *ctx = req->ctx; 1290 struct io_uring_zcrx_cqe *rcqe; 1291 struct io_zcrx_area *area; 1292 struct io_uring_cqe *cqe; 1293 u64 offset; 1294 1295 if (!io_defer_get_uncommited_cqe(ctx, &cqe)) 1296 return false; 1297 1298 cqe->user_data = req->cqe.user_data; 1299 cqe->res = len; 1300 cqe->flags = IORING_CQE_F_MORE; 1301 if (ctx->flags & IORING_SETUP_CQE_MIXED) 1302 cqe->flags |= IORING_CQE_F_32; 1303 1304 area = io_zcrx_iov_to_area(niov); 1305 offset = off + (net_iov_idx(niov) << ifq->niov_shift); 1306 rcqe = (struct io_uring_zcrx_cqe *)(cqe + 1); 1307 rcqe->off = offset + ((u64)area->area_id << IORING_ZCRX_AREA_SHIFT); 1308 rcqe->__pad = 0; 1309 return true; 1310 } 1311 1312 static struct net_iov *io_alloc_fallback_niov(struct io_zcrx_ifq *ifq) 1313 { 1314 struct io_zcrx_area *area = ifq->area; 1315 struct net_iov *niov = NULL; 1316 1317 if (!ifq->kern_readable) 1318 return NULL; 1319 1320 scoped_guard(spinlock_bh, &area->freelist_lock) 1321 niov = zcrx_get_free_niov(area); 1322 1323 if (niov) 1324 page_pool_fragment_netmem(net_iov_to_netmem(niov), 1); 1325 return niov; 1326 } 1327 1328 struct io_copy_cache { 1329 struct page *page; 1330 unsigned long offset; 1331 size_t size; 1332 }; 1333 1334 static ssize_t io_copy_page(struct io_copy_cache *cc, struct page *src_page, 1335 unsigned int src_offset, size_t len) 1336 { 1337 size_t copied = 0; 1338 1339 len = min(len, cc->size); 1340 1341 while (len) { 1342 void *src_addr, *dst_addr; 1343 struct page *dst_page = cc->page; 1344 unsigned dst_offset = cc->offset; 1345 size_t n = len; 1346 1347 if (folio_test_partial_kmap(page_folio(dst_page)) || 1348 folio_test_partial_kmap(page_folio(src_page))) { 1349 dst_page += dst_offset / PAGE_SIZE; 1350 dst_offset = offset_in_page(dst_offset); 1351 src_page += src_offset / PAGE_SIZE; 1352 src_offset = offset_in_page(src_offset); 1353 n = min(PAGE_SIZE - src_offset, PAGE_SIZE - dst_offset); 1354 n = min(n, len); 1355 } 1356 1357 dst_addr = kmap_local_page(dst_page) + dst_offset; 1358 src_addr = kmap_local_page(src_page) + src_offset; 1359 1360 memcpy(dst_addr, src_addr, n); 1361 1362 kunmap_local(src_addr); 1363 kunmap_local(dst_addr); 1364 1365 cc->size -= n; 1366 cc->offset += n; 1367 src_offset += n; 1368 len -= n; 1369 copied += n; 1370 } 1371 return copied; 1372 } 1373 1374 static ssize_t io_zcrx_copy_chunk(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1375 struct page *src_page, unsigned int src_offset, 1376 size_t len) 1377 { 1378 size_t copied = 0; 1379 int ret = 0; 1380 1381 while (len) { 1382 struct io_copy_cache cc; 1383 struct net_iov *niov; 1384 size_t n; 1385 1386 niov = io_alloc_fallback_niov(ifq); 1387 if (!niov) { 1388 ret = -ENOMEM; 1389 break; 1390 } 1391 1392 cc.page = io_zcrx_iov_page(niov); 1393 cc.offset = 0; 1394 cc.size = PAGE_SIZE; 1395 1396 n = io_copy_page(&cc, src_page, src_offset, len); 1397 1398 if (!io_zcrx_queue_cqe(req, niov, ifq, 0, n)) { 1399 io_zcrx_return_niov(niov); 1400 ret = -ENOSPC; 1401 break; 1402 } 1403 1404 io_zcrx_get_niov_uref(niov); 1405 src_offset += n; 1406 len -= n; 1407 copied += n; 1408 } 1409 1410 return copied ? copied : ret; 1411 } 1412 1413 static int io_zcrx_copy_frag(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1414 const skb_frag_t *frag, int off, int len) 1415 { 1416 struct page *page = skb_frag_page(frag); 1417 1418 return io_zcrx_copy_chunk(req, ifq, page, off + skb_frag_off(frag), len); 1419 } 1420 1421 static int io_zcrx_recv_frag(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1422 const skb_frag_t *frag, int off, int len) 1423 { 1424 struct net_iov *niov; 1425 struct page_pool *pp; 1426 1427 if (unlikely(!skb_frag_is_net_iov(frag))) 1428 return io_zcrx_copy_frag(req, ifq, frag, off, len); 1429 1430 niov = netmem_to_net_iov(frag->netmem); 1431 pp = niov->desc.pp; 1432 1433 if (!pp || pp->mp_ops != &io_uring_pp_zc_ops || io_pp_to_ifq(pp) != ifq) 1434 return -EFAULT; 1435 1436 if (!io_zcrx_queue_cqe(req, niov, ifq, off + skb_frag_off(frag), len)) 1437 return -ENOSPC; 1438 1439 /* 1440 * Prevent it from being recycled while user is accessing it. 1441 * It has to be done before grabbing a user reference. 1442 */ 1443 page_pool_ref_netmem(net_iov_to_netmem(niov)); 1444 io_zcrx_get_niov_uref(niov); 1445 return len; 1446 } 1447 1448 static int 1449 io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, 1450 unsigned int offset, size_t len) 1451 { 1452 struct io_zcrx_args *args = desc->arg.data; 1453 struct io_zcrx_ifq *ifq = args->ifq; 1454 struct io_kiocb *req = args->req; 1455 struct sk_buff *frag_iter; 1456 unsigned start, start_off = offset; 1457 int i, copy, end, off; 1458 int ret = 0; 1459 1460 len = min_t(size_t, len, desc->count); 1461 /* 1462 * __tcp_read_sock() always calls io_zcrx_recv_skb one last time, even 1463 * if desc->count is already 0. This is caused by the if (offset + 1 != 1464 * skb->len) check. Return early in this case to break out of 1465 * __tcp_read_sock(). 1466 */ 1467 if (!len) 1468 return 0; 1469 if (unlikely(args->nr_skbs++ > IO_SKBS_PER_CALL_LIMIT)) 1470 return -EAGAIN; 1471 1472 if (unlikely(offset < skb_headlen(skb))) { 1473 ssize_t copied; 1474 size_t to_copy; 1475 1476 to_copy = min_t(size_t, skb_headlen(skb) - offset, len); 1477 copied = io_zcrx_copy_chunk(req, ifq, virt_to_page(skb->data), 1478 offset_in_page(skb->data) + offset, 1479 to_copy); 1480 if (copied < 0) { 1481 ret = copied; 1482 goto out; 1483 } 1484 offset += copied; 1485 len -= copied; 1486 if (!len) 1487 goto out; 1488 if (offset != skb_headlen(skb)) 1489 goto out; 1490 } 1491 1492 start = skb_headlen(skb); 1493 1494 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 1495 const skb_frag_t *frag; 1496 1497 if (WARN_ON(start > offset + len)) 1498 return -EFAULT; 1499 1500 frag = &skb_shinfo(skb)->frags[i]; 1501 end = start + skb_frag_size(frag); 1502 1503 if (offset < end) { 1504 copy = end - offset; 1505 if (copy > len) 1506 copy = len; 1507 1508 off = offset - start; 1509 ret = io_zcrx_recv_frag(req, ifq, frag, off, copy); 1510 if (ret < 0) 1511 goto out; 1512 1513 offset += ret; 1514 len -= ret; 1515 if (len == 0 || ret != copy) 1516 goto out; 1517 } 1518 start = end; 1519 } 1520 1521 skb_walk_frags(skb, frag_iter) { 1522 if (WARN_ON(start > offset + len)) 1523 return -EFAULT; 1524 1525 end = start + frag_iter->len; 1526 if (offset < end) { 1527 size_t count; 1528 1529 copy = end - offset; 1530 if (copy > len) 1531 copy = len; 1532 1533 off = offset - start; 1534 count = desc->count; 1535 ret = io_zcrx_recv_skb(desc, frag_iter, off, copy); 1536 desc->count = count; 1537 if (ret < 0) 1538 goto out; 1539 1540 offset += ret; 1541 len -= ret; 1542 if (len == 0 || ret != copy) 1543 goto out; 1544 } 1545 start = end; 1546 } 1547 1548 out: 1549 if (offset == start_off) 1550 return ret; 1551 desc->count -= (offset - start_off); 1552 return offset - start_off; 1553 } 1554 1555 static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1556 struct sock *sk, int flags, 1557 unsigned issue_flags, unsigned int *outlen) 1558 { 1559 unsigned int len = *outlen; 1560 struct io_zcrx_args args = { 1561 .req = req, 1562 .ifq = ifq, 1563 .sock = sk->sk_socket, 1564 }; 1565 read_descriptor_t rd_desc = { 1566 .count = len ? len : UINT_MAX, 1567 .arg.data = &args, 1568 }; 1569 int ret; 1570 1571 lock_sock(sk); 1572 ret = tcp_read_sock(sk, &rd_desc, io_zcrx_recv_skb); 1573 if (len && ret > 0) 1574 *outlen = len - ret; 1575 if (ret <= 0) { 1576 if (ret < 0 || sock_flag(sk, SOCK_DONE)) 1577 goto out; 1578 if (sk->sk_err) 1579 ret = sock_error(sk); 1580 else if (sk->sk_shutdown & RCV_SHUTDOWN) 1581 goto out; 1582 else if (sk->sk_state == TCP_CLOSE) 1583 ret = -ENOTCONN; 1584 else 1585 ret = -EAGAIN; 1586 } else if (unlikely(args.nr_skbs > IO_SKBS_PER_CALL_LIMIT) && 1587 (issue_flags & IO_URING_F_MULTISHOT)) { 1588 ret = IOU_REQUEUE; 1589 } else if (sock_flag(sk, SOCK_DONE)) { 1590 /* Make it to retry until it finally gets 0. */ 1591 if (issue_flags & IO_URING_F_MULTISHOT) 1592 ret = IOU_REQUEUE; 1593 else 1594 ret = -EAGAIN; 1595 } 1596 out: 1597 release_sock(sk); 1598 return ret; 1599 } 1600 1601 int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1602 struct socket *sock, unsigned int flags, 1603 unsigned issue_flags, unsigned int *len) 1604 { 1605 struct sock *sk = sock->sk; 1606 const struct proto *prot = READ_ONCE(sk->sk_prot); 1607 1608 if (prot->recvmsg != tcp_recvmsg) 1609 return -EPROTONOSUPPORT; 1610 1611 sock_rps_record_flow(sk); 1612 return io_zcrx_tcp_recvmsg(req, ifq, sk, flags, issue_flags, len); 1613 } 1614