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 memset(ifq->rq.ring, 0, sizeof(*ifq->rq.ring)); 400 return 0; 401 } 402 403 static void io_free_rbuf_ring(struct io_zcrx_ifq *ifq) 404 { 405 io_free_region(ifq->user, &ifq->rq_region); 406 ifq->rq.ring = NULL; 407 ifq->rq.rqes = NULL; 408 } 409 410 static void io_zcrx_free_area(struct io_zcrx_ifq *ifq, 411 struct io_zcrx_area *area) 412 { 413 io_zcrx_unmap_area(ifq, area); 414 io_release_area_mem(&area->mem); 415 416 if (area->mem.account_pages) 417 io_unaccount_mem(ifq->user, ifq->mm_account, 418 area->mem.account_pages); 419 420 kvfree(area->freelist); 421 kvfree(area->nia.niovs); 422 kvfree(area->user_refs); 423 kfree(area); 424 } 425 426 static int io_zcrx_append_area(struct io_zcrx_ifq *ifq, 427 struct io_zcrx_area *area) 428 { 429 bool kern_readable = !area->mem.is_dmabuf; 430 431 if (WARN_ON_ONCE(ifq->area)) 432 return -EINVAL; 433 if (WARN_ON_ONCE(ifq->kern_readable != kern_readable)) 434 return -EINVAL; 435 436 ifq->area = area; 437 return 0; 438 } 439 440 static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, 441 struct io_uring_zcrx_area_reg *area_reg, 442 struct io_uring_zcrx_ifq_reg *reg) 443 { 444 int buf_size_shift = PAGE_SHIFT; 445 struct io_zcrx_area *area; 446 unsigned nr_iovs; 447 int i, ret; 448 449 if (reg->rx_buf_len) { 450 if (!is_power_of_2(reg->rx_buf_len) || 451 reg->rx_buf_len < PAGE_SIZE) 452 return -EINVAL; 453 buf_size_shift = ilog2(reg->rx_buf_len); 454 } 455 if (!ifq->dev && buf_size_shift != PAGE_SHIFT) 456 return -EOPNOTSUPP; 457 458 ret = -ENOMEM; 459 area = kzalloc_obj(*area); 460 if (!area) 461 goto err; 462 area->ifq = ifq; 463 464 ret = io_import_area(ifq, &area->mem, area_reg); 465 if (ret) 466 goto err; 467 if (ifq->dev) 468 area->is_mapped = true; 469 470 if (ifq->dev && buf_size_shift > io_area_max_shift(&area->mem)) { 471 ret = -ERANGE; 472 goto err; 473 } 474 475 ifq->niov_shift = buf_size_shift; 476 nr_iovs = area->mem.size >> ifq->niov_shift; 477 area->nia.num_niovs = nr_iovs; 478 479 ret = -ENOMEM; 480 area->nia.niovs = kvmalloc_objs(area->nia.niovs[0], nr_iovs, 481 GFP_KERNEL_ACCOUNT | __GFP_ZERO); 482 if (!area->nia.niovs) 483 goto err; 484 485 area->freelist = kvmalloc_array(nr_iovs, sizeof(area->freelist[0]), 486 GFP_KERNEL_ACCOUNT | __GFP_ZERO); 487 if (!area->freelist) 488 goto err; 489 490 area->user_refs = kvmalloc_objs(area->user_refs[0], nr_iovs, 491 GFP_KERNEL_ACCOUNT | __GFP_ZERO); 492 if (!area->user_refs) 493 goto err; 494 495 for (i = 0; i < nr_iovs; i++) { 496 struct net_iov *niov = &area->nia.niovs[i]; 497 498 niov->owner = &area->nia; 499 area->freelist[i] = i; 500 atomic_set(&area->user_refs[i], 0); 501 niov->type = NET_IOV_IOURING; 502 } 503 504 if (ifq->dev) { 505 ret = io_populate_area_dma(ifq, area); 506 if (ret) 507 goto err; 508 } 509 510 area->free_count = nr_iovs; 511 /* we're only supporting one area per ifq for now */ 512 area->area_id = 0; 513 area_reg->rq_area_token = (u64)area->area_id << IORING_ZCRX_AREA_SHIFT; 514 spin_lock_init(&area->freelist_lock); 515 516 ret = io_zcrx_append_area(ifq, area); 517 if (!ret) 518 return 0; 519 err: 520 if (area) 521 io_zcrx_free_area(ifq, area); 522 return ret; 523 } 524 525 static struct io_zcrx_ifq *io_zcrx_ifq_alloc(struct io_ring_ctx *ctx) 526 { 527 struct io_zcrx_ifq *ifq; 528 529 ifq = kzalloc_obj(*ifq); 530 if (!ifq) 531 return NULL; 532 533 ifq->if_rxq = -1; 534 spin_lock_init(&ifq->rq.lock); 535 mutex_init(&ifq->pp_lock); 536 refcount_set(&ifq->refs, 1); 537 refcount_set(&ifq->user_refs, 1); 538 return ifq; 539 } 540 541 static void io_zcrx_drop_netdev(struct io_zcrx_ifq *ifq) 542 { 543 guard(mutex)(&ifq->pp_lock); 544 545 if (!ifq->netdev) 546 return; 547 netdev_put(ifq->netdev, &ifq->netdev_tracker); 548 ifq->netdev = NULL; 549 } 550 551 static void io_close_queue(struct io_zcrx_ifq *ifq) 552 { 553 struct net_device *netdev; 554 netdevice_tracker netdev_tracker; 555 struct pp_memory_provider_params p = { 556 .mp_ops = &io_uring_pp_zc_ops, 557 .mp_priv = ifq, 558 }; 559 560 scoped_guard(mutex, &ifq->pp_lock) { 561 netdev = ifq->netdev; 562 netdev_tracker = ifq->netdev_tracker; 563 ifq->netdev = NULL; 564 } 565 566 if (netdev) { 567 if (ifq->if_rxq != -1) { 568 netdev_lock(netdev); 569 netif_mp_close_rxq(netdev, ifq->if_rxq, &p); 570 netdev_unlock(netdev); 571 } 572 netdev_put(netdev, &netdev_tracker); 573 } 574 ifq->if_rxq = -1; 575 } 576 577 static void io_zcrx_ifq_free(struct io_zcrx_ifq *ifq) 578 { 579 io_close_queue(ifq); 580 581 if (ifq->area) 582 io_zcrx_free_area(ifq, ifq->area); 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 free_uid(ifq->user); 590 mutex_destroy(&ifq->pp_lock); 591 kfree(ifq); 592 } 593 594 static void io_put_zcrx_ifq(struct io_zcrx_ifq *ifq) 595 { 596 if (refcount_dec_and_test(&ifq->refs)) 597 io_zcrx_ifq_free(ifq); 598 } 599 600 static void io_zcrx_return_niov_freelist(struct net_iov *niov) 601 { 602 struct io_zcrx_area *area = io_zcrx_iov_to_area(niov); 603 604 guard(spinlock_bh)(&area->freelist_lock); 605 if (WARN_ON_ONCE(area->free_count >= area->nia.num_niovs)) 606 return; 607 area->freelist[area->free_count++] = net_iov_idx(niov); 608 } 609 610 static struct net_iov *zcrx_get_free_niov(struct io_zcrx_area *area) 611 { 612 unsigned niov_idx; 613 614 lockdep_assert_held(&area->freelist_lock); 615 616 if (unlikely(!area->free_count)) 617 return NULL; 618 619 niov_idx = area->freelist[--area->free_count]; 620 return &area->nia.niovs[niov_idx]; 621 } 622 623 static void io_zcrx_return_niov(struct net_iov *niov) 624 { 625 netmem_ref netmem = net_iov_to_netmem(niov); 626 627 if (!niov->desc.pp) { 628 /* copy fallback allocated niovs */ 629 io_zcrx_return_niov_freelist(niov); 630 return; 631 } 632 page_pool_put_unrefed_netmem(niov->desc.pp, netmem, -1, false); 633 } 634 635 static void io_zcrx_scrub(struct io_zcrx_ifq *ifq) 636 { 637 struct io_zcrx_area *area = ifq->area; 638 int i; 639 640 if (!area) 641 return; 642 643 /* Reclaim back all buffers given to the user space. */ 644 for (i = 0; i < area->nia.num_niovs; i++) { 645 struct net_iov *niov = &area->nia.niovs[i]; 646 int nr; 647 648 if (!atomic_read(io_get_user_counter(niov))) 649 continue; 650 nr = atomic_xchg(io_get_user_counter(niov), 0); 651 if (nr && !page_pool_unref_netmem(net_iov_to_netmem(niov), nr)) 652 io_zcrx_return_niov(niov); 653 } 654 } 655 656 static void zcrx_unregister_user(struct io_zcrx_ifq *ifq) 657 { 658 if (refcount_dec_and_test(&ifq->user_refs)) { 659 io_close_queue(ifq); 660 io_zcrx_scrub(ifq); 661 } 662 } 663 664 static void zcrx_unregister(struct io_zcrx_ifq *ifq) 665 { 666 zcrx_unregister_user(ifq); 667 io_put_zcrx_ifq(ifq); 668 } 669 670 struct io_mapped_region *io_zcrx_get_region(struct io_ring_ctx *ctx, 671 unsigned int id) 672 { 673 struct io_zcrx_ifq *ifq = xa_load(&ctx->zcrx_ctxs, id); 674 675 lockdep_assert_held(&ctx->mmap_lock); 676 677 return ifq ? &ifq->rq_region : NULL; 678 } 679 680 static int zcrx_box_release(struct inode *inode, struct file *file) 681 { 682 struct io_zcrx_ifq *ifq = file->private_data; 683 684 if (WARN_ON_ONCE(!ifq)) 685 return -EFAULT; 686 zcrx_unregister(ifq); 687 return 0; 688 } 689 690 static const struct file_operations zcrx_box_fops = { 691 .owner = THIS_MODULE, 692 .release = zcrx_box_release, 693 }; 694 695 static int zcrx_export(struct io_ring_ctx *ctx, struct io_zcrx_ifq *ifq, 696 struct zcrx_ctrl *ctrl, void __user *arg) 697 { 698 struct zcrx_ctrl_export *ce = &ctrl->zc_export; 699 struct file *file; 700 int fd = -1; 701 702 if (!mem_is_zero(ce, sizeof(*ce))) 703 return -EINVAL; 704 fd = get_unused_fd_flags(O_CLOEXEC); 705 if (fd < 0) 706 return fd; 707 708 ce->zcrx_fd = fd; 709 if (copy_to_user(arg, ctrl, sizeof(*ctrl))) { 710 put_unused_fd(fd); 711 return -EFAULT; 712 } 713 714 refcount_inc(&ifq->refs); 715 refcount_inc(&ifq->user_refs); 716 717 file = anon_inode_create_getfile("[zcrx]", &zcrx_box_fops, 718 ifq, O_CLOEXEC, NULL); 719 if (IS_ERR(file)) { 720 put_unused_fd(fd); 721 zcrx_unregister(ifq); 722 return PTR_ERR(file); 723 } 724 725 fd_install(fd, file); 726 return 0; 727 } 728 729 static int import_zcrx(struct io_ring_ctx *ctx, 730 struct io_uring_zcrx_ifq_reg __user *arg, 731 struct io_uring_zcrx_ifq_reg *reg) 732 { 733 struct io_zcrx_ifq *ifq; 734 struct file *file; 735 int fd, ret; 736 u32 id; 737 738 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 739 return -EINVAL; 740 if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED))) 741 return -EINVAL; 742 if (reg->if_rxq || reg->rq_entries || reg->area_ptr || reg->region_ptr) 743 return -EINVAL; 744 if (reg->flags & ~ZCRX_REG_IMPORT) 745 return -EINVAL; 746 747 fd = reg->if_idx; 748 CLASS(fd, f)(fd); 749 if (fd_empty(f)) 750 return -EBADF; 751 752 file = fd_file(f); 753 if (file->f_op != &zcrx_box_fops || !file->private_data) 754 return -EBADF; 755 756 ifq = file->private_data; 757 refcount_inc(&ifq->refs); 758 refcount_inc(&ifq->user_refs); 759 760 scoped_guard(mutex, &ctx->mmap_lock) { 761 ret = xa_alloc(&ctx->zcrx_ctxs, &id, NULL, xa_limit_31b, GFP_KERNEL); 762 if (ret) 763 goto err; 764 } 765 766 reg->zcrx_id = id; 767 io_fill_zcrx_offsets(®->offsets); 768 if (copy_to_user(arg, reg, sizeof(*reg))) { 769 ret = -EFAULT; 770 goto err_xa_erase; 771 } 772 773 scoped_guard(mutex, &ctx->mmap_lock) { 774 ret = -ENOMEM; 775 if (xa_store(&ctx->zcrx_ctxs, id, ifq, GFP_KERNEL)) 776 goto err_xa_erase; 777 } 778 779 return 0; 780 err_xa_erase: 781 scoped_guard(mutex, &ctx->mmap_lock) 782 xa_erase(&ctx->zcrx_ctxs, id); 783 err: 784 zcrx_unregister(ifq); 785 return ret; 786 } 787 788 static int zcrx_register_netdev(struct io_zcrx_ifq *ifq, 789 struct io_uring_zcrx_ifq_reg *reg, 790 struct io_uring_zcrx_area_reg *area) 791 { 792 struct pp_memory_provider_params mp_param = {}; 793 unsigned if_rxq = reg->if_rxq; 794 int ret; 795 796 ifq->netdev = netdev_get_by_index_lock(current->nsproxy->net_ns, 797 reg->if_idx); 798 if (!ifq->netdev) 799 return -ENODEV; 800 801 netdev_hold(ifq->netdev, &ifq->netdev_tracker, GFP_KERNEL); 802 803 ifq->dev = netdev_queue_get_dma_dev(ifq->netdev, if_rxq, NETDEV_QUEUE_TYPE_RX); 804 if (!ifq->dev) { 805 ret = -EOPNOTSUPP; 806 goto netdev_put_unlock; 807 } 808 get_device(ifq->dev); 809 810 ret = io_zcrx_create_area(ifq, area, reg); 811 if (ret) 812 goto netdev_put_unlock; 813 814 if (reg->rx_buf_len) 815 mp_param.rx_page_size = 1U << ifq->niov_shift; 816 mp_param.mp_ops = &io_uring_pp_zc_ops; 817 mp_param.mp_priv = ifq; 818 ret = netif_mp_open_rxq(ifq->netdev, if_rxq, &mp_param, NULL); 819 if (ret) 820 goto netdev_put_unlock; 821 822 ifq->if_rxq = if_rxq; 823 ret = 0; 824 netdev_put_unlock: 825 netdev_unlock(ifq->netdev); 826 return ret; 827 } 828 829 int io_register_zcrx(struct io_ring_ctx *ctx, 830 struct io_uring_zcrx_ifq_reg __user *arg) 831 { 832 struct io_uring_zcrx_area_reg area; 833 struct io_uring_zcrx_ifq_reg reg; 834 struct io_uring_region_desc rd; 835 struct io_zcrx_ifq *ifq; 836 int ret; 837 u32 id; 838 839 /* 840 * 1. Interface queue allocation. 841 * 2. It can observe data destined for sockets of other tasks. 842 */ 843 if (!capable(CAP_NET_ADMIN)) 844 return -EPERM; 845 846 /* mandatory io_uring features for zc rx */ 847 if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) 848 return -EINVAL; 849 if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED))) 850 return -EINVAL; 851 if (copy_from_user(®, arg, sizeof(reg))) 852 return -EFAULT; 853 if (!mem_is_zero(®.__resv, sizeof(reg.__resv)) || reg.zcrx_id) 854 return -EINVAL; 855 if (reg.flags & ~ZCRX_SUPPORTED_REG_FLAGS) 856 return -EINVAL; 857 if (reg.flags & ZCRX_REG_IMPORT) 858 return import_zcrx(ctx, arg, ®); 859 if (copy_from_user(&rd, u64_to_user_ptr(reg.region_ptr), sizeof(rd))) 860 return -EFAULT; 861 if (reg.if_rxq == -1 || !reg.rq_entries) 862 return -EINVAL; 863 if ((reg.if_rxq || reg.if_idx) && (reg.flags & ZCRX_REG_NODEV)) 864 return -EINVAL; 865 if (reg.rq_entries > IO_RQ_MAX_ENTRIES) { 866 if (!(ctx->flags & IORING_SETUP_CLAMP)) 867 return -EINVAL; 868 reg.rq_entries = IO_RQ_MAX_ENTRIES; 869 } 870 reg.rq_entries = roundup_pow_of_two(reg.rq_entries); 871 872 if (copy_from_user(&area, u64_to_user_ptr(reg.area_ptr), sizeof(area))) 873 return -EFAULT; 874 875 ifq = io_zcrx_ifq_alloc(ctx); 876 if (!ifq) 877 return -ENOMEM; 878 879 if (ctx->user) { 880 get_uid(ctx->user); 881 ifq->user = ctx->user; 882 } 883 if (ctx->mm_account) { 884 mmgrab(ctx->mm_account); 885 ifq->mm_account = ctx->mm_account; 886 } 887 ifq->rq.nr_entries = reg.rq_entries; 888 889 scoped_guard(mutex, &ctx->mmap_lock) { 890 /* preallocate id */ 891 ret = xa_alloc(&ctx->zcrx_ctxs, &id, NULL, xa_limit_31b, GFP_KERNEL); 892 if (ret) 893 goto ifq_free; 894 } 895 896 ret = io_allocate_rbuf_ring(ctx, ifq, ®, &rd, id); 897 if (ret) 898 goto err; 899 900 ifq->kern_readable = !(area.flags & IORING_ZCRX_AREA_DMABUF); 901 902 if (!(reg.flags & ZCRX_REG_NODEV)) { 903 ret = zcrx_register_netdev(ifq, ®, &area); 904 if (ret) 905 goto err; 906 } else { 907 ret = io_zcrx_create_area(ifq, &area, ®); 908 if (ret) 909 goto err; 910 } 911 912 reg.zcrx_id = id; 913 914 scoped_guard(mutex, &ctx->mmap_lock) { 915 /* publish ifq */ 916 ret = -ENOMEM; 917 if (xa_store(&ctx->zcrx_ctxs, id, ifq, GFP_KERNEL)) 918 goto err; 919 } 920 921 reg.rx_buf_len = 1U << ifq->niov_shift; 922 923 if (copy_to_user(arg, ®, sizeof(reg)) || 924 copy_to_user(u64_to_user_ptr(reg.region_ptr), &rd, sizeof(rd)) || 925 copy_to_user(u64_to_user_ptr(reg.area_ptr), &area, sizeof(area))) { 926 ret = -EFAULT; 927 goto err; 928 } 929 return 0; 930 err: 931 scoped_guard(mutex, &ctx->mmap_lock) 932 xa_erase(&ctx->zcrx_ctxs, id); 933 ifq_free: 934 zcrx_unregister(ifq); 935 return ret; 936 } 937 938 static inline bool is_zcrx_entry_marked(struct io_ring_ctx *ctx, unsigned long id) 939 { 940 return xa_get_mark(&ctx->zcrx_ctxs, id, XA_MARK_1); 941 } 942 943 static inline void set_zcrx_entry_mark(struct io_ring_ctx *ctx, unsigned long id) 944 { 945 xa_set_mark(&ctx->zcrx_ctxs, id, XA_MARK_1); 946 } 947 948 void io_terminate_zcrx(struct io_ring_ctx *ctx) 949 { 950 struct io_zcrx_ifq *ifq; 951 unsigned long id = 0; 952 953 lockdep_assert_held(&ctx->uring_lock); 954 955 while (1) { 956 scoped_guard(mutex, &ctx->mmap_lock) 957 ifq = xa_find(&ctx->zcrx_ctxs, &id, ULONG_MAX, XA_PRESENT); 958 if (!ifq) 959 break; 960 if (WARN_ON_ONCE(is_zcrx_entry_marked(ctx, id))) 961 break; 962 set_zcrx_entry_mark(ctx, id); 963 id++; 964 zcrx_unregister_user(ifq); 965 } 966 } 967 968 void io_unregister_zcrx(struct io_ring_ctx *ctx) 969 { 970 struct io_zcrx_ifq *ifq; 971 972 lockdep_assert_held(&ctx->uring_lock); 973 974 while (1) { 975 scoped_guard(mutex, &ctx->mmap_lock) { 976 unsigned long id = 0; 977 978 ifq = xa_find(&ctx->zcrx_ctxs, &id, ULONG_MAX, XA_PRESENT); 979 if (ifq) { 980 if (WARN_ON_ONCE(!is_zcrx_entry_marked(ctx, id))) { 981 ifq = NULL; 982 break; 983 } 984 xa_erase(&ctx->zcrx_ctxs, id); 985 } 986 } 987 if (!ifq) 988 break; 989 io_put_zcrx_ifq(ifq); 990 } 991 992 xa_destroy(&ctx->zcrx_ctxs); 993 } 994 995 static inline u32 zcrx_rq_entries(struct zcrx_rq *rq) 996 { 997 u32 entries; 998 999 entries = smp_load_acquire(&rq->ring->tail) - rq->cached_head; 1000 return min(entries, rq->nr_entries); 1001 } 1002 1003 static struct io_uring_zcrx_rqe *zcrx_next_rqe(struct zcrx_rq *rq, unsigned mask) 1004 { 1005 unsigned int idx = rq->cached_head++ & mask; 1006 1007 return &rq->rqes[idx]; 1008 } 1009 1010 static inline bool io_parse_rqe(struct io_uring_zcrx_rqe *rqe, 1011 struct io_zcrx_ifq *ifq, 1012 struct net_iov **ret_niov) 1013 { 1014 __u64 off = READ_ONCE(rqe->off); 1015 unsigned niov_idx, area_idx; 1016 struct io_zcrx_area *area; 1017 1018 area_idx = off >> IORING_ZCRX_AREA_SHIFT; 1019 niov_idx = (off & ~IORING_ZCRX_AREA_MASK) >> ifq->niov_shift; 1020 1021 if (unlikely(rqe->__pad || area_idx)) 1022 return false; 1023 area = ifq->area; 1024 1025 if (unlikely(niov_idx >= area->nia.num_niovs)) 1026 return false; 1027 niov_idx = array_index_nospec(niov_idx, area->nia.num_niovs); 1028 1029 *ret_niov = &area->nia.niovs[niov_idx]; 1030 return true; 1031 } 1032 1033 static unsigned io_zcrx_ring_refill(struct page_pool *pp, 1034 struct io_zcrx_ifq *ifq, 1035 netmem_ref *netmems, unsigned to_alloc) 1036 { 1037 struct zcrx_rq *rq = &ifq->rq; 1038 unsigned int mask = rq->nr_entries - 1; 1039 unsigned int entries; 1040 unsigned allocated = 0; 1041 1042 guard(spinlock_bh)(&rq->lock); 1043 1044 entries = zcrx_rq_entries(rq); 1045 entries = min_t(unsigned, entries, to_alloc); 1046 if (unlikely(!entries)) 1047 return 0; 1048 1049 do { 1050 struct io_uring_zcrx_rqe *rqe = zcrx_next_rqe(rq, mask); 1051 struct net_iov *niov; 1052 netmem_ref netmem; 1053 1054 if (!io_parse_rqe(rqe, ifq, &niov)) 1055 continue; 1056 if (!io_zcrx_put_niov_uref(niov)) 1057 continue; 1058 1059 netmem = net_iov_to_netmem(niov); 1060 if (!page_pool_unref_and_test(netmem)) 1061 continue; 1062 1063 if (unlikely(niov->desc.pp != pp)) { 1064 io_zcrx_return_niov(niov); 1065 continue; 1066 } 1067 1068 netmems[allocated] = netmem; 1069 allocated++; 1070 } while (--entries); 1071 1072 smp_store_release(&rq->ring->head, rq->cached_head); 1073 return allocated; 1074 } 1075 1076 static unsigned io_zcrx_refill_slow(struct page_pool *pp, struct io_zcrx_ifq *ifq, 1077 netmem_ref *netmems, unsigned to_alloc) 1078 { 1079 struct io_zcrx_area *area = ifq->area; 1080 unsigned allocated = 0; 1081 1082 guard(spinlock_bh)(&area->freelist_lock); 1083 1084 for (allocated = 0; allocated < to_alloc; allocated++) { 1085 struct net_iov *niov = zcrx_get_free_niov(area); 1086 1087 if (!niov) 1088 break; 1089 net_mp_niov_set_page_pool(pp, niov); 1090 netmems[allocated] = net_iov_to_netmem(niov); 1091 } 1092 return allocated; 1093 } 1094 1095 static netmem_ref io_pp_zc_alloc_netmems(struct page_pool *pp, gfp_t gfp) 1096 { 1097 struct io_zcrx_ifq *ifq = io_pp_to_ifq(pp); 1098 netmem_ref *netmems = pp->alloc.cache; 1099 unsigned to_alloc = PP_ALLOC_CACHE_REFILL; 1100 unsigned allocated; 1101 1102 /* pp should already be ensuring that */ 1103 if (WARN_ON_ONCE(pp->alloc.count)) 1104 return 0; 1105 1106 allocated = io_zcrx_ring_refill(pp, ifq, netmems, to_alloc); 1107 if (likely(allocated)) 1108 goto out_return; 1109 1110 allocated = io_zcrx_refill_slow(pp, ifq, netmems, to_alloc); 1111 if (!allocated) 1112 return 0; 1113 out_return: 1114 zcrx_sync_for_device(pp, ifq, netmems, allocated); 1115 allocated--; 1116 pp->alloc.count += allocated; 1117 return netmems[allocated]; 1118 } 1119 1120 static bool io_pp_zc_release_netmem(struct page_pool *pp, netmem_ref netmem) 1121 { 1122 struct net_iov *niov; 1123 1124 if (WARN_ON_ONCE(!netmem_is_net_iov(netmem))) 1125 return false; 1126 1127 niov = netmem_to_net_iov(netmem); 1128 net_mp_niov_clear_page_pool(niov); 1129 io_zcrx_return_niov_freelist(niov); 1130 return false; 1131 } 1132 1133 static int io_pp_zc_init(struct page_pool *pp) 1134 { 1135 struct io_zcrx_ifq *ifq = io_pp_to_ifq(pp); 1136 1137 if (WARN_ON_ONCE(!ifq)) 1138 return -EINVAL; 1139 if (WARN_ON_ONCE(ifq->dev != pp->p.dev)) 1140 return -EINVAL; 1141 if (WARN_ON_ONCE(!pp->dma_map)) 1142 return -EOPNOTSUPP; 1143 if (pp->p.order + PAGE_SHIFT != ifq->niov_shift) 1144 return -EINVAL; 1145 if (pp->p.dma_dir != DMA_FROM_DEVICE) 1146 return -EOPNOTSUPP; 1147 1148 refcount_inc(&ifq->refs); 1149 return 0; 1150 } 1151 1152 static void io_pp_zc_destroy(struct page_pool *pp) 1153 { 1154 io_put_zcrx_ifq(io_pp_to_ifq(pp)); 1155 } 1156 1157 static int io_pp_nl_fill(void *mp_priv, struct sk_buff *rsp, 1158 struct netdev_rx_queue *rxq) 1159 { 1160 struct nlattr *nest; 1161 int type; 1162 1163 type = rxq ? NETDEV_A_QUEUE_IO_URING : NETDEV_A_PAGE_POOL_IO_URING; 1164 nest = nla_nest_start(rsp, type); 1165 if (!nest) 1166 return -EMSGSIZE; 1167 nla_nest_end(rsp, nest); 1168 1169 return 0; 1170 } 1171 1172 static void io_pp_uninstall(void *mp_priv, struct netdev_rx_queue *rxq) 1173 { 1174 struct pp_memory_provider_params *p = &rxq->mp_params; 1175 struct io_zcrx_ifq *ifq = mp_priv; 1176 1177 io_zcrx_drop_netdev(ifq); 1178 if (ifq->area) 1179 io_zcrx_unmap_area(ifq, ifq->area); 1180 1181 p->mp_ops = NULL; 1182 p->mp_priv = NULL; 1183 } 1184 1185 static const struct memory_provider_ops io_uring_pp_zc_ops = { 1186 .alloc_netmems = io_pp_zc_alloc_netmems, 1187 .release_netmem = io_pp_zc_release_netmem, 1188 .init = io_pp_zc_init, 1189 .destroy = io_pp_zc_destroy, 1190 .nl_fill = io_pp_nl_fill, 1191 .uninstall = io_pp_uninstall, 1192 }; 1193 1194 static unsigned zcrx_parse_rq(netmem_ref *netmem_array, unsigned nr, 1195 struct io_zcrx_ifq *zcrx, struct zcrx_rq *rq) 1196 { 1197 unsigned int mask = rq->nr_entries - 1; 1198 unsigned int i; 1199 1200 nr = min(nr, zcrx_rq_entries(rq)); 1201 for (i = 0; i < nr; i++) { 1202 struct io_uring_zcrx_rqe *rqe = zcrx_next_rqe(rq, mask); 1203 struct net_iov *niov; 1204 1205 if (!io_parse_rqe(rqe, zcrx, &niov)) 1206 break; 1207 netmem_array[i] = net_iov_to_netmem(niov); 1208 } 1209 1210 smp_store_release(&rq->ring->head, rq->cached_head); 1211 return i; 1212 } 1213 1214 #define ZCRX_FLUSH_BATCH 32 1215 1216 static void zcrx_return_buffers(netmem_ref *netmems, unsigned nr) 1217 { 1218 unsigned i; 1219 1220 for (i = 0; i < nr; i++) { 1221 netmem_ref netmem = netmems[i]; 1222 struct net_iov *niov = netmem_to_net_iov(netmem); 1223 1224 if (!io_zcrx_put_niov_uref(niov)) 1225 continue; 1226 if (!page_pool_unref_and_test(netmem)) 1227 continue; 1228 io_zcrx_return_niov(niov); 1229 } 1230 } 1231 1232 static int zcrx_flush_rq(struct io_ring_ctx *ctx, struct io_zcrx_ifq *zcrx, 1233 struct zcrx_ctrl *ctrl) 1234 { 1235 struct zcrx_ctrl_flush_rq *frq = &ctrl->zc_flush; 1236 netmem_ref netmems[ZCRX_FLUSH_BATCH]; 1237 unsigned total = 0; 1238 unsigned nr; 1239 1240 if (!mem_is_zero(&frq->__resv, sizeof(frq->__resv))) 1241 return -EINVAL; 1242 1243 do { 1244 struct zcrx_rq *rq = &zcrx->rq; 1245 1246 scoped_guard(spinlock_bh, &rq->lock) { 1247 nr = zcrx_parse_rq(netmems, ZCRX_FLUSH_BATCH, zcrx, rq); 1248 zcrx_return_buffers(netmems, nr); 1249 } 1250 1251 total += nr; 1252 1253 if (fatal_signal_pending(current)) 1254 break; 1255 cond_resched(); 1256 } while (nr == ZCRX_FLUSH_BATCH && total < zcrx->rq.nr_entries); 1257 1258 return 0; 1259 } 1260 1261 int io_zcrx_ctrl(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args) 1262 { 1263 struct zcrx_ctrl ctrl; 1264 struct io_zcrx_ifq *zcrx; 1265 1266 BUILD_BUG_ON(sizeof(ctrl.zc_export) != sizeof(ctrl.zc_flush)); 1267 1268 if (nr_args) 1269 return -EINVAL; 1270 if (copy_from_user(&ctrl, arg, sizeof(ctrl))) 1271 return -EFAULT; 1272 if (!mem_is_zero(&ctrl.__resv, sizeof(ctrl.__resv))) 1273 return -EFAULT; 1274 1275 zcrx = xa_load(&ctx->zcrx_ctxs, ctrl.zcrx_id); 1276 if (!zcrx) 1277 return -ENXIO; 1278 1279 switch (ctrl.op) { 1280 case ZCRX_CTRL_FLUSH_RQ: 1281 return zcrx_flush_rq(ctx, zcrx, &ctrl); 1282 case ZCRX_CTRL_EXPORT: 1283 return zcrx_export(ctx, zcrx, &ctrl, arg); 1284 } 1285 1286 return -EOPNOTSUPP; 1287 } 1288 1289 static bool io_zcrx_queue_cqe(struct io_kiocb *req, struct net_iov *niov, 1290 struct io_zcrx_ifq *ifq, int off, int len) 1291 { 1292 struct io_ring_ctx *ctx = req->ctx; 1293 struct io_uring_zcrx_cqe *rcqe; 1294 struct io_zcrx_area *area; 1295 struct io_uring_cqe *cqe; 1296 u64 offset; 1297 1298 if (!io_defer_get_uncommited_cqe(ctx, &cqe)) 1299 return false; 1300 1301 cqe->user_data = req->cqe.user_data; 1302 cqe->res = len; 1303 cqe->flags = IORING_CQE_F_MORE; 1304 if (ctx->flags & IORING_SETUP_CQE_MIXED) 1305 cqe->flags |= IORING_CQE_F_32; 1306 1307 area = io_zcrx_iov_to_area(niov); 1308 offset = off + (net_iov_idx(niov) << ifq->niov_shift); 1309 rcqe = (struct io_uring_zcrx_cqe *)(cqe + 1); 1310 rcqe->off = offset + ((u64)area->area_id << IORING_ZCRX_AREA_SHIFT); 1311 rcqe->__pad = 0; 1312 return true; 1313 } 1314 1315 static struct net_iov *io_alloc_fallback_niov(struct io_zcrx_ifq *ifq) 1316 { 1317 struct io_zcrx_area *area = ifq->area; 1318 struct net_iov *niov = NULL; 1319 1320 if (!ifq->kern_readable) 1321 return NULL; 1322 1323 scoped_guard(spinlock_bh, &area->freelist_lock) 1324 niov = zcrx_get_free_niov(area); 1325 1326 if (niov) 1327 page_pool_fragment_netmem(net_iov_to_netmem(niov), 1); 1328 return niov; 1329 } 1330 1331 struct io_copy_cache { 1332 struct page *page; 1333 unsigned long offset; 1334 size_t size; 1335 }; 1336 1337 static ssize_t io_copy_page(struct io_copy_cache *cc, struct page *src_page, 1338 unsigned int src_offset, size_t len) 1339 { 1340 size_t copied = 0; 1341 1342 len = min(len, cc->size); 1343 1344 while (len) { 1345 void *src_addr, *dst_addr; 1346 struct page *dst_page = cc->page; 1347 unsigned dst_offset = cc->offset; 1348 size_t n = len; 1349 1350 if (folio_test_partial_kmap(page_folio(dst_page)) || 1351 folio_test_partial_kmap(page_folio(src_page))) { 1352 dst_page += dst_offset / PAGE_SIZE; 1353 dst_offset = offset_in_page(dst_offset); 1354 src_page += src_offset / PAGE_SIZE; 1355 src_offset = offset_in_page(src_offset); 1356 n = min(PAGE_SIZE - src_offset, PAGE_SIZE - dst_offset); 1357 n = min(n, len); 1358 } 1359 1360 dst_addr = kmap_local_page(dst_page) + dst_offset; 1361 src_addr = kmap_local_page(src_page) + src_offset; 1362 1363 memcpy(dst_addr, src_addr, n); 1364 1365 kunmap_local(src_addr); 1366 kunmap_local(dst_addr); 1367 1368 cc->size -= n; 1369 cc->offset += n; 1370 src_offset += n; 1371 len -= n; 1372 copied += n; 1373 } 1374 return copied; 1375 } 1376 1377 static ssize_t io_zcrx_copy_chunk(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1378 struct page *src_page, unsigned int src_offset, 1379 size_t len) 1380 { 1381 size_t copied = 0; 1382 int ret = 0; 1383 1384 while (len) { 1385 struct io_copy_cache cc; 1386 struct net_iov *niov; 1387 size_t n; 1388 1389 niov = io_alloc_fallback_niov(ifq); 1390 if (!niov) { 1391 ret = -ENOMEM; 1392 break; 1393 } 1394 1395 cc.page = io_zcrx_iov_page(niov); 1396 cc.offset = 0; 1397 cc.size = PAGE_SIZE; 1398 1399 n = io_copy_page(&cc, src_page, src_offset, len); 1400 1401 if (!io_zcrx_queue_cqe(req, niov, ifq, 0, n)) { 1402 io_zcrx_return_niov(niov); 1403 ret = -ENOSPC; 1404 break; 1405 } 1406 1407 io_zcrx_get_niov_uref(niov); 1408 src_offset += n; 1409 len -= n; 1410 copied += n; 1411 } 1412 1413 return copied ? copied : ret; 1414 } 1415 1416 static int io_zcrx_copy_frag(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1417 const skb_frag_t *frag, int off, int len) 1418 { 1419 struct page *page = skb_frag_page(frag); 1420 1421 return io_zcrx_copy_chunk(req, ifq, page, off + skb_frag_off(frag), len); 1422 } 1423 1424 static int io_zcrx_recv_frag(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1425 const skb_frag_t *frag, int off, int len) 1426 { 1427 struct net_iov *niov; 1428 struct page_pool *pp; 1429 1430 if (unlikely(!skb_frag_is_net_iov(frag))) 1431 return io_zcrx_copy_frag(req, ifq, frag, off, len); 1432 1433 niov = netmem_to_net_iov(frag->netmem); 1434 pp = niov->desc.pp; 1435 1436 if (!pp || pp->mp_ops != &io_uring_pp_zc_ops || io_pp_to_ifq(pp) != ifq) 1437 return -EFAULT; 1438 1439 if (!io_zcrx_queue_cqe(req, niov, ifq, off + skb_frag_off(frag), len)) 1440 return -ENOSPC; 1441 1442 /* 1443 * Prevent it from being recycled while user is accessing it. 1444 * It has to be done before grabbing a user reference. 1445 */ 1446 page_pool_ref_netmem(net_iov_to_netmem(niov)); 1447 io_zcrx_get_niov_uref(niov); 1448 return len; 1449 } 1450 1451 static int 1452 io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, 1453 unsigned int offset, size_t len) 1454 { 1455 struct io_zcrx_args *args = desc->arg.data; 1456 struct io_zcrx_ifq *ifq = args->ifq; 1457 struct io_kiocb *req = args->req; 1458 struct sk_buff *frag_iter; 1459 unsigned start, start_off = offset; 1460 int i, copy, end, off; 1461 int ret = 0; 1462 1463 len = min_t(size_t, len, desc->count); 1464 /* 1465 * __tcp_read_sock() always calls io_zcrx_recv_skb one last time, even 1466 * if desc->count is already 0. This is caused by the if (offset + 1 != 1467 * skb->len) check. Return early in this case to break out of 1468 * __tcp_read_sock(). 1469 */ 1470 if (!len) 1471 return 0; 1472 if (unlikely(args->nr_skbs++ > IO_SKBS_PER_CALL_LIMIT)) 1473 return -EAGAIN; 1474 1475 if (unlikely(offset < skb_headlen(skb))) { 1476 ssize_t copied; 1477 size_t to_copy; 1478 1479 to_copy = min_t(size_t, skb_headlen(skb) - offset, len); 1480 copied = io_zcrx_copy_chunk(req, ifq, virt_to_page(skb->data), 1481 offset_in_page(skb->data) + offset, 1482 to_copy); 1483 if (copied < 0) { 1484 ret = copied; 1485 goto out; 1486 } 1487 offset += copied; 1488 len -= copied; 1489 if (!len) 1490 goto out; 1491 if (offset != skb_headlen(skb)) 1492 goto out; 1493 } 1494 1495 start = skb_headlen(skb); 1496 1497 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { 1498 const skb_frag_t *frag; 1499 1500 if (WARN_ON(start > offset + len)) 1501 return -EFAULT; 1502 1503 frag = &skb_shinfo(skb)->frags[i]; 1504 end = start + skb_frag_size(frag); 1505 1506 if (offset < end) { 1507 copy = end - offset; 1508 if (copy > len) 1509 copy = len; 1510 1511 off = offset - start; 1512 ret = io_zcrx_recv_frag(req, ifq, frag, off, copy); 1513 if (ret < 0) 1514 goto out; 1515 1516 offset += ret; 1517 len -= ret; 1518 if (len == 0 || ret != copy) 1519 goto out; 1520 } 1521 start = end; 1522 } 1523 1524 skb_walk_frags(skb, frag_iter) { 1525 if (WARN_ON(start > offset + len)) 1526 return -EFAULT; 1527 1528 end = start + frag_iter->len; 1529 if (offset < end) { 1530 size_t count; 1531 1532 copy = end - offset; 1533 if (copy > len) 1534 copy = len; 1535 1536 off = offset - start; 1537 count = desc->count; 1538 ret = io_zcrx_recv_skb(desc, frag_iter, off, copy); 1539 desc->count = count; 1540 if (ret < 0) 1541 goto out; 1542 1543 offset += ret; 1544 len -= ret; 1545 if (len == 0 || ret != copy) 1546 goto out; 1547 } 1548 start = end; 1549 } 1550 1551 out: 1552 if (offset == start_off) 1553 return ret; 1554 desc->count -= (offset - start_off); 1555 return offset - start_off; 1556 } 1557 1558 static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1559 struct sock *sk, int flags, 1560 unsigned issue_flags, unsigned int *outlen) 1561 { 1562 unsigned int len = *outlen; 1563 struct io_zcrx_args args = { 1564 .req = req, 1565 .ifq = ifq, 1566 .sock = sk->sk_socket, 1567 }; 1568 read_descriptor_t rd_desc = { 1569 .count = len ? len : UINT_MAX, 1570 .arg.data = &args, 1571 }; 1572 int ret; 1573 1574 lock_sock(sk); 1575 ret = tcp_read_sock(sk, &rd_desc, io_zcrx_recv_skb); 1576 if (len && ret > 0) 1577 *outlen = len - ret; 1578 if (ret <= 0) { 1579 if (ret < 0 || sock_flag(sk, SOCK_DONE)) 1580 goto out; 1581 if (sk->sk_err) 1582 ret = sock_error(sk); 1583 else if (sk->sk_shutdown & RCV_SHUTDOWN) 1584 goto out; 1585 else if (sk->sk_state == TCP_CLOSE) 1586 ret = -ENOTCONN; 1587 else 1588 ret = -EAGAIN; 1589 } else if (unlikely(args.nr_skbs > IO_SKBS_PER_CALL_LIMIT) && 1590 (issue_flags & IO_URING_F_MULTISHOT)) { 1591 ret = IOU_REQUEUE; 1592 } else if (sock_flag(sk, SOCK_DONE)) { 1593 /* Make it to retry until it finally gets 0. */ 1594 if (issue_flags & IO_URING_F_MULTISHOT) 1595 ret = IOU_REQUEUE; 1596 else 1597 ret = -EAGAIN; 1598 } 1599 out: 1600 release_sock(sk); 1601 return ret; 1602 } 1603 1604 int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq, 1605 struct socket *sock, unsigned int flags, 1606 unsigned issue_flags, unsigned int *len) 1607 { 1608 struct sock *sk = sock->sk; 1609 const struct proto *prot = READ_ONCE(sk->sk_prot); 1610 1611 if (prot->recvmsg != tcp_recvmsg) 1612 return -EPROTONOSUPPORT; 1613 1614 sock_rps_record_flow(sk); 1615 return io_zcrx_tcp_recvmsg(req, ifq, sk, flags, issue_flags, len); 1616 } 1617