1 /* Copyright (C) 2009 Red Hat, Inc. 2 * Author: Michael S. Tsirkin <mst@redhat.com> 3 * 4 * This work is licensed under the terms of the GNU GPL, version 2. 5 * 6 * virtio-net server in host kernel. 7 */ 8 9 #include <linux/compat.h> 10 #include <linux/eventfd.h> 11 #include <linux/vhost.h> 12 #include <linux/virtio_net.h> 13 #include <linux/miscdevice.h> 14 #include <linux/module.h> 15 #include <linux/moduleparam.h> 16 #include <linux/mutex.h> 17 #include <linux/workqueue.h> 18 #include <linux/file.h> 19 #include <linux/slab.h> 20 #include <linux/sched/clock.h> 21 #include <linux/sched/signal.h> 22 #include <linux/vmalloc.h> 23 24 #include <linux/net.h> 25 #include <linux/if_packet.h> 26 #include <linux/if_arp.h> 27 #include <linux/if_tun.h> 28 #include <linux/if_macvlan.h> 29 #include <linux/if_tap.h> 30 #include <linux/if_vlan.h> 31 #include <linux/skb_array.h> 32 #include <linux/skbuff.h> 33 34 #include <net/sock.h> 35 36 #include "vhost.h" 37 38 static int experimental_zcopytx = 1; 39 module_param(experimental_zcopytx, int, 0444); 40 MODULE_PARM_DESC(experimental_zcopytx, "Enable Zero Copy TX;" 41 " 1 -Enable; 0 - Disable"); 42 43 /* Max number of bytes transferred before requeueing the job. 44 * Using this limit prevents one virtqueue from starving others. */ 45 #define VHOST_NET_WEIGHT 0x80000 46 47 /* MAX number of TX used buffers for outstanding zerocopy */ 48 #define VHOST_MAX_PEND 128 49 #define VHOST_GOODCOPY_LEN 256 50 51 /* 52 * For transmit, used buffer len is unused; we override it to track buffer 53 * status internally; used for zerocopy tx only. 54 */ 55 /* Lower device DMA failed */ 56 #define VHOST_DMA_FAILED_LEN ((__force __virtio32)3) 57 /* Lower device DMA done */ 58 #define VHOST_DMA_DONE_LEN ((__force __virtio32)2) 59 /* Lower device DMA in progress */ 60 #define VHOST_DMA_IN_PROGRESS ((__force __virtio32)1) 61 /* Buffer unused */ 62 #define VHOST_DMA_CLEAR_LEN ((__force __virtio32)0) 63 64 #define VHOST_DMA_IS_DONE(len) ((__force u32)(len) >= (__force u32)VHOST_DMA_DONE_LEN) 65 66 enum { 67 VHOST_NET_FEATURES = VHOST_FEATURES | 68 (1ULL << VHOST_NET_F_VIRTIO_NET_HDR) | 69 (1ULL << VIRTIO_NET_F_MRG_RXBUF) | 70 (1ULL << VIRTIO_F_IOMMU_PLATFORM) 71 }; 72 73 enum { 74 VHOST_NET_VQ_RX = 0, 75 VHOST_NET_VQ_TX = 1, 76 VHOST_NET_VQ_MAX = 2, 77 }; 78 79 struct vhost_net_ubuf_ref { 80 /* refcount follows semantics similar to kref: 81 * 0: object is released 82 * 1: no outstanding ubufs 83 * >1: outstanding ubufs 84 */ 85 atomic_t refcount; 86 wait_queue_head_t wait; 87 struct vhost_virtqueue *vq; 88 }; 89 90 #define VHOST_RX_BATCH 64 91 struct vhost_net_buf { 92 void **queue; 93 int tail; 94 int head; 95 }; 96 97 struct vhost_net_virtqueue { 98 struct vhost_virtqueue vq; 99 size_t vhost_hlen; 100 size_t sock_hlen; 101 /* vhost zerocopy support fields below: */ 102 /* last used idx for outstanding DMA zerocopy buffers */ 103 int upend_idx; 104 /* first used idx for DMA done zerocopy buffers */ 105 int done_idx; 106 /* an array of userspace buffers info */ 107 struct ubuf_info *ubuf_info; 108 /* Reference counting for outstanding ubufs. 109 * Protected by vq mutex. Writers must also take device mutex. */ 110 struct vhost_net_ubuf_ref *ubufs; 111 struct ptr_ring *rx_ring; 112 struct vhost_net_buf rxq; 113 }; 114 115 struct vhost_net { 116 struct vhost_dev dev; 117 struct vhost_net_virtqueue vqs[VHOST_NET_VQ_MAX]; 118 struct vhost_poll poll[VHOST_NET_VQ_MAX]; 119 /* Number of TX recently submitted. 120 * Protected by tx vq lock. */ 121 unsigned tx_packets; 122 /* Number of times zerocopy TX recently failed. 123 * Protected by tx vq lock. */ 124 unsigned tx_zcopy_err; 125 /* Flush in progress. Protected by tx vq lock. */ 126 bool tx_flush; 127 }; 128 129 static unsigned vhost_net_zcopy_mask __read_mostly; 130 131 static void *vhost_net_buf_get_ptr(struct vhost_net_buf *rxq) 132 { 133 if (rxq->tail != rxq->head) 134 return rxq->queue[rxq->head]; 135 else 136 return NULL; 137 } 138 139 static int vhost_net_buf_get_size(struct vhost_net_buf *rxq) 140 { 141 return rxq->tail - rxq->head; 142 } 143 144 static int vhost_net_buf_is_empty(struct vhost_net_buf *rxq) 145 { 146 return rxq->tail == rxq->head; 147 } 148 149 static void *vhost_net_buf_consume(struct vhost_net_buf *rxq) 150 { 151 void *ret = vhost_net_buf_get_ptr(rxq); 152 ++rxq->head; 153 return ret; 154 } 155 156 static int vhost_net_buf_produce(struct vhost_net_virtqueue *nvq) 157 { 158 struct vhost_net_buf *rxq = &nvq->rxq; 159 160 rxq->head = 0; 161 rxq->tail = ptr_ring_consume_batched(nvq->rx_ring, rxq->queue, 162 VHOST_RX_BATCH); 163 return rxq->tail; 164 } 165 166 static void vhost_net_buf_unproduce(struct vhost_net_virtqueue *nvq) 167 { 168 struct vhost_net_buf *rxq = &nvq->rxq; 169 170 if (nvq->rx_ring && !vhost_net_buf_is_empty(rxq)) { 171 ptr_ring_unconsume(nvq->rx_ring, rxq->queue + rxq->head, 172 vhost_net_buf_get_size(rxq), 173 tun_ptr_free); 174 rxq->head = rxq->tail = 0; 175 } 176 } 177 178 static int vhost_net_buf_peek_len(void *ptr) 179 { 180 if (tun_is_xdp_buff(ptr)) { 181 struct xdp_buff *xdp = tun_ptr_to_xdp(ptr); 182 183 return xdp->data_end - xdp->data; 184 } 185 186 return __skb_array_len_with_tag(ptr); 187 } 188 189 static int vhost_net_buf_peek(struct vhost_net_virtqueue *nvq) 190 { 191 struct vhost_net_buf *rxq = &nvq->rxq; 192 193 if (!vhost_net_buf_is_empty(rxq)) 194 goto out; 195 196 if (!vhost_net_buf_produce(nvq)) 197 return 0; 198 199 out: 200 return vhost_net_buf_peek_len(vhost_net_buf_get_ptr(rxq)); 201 } 202 203 static void vhost_net_buf_init(struct vhost_net_buf *rxq) 204 { 205 rxq->head = rxq->tail = 0; 206 } 207 208 static void vhost_net_enable_zcopy(int vq) 209 { 210 vhost_net_zcopy_mask |= 0x1 << vq; 211 } 212 213 static struct vhost_net_ubuf_ref * 214 vhost_net_ubuf_alloc(struct vhost_virtqueue *vq, bool zcopy) 215 { 216 struct vhost_net_ubuf_ref *ubufs; 217 /* No zero copy backend? Nothing to count. */ 218 if (!zcopy) 219 return NULL; 220 ubufs = kmalloc(sizeof(*ubufs), GFP_KERNEL); 221 if (!ubufs) 222 return ERR_PTR(-ENOMEM); 223 atomic_set(&ubufs->refcount, 1); 224 init_waitqueue_head(&ubufs->wait); 225 ubufs->vq = vq; 226 return ubufs; 227 } 228 229 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs) 230 { 231 int r = atomic_sub_return(1, &ubufs->refcount); 232 if (unlikely(!r)) 233 wake_up(&ubufs->wait); 234 return r; 235 } 236 237 static void vhost_net_ubuf_put_and_wait(struct vhost_net_ubuf_ref *ubufs) 238 { 239 vhost_net_ubuf_put(ubufs); 240 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount)); 241 } 242 243 static void vhost_net_ubuf_put_wait_and_free(struct vhost_net_ubuf_ref *ubufs) 244 { 245 vhost_net_ubuf_put_and_wait(ubufs); 246 kfree(ubufs); 247 } 248 249 static void vhost_net_clear_ubuf_info(struct vhost_net *n) 250 { 251 int i; 252 253 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { 254 kfree(n->vqs[i].ubuf_info); 255 n->vqs[i].ubuf_info = NULL; 256 } 257 } 258 259 static int vhost_net_set_ubuf_info(struct vhost_net *n) 260 { 261 bool zcopy; 262 int i; 263 264 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { 265 zcopy = vhost_net_zcopy_mask & (0x1 << i); 266 if (!zcopy) 267 continue; 268 n->vqs[i].ubuf_info = kmalloc(sizeof(*n->vqs[i].ubuf_info) * 269 UIO_MAXIOV, GFP_KERNEL); 270 if (!n->vqs[i].ubuf_info) 271 goto err; 272 } 273 return 0; 274 275 err: 276 vhost_net_clear_ubuf_info(n); 277 return -ENOMEM; 278 } 279 280 static void vhost_net_vq_reset(struct vhost_net *n) 281 { 282 int i; 283 284 vhost_net_clear_ubuf_info(n); 285 286 for (i = 0; i < VHOST_NET_VQ_MAX; i++) { 287 n->vqs[i].done_idx = 0; 288 n->vqs[i].upend_idx = 0; 289 n->vqs[i].ubufs = NULL; 290 n->vqs[i].vhost_hlen = 0; 291 n->vqs[i].sock_hlen = 0; 292 vhost_net_buf_init(&n->vqs[i].rxq); 293 } 294 295 } 296 297 static void vhost_net_tx_packet(struct vhost_net *net) 298 { 299 ++net->tx_packets; 300 if (net->tx_packets < 1024) 301 return; 302 net->tx_packets = 0; 303 net->tx_zcopy_err = 0; 304 } 305 306 static void vhost_net_tx_err(struct vhost_net *net) 307 { 308 ++net->tx_zcopy_err; 309 } 310 311 static bool vhost_net_tx_select_zcopy(struct vhost_net *net) 312 { 313 /* TX flush waits for outstanding DMAs to be done. 314 * Don't start new DMAs. 315 */ 316 return !net->tx_flush && 317 net->tx_packets / 64 >= net->tx_zcopy_err; 318 } 319 320 static bool vhost_sock_zcopy(struct socket *sock) 321 { 322 return unlikely(experimental_zcopytx) && 323 sock_flag(sock->sk, SOCK_ZEROCOPY); 324 } 325 326 /* In case of DMA done not in order in lower device driver for some reason. 327 * upend_idx is used to track end of used idx, done_idx is used to track head 328 * of used idx. Once lower device DMA done contiguously, we will signal KVM 329 * guest used idx. 330 */ 331 static void vhost_zerocopy_signal_used(struct vhost_net *net, 332 struct vhost_virtqueue *vq) 333 { 334 struct vhost_net_virtqueue *nvq = 335 container_of(vq, struct vhost_net_virtqueue, vq); 336 int i, add; 337 int j = 0; 338 339 for (i = nvq->done_idx; i != nvq->upend_idx; i = (i + 1) % UIO_MAXIOV) { 340 if (vq->heads[i].len == VHOST_DMA_FAILED_LEN) 341 vhost_net_tx_err(net); 342 if (VHOST_DMA_IS_DONE(vq->heads[i].len)) { 343 vq->heads[i].len = VHOST_DMA_CLEAR_LEN; 344 ++j; 345 } else 346 break; 347 } 348 while (j) { 349 add = min(UIO_MAXIOV - nvq->done_idx, j); 350 vhost_add_used_and_signal_n(vq->dev, vq, 351 &vq->heads[nvq->done_idx], add); 352 nvq->done_idx = (nvq->done_idx + add) % UIO_MAXIOV; 353 j -= add; 354 } 355 } 356 357 static void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool success) 358 { 359 struct vhost_net_ubuf_ref *ubufs = ubuf->ctx; 360 struct vhost_virtqueue *vq = ubufs->vq; 361 int cnt; 362 363 rcu_read_lock_bh(); 364 365 /* set len to mark this desc buffers done DMA */ 366 vq->heads[ubuf->desc].len = success ? 367 VHOST_DMA_DONE_LEN : VHOST_DMA_FAILED_LEN; 368 cnt = vhost_net_ubuf_put(ubufs); 369 370 /* 371 * Trigger polling thread if guest stopped submitting new buffers: 372 * in this case, the refcount after decrement will eventually reach 1. 373 * We also trigger polling periodically after each 16 packets 374 * (the value 16 here is more or less arbitrary, it's tuned to trigger 375 * less than 10% of times). 376 */ 377 if (cnt <= 1 || !(cnt % 16)) 378 vhost_poll_queue(&vq->poll); 379 380 rcu_read_unlock_bh(); 381 } 382 383 static inline unsigned long busy_clock(void) 384 { 385 return local_clock() >> 10; 386 } 387 388 static bool vhost_can_busy_poll(struct vhost_dev *dev, 389 unsigned long endtime) 390 { 391 return likely(!need_resched()) && 392 likely(!time_after(busy_clock(), endtime)) && 393 likely(!signal_pending(current)) && 394 !vhost_has_work(dev); 395 } 396 397 static void vhost_net_disable_vq(struct vhost_net *n, 398 struct vhost_virtqueue *vq) 399 { 400 struct vhost_net_virtqueue *nvq = 401 container_of(vq, struct vhost_net_virtqueue, vq); 402 struct vhost_poll *poll = n->poll + (nvq - n->vqs); 403 if (!vq->private_data) 404 return; 405 vhost_poll_stop(poll); 406 } 407 408 static int vhost_net_enable_vq(struct vhost_net *n, 409 struct vhost_virtqueue *vq) 410 { 411 struct vhost_net_virtqueue *nvq = 412 container_of(vq, struct vhost_net_virtqueue, vq); 413 struct vhost_poll *poll = n->poll + (nvq - n->vqs); 414 struct socket *sock; 415 416 sock = vq->private_data; 417 if (!sock) 418 return 0; 419 420 return vhost_poll_start(poll, sock->file); 421 } 422 423 static int vhost_net_tx_get_vq_desc(struct vhost_net *net, 424 struct vhost_virtqueue *vq, 425 struct iovec iov[], unsigned int iov_size, 426 unsigned int *out_num, unsigned int *in_num) 427 { 428 unsigned long uninitialized_var(endtime); 429 int r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), 430 out_num, in_num, NULL, NULL); 431 432 if (r == vq->num && vq->busyloop_timeout) { 433 preempt_disable(); 434 endtime = busy_clock() + vq->busyloop_timeout; 435 while (vhost_can_busy_poll(vq->dev, endtime) && 436 vhost_vq_avail_empty(vq->dev, vq)) 437 cpu_relax(); 438 preempt_enable(); 439 r = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), 440 out_num, in_num, NULL, NULL); 441 } 442 443 return r; 444 } 445 446 static bool vhost_exceeds_maxpend(struct vhost_net *net) 447 { 448 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; 449 struct vhost_virtqueue *vq = &nvq->vq; 450 451 return (nvq->upend_idx + UIO_MAXIOV - nvq->done_idx) % UIO_MAXIOV > 452 min_t(unsigned int, VHOST_MAX_PEND, vq->num >> 2); 453 } 454 455 /* Expects to be always run from workqueue - which acts as 456 * read-size critical section for our kind of RCU. */ 457 static void handle_tx(struct vhost_net *net) 458 { 459 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; 460 struct vhost_virtqueue *vq = &nvq->vq; 461 unsigned out, in; 462 int head; 463 struct msghdr msg = { 464 .msg_name = NULL, 465 .msg_namelen = 0, 466 .msg_control = NULL, 467 .msg_controllen = 0, 468 .msg_flags = MSG_DONTWAIT, 469 }; 470 size_t len, total_len = 0; 471 int err; 472 size_t hdr_size; 473 struct socket *sock; 474 struct vhost_net_ubuf_ref *uninitialized_var(ubufs); 475 bool zcopy, zcopy_used; 476 477 mutex_lock(&vq->mutex); 478 sock = vq->private_data; 479 if (!sock) 480 goto out; 481 482 if (!vq_iotlb_prefetch(vq)) 483 goto out; 484 485 vhost_disable_notify(&net->dev, vq); 486 vhost_net_disable_vq(net, vq); 487 488 hdr_size = nvq->vhost_hlen; 489 zcopy = nvq->ubufs; 490 491 for (;;) { 492 /* Release DMAs done buffers first */ 493 if (zcopy) 494 vhost_zerocopy_signal_used(net, vq); 495 496 497 head = vhost_net_tx_get_vq_desc(net, vq, vq->iov, 498 ARRAY_SIZE(vq->iov), 499 &out, &in); 500 /* On error, stop handling until the next kick. */ 501 if (unlikely(head < 0)) 502 break; 503 /* Nothing new? Wait for eventfd to tell us they refilled. */ 504 if (head == vq->num) { 505 if (unlikely(vhost_enable_notify(&net->dev, vq))) { 506 vhost_disable_notify(&net->dev, vq); 507 continue; 508 } 509 break; 510 } 511 if (in) { 512 vq_err(vq, "Unexpected descriptor format for TX: " 513 "out %d, int %d\n", out, in); 514 break; 515 } 516 /* Skip header. TODO: support TSO. */ 517 len = iov_length(vq->iov, out); 518 iov_iter_init(&msg.msg_iter, WRITE, vq->iov, out, len); 519 iov_iter_advance(&msg.msg_iter, hdr_size); 520 /* Sanity check */ 521 if (!msg_data_left(&msg)) { 522 vq_err(vq, "Unexpected header len for TX: " 523 "%zd expected %zd\n", 524 len, hdr_size); 525 break; 526 } 527 len = msg_data_left(&msg); 528 529 zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN 530 && !vhost_exceeds_maxpend(net) 531 && vhost_net_tx_select_zcopy(net); 532 533 /* use msg_control to pass vhost zerocopy ubuf info to skb */ 534 if (zcopy_used) { 535 struct ubuf_info *ubuf; 536 ubuf = nvq->ubuf_info + nvq->upend_idx; 537 538 vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head); 539 vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS; 540 ubuf->callback = vhost_zerocopy_callback; 541 ubuf->ctx = nvq->ubufs; 542 ubuf->desc = nvq->upend_idx; 543 refcount_set(&ubuf->refcnt, 1); 544 msg.msg_control = ubuf; 545 msg.msg_controllen = sizeof(ubuf); 546 ubufs = nvq->ubufs; 547 atomic_inc(&ubufs->refcount); 548 nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV; 549 } else { 550 msg.msg_control = NULL; 551 ubufs = NULL; 552 } 553 554 total_len += len; 555 if (total_len < VHOST_NET_WEIGHT && 556 !vhost_vq_avail_empty(&net->dev, vq) && 557 likely(!vhost_exceeds_maxpend(net))) { 558 msg.msg_flags |= MSG_MORE; 559 } else { 560 msg.msg_flags &= ~MSG_MORE; 561 } 562 563 /* TODO: Check specific error and bomb out unless ENOBUFS? */ 564 err = sock->ops->sendmsg(sock, &msg, len); 565 if (unlikely(err < 0)) { 566 if (zcopy_used) { 567 vhost_net_ubuf_put(ubufs); 568 nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) 569 % UIO_MAXIOV; 570 } 571 vhost_discard_vq_desc(vq, 1); 572 vhost_net_enable_vq(net, vq); 573 break; 574 } 575 if (err != len) 576 pr_debug("Truncated TX packet: " 577 " len %d != %zd\n", err, len); 578 if (!zcopy_used) 579 vhost_add_used_and_signal(&net->dev, vq, head, 0); 580 else 581 vhost_zerocopy_signal_used(net, vq); 582 vhost_net_tx_packet(net); 583 if (unlikely(total_len >= VHOST_NET_WEIGHT)) { 584 vhost_poll_queue(&vq->poll); 585 break; 586 } 587 } 588 out: 589 mutex_unlock(&vq->mutex); 590 } 591 592 static int peek_head_len(struct vhost_net_virtqueue *rvq, struct sock *sk) 593 { 594 struct sk_buff *head; 595 int len = 0; 596 unsigned long flags; 597 598 if (rvq->rx_ring) 599 return vhost_net_buf_peek(rvq); 600 601 spin_lock_irqsave(&sk->sk_receive_queue.lock, flags); 602 head = skb_peek(&sk->sk_receive_queue); 603 if (likely(head)) { 604 len = head->len; 605 if (skb_vlan_tag_present(head)) 606 len += VLAN_HLEN; 607 } 608 609 spin_unlock_irqrestore(&sk->sk_receive_queue.lock, flags); 610 return len; 611 } 612 613 static int sk_has_rx_data(struct sock *sk) 614 { 615 struct socket *sock = sk->sk_socket; 616 617 if (sock->ops->peek_len) 618 return sock->ops->peek_len(sock); 619 620 return skb_queue_empty(&sk->sk_receive_queue); 621 } 622 623 static int vhost_net_rx_peek_head_len(struct vhost_net *net, struct sock *sk) 624 { 625 struct vhost_net_virtqueue *rvq = &net->vqs[VHOST_NET_VQ_RX]; 626 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_TX]; 627 struct vhost_virtqueue *vq = &nvq->vq; 628 unsigned long uninitialized_var(endtime); 629 int len = peek_head_len(rvq, sk); 630 631 if (!len && vq->busyloop_timeout) { 632 /* Both tx vq and rx socket were polled here */ 633 mutex_lock_nested(&vq->mutex, 1); 634 vhost_disable_notify(&net->dev, vq); 635 636 preempt_disable(); 637 endtime = busy_clock() + vq->busyloop_timeout; 638 639 while (vhost_can_busy_poll(&net->dev, endtime) && 640 !sk_has_rx_data(sk) && 641 vhost_vq_avail_empty(&net->dev, vq)) 642 cpu_relax(); 643 644 preempt_enable(); 645 646 if (!vhost_vq_avail_empty(&net->dev, vq)) 647 vhost_poll_queue(&vq->poll); 648 else if (unlikely(vhost_enable_notify(&net->dev, vq))) { 649 vhost_disable_notify(&net->dev, vq); 650 vhost_poll_queue(&vq->poll); 651 } 652 653 mutex_unlock(&vq->mutex); 654 655 len = peek_head_len(rvq, sk); 656 } 657 658 return len; 659 } 660 661 /* This is a multi-buffer version of vhost_get_desc, that works if 662 * vq has read descriptors only. 663 * @vq - the relevant virtqueue 664 * @datalen - data length we'll be reading 665 * @iovcount - returned count of io vectors we fill 666 * @log - vhost log 667 * @log_num - log offset 668 * @quota - headcount quota, 1 for big buffer 669 * returns number of buffer heads allocated, negative on error 670 */ 671 static int get_rx_bufs(struct vhost_virtqueue *vq, 672 struct vring_used_elem *heads, 673 int datalen, 674 unsigned *iovcount, 675 struct vhost_log *log, 676 unsigned *log_num, 677 unsigned int quota) 678 { 679 unsigned int out, in; 680 int seg = 0; 681 int headcount = 0; 682 unsigned d; 683 int r, nlogs = 0; 684 /* len is always initialized before use since we are always called with 685 * datalen > 0. 686 */ 687 u32 uninitialized_var(len); 688 689 while (datalen > 0 && headcount < quota) { 690 if (unlikely(seg >= UIO_MAXIOV)) { 691 r = -ENOBUFS; 692 goto err; 693 } 694 r = vhost_get_vq_desc(vq, vq->iov + seg, 695 ARRAY_SIZE(vq->iov) - seg, &out, 696 &in, log, log_num); 697 if (unlikely(r < 0)) 698 goto err; 699 700 d = r; 701 if (d == vq->num) { 702 r = 0; 703 goto err; 704 } 705 if (unlikely(out || in <= 0)) { 706 vq_err(vq, "unexpected descriptor format for RX: " 707 "out %d, in %d\n", out, in); 708 r = -EINVAL; 709 goto err; 710 } 711 if (unlikely(log)) { 712 nlogs += *log_num; 713 log += *log_num; 714 } 715 heads[headcount].id = cpu_to_vhost32(vq, d); 716 len = iov_length(vq->iov + seg, in); 717 heads[headcount].len = cpu_to_vhost32(vq, len); 718 datalen -= len; 719 ++headcount; 720 seg += in; 721 } 722 heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen); 723 *iovcount = seg; 724 if (unlikely(log)) 725 *log_num = nlogs; 726 727 /* Detect overrun */ 728 if (unlikely(datalen > 0)) { 729 r = UIO_MAXIOV + 1; 730 goto err; 731 } 732 return headcount; 733 err: 734 vhost_discard_vq_desc(vq, headcount); 735 return r; 736 } 737 738 /* Expects to be always run from workqueue - which acts as 739 * read-size critical section for our kind of RCU. */ 740 static void handle_rx(struct vhost_net *net) 741 { 742 struct vhost_net_virtqueue *nvq = &net->vqs[VHOST_NET_VQ_RX]; 743 struct vhost_virtqueue *vq = &nvq->vq; 744 unsigned uninitialized_var(in), log; 745 struct vhost_log *vq_log; 746 struct msghdr msg = { 747 .msg_name = NULL, 748 .msg_namelen = 0, 749 .msg_control = NULL, /* FIXME: get and handle RX aux data. */ 750 .msg_controllen = 0, 751 .msg_flags = MSG_DONTWAIT, 752 }; 753 struct virtio_net_hdr hdr = { 754 .flags = 0, 755 .gso_type = VIRTIO_NET_HDR_GSO_NONE 756 }; 757 size_t total_len = 0; 758 int err, mergeable; 759 s16 headcount, nheads = 0; 760 size_t vhost_hlen, sock_hlen; 761 size_t vhost_len, sock_len; 762 struct socket *sock; 763 struct iov_iter fixup; 764 __virtio16 num_buffers; 765 766 mutex_lock_nested(&vq->mutex, 0); 767 sock = vq->private_data; 768 if (!sock) 769 goto out; 770 771 if (!vq_iotlb_prefetch(vq)) 772 goto out; 773 774 vhost_disable_notify(&net->dev, vq); 775 vhost_net_disable_vq(net, vq); 776 777 vhost_hlen = nvq->vhost_hlen; 778 sock_hlen = nvq->sock_hlen; 779 780 vq_log = unlikely(vhost_has_feature(vq, VHOST_F_LOG_ALL)) ? 781 vq->log : NULL; 782 mergeable = vhost_has_feature(vq, VIRTIO_NET_F_MRG_RXBUF); 783 784 while ((sock_len = vhost_net_rx_peek_head_len(net, sock->sk))) { 785 sock_len += sock_hlen; 786 vhost_len = sock_len + vhost_hlen; 787 headcount = get_rx_bufs(vq, vq->heads + nheads, vhost_len, 788 &in, vq_log, &log, 789 likely(mergeable) ? UIO_MAXIOV : 1); 790 /* On error, stop handling until the next kick. */ 791 if (unlikely(headcount < 0)) 792 goto out; 793 /* OK, now we need to know about added descriptors. */ 794 if (!headcount) { 795 if (unlikely(vhost_enable_notify(&net->dev, vq))) { 796 /* They have slipped one in as we were 797 * doing that: check again. */ 798 vhost_disable_notify(&net->dev, vq); 799 continue; 800 } 801 /* Nothing new? Wait for eventfd to tell us 802 * they refilled. */ 803 goto out; 804 } 805 if (nvq->rx_ring) 806 msg.msg_control = vhost_net_buf_consume(&nvq->rxq); 807 /* On overrun, truncate and discard */ 808 if (unlikely(headcount > UIO_MAXIOV)) { 809 iov_iter_init(&msg.msg_iter, READ, vq->iov, 1, 1); 810 err = sock->ops->recvmsg(sock, &msg, 811 1, MSG_DONTWAIT | MSG_TRUNC); 812 pr_debug("Discarded rx packet: len %zd\n", sock_len); 813 continue; 814 } 815 /* We don't need to be notified again. */ 816 iov_iter_init(&msg.msg_iter, READ, vq->iov, in, vhost_len); 817 fixup = msg.msg_iter; 818 if (unlikely((vhost_hlen))) { 819 /* We will supply the header ourselves 820 * TODO: support TSO. 821 */ 822 iov_iter_advance(&msg.msg_iter, vhost_hlen); 823 } 824 err = sock->ops->recvmsg(sock, &msg, 825 sock_len, MSG_DONTWAIT | MSG_TRUNC); 826 /* Userspace might have consumed the packet meanwhile: 827 * it's not supposed to do this usually, but might be hard 828 * to prevent. Discard data we got (if any) and keep going. */ 829 if (unlikely(err != sock_len)) { 830 pr_debug("Discarded rx packet: " 831 " len %d, expected %zd\n", err, sock_len); 832 vhost_discard_vq_desc(vq, headcount); 833 continue; 834 } 835 /* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */ 836 if (unlikely(vhost_hlen)) { 837 if (copy_to_iter(&hdr, sizeof(hdr), 838 &fixup) != sizeof(hdr)) { 839 vq_err(vq, "Unable to write vnet_hdr " 840 "at addr %p\n", vq->iov->iov_base); 841 goto out; 842 } 843 } else { 844 /* Header came from socket; we'll need to patch 845 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF 846 */ 847 iov_iter_advance(&fixup, sizeof(hdr)); 848 } 849 /* TODO: Should check and handle checksum. */ 850 851 num_buffers = cpu_to_vhost16(vq, headcount); 852 if (likely(mergeable) && 853 copy_to_iter(&num_buffers, sizeof num_buffers, 854 &fixup) != sizeof num_buffers) { 855 vq_err(vq, "Failed num_buffers write"); 856 vhost_discard_vq_desc(vq, headcount); 857 goto out; 858 } 859 nheads += headcount; 860 if (nheads > VHOST_RX_BATCH) { 861 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads, 862 nheads); 863 nheads = 0; 864 } 865 if (unlikely(vq_log)) 866 vhost_log_write(vq, vq_log, log, vhost_len); 867 total_len += vhost_len; 868 if (unlikely(total_len >= VHOST_NET_WEIGHT)) { 869 vhost_poll_queue(&vq->poll); 870 goto out; 871 } 872 } 873 vhost_net_enable_vq(net, vq); 874 out: 875 if (nheads) 876 vhost_add_used_and_signal_n(&net->dev, vq, vq->heads, 877 nheads); 878 mutex_unlock(&vq->mutex); 879 } 880 881 static void handle_tx_kick(struct vhost_work *work) 882 { 883 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, 884 poll.work); 885 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); 886 887 handle_tx(net); 888 } 889 890 static void handle_rx_kick(struct vhost_work *work) 891 { 892 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, 893 poll.work); 894 struct vhost_net *net = container_of(vq->dev, struct vhost_net, dev); 895 896 handle_rx(net); 897 } 898 899 static void handle_tx_net(struct vhost_work *work) 900 { 901 struct vhost_net *net = container_of(work, struct vhost_net, 902 poll[VHOST_NET_VQ_TX].work); 903 handle_tx(net); 904 } 905 906 static void handle_rx_net(struct vhost_work *work) 907 { 908 struct vhost_net *net = container_of(work, struct vhost_net, 909 poll[VHOST_NET_VQ_RX].work); 910 handle_rx(net); 911 } 912 913 static int vhost_net_open(struct inode *inode, struct file *f) 914 { 915 struct vhost_net *n; 916 struct vhost_dev *dev; 917 struct vhost_virtqueue **vqs; 918 void **queue; 919 int i; 920 921 n = kvmalloc(sizeof *n, GFP_KERNEL | __GFP_RETRY_MAYFAIL); 922 if (!n) 923 return -ENOMEM; 924 vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL); 925 if (!vqs) { 926 kvfree(n); 927 return -ENOMEM; 928 } 929 930 queue = kmalloc_array(VHOST_RX_BATCH, sizeof(void *), 931 GFP_KERNEL); 932 if (!queue) { 933 kfree(vqs); 934 kvfree(n); 935 return -ENOMEM; 936 } 937 n->vqs[VHOST_NET_VQ_RX].rxq.queue = queue; 938 939 dev = &n->dev; 940 vqs[VHOST_NET_VQ_TX] = &n->vqs[VHOST_NET_VQ_TX].vq; 941 vqs[VHOST_NET_VQ_RX] = &n->vqs[VHOST_NET_VQ_RX].vq; 942 n->vqs[VHOST_NET_VQ_TX].vq.handle_kick = handle_tx_kick; 943 n->vqs[VHOST_NET_VQ_RX].vq.handle_kick = handle_rx_kick; 944 for (i = 0; i < VHOST_NET_VQ_MAX; i++) { 945 n->vqs[i].ubufs = NULL; 946 n->vqs[i].ubuf_info = NULL; 947 n->vqs[i].upend_idx = 0; 948 n->vqs[i].done_idx = 0; 949 n->vqs[i].vhost_hlen = 0; 950 n->vqs[i].sock_hlen = 0; 951 n->vqs[i].rx_ring = NULL; 952 vhost_net_buf_init(&n->vqs[i].rxq); 953 } 954 vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX); 955 956 vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev); 957 vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev); 958 959 f->private_data = n; 960 961 return 0; 962 } 963 964 static struct socket *vhost_net_stop_vq(struct vhost_net *n, 965 struct vhost_virtqueue *vq) 966 { 967 struct socket *sock; 968 struct vhost_net_virtqueue *nvq = 969 container_of(vq, struct vhost_net_virtqueue, vq); 970 971 mutex_lock(&vq->mutex); 972 sock = vq->private_data; 973 vhost_net_disable_vq(n, vq); 974 vq->private_data = NULL; 975 vhost_net_buf_unproduce(nvq); 976 nvq->rx_ring = NULL; 977 mutex_unlock(&vq->mutex); 978 return sock; 979 } 980 981 static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, 982 struct socket **rx_sock) 983 { 984 *tx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_TX].vq); 985 *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq); 986 } 987 988 static void vhost_net_flush_vq(struct vhost_net *n, int index) 989 { 990 vhost_poll_flush(n->poll + index); 991 vhost_poll_flush(&n->vqs[index].vq.poll); 992 } 993 994 static void vhost_net_flush(struct vhost_net *n) 995 { 996 vhost_net_flush_vq(n, VHOST_NET_VQ_TX); 997 vhost_net_flush_vq(n, VHOST_NET_VQ_RX); 998 if (n->vqs[VHOST_NET_VQ_TX].ubufs) { 999 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); 1000 n->tx_flush = true; 1001 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); 1002 /* Wait for all lower device DMAs done. */ 1003 vhost_net_ubuf_put_and_wait(n->vqs[VHOST_NET_VQ_TX].ubufs); 1004 mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); 1005 n->tx_flush = false; 1006 atomic_set(&n->vqs[VHOST_NET_VQ_TX].ubufs->refcount, 1); 1007 mutex_unlock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); 1008 } 1009 } 1010 1011 static int vhost_net_release(struct inode *inode, struct file *f) 1012 { 1013 struct vhost_net *n = f->private_data; 1014 struct socket *tx_sock; 1015 struct socket *rx_sock; 1016 1017 vhost_net_stop(n, &tx_sock, &rx_sock); 1018 vhost_net_flush(n); 1019 vhost_dev_stop(&n->dev); 1020 vhost_dev_cleanup(&n->dev); 1021 vhost_net_vq_reset(n); 1022 if (tx_sock) 1023 sockfd_put(tx_sock); 1024 if (rx_sock) 1025 sockfd_put(rx_sock); 1026 /* Make sure no callbacks are outstanding */ 1027 synchronize_rcu_bh(); 1028 /* We do an extra flush before freeing memory, 1029 * since jobs can re-queue themselves. */ 1030 vhost_net_flush(n); 1031 kfree(n->vqs[VHOST_NET_VQ_RX].rxq.queue); 1032 kfree(n->dev.vqs); 1033 kvfree(n); 1034 return 0; 1035 } 1036 1037 static struct socket *get_raw_socket(int fd) 1038 { 1039 struct { 1040 struct sockaddr_ll sa; 1041 char buf[MAX_ADDR_LEN]; 1042 } uaddr; 1043 int uaddr_len = sizeof uaddr, r; 1044 struct socket *sock = sockfd_lookup(fd, &r); 1045 1046 if (!sock) 1047 return ERR_PTR(-ENOTSOCK); 1048 1049 /* Parameter checking */ 1050 if (sock->sk->sk_type != SOCK_RAW) { 1051 r = -ESOCKTNOSUPPORT; 1052 goto err; 1053 } 1054 1055 r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 1056 &uaddr_len, 0); 1057 if (r) 1058 goto err; 1059 1060 if (uaddr.sa.sll_family != AF_PACKET) { 1061 r = -EPFNOSUPPORT; 1062 goto err; 1063 } 1064 return sock; 1065 err: 1066 sockfd_put(sock); 1067 return ERR_PTR(r); 1068 } 1069 1070 static struct ptr_ring *get_tap_ptr_ring(int fd) 1071 { 1072 struct ptr_ring *ring; 1073 struct file *file = fget(fd); 1074 1075 if (!file) 1076 return NULL; 1077 ring = tun_get_tx_ring(file); 1078 if (!IS_ERR(ring)) 1079 goto out; 1080 ring = tap_get_ptr_ring(file); 1081 if (!IS_ERR(ring)) 1082 goto out; 1083 ring = NULL; 1084 out: 1085 fput(file); 1086 return ring; 1087 } 1088 1089 static struct socket *get_tap_socket(int fd) 1090 { 1091 struct file *file = fget(fd); 1092 struct socket *sock; 1093 1094 if (!file) 1095 return ERR_PTR(-EBADF); 1096 sock = tun_get_socket(file); 1097 if (!IS_ERR(sock)) 1098 return sock; 1099 sock = tap_get_socket(file); 1100 if (IS_ERR(sock)) 1101 fput(file); 1102 return sock; 1103 } 1104 1105 static struct socket *get_socket(int fd) 1106 { 1107 struct socket *sock; 1108 1109 /* special case to disable backend */ 1110 if (fd == -1) 1111 return NULL; 1112 sock = get_raw_socket(fd); 1113 if (!IS_ERR(sock)) 1114 return sock; 1115 sock = get_tap_socket(fd); 1116 if (!IS_ERR(sock)) 1117 return sock; 1118 return ERR_PTR(-ENOTSOCK); 1119 } 1120 1121 static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) 1122 { 1123 struct socket *sock, *oldsock; 1124 struct vhost_virtqueue *vq; 1125 struct vhost_net_virtqueue *nvq; 1126 struct vhost_net_ubuf_ref *ubufs, *oldubufs = NULL; 1127 int r; 1128 1129 mutex_lock(&n->dev.mutex); 1130 r = vhost_dev_check_owner(&n->dev); 1131 if (r) 1132 goto err; 1133 1134 if (index >= VHOST_NET_VQ_MAX) { 1135 r = -ENOBUFS; 1136 goto err; 1137 } 1138 vq = &n->vqs[index].vq; 1139 nvq = &n->vqs[index]; 1140 mutex_lock(&vq->mutex); 1141 1142 /* Verify that ring has been setup correctly. */ 1143 if (!vhost_vq_access_ok(vq)) { 1144 r = -EFAULT; 1145 goto err_vq; 1146 } 1147 sock = get_socket(fd); 1148 if (IS_ERR(sock)) { 1149 r = PTR_ERR(sock); 1150 goto err_vq; 1151 } 1152 1153 /* start polling new socket */ 1154 oldsock = vq->private_data; 1155 if (sock != oldsock) { 1156 ubufs = vhost_net_ubuf_alloc(vq, 1157 sock && vhost_sock_zcopy(sock)); 1158 if (IS_ERR(ubufs)) { 1159 r = PTR_ERR(ubufs); 1160 goto err_ubufs; 1161 } 1162 1163 vhost_net_disable_vq(n, vq); 1164 vq->private_data = sock; 1165 vhost_net_buf_unproduce(nvq); 1166 r = vhost_vq_init_access(vq); 1167 if (r) 1168 goto err_used; 1169 r = vhost_net_enable_vq(n, vq); 1170 if (r) 1171 goto err_used; 1172 if (index == VHOST_NET_VQ_RX) 1173 nvq->rx_ring = get_tap_ptr_ring(fd); 1174 1175 oldubufs = nvq->ubufs; 1176 nvq->ubufs = ubufs; 1177 1178 n->tx_packets = 0; 1179 n->tx_zcopy_err = 0; 1180 n->tx_flush = false; 1181 } 1182 1183 mutex_unlock(&vq->mutex); 1184 1185 if (oldubufs) { 1186 vhost_net_ubuf_put_wait_and_free(oldubufs); 1187 mutex_lock(&vq->mutex); 1188 vhost_zerocopy_signal_used(n, vq); 1189 mutex_unlock(&vq->mutex); 1190 } 1191 1192 if (oldsock) { 1193 vhost_net_flush_vq(n, index); 1194 sockfd_put(oldsock); 1195 } 1196 1197 mutex_unlock(&n->dev.mutex); 1198 return 0; 1199 1200 err_used: 1201 vq->private_data = oldsock; 1202 vhost_net_enable_vq(n, vq); 1203 if (ubufs) 1204 vhost_net_ubuf_put_wait_and_free(ubufs); 1205 err_ubufs: 1206 sockfd_put(sock); 1207 err_vq: 1208 mutex_unlock(&vq->mutex); 1209 err: 1210 mutex_unlock(&n->dev.mutex); 1211 return r; 1212 } 1213 1214 static long vhost_net_reset_owner(struct vhost_net *n) 1215 { 1216 struct socket *tx_sock = NULL; 1217 struct socket *rx_sock = NULL; 1218 long err; 1219 struct vhost_umem *umem; 1220 1221 mutex_lock(&n->dev.mutex); 1222 err = vhost_dev_check_owner(&n->dev); 1223 if (err) 1224 goto done; 1225 umem = vhost_dev_reset_owner_prepare(); 1226 if (!umem) { 1227 err = -ENOMEM; 1228 goto done; 1229 } 1230 vhost_net_stop(n, &tx_sock, &rx_sock); 1231 vhost_net_flush(n); 1232 vhost_dev_stop(&n->dev); 1233 vhost_dev_reset_owner(&n->dev, umem); 1234 vhost_net_vq_reset(n); 1235 done: 1236 mutex_unlock(&n->dev.mutex); 1237 if (tx_sock) 1238 sockfd_put(tx_sock); 1239 if (rx_sock) 1240 sockfd_put(rx_sock); 1241 return err; 1242 } 1243 1244 static int vhost_net_set_features(struct vhost_net *n, u64 features) 1245 { 1246 size_t vhost_hlen, sock_hlen, hdr_len; 1247 int i; 1248 1249 hdr_len = (features & ((1ULL << VIRTIO_NET_F_MRG_RXBUF) | 1250 (1ULL << VIRTIO_F_VERSION_1))) ? 1251 sizeof(struct virtio_net_hdr_mrg_rxbuf) : 1252 sizeof(struct virtio_net_hdr); 1253 if (features & (1 << VHOST_NET_F_VIRTIO_NET_HDR)) { 1254 /* vhost provides vnet_hdr */ 1255 vhost_hlen = hdr_len; 1256 sock_hlen = 0; 1257 } else { 1258 /* socket provides vnet_hdr */ 1259 vhost_hlen = 0; 1260 sock_hlen = hdr_len; 1261 } 1262 mutex_lock(&n->dev.mutex); 1263 if ((features & (1 << VHOST_F_LOG_ALL)) && 1264 !vhost_log_access_ok(&n->dev)) 1265 goto out_unlock; 1266 1267 if ((features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))) { 1268 if (vhost_init_device_iotlb(&n->dev, true)) 1269 goto out_unlock; 1270 } 1271 1272 for (i = 0; i < VHOST_NET_VQ_MAX; ++i) { 1273 mutex_lock(&n->vqs[i].vq.mutex); 1274 n->vqs[i].vq.acked_features = features; 1275 n->vqs[i].vhost_hlen = vhost_hlen; 1276 n->vqs[i].sock_hlen = sock_hlen; 1277 mutex_unlock(&n->vqs[i].vq.mutex); 1278 } 1279 mutex_unlock(&n->dev.mutex); 1280 return 0; 1281 1282 out_unlock: 1283 mutex_unlock(&n->dev.mutex); 1284 return -EFAULT; 1285 } 1286 1287 static long vhost_net_set_owner(struct vhost_net *n) 1288 { 1289 int r; 1290 1291 mutex_lock(&n->dev.mutex); 1292 if (vhost_dev_has_owner(&n->dev)) { 1293 r = -EBUSY; 1294 goto out; 1295 } 1296 r = vhost_net_set_ubuf_info(n); 1297 if (r) 1298 goto out; 1299 r = vhost_dev_set_owner(&n->dev); 1300 if (r) 1301 vhost_net_clear_ubuf_info(n); 1302 vhost_net_flush(n); 1303 out: 1304 mutex_unlock(&n->dev.mutex); 1305 return r; 1306 } 1307 1308 static long vhost_net_ioctl(struct file *f, unsigned int ioctl, 1309 unsigned long arg) 1310 { 1311 struct vhost_net *n = f->private_data; 1312 void __user *argp = (void __user *)arg; 1313 u64 __user *featurep = argp; 1314 struct vhost_vring_file backend; 1315 u64 features; 1316 int r; 1317 1318 switch (ioctl) { 1319 case VHOST_NET_SET_BACKEND: 1320 if (copy_from_user(&backend, argp, sizeof backend)) 1321 return -EFAULT; 1322 return vhost_net_set_backend(n, backend.index, backend.fd); 1323 case VHOST_GET_FEATURES: 1324 features = VHOST_NET_FEATURES; 1325 if (copy_to_user(featurep, &features, sizeof features)) 1326 return -EFAULT; 1327 return 0; 1328 case VHOST_SET_FEATURES: 1329 if (copy_from_user(&features, featurep, sizeof features)) 1330 return -EFAULT; 1331 if (features & ~VHOST_NET_FEATURES) 1332 return -EOPNOTSUPP; 1333 return vhost_net_set_features(n, features); 1334 case VHOST_RESET_OWNER: 1335 return vhost_net_reset_owner(n); 1336 case VHOST_SET_OWNER: 1337 return vhost_net_set_owner(n); 1338 default: 1339 mutex_lock(&n->dev.mutex); 1340 r = vhost_dev_ioctl(&n->dev, ioctl, argp); 1341 if (r == -ENOIOCTLCMD) 1342 r = vhost_vring_ioctl(&n->dev, ioctl, argp); 1343 else 1344 vhost_net_flush(n); 1345 mutex_unlock(&n->dev.mutex); 1346 return r; 1347 } 1348 } 1349 1350 #ifdef CONFIG_COMPAT 1351 static long vhost_net_compat_ioctl(struct file *f, unsigned int ioctl, 1352 unsigned long arg) 1353 { 1354 return vhost_net_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); 1355 } 1356 #endif 1357 1358 static ssize_t vhost_net_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) 1359 { 1360 struct file *file = iocb->ki_filp; 1361 struct vhost_net *n = file->private_data; 1362 struct vhost_dev *dev = &n->dev; 1363 int noblock = file->f_flags & O_NONBLOCK; 1364 1365 return vhost_chr_read_iter(dev, to, noblock); 1366 } 1367 1368 static ssize_t vhost_net_chr_write_iter(struct kiocb *iocb, 1369 struct iov_iter *from) 1370 { 1371 struct file *file = iocb->ki_filp; 1372 struct vhost_net *n = file->private_data; 1373 struct vhost_dev *dev = &n->dev; 1374 1375 return vhost_chr_write_iter(dev, from); 1376 } 1377 1378 static __poll_t vhost_net_chr_poll(struct file *file, poll_table *wait) 1379 { 1380 struct vhost_net *n = file->private_data; 1381 struct vhost_dev *dev = &n->dev; 1382 1383 return vhost_chr_poll(file, dev, wait); 1384 } 1385 1386 static const struct file_operations vhost_net_fops = { 1387 .owner = THIS_MODULE, 1388 .release = vhost_net_release, 1389 .read_iter = vhost_net_chr_read_iter, 1390 .write_iter = vhost_net_chr_write_iter, 1391 .poll = vhost_net_chr_poll, 1392 .unlocked_ioctl = vhost_net_ioctl, 1393 #ifdef CONFIG_COMPAT 1394 .compat_ioctl = vhost_net_compat_ioctl, 1395 #endif 1396 .open = vhost_net_open, 1397 .llseek = noop_llseek, 1398 }; 1399 1400 static struct miscdevice vhost_net_misc = { 1401 .minor = VHOST_NET_MINOR, 1402 .name = "vhost-net", 1403 .fops = &vhost_net_fops, 1404 }; 1405 1406 static int vhost_net_init(void) 1407 { 1408 if (experimental_zcopytx) 1409 vhost_net_enable_zcopy(VHOST_NET_VQ_TX); 1410 return misc_register(&vhost_net_misc); 1411 } 1412 module_init(vhost_net_init); 1413 1414 static void vhost_net_exit(void) 1415 { 1416 misc_deregister(&vhost_net_misc); 1417 } 1418 module_exit(vhost_net_exit); 1419 1420 MODULE_VERSION("0.0.1"); 1421 MODULE_LICENSE("GPL v2"); 1422 MODULE_AUTHOR("Michael S. Tsirkin"); 1423 MODULE_DESCRIPTION("Host kernel accelerator for virtio net"); 1424 MODULE_ALIAS_MISCDEV(VHOST_NET_MINOR); 1425 MODULE_ALIAS("devname:vhost-net"); 1426