1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * vhost transport for vsock 4 * 5 * Copyright (C) 2013-2015 Red Hat, Inc. 6 * Author: Asias He <asias@redhat.com> 7 * Stefan Hajnoczi <stefanha@redhat.com> 8 */ 9 #include <linux/miscdevice.h> 10 #include <linux/atomic.h> 11 #include <linux/module.h> 12 #include <linux/mutex.h> 13 #include <linux/vmalloc.h> 14 #include <net/sock.h> 15 #include <linux/virtio_vsock.h> 16 #include <linux/vhost.h> 17 #include <linux/hashtable.h> 18 19 #include <net/af_vsock.h> 20 #include "vhost.h" 21 22 #define VHOST_VSOCK_DEFAULT_HOST_CID 2 23 /* Max number of bytes transferred before requeueing the job. 24 * Using this limit prevents one virtqueue from starving others. */ 25 #define VHOST_VSOCK_WEIGHT 0x80000 26 /* Max number of packets transferred before requeueing the job. 27 * Using this limit prevents one virtqueue from starving others with 28 * small pkts. 29 */ 30 #define VHOST_VSOCK_PKT_WEIGHT 256 31 32 enum { 33 VHOST_VSOCK_FEATURES = VHOST_FEATURES | 34 (1ULL << VIRTIO_F_ACCESS_PLATFORM) | 35 (1ULL << VIRTIO_VSOCK_F_SEQPACKET) 36 }; 37 38 enum { 39 VHOST_VSOCK_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) 40 }; 41 42 /* Used to track all the vhost_vsock instances on the system. */ 43 static DEFINE_MUTEX(vhost_vsock_mutex); 44 static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8); 45 46 struct vhost_vsock { 47 struct vhost_dev dev; 48 struct vhost_virtqueue vqs[2]; 49 50 /* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */ 51 struct hlist_node hash; 52 53 struct vhost_work send_pkt_work; 54 spinlock_t send_pkt_list_lock; 55 struct list_head send_pkt_list; /* host->guest pending packets */ 56 57 atomic_t queued_replies; 58 59 u32 guest_cid; 60 bool seqpacket_allow; 61 }; 62 63 static u32 vhost_transport_get_local_cid(void) 64 { 65 return VHOST_VSOCK_DEFAULT_HOST_CID; 66 } 67 68 /* Callers that dereference the return value must hold vhost_vsock_mutex or the 69 * RCU read lock. 70 */ 71 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) 72 { 73 struct vhost_vsock *vsock; 74 75 hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) { 76 u32 other_cid = vsock->guest_cid; 77 78 /* Skip instances that have no CID yet */ 79 if (other_cid == 0) 80 continue; 81 82 if (other_cid == guest_cid) 83 return vsock; 84 85 } 86 87 return NULL; 88 } 89 90 static void 91 vhost_transport_do_send_pkt(struct vhost_vsock *vsock, 92 struct vhost_virtqueue *vq) 93 { 94 struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; 95 int pkts = 0, total_len = 0; 96 bool added = false; 97 bool restart_tx = false; 98 99 mutex_lock(&vq->mutex); 100 101 if (!vhost_vq_get_backend(vq)) 102 goto out; 103 104 if (!vq_meta_prefetch(vq)) 105 goto out; 106 107 /* Avoid further vmexits, we're already processing the virtqueue */ 108 vhost_disable_notify(&vsock->dev, vq); 109 110 do { 111 struct virtio_vsock_pkt *pkt; 112 struct iov_iter iov_iter; 113 unsigned out, in; 114 size_t nbytes; 115 size_t iov_len, payload_len; 116 int head; 117 bool restore_flag = false; 118 119 spin_lock_bh(&vsock->send_pkt_list_lock); 120 if (list_empty(&vsock->send_pkt_list)) { 121 spin_unlock_bh(&vsock->send_pkt_list_lock); 122 vhost_enable_notify(&vsock->dev, vq); 123 break; 124 } 125 126 pkt = list_first_entry(&vsock->send_pkt_list, 127 struct virtio_vsock_pkt, list); 128 list_del_init(&pkt->list); 129 spin_unlock_bh(&vsock->send_pkt_list_lock); 130 131 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), 132 &out, &in, NULL, NULL); 133 if (head < 0) { 134 spin_lock_bh(&vsock->send_pkt_list_lock); 135 list_add(&pkt->list, &vsock->send_pkt_list); 136 spin_unlock_bh(&vsock->send_pkt_list_lock); 137 break; 138 } 139 140 if (head == vq->num) { 141 spin_lock_bh(&vsock->send_pkt_list_lock); 142 list_add(&pkt->list, &vsock->send_pkt_list); 143 spin_unlock_bh(&vsock->send_pkt_list_lock); 144 145 /* We cannot finish yet if more buffers snuck in while 146 * re-enabling notify. 147 */ 148 if (unlikely(vhost_enable_notify(&vsock->dev, vq))) { 149 vhost_disable_notify(&vsock->dev, vq); 150 continue; 151 } 152 break; 153 } 154 155 if (out) { 156 virtio_transport_free_pkt(pkt); 157 vq_err(vq, "Expected 0 output buffers, got %u\n", out); 158 break; 159 } 160 161 iov_len = iov_length(&vq->iov[out], in); 162 if (iov_len < sizeof(pkt->hdr)) { 163 virtio_transport_free_pkt(pkt); 164 vq_err(vq, "Buffer len [%zu] too small\n", iov_len); 165 break; 166 } 167 168 iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len); 169 payload_len = pkt->len - pkt->off; 170 171 /* If the packet is greater than the space available in the 172 * buffer, we split it using multiple buffers. 173 */ 174 if (payload_len > iov_len - sizeof(pkt->hdr)) { 175 payload_len = iov_len - sizeof(pkt->hdr); 176 177 /* As we are copying pieces of large packet's buffer to 178 * small rx buffers, headers of packets in rx queue are 179 * created dynamically and are initialized with header 180 * of current packet(except length). But in case of 181 * SOCK_SEQPACKET, we also must clear record delimeter 182 * bit(VIRTIO_VSOCK_SEQ_EOR). Otherwise, instead of one 183 * packet with delimeter(which marks end of record), 184 * there will be sequence of packets with delimeter 185 * bit set. After initialized header will be copied to 186 * rx buffer, this bit will be restored. 187 */ 188 if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) { 189 pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR); 190 restore_flag = true; 191 } 192 } 193 194 /* Set the correct length in the header */ 195 pkt->hdr.len = cpu_to_le32(payload_len); 196 197 nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter); 198 if (nbytes != sizeof(pkt->hdr)) { 199 virtio_transport_free_pkt(pkt); 200 vq_err(vq, "Faulted on copying pkt hdr\n"); 201 break; 202 } 203 204 nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len, 205 &iov_iter); 206 if (nbytes != payload_len) { 207 virtio_transport_free_pkt(pkt); 208 vq_err(vq, "Faulted on copying pkt buf\n"); 209 break; 210 } 211 212 /* Deliver to monitoring devices all packets that we 213 * will transmit. 214 */ 215 virtio_transport_deliver_tap_pkt(pkt); 216 217 vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len); 218 added = true; 219 220 pkt->off += payload_len; 221 total_len += payload_len; 222 223 /* If we didn't send all the payload we can requeue the packet 224 * to send it with the next available buffer. 225 */ 226 if (pkt->off < pkt->len) { 227 if (restore_flag) 228 pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR); 229 230 /* We are queueing the same virtio_vsock_pkt to handle 231 * the remaining bytes, and we want to deliver it 232 * to monitoring devices in the next iteration. 233 */ 234 pkt->tap_delivered = false; 235 236 spin_lock_bh(&vsock->send_pkt_list_lock); 237 list_add(&pkt->list, &vsock->send_pkt_list); 238 spin_unlock_bh(&vsock->send_pkt_list_lock); 239 } else { 240 if (pkt->reply) { 241 int val; 242 243 val = atomic_dec_return(&vsock->queued_replies); 244 245 /* Do we have resources to resume tx 246 * processing? 247 */ 248 if (val + 1 == tx_vq->num) 249 restart_tx = true; 250 } 251 252 virtio_transport_free_pkt(pkt); 253 } 254 } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); 255 if (added) 256 vhost_signal(&vsock->dev, vq); 257 258 out: 259 mutex_unlock(&vq->mutex); 260 261 if (restart_tx) 262 vhost_poll_queue(&tx_vq->poll); 263 } 264 265 static void vhost_transport_send_pkt_work(struct vhost_work *work) 266 { 267 struct vhost_virtqueue *vq; 268 struct vhost_vsock *vsock; 269 270 vsock = container_of(work, struct vhost_vsock, send_pkt_work); 271 vq = &vsock->vqs[VSOCK_VQ_RX]; 272 273 vhost_transport_do_send_pkt(vsock, vq); 274 } 275 276 static int 277 vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt) 278 { 279 struct vhost_vsock *vsock; 280 int len = pkt->len; 281 282 rcu_read_lock(); 283 284 /* Find the vhost_vsock according to guest context id */ 285 vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid)); 286 if (!vsock) { 287 rcu_read_unlock(); 288 virtio_transport_free_pkt(pkt); 289 return -ENODEV; 290 } 291 292 if (pkt->reply) 293 atomic_inc(&vsock->queued_replies); 294 295 spin_lock_bh(&vsock->send_pkt_list_lock); 296 list_add_tail(&pkt->list, &vsock->send_pkt_list); 297 spin_unlock_bh(&vsock->send_pkt_list_lock); 298 299 vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); 300 301 rcu_read_unlock(); 302 return len; 303 } 304 305 static int 306 vhost_transport_cancel_pkt(struct vsock_sock *vsk) 307 { 308 struct vhost_vsock *vsock; 309 struct virtio_vsock_pkt *pkt, *n; 310 int cnt = 0; 311 int ret = -ENODEV; 312 LIST_HEAD(freeme); 313 314 rcu_read_lock(); 315 316 /* Find the vhost_vsock according to guest context id */ 317 vsock = vhost_vsock_get(vsk->remote_addr.svm_cid); 318 if (!vsock) 319 goto out; 320 321 spin_lock_bh(&vsock->send_pkt_list_lock); 322 list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) { 323 if (pkt->vsk != vsk) 324 continue; 325 list_move(&pkt->list, &freeme); 326 } 327 spin_unlock_bh(&vsock->send_pkt_list_lock); 328 329 list_for_each_entry_safe(pkt, n, &freeme, list) { 330 if (pkt->reply) 331 cnt++; 332 list_del(&pkt->list); 333 virtio_transport_free_pkt(pkt); 334 } 335 336 if (cnt) { 337 struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; 338 int new_cnt; 339 340 new_cnt = atomic_sub_return(cnt, &vsock->queued_replies); 341 if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num) 342 vhost_poll_queue(&tx_vq->poll); 343 } 344 345 ret = 0; 346 out: 347 rcu_read_unlock(); 348 return ret; 349 } 350 351 static struct virtio_vsock_pkt * 352 vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq, 353 unsigned int out, unsigned int in) 354 { 355 struct virtio_vsock_pkt *pkt; 356 struct iov_iter iov_iter; 357 size_t nbytes; 358 size_t len; 359 360 if (in != 0) { 361 vq_err(vq, "Expected 0 input buffers, got %u\n", in); 362 return NULL; 363 } 364 365 pkt = kzalloc(sizeof(*pkt), GFP_KERNEL); 366 if (!pkt) 367 return NULL; 368 369 len = iov_length(vq->iov, out); 370 iov_iter_init(&iov_iter, WRITE, vq->iov, out, len); 371 372 nbytes = copy_from_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter); 373 if (nbytes != sizeof(pkt->hdr)) { 374 vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n", 375 sizeof(pkt->hdr), nbytes); 376 kfree(pkt); 377 return NULL; 378 } 379 380 pkt->len = le32_to_cpu(pkt->hdr.len); 381 382 /* No payload */ 383 if (!pkt->len) 384 return pkt; 385 386 /* The pkt is too big */ 387 if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) { 388 kfree(pkt); 389 return NULL; 390 } 391 392 pkt->buf = kmalloc(pkt->len, GFP_KERNEL); 393 if (!pkt->buf) { 394 kfree(pkt); 395 return NULL; 396 } 397 398 pkt->buf_len = pkt->len; 399 400 nbytes = copy_from_iter(pkt->buf, pkt->len, &iov_iter); 401 if (nbytes != pkt->len) { 402 vq_err(vq, "Expected %u byte payload, got %zu bytes\n", 403 pkt->len, nbytes); 404 virtio_transport_free_pkt(pkt); 405 return NULL; 406 } 407 408 return pkt; 409 } 410 411 /* Is there space left for replies to rx packets? */ 412 static bool vhost_vsock_more_replies(struct vhost_vsock *vsock) 413 { 414 struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX]; 415 int val; 416 417 smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */ 418 val = atomic_read(&vsock->queued_replies); 419 420 return val < vq->num; 421 } 422 423 static bool vhost_transport_seqpacket_allow(u32 remote_cid); 424 425 static struct virtio_transport vhost_transport = { 426 .transport = { 427 .module = THIS_MODULE, 428 429 .get_local_cid = vhost_transport_get_local_cid, 430 431 .init = virtio_transport_do_socket_init, 432 .destruct = virtio_transport_destruct, 433 .release = virtio_transport_release, 434 .connect = virtio_transport_connect, 435 .shutdown = virtio_transport_shutdown, 436 .cancel_pkt = vhost_transport_cancel_pkt, 437 438 .dgram_enqueue = virtio_transport_dgram_enqueue, 439 .dgram_dequeue = virtio_transport_dgram_dequeue, 440 .dgram_bind = virtio_transport_dgram_bind, 441 .dgram_allow = virtio_transport_dgram_allow, 442 443 .stream_enqueue = virtio_transport_stream_enqueue, 444 .stream_dequeue = virtio_transport_stream_dequeue, 445 .stream_has_data = virtio_transport_stream_has_data, 446 .stream_has_space = virtio_transport_stream_has_space, 447 .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, 448 .stream_is_active = virtio_transport_stream_is_active, 449 .stream_allow = virtio_transport_stream_allow, 450 451 .seqpacket_dequeue = virtio_transport_seqpacket_dequeue, 452 .seqpacket_enqueue = virtio_transport_seqpacket_enqueue, 453 .seqpacket_allow = vhost_transport_seqpacket_allow, 454 .seqpacket_has_data = virtio_transport_seqpacket_has_data, 455 456 .notify_poll_in = virtio_transport_notify_poll_in, 457 .notify_poll_out = virtio_transport_notify_poll_out, 458 .notify_recv_init = virtio_transport_notify_recv_init, 459 .notify_recv_pre_block = virtio_transport_notify_recv_pre_block, 460 .notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue, 461 .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue, 462 .notify_send_init = virtio_transport_notify_send_init, 463 .notify_send_pre_block = virtio_transport_notify_send_pre_block, 464 .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, 465 .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, 466 .notify_buffer_size = virtio_transport_notify_buffer_size, 467 468 }, 469 470 .send_pkt = vhost_transport_send_pkt, 471 }; 472 473 static bool vhost_transport_seqpacket_allow(u32 remote_cid) 474 { 475 struct vhost_vsock *vsock; 476 bool seqpacket_allow = false; 477 478 rcu_read_lock(); 479 vsock = vhost_vsock_get(remote_cid); 480 481 if (vsock) 482 seqpacket_allow = vsock->seqpacket_allow; 483 484 rcu_read_unlock(); 485 486 return seqpacket_allow; 487 } 488 489 static void vhost_vsock_handle_tx_kick(struct vhost_work *work) 490 { 491 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, 492 poll.work); 493 struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock, 494 dev); 495 struct virtio_vsock_pkt *pkt; 496 int head, pkts = 0, total_len = 0; 497 unsigned int out, in; 498 bool added = false; 499 500 mutex_lock(&vq->mutex); 501 502 if (!vhost_vq_get_backend(vq)) 503 goto out; 504 505 if (!vq_meta_prefetch(vq)) 506 goto out; 507 508 vhost_disable_notify(&vsock->dev, vq); 509 do { 510 u32 len; 511 512 if (!vhost_vsock_more_replies(vsock)) { 513 /* Stop tx until the device processes already 514 * pending replies. Leave tx virtqueue 515 * callbacks disabled. 516 */ 517 goto no_more_replies; 518 } 519 520 head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), 521 &out, &in, NULL, NULL); 522 if (head < 0) 523 break; 524 525 if (head == vq->num) { 526 if (unlikely(vhost_enable_notify(&vsock->dev, vq))) { 527 vhost_disable_notify(&vsock->dev, vq); 528 continue; 529 } 530 break; 531 } 532 533 pkt = vhost_vsock_alloc_pkt(vq, out, in); 534 if (!pkt) { 535 vq_err(vq, "Faulted on pkt\n"); 536 continue; 537 } 538 539 len = pkt->len; 540 541 /* Deliver to monitoring devices all received packets */ 542 virtio_transport_deliver_tap_pkt(pkt); 543 544 /* Only accept correctly addressed packets */ 545 if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid && 546 le64_to_cpu(pkt->hdr.dst_cid) == 547 vhost_transport_get_local_cid()) 548 virtio_transport_recv_pkt(&vhost_transport, pkt); 549 else 550 virtio_transport_free_pkt(pkt); 551 552 len += sizeof(pkt->hdr); 553 vhost_add_used(vq, head, len); 554 total_len += len; 555 added = true; 556 } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); 557 558 no_more_replies: 559 if (added) 560 vhost_signal(&vsock->dev, vq); 561 562 out: 563 mutex_unlock(&vq->mutex); 564 } 565 566 static void vhost_vsock_handle_rx_kick(struct vhost_work *work) 567 { 568 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, 569 poll.work); 570 struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock, 571 dev); 572 573 vhost_transport_do_send_pkt(vsock, vq); 574 } 575 576 static int vhost_vsock_start(struct vhost_vsock *vsock) 577 { 578 struct vhost_virtqueue *vq; 579 size_t i; 580 int ret; 581 582 mutex_lock(&vsock->dev.mutex); 583 584 ret = vhost_dev_check_owner(&vsock->dev); 585 if (ret) 586 goto err; 587 588 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { 589 vq = &vsock->vqs[i]; 590 591 mutex_lock(&vq->mutex); 592 593 if (!vhost_vq_access_ok(vq)) { 594 ret = -EFAULT; 595 goto err_vq; 596 } 597 598 if (!vhost_vq_get_backend(vq)) { 599 vhost_vq_set_backend(vq, vsock); 600 ret = vhost_vq_init_access(vq); 601 if (ret) 602 goto err_vq; 603 } 604 605 mutex_unlock(&vq->mutex); 606 } 607 608 /* Some packets may have been queued before the device was started, 609 * let's kick the send worker to send them. 610 */ 611 vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); 612 613 mutex_unlock(&vsock->dev.mutex); 614 return 0; 615 616 err_vq: 617 vhost_vq_set_backend(vq, NULL); 618 mutex_unlock(&vq->mutex); 619 620 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { 621 vq = &vsock->vqs[i]; 622 623 mutex_lock(&vq->mutex); 624 vhost_vq_set_backend(vq, NULL); 625 mutex_unlock(&vq->mutex); 626 } 627 err: 628 mutex_unlock(&vsock->dev.mutex); 629 return ret; 630 } 631 632 static int vhost_vsock_stop(struct vhost_vsock *vsock) 633 { 634 size_t i; 635 int ret; 636 637 mutex_lock(&vsock->dev.mutex); 638 639 ret = vhost_dev_check_owner(&vsock->dev); 640 if (ret) 641 goto err; 642 643 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { 644 struct vhost_virtqueue *vq = &vsock->vqs[i]; 645 646 mutex_lock(&vq->mutex); 647 vhost_vq_set_backend(vq, NULL); 648 mutex_unlock(&vq->mutex); 649 } 650 651 err: 652 mutex_unlock(&vsock->dev.mutex); 653 return ret; 654 } 655 656 static void vhost_vsock_free(struct vhost_vsock *vsock) 657 { 658 kvfree(vsock); 659 } 660 661 static int vhost_vsock_dev_open(struct inode *inode, struct file *file) 662 { 663 struct vhost_virtqueue **vqs; 664 struct vhost_vsock *vsock; 665 int ret; 666 667 /* This struct is large and allocation could fail, fall back to vmalloc 668 * if there is no other way. 669 */ 670 vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL); 671 if (!vsock) 672 return -ENOMEM; 673 674 vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL); 675 if (!vqs) { 676 ret = -ENOMEM; 677 goto out; 678 } 679 680 vsock->guest_cid = 0; /* no CID assigned yet */ 681 682 atomic_set(&vsock->queued_replies, 0); 683 684 vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX]; 685 vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX]; 686 vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick; 687 vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick; 688 689 vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs), 690 UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT, 691 VHOST_VSOCK_WEIGHT, true, NULL); 692 693 file->private_data = vsock; 694 spin_lock_init(&vsock->send_pkt_list_lock); 695 INIT_LIST_HEAD(&vsock->send_pkt_list); 696 vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work); 697 return 0; 698 699 out: 700 vhost_vsock_free(vsock); 701 return ret; 702 } 703 704 static void vhost_vsock_flush(struct vhost_vsock *vsock) 705 { 706 int i; 707 708 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) 709 if (vsock->vqs[i].handle_kick) 710 vhost_poll_flush(&vsock->vqs[i].poll); 711 vhost_work_dev_flush(&vsock->dev); 712 } 713 714 static void vhost_vsock_reset_orphans(struct sock *sk) 715 { 716 struct vsock_sock *vsk = vsock_sk(sk); 717 718 /* vmci_transport.c doesn't take sk_lock here either. At least we're 719 * under vsock_table_lock so the sock cannot disappear while we're 720 * executing. 721 */ 722 723 /* If the peer is still valid, no need to reset connection */ 724 if (vhost_vsock_get(vsk->remote_addr.svm_cid)) 725 return; 726 727 /* If the close timeout is pending, let it expire. This avoids races 728 * with the timeout callback. 729 */ 730 if (vsk->close_work_scheduled) 731 return; 732 733 sock_set_flag(sk, SOCK_DONE); 734 vsk->peer_shutdown = SHUTDOWN_MASK; 735 sk->sk_state = SS_UNCONNECTED; 736 sk->sk_err = ECONNRESET; 737 sk_error_report(sk); 738 } 739 740 static int vhost_vsock_dev_release(struct inode *inode, struct file *file) 741 { 742 struct vhost_vsock *vsock = file->private_data; 743 744 mutex_lock(&vhost_vsock_mutex); 745 if (vsock->guest_cid) 746 hash_del_rcu(&vsock->hash); 747 mutex_unlock(&vhost_vsock_mutex); 748 749 /* Wait for other CPUs to finish using vsock */ 750 synchronize_rcu(); 751 752 /* Iterating over all connections for all CIDs to find orphans is 753 * inefficient. Room for improvement here. */ 754 vsock_for_each_connected_socket(vhost_vsock_reset_orphans); 755 756 vhost_vsock_stop(vsock); 757 vhost_vsock_flush(vsock); 758 vhost_dev_stop(&vsock->dev); 759 760 spin_lock_bh(&vsock->send_pkt_list_lock); 761 while (!list_empty(&vsock->send_pkt_list)) { 762 struct virtio_vsock_pkt *pkt; 763 764 pkt = list_first_entry(&vsock->send_pkt_list, 765 struct virtio_vsock_pkt, list); 766 list_del_init(&pkt->list); 767 virtio_transport_free_pkt(pkt); 768 } 769 spin_unlock_bh(&vsock->send_pkt_list_lock); 770 771 vhost_dev_cleanup(&vsock->dev); 772 kfree(vsock->dev.vqs); 773 vhost_vsock_free(vsock); 774 return 0; 775 } 776 777 static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid) 778 { 779 struct vhost_vsock *other; 780 781 /* Refuse reserved CIDs */ 782 if (guest_cid <= VMADDR_CID_HOST || 783 guest_cid == U32_MAX) 784 return -EINVAL; 785 786 /* 64-bit CIDs are not yet supported */ 787 if (guest_cid > U32_MAX) 788 return -EINVAL; 789 790 /* Refuse if CID is assigned to the guest->host transport (i.e. nested 791 * VM), to make the loopback work. 792 */ 793 if (vsock_find_cid(guest_cid)) 794 return -EADDRINUSE; 795 796 /* Refuse if CID is already in use */ 797 mutex_lock(&vhost_vsock_mutex); 798 other = vhost_vsock_get(guest_cid); 799 if (other && other != vsock) { 800 mutex_unlock(&vhost_vsock_mutex); 801 return -EADDRINUSE; 802 } 803 804 if (vsock->guest_cid) 805 hash_del_rcu(&vsock->hash); 806 807 vsock->guest_cid = guest_cid; 808 hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid); 809 mutex_unlock(&vhost_vsock_mutex); 810 811 return 0; 812 } 813 814 static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features) 815 { 816 struct vhost_virtqueue *vq; 817 int i; 818 819 if (features & ~VHOST_VSOCK_FEATURES) 820 return -EOPNOTSUPP; 821 822 mutex_lock(&vsock->dev.mutex); 823 if ((features & (1 << VHOST_F_LOG_ALL)) && 824 !vhost_log_access_ok(&vsock->dev)) { 825 goto err; 826 } 827 828 if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) { 829 if (vhost_init_device_iotlb(&vsock->dev, true)) 830 goto err; 831 } 832 833 if (features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET)) 834 vsock->seqpacket_allow = true; 835 836 for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { 837 vq = &vsock->vqs[i]; 838 mutex_lock(&vq->mutex); 839 vq->acked_features = features; 840 mutex_unlock(&vq->mutex); 841 } 842 mutex_unlock(&vsock->dev.mutex); 843 return 0; 844 845 err: 846 mutex_unlock(&vsock->dev.mutex); 847 return -EFAULT; 848 } 849 850 static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, 851 unsigned long arg) 852 { 853 struct vhost_vsock *vsock = f->private_data; 854 void __user *argp = (void __user *)arg; 855 u64 guest_cid; 856 u64 features; 857 int start; 858 int r; 859 860 switch (ioctl) { 861 case VHOST_VSOCK_SET_GUEST_CID: 862 if (copy_from_user(&guest_cid, argp, sizeof(guest_cid))) 863 return -EFAULT; 864 return vhost_vsock_set_cid(vsock, guest_cid); 865 case VHOST_VSOCK_SET_RUNNING: 866 if (copy_from_user(&start, argp, sizeof(start))) 867 return -EFAULT; 868 if (start) 869 return vhost_vsock_start(vsock); 870 else 871 return vhost_vsock_stop(vsock); 872 case VHOST_GET_FEATURES: 873 features = VHOST_VSOCK_FEATURES; 874 if (copy_to_user(argp, &features, sizeof(features))) 875 return -EFAULT; 876 return 0; 877 case VHOST_SET_FEATURES: 878 if (copy_from_user(&features, argp, sizeof(features))) 879 return -EFAULT; 880 return vhost_vsock_set_features(vsock, features); 881 case VHOST_GET_BACKEND_FEATURES: 882 features = VHOST_VSOCK_BACKEND_FEATURES; 883 if (copy_to_user(argp, &features, sizeof(features))) 884 return -EFAULT; 885 return 0; 886 case VHOST_SET_BACKEND_FEATURES: 887 if (copy_from_user(&features, argp, sizeof(features))) 888 return -EFAULT; 889 if (features & ~VHOST_VSOCK_BACKEND_FEATURES) 890 return -EOPNOTSUPP; 891 vhost_set_backend_features(&vsock->dev, features); 892 return 0; 893 default: 894 mutex_lock(&vsock->dev.mutex); 895 r = vhost_dev_ioctl(&vsock->dev, ioctl, argp); 896 if (r == -ENOIOCTLCMD) 897 r = vhost_vring_ioctl(&vsock->dev, ioctl, argp); 898 else 899 vhost_vsock_flush(vsock); 900 mutex_unlock(&vsock->dev.mutex); 901 return r; 902 } 903 } 904 905 static ssize_t vhost_vsock_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) 906 { 907 struct file *file = iocb->ki_filp; 908 struct vhost_vsock *vsock = file->private_data; 909 struct vhost_dev *dev = &vsock->dev; 910 int noblock = file->f_flags & O_NONBLOCK; 911 912 return vhost_chr_read_iter(dev, to, noblock); 913 } 914 915 static ssize_t vhost_vsock_chr_write_iter(struct kiocb *iocb, 916 struct iov_iter *from) 917 { 918 struct file *file = iocb->ki_filp; 919 struct vhost_vsock *vsock = file->private_data; 920 struct vhost_dev *dev = &vsock->dev; 921 922 return vhost_chr_write_iter(dev, from); 923 } 924 925 static __poll_t vhost_vsock_chr_poll(struct file *file, poll_table *wait) 926 { 927 struct vhost_vsock *vsock = file->private_data; 928 struct vhost_dev *dev = &vsock->dev; 929 930 return vhost_chr_poll(file, dev, wait); 931 } 932 933 static const struct file_operations vhost_vsock_fops = { 934 .owner = THIS_MODULE, 935 .open = vhost_vsock_dev_open, 936 .release = vhost_vsock_dev_release, 937 .llseek = noop_llseek, 938 .unlocked_ioctl = vhost_vsock_dev_ioctl, 939 .compat_ioctl = compat_ptr_ioctl, 940 .read_iter = vhost_vsock_chr_read_iter, 941 .write_iter = vhost_vsock_chr_write_iter, 942 .poll = vhost_vsock_chr_poll, 943 }; 944 945 static struct miscdevice vhost_vsock_misc = { 946 .minor = VHOST_VSOCK_MINOR, 947 .name = "vhost-vsock", 948 .fops = &vhost_vsock_fops, 949 }; 950 951 static int __init vhost_vsock_init(void) 952 { 953 int ret; 954 955 ret = vsock_core_register(&vhost_transport.transport, 956 VSOCK_TRANSPORT_F_H2G); 957 if (ret < 0) 958 return ret; 959 return misc_register(&vhost_vsock_misc); 960 }; 961 962 static void __exit vhost_vsock_exit(void) 963 { 964 misc_deregister(&vhost_vsock_misc); 965 vsock_core_unregister(&vhost_transport.transport); 966 }; 967 968 module_init(vhost_vsock_init); 969 module_exit(vhost_vsock_exit); 970 MODULE_LICENSE("GPL v2"); 971 MODULE_AUTHOR("Asias He"); 972 MODULE_DESCRIPTION("vhost transport for vsock "); 973 MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR); 974 MODULE_ALIAS("devname:vhost-vsock"); 975