1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Hyper-V transport for vsock 4 * 5 * Hyper-V Sockets supplies a byte-stream based communication mechanism 6 * between the host and the VM. This driver implements the necessary 7 * support in the VM by introducing the new vsock transport. 8 * 9 * Copyright (c) 2017, Microsoft Corporation. 10 */ 11 #include <linux/module.h> 12 #include <linux/vmalloc.h> 13 #include <linux/hyperv.h> 14 #include <net/sock.h> 15 #include <net/af_vsock.h> 16 #include <asm/hyperv-tlfs.h> 17 18 /* Older (VMBUS version 'VERSION_WIN10' or before) Windows hosts have some 19 * stricter requirements on the hv_sock ring buffer size of six 4K pages. 20 * hyperv-tlfs defines HV_HYP_PAGE_SIZE as 4K. Newer hosts don't have this 21 * limitation; but, keep the defaults the same for compat. 22 */ 23 #define RINGBUFFER_HVS_RCV_SIZE (HV_HYP_PAGE_SIZE * 6) 24 #define RINGBUFFER_HVS_SND_SIZE (HV_HYP_PAGE_SIZE * 6) 25 #define RINGBUFFER_HVS_MAX_SIZE (HV_HYP_PAGE_SIZE * 64) 26 27 /* The MTU is 16KB per the host side's design */ 28 #define HVS_MTU_SIZE (1024 * 16) 29 30 /* How long to wait for graceful shutdown of a connection */ 31 #define HVS_CLOSE_TIMEOUT (8 * HZ) 32 33 struct vmpipe_proto_header { 34 u32 pkt_type; 35 u32 data_size; 36 }; 37 38 /* For recv, we use the VMBus in-place packet iterator APIs to directly copy 39 * data from the ringbuffer into the userspace buffer. 40 */ 41 struct hvs_recv_buf { 42 /* The header before the payload data */ 43 struct vmpipe_proto_header hdr; 44 45 /* The payload */ 46 u8 data[HVS_MTU_SIZE]; 47 }; 48 49 /* We can send up to HVS_MTU_SIZE bytes of payload to the host, but let's use 50 * a smaller size, i.e. HVS_SEND_BUF_SIZE, to maximize concurrency between the 51 * guest and the host processing as one VMBUS packet is the smallest processing 52 * unit. 53 * 54 * Note: the buffer can be eliminated in the future when we add new VMBus 55 * ringbuffer APIs that allow us to directly copy data from userspace buffer 56 * to VMBus ringbuffer. 57 */ 58 #define HVS_SEND_BUF_SIZE \ 59 (HV_HYP_PAGE_SIZE - sizeof(struct vmpipe_proto_header)) 60 61 struct hvs_send_buf { 62 /* The header before the payload data */ 63 struct vmpipe_proto_header hdr; 64 65 /* The payload */ 66 u8 data[HVS_SEND_BUF_SIZE]; 67 }; 68 69 #define HVS_HEADER_LEN (sizeof(struct vmpacket_descriptor) + \ 70 sizeof(struct vmpipe_proto_header)) 71 72 /* See 'prev_indices' in hv_ringbuffer_read(), hv_ringbuffer_write(), and 73 * __hv_pkt_iter_next(). 74 */ 75 #define VMBUS_PKT_TRAILER_SIZE (sizeof(u64)) 76 77 #define HVS_PKT_LEN(payload_len) (HVS_HEADER_LEN + \ 78 ALIGN((payload_len), 8) + \ 79 VMBUS_PKT_TRAILER_SIZE) 80 81 union hvs_service_id { 82 guid_t srv_id; 83 84 struct { 85 unsigned int svm_port; 86 unsigned char b[sizeof(guid_t) - sizeof(unsigned int)]; 87 }; 88 }; 89 90 /* Per-socket state (accessed via vsk->trans) */ 91 struct hvsock { 92 struct vsock_sock *vsk; 93 94 guid_t vm_srv_id; 95 guid_t host_srv_id; 96 97 struct vmbus_channel *chan; 98 struct vmpacket_descriptor *recv_desc; 99 100 /* The length of the payload not delivered to userland yet */ 101 u32 recv_data_len; 102 /* The offset of the payload */ 103 u32 recv_data_off; 104 105 /* Have we sent the zero-length packet (FIN)? */ 106 bool fin_sent; 107 }; 108 109 /* In the VM, we support Hyper-V Sockets with AF_VSOCK, and the endpoint is 110 * <cid, port> (see struct sockaddr_vm). Note: cid is not really used here: 111 * when we write apps to connect to the host, we can only use VMADDR_CID_ANY 112 * or VMADDR_CID_HOST (both are equivalent) as the remote cid, and when we 113 * write apps to bind() & listen() in the VM, we can only use VMADDR_CID_ANY 114 * as the local cid. 115 * 116 * On the host, Hyper-V Sockets are supported by Winsock AF_HYPERV: 117 * https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user- 118 * guide/make-integration-service, and the endpoint is <VmID, ServiceId> with 119 * the below sockaddr: 120 * 121 * struct SOCKADDR_HV 122 * { 123 * ADDRESS_FAMILY Family; 124 * USHORT Reserved; 125 * GUID VmId; 126 * GUID ServiceId; 127 * }; 128 * Note: VmID is not used by Linux VM and actually it isn't transmitted via 129 * VMBus, because here it's obvious the host and the VM can easily identify 130 * each other. Though the VmID is useful on the host, especially in the case 131 * of Windows container, Linux VM doesn't need it at all. 132 * 133 * To make use of the AF_VSOCK infrastructure in Linux VM, we have to limit 134 * the available GUID space of SOCKADDR_HV so that we can create a mapping 135 * between AF_VSOCK port and SOCKADDR_HV Service GUID. The rule of writing 136 * Hyper-V Sockets apps on the host and in Linux VM is: 137 * 138 **************************************************************************** 139 * The only valid Service GUIDs, from the perspectives of both the host and * 140 * Linux VM, that can be connected by the other end, must conform to this * 141 * format: <port>-facb-11e6-bd58-64006a7986d3. * 142 **************************************************************************** 143 * 144 * When we write apps on the host to connect(), the GUID ServiceID is used. 145 * When we write apps in Linux VM to connect(), we only need to specify the 146 * port and the driver will form the GUID and use that to request the host. 147 * 148 */ 149 150 /* 00000000-facb-11e6-bd58-64006a7986d3 */ 151 static const guid_t srv_id_template = 152 GUID_INIT(0x00000000, 0xfacb, 0x11e6, 0xbd, 0x58, 153 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3); 154 155 static bool hvs_check_transport(struct vsock_sock *vsk); 156 157 static bool is_valid_srv_id(const guid_t *id) 158 { 159 return !memcmp(&id->b[4], &srv_id_template.b[4], sizeof(guid_t) - 4); 160 } 161 162 static unsigned int get_port_by_srv_id(const guid_t *svr_id) 163 { 164 return *((unsigned int *)svr_id); 165 } 166 167 static void hvs_addr_init(struct sockaddr_vm *addr, const guid_t *svr_id) 168 { 169 unsigned int port = get_port_by_srv_id(svr_id); 170 171 vsock_addr_init(addr, VMADDR_CID_ANY, port); 172 } 173 174 static void hvs_set_channel_pending_send_size(struct vmbus_channel *chan) 175 { 176 set_channel_pending_send_size(chan, 177 HVS_PKT_LEN(HVS_SEND_BUF_SIZE)); 178 179 virt_mb(); 180 } 181 182 static bool hvs_channel_readable(struct vmbus_channel *chan) 183 { 184 u32 readable = hv_get_bytes_to_read(&chan->inbound); 185 186 /* 0-size payload means FIN */ 187 return readable >= HVS_PKT_LEN(0); 188 } 189 190 static int hvs_channel_readable_payload(struct vmbus_channel *chan) 191 { 192 u32 readable = hv_get_bytes_to_read(&chan->inbound); 193 194 if (readable > HVS_PKT_LEN(0)) { 195 /* At least we have 1 byte to read. We don't need to return 196 * the exact readable bytes: see vsock_stream_recvmsg() -> 197 * vsock_stream_has_data(). 198 */ 199 return 1; 200 } 201 202 if (readable == HVS_PKT_LEN(0)) { 203 /* 0-size payload means FIN */ 204 return 0; 205 } 206 207 /* No payload or FIN */ 208 return -1; 209 } 210 211 static size_t hvs_channel_writable_bytes(struct vmbus_channel *chan) 212 { 213 u32 writeable = hv_get_bytes_to_write(&chan->outbound); 214 size_t ret; 215 216 /* The ringbuffer mustn't be 100% full, and we should reserve a 217 * zero-length-payload packet for the FIN: see hv_ringbuffer_write() 218 * and hvs_shutdown(). 219 */ 220 if (writeable <= HVS_PKT_LEN(1) + HVS_PKT_LEN(0)) 221 return 0; 222 223 ret = writeable - HVS_PKT_LEN(1) - HVS_PKT_LEN(0); 224 225 return round_down(ret, 8); 226 } 227 228 static int hvs_send_data(struct vmbus_channel *chan, 229 struct hvs_send_buf *send_buf, size_t to_write) 230 { 231 send_buf->hdr.pkt_type = 1; 232 send_buf->hdr.data_size = to_write; 233 return vmbus_sendpacket(chan, &send_buf->hdr, 234 sizeof(send_buf->hdr) + to_write, 235 0, VM_PKT_DATA_INBAND, 0); 236 } 237 238 static void hvs_channel_cb(void *ctx) 239 { 240 struct sock *sk = (struct sock *)ctx; 241 struct vsock_sock *vsk = vsock_sk(sk); 242 struct hvsock *hvs = vsk->trans; 243 struct vmbus_channel *chan = hvs->chan; 244 245 if (hvs_channel_readable(chan)) 246 sk->sk_data_ready(sk); 247 248 if (hv_get_bytes_to_write(&chan->outbound) > 0) 249 sk->sk_write_space(sk); 250 } 251 252 static void hvs_do_close_lock_held(struct vsock_sock *vsk, 253 bool cancel_timeout) 254 { 255 struct sock *sk = sk_vsock(vsk); 256 257 sock_set_flag(sk, SOCK_DONE); 258 vsk->peer_shutdown = SHUTDOWN_MASK; 259 if (vsock_stream_has_data(vsk) <= 0) 260 sk->sk_state = TCP_CLOSING; 261 sk->sk_state_change(sk); 262 if (vsk->close_work_scheduled && 263 (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) { 264 vsk->close_work_scheduled = false; 265 vsock_remove_sock(vsk); 266 267 /* Release the reference taken while scheduling the timeout */ 268 sock_put(sk); 269 } 270 } 271 272 static void hvs_close_connection(struct vmbus_channel *chan) 273 { 274 struct sock *sk = get_per_channel_state(chan); 275 276 lock_sock(sk); 277 hvs_do_close_lock_held(vsock_sk(sk), true); 278 release_sock(sk); 279 280 /* Release the refcnt for the channel that's opened in 281 * hvs_open_connection(). 282 */ 283 sock_put(sk); 284 } 285 286 static void hvs_open_connection(struct vmbus_channel *chan) 287 { 288 guid_t *if_instance, *if_type; 289 unsigned char conn_from_host; 290 291 struct sockaddr_vm addr; 292 struct sock *sk, *new = NULL; 293 struct vsock_sock *vnew = NULL; 294 struct hvsock *hvs = NULL; 295 struct hvsock *hvs_new = NULL; 296 int rcvbuf; 297 int ret; 298 int sndbuf; 299 300 if_type = &chan->offermsg.offer.if_type; 301 if_instance = &chan->offermsg.offer.if_instance; 302 conn_from_host = chan->offermsg.offer.u.pipe.user_def[0]; 303 if (!is_valid_srv_id(if_type)) 304 return; 305 306 hvs_addr_init(&addr, conn_from_host ? if_type : if_instance); 307 sk = vsock_find_bound_socket(&addr); 308 if (!sk) 309 return; 310 311 lock_sock(sk); 312 if ((conn_from_host && sk->sk_state != TCP_LISTEN) || 313 (!conn_from_host && sk->sk_state != TCP_SYN_SENT)) 314 goto out; 315 316 if (conn_from_host) { 317 if (sk->sk_ack_backlog >= sk->sk_max_ack_backlog) 318 goto out; 319 320 new = vsock_create_connected(sk); 321 if (!new) 322 goto out; 323 324 new->sk_state = TCP_SYN_SENT; 325 vnew = vsock_sk(new); 326 327 hvs_addr_init(&vnew->local_addr, if_type); 328 329 /* Remote peer is always the host */ 330 vsock_addr_init(&vnew->remote_addr, 331 VMADDR_CID_HOST, VMADDR_PORT_ANY); 332 vnew->remote_addr.svm_port = get_port_by_srv_id(if_instance); 333 ret = vsock_assign_transport(vnew, vsock_sk(sk)); 334 /* Transport assigned (looking at remote_addr) must be the 335 * same where we received the request. 336 */ 337 if (ret || !hvs_check_transport(vnew)) { 338 sock_put(new); 339 goto out; 340 } 341 hvs_new = vnew->trans; 342 hvs_new->chan = chan; 343 } else { 344 hvs = vsock_sk(sk)->trans; 345 hvs->chan = chan; 346 } 347 348 set_channel_read_mode(chan, HV_CALL_DIRECT); 349 350 /* Use the socket buffer sizes as hints for the VMBUS ring size. For 351 * server side sockets, 'sk' is the parent socket and thus, this will 352 * allow the child sockets to inherit the size from the parent. Keep 353 * the mins to the default value and align to page size as per VMBUS 354 * requirements. 355 * For the max, the socket core library will limit the socket buffer 356 * size that can be set by the user, but, since currently, the hv_sock 357 * VMBUS ring buffer is physically contiguous allocation, restrict it 358 * further. 359 * Older versions of hv_sock host side code cannot handle bigger VMBUS 360 * ring buffer size. Use the version number to limit the change to newer 361 * versions. 362 */ 363 if (vmbus_proto_version < VERSION_WIN10_V5) { 364 sndbuf = RINGBUFFER_HVS_SND_SIZE; 365 rcvbuf = RINGBUFFER_HVS_RCV_SIZE; 366 } else { 367 sndbuf = max_t(int, sk->sk_sndbuf, RINGBUFFER_HVS_SND_SIZE); 368 sndbuf = min_t(int, sndbuf, RINGBUFFER_HVS_MAX_SIZE); 369 sndbuf = ALIGN(sndbuf, HV_HYP_PAGE_SIZE); 370 rcvbuf = max_t(int, sk->sk_rcvbuf, RINGBUFFER_HVS_RCV_SIZE); 371 rcvbuf = min_t(int, rcvbuf, RINGBUFFER_HVS_MAX_SIZE); 372 rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE); 373 } 374 375 ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb, 376 conn_from_host ? new : sk); 377 if (ret != 0) { 378 if (conn_from_host) { 379 hvs_new->chan = NULL; 380 sock_put(new); 381 } else { 382 hvs->chan = NULL; 383 } 384 goto out; 385 } 386 387 set_per_channel_state(chan, conn_from_host ? new : sk); 388 389 /* This reference will be dropped by hvs_close_connection(). */ 390 sock_hold(conn_from_host ? new : sk); 391 vmbus_set_chn_rescind_callback(chan, hvs_close_connection); 392 393 /* Set the pending send size to max packet size to always get 394 * notifications from the host when there is enough writable space. 395 * The host is optimized to send notifications only when the pending 396 * size boundary is crossed, and not always. 397 */ 398 hvs_set_channel_pending_send_size(chan); 399 400 if (conn_from_host) { 401 new->sk_state = TCP_ESTABLISHED; 402 sk_acceptq_added(sk); 403 404 hvs_new->vm_srv_id = *if_type; 405 hvs_new->host_srv_id = *if_instance; 406 407 vsock_insert_connected(vnew); 408 409 vsock_enqueue_accept(sk, new); 410 } else { 411 sk->sk_state = TCP_ESTABLISHED; 412 sk->sk_socket->state = SS_CONNECTED; 413 414 vsock_insert_connected(vsock_sk(sk)); 415 } 416 417 sk->sk_state_change(sk); 418 419 out: 420 /* Release refcnt obtained when we called vsock_find_bound_socket() */ 421 sock_put(sk); 422 423 release_sock(sk); 424 } 425 426 static u32 hvs_get_local_cid(void) 427 { 428 return VMADDR_CID_ANY; 429 } 430 431 static int hvs_sock_init(struct vsock_sock *vsk, struct vsock_sock *psk) 432 { 433 struct hvsock *hvs; 434 struct sock *sk = sk_vsock(vsk); 435 436 hvs = kzalloc(sizeof(*hvs), GFP_KERNEL); 437 if (!hvs) 438 return -ENOMEM; 439 440 vsk->trans = hvs; 441 hvs->vsk = vsk; 442 sk->sk_sndbuf = RINGBUFFER_HVS_SND_SIZE; 443 sk->sk_rcvbuf = RINGBUFFER_HVS_RCV_SIZE; 444 return 0; 445 } 446 447 static int hvs_connect(struct vsock_sock *vsk) 448 { 449 union hvs_service_id vm, host; 450 struct hvsock *h = vsk->trans; 451 452 vm.srv_id = srv_id_template; 453 vm.svm_port = vsk->local_addr.svm_port; 454 h->vm_srv_id = vm.srv_id; 455 456 host.srv_id = srv_id_template; 457 host.svm_port = vsk->remote_addr.svm_port; 458 h->host_srv_id = host.srv_id; 459 460 return vmbus_send_tl_connect_request(&h->vm_srv_id, &h->host_srv_id); 461 } 462 463 static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode) 464 { 465 struct vmpipe_proto_header hdr; 466 467 if (hvs->fin_sent || !hvs->chan) 468 return; 469 470 /* It can't fail: see hvs_channel_writable_bytes(). */ 471 (void)hvs_send_data(hvs->chan, (struct hvs_send_buf *)&hdr, 0); 472 hvs->fin_sent = true; 473 } 474 475 static int hvs_shutdown(struct vsock_sock *vsk, int mode) 476 { 477 if (!(mode & SEND_SHUTDOWN)) 478 return 0; 479 480 hvs_shutdown_lock_held(vsk->trans, mode); 481 return 0; 482 } 483 484 static void hvs_close_timeout(struct work_struct *work) 485 { 486 struct vsock_sock *vsk = 487 container_of(work, struct vsock_sock, close_work.work); 488 struct sock *sk = sk_vsock(vsk); 489 490 sock_hold(sk); 491 lock_sock(sk); 492 if (!sock_flag(sk, SOCK_DONE)) 493 hvs_do_close_lock_held(vsk, false); 494 495 vsk->close_work_scheduled = false; 496 release_sock(sk); 497 sock_put(sk); 498 } 499 500 /* Returns true, if it is safe to remove socket; false otherwise */ 501 static bool hvs_close_lock_held(struct vsock_sock *vsk) 502 { 503 struct sock *sk = sk_vsock(vsk); 504 505 if (!(sk->sk_state == TCP_ESTABLISHED || 506 sk->sk_state == TCP_CLOSING)) 507 return true; 508 509 if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK) 510 hvs_shutdown_lock_held(vsk->trans, SHUTDOWN_MASK); 511 512 if (sock_flag(sk, SOCK_DONE)) 513 return true; 514 515 /* This reference will be dropped by the delayed close routine */ 516 sock_hold(sk); 517 INIT_DELAYED_WORK(&vsk->close_work, hvs_close_timeout); 518 vsk->close_work_scheduled = true; 519 schedule_delayed_work(&vsk->close_work, HVS_CLOSE_TIMEOUT); 520 return false; 521 } 522 523 static void hvs_release(struct vsock_sock *vsk) 524 { 525 bool remove_sock; 526 527 remove_sock = hvs_close_lock_held(vsk); 528 if (remove_sock) 529 vsock_remove_sock(vsk); 530 } 531 532 static void hvs_destruct(struct vsock_sock *vsk) 533 { 534 struct hvsock *hvs = vsk->trans; 535 struct vmbus_channel *chan = hvs->chan; 536 537 if (chan) 538 vmbus_hvsock_device_unregister(chan); 539 540 kfree(hvs); 541 } 542 543 static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr) 544 { 545 return -EOPNOTSUPP; 546 } 547 548 static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, 549 size_t len, int flags) 550 { 551 return -EOPNOTSUPP; 552 } 553 554 static int hvs_dgram_enqueue(struct vsock_sock *vsk, 555 struct sockaddr_vm *remote, struct msghdr *msg, 556 size_t dgram_len) 557 { 558 return -EOPNOTSUPP; 559 } 560 561 static bool hvs_dgram_allow(u32 cid, u32 port) 562 { 563 return false; 564 } 565 566 static int hvs_update_recv_data(struct hvsock *hvs) 567 { 568 struct hvs_recv_buf *recv_buf; 569 u32 payload_len; 570 571 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); 572 payload_len = recv_buf->hdr.data_size; 573 574 if (payload_len > HVS_MTU_SIZE) 575 return -EIO; 576 577 if (payload_len == 0) 578 hvs->vsk->peer_shutdown |= SEND_SHUTDOWN; 579 580 hvs->recv_data_len = payload_len; 581 hvs->recv_data_off = 0; 582 583 return 0; 584 } 585 586 static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg, 587 size_t len, int flags) 588 { 589 struct hvsock *hvs = vsk->trans; 590 bool need_refill = !hvs->recv_desc; 591 struct hvs_recv_buf *recv_buf; 592 u32 to_read; 593 int ret; 594 595 if (flags & MSG_PEEK) 596 return -EOPNOTSUPP; 597 598 if (need_refill) { 599 hvs->recv_desc = hv_pkt_iter_first(hvs->chan); 600 ret = hvs_update_recv_data(hvs); 601 if (ret) 602 return ret; 603 } 604 605 recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1); 606 to_read = min_t(u32, len, hvs->recv_data_len); 607 ret = memcpy_to_msg(msg, recv_buf->data + hvs->recv_data_off, to_read); 608 if (ret != 0) 609 return ret; 610 611 hvs->recv_data_len -= to_read; 612 if (hvs->recv_data_len == 0) { 613 hvs->recv_desc = hv_pkt_iter_next(hvs->chan, hvs->recv_desc); 614 if (hvs->recv_desc) { 615 ret = hvs_update_recv_data(hvs); 616 if (ret) 617 return ret; 618 } 619 } else { 620 hvs->recv_data_off += to_read; 621 } 622 623 return to_read; 624 } 625 626 static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg, 627 size_t len) 628 { 629 struct hvsock *hvs = vsk->trans; 630 struct vmbus_channel *chan = hvs->chan; 631 struct hvs_send_buf *send_buf; 632 ssize_t to_write, max_writable; 633 ssize_t ret = 0; 634 ssize_t bytes_written = 0; 635 636 BUILD_BUG_ON(sizeof(*send_buf) != HV_HYP_PAGE_SIZE); 637 638 send_buf = kmalloc(sizeof(*send_buf), GFP_KERNEL); 639 if (!send_buf) 640 return -ENOMEM; 641 642 /* Reader(s) could be draining data from the channel as we write. 643 * Maximize bandwidth, by iterating until the channel is found to be 644 * full. 645 */ 646 while (len) { 647 max_writable = hvs_channel_writable_bytes(chan); 648 if (!max_writable) 649 break; 650 to_write = min_t(ssize_t, len, max_writable); 651 to_write = min_t(ssize_t, to_write, HVS_SEND_BUF_SIZE); 652 /* memcpy_from_msg is safe for loop as it advances the offsets 653 * within the message iterator. 654 */ 655 ret = memcpy_from_msg(send_buf->data, msg, to_write); 656 if (ret < 0) 657 goto out; 658 659 ret = hvs_send_data(hvs->chan, send_buf, to_write); 660 if (ret < 0) 661 goto out; 662 663 bytes_written += to_write; 664 len -= to_write; 665 } 666 out: 667 /* If any data has been sent, return that */ 668 if (bytes_written) 669 ret = bytes_written; 670 kfree(send_buf); 671 return ret; 672 } 673 674 static s64 hvs_stream_has_data(struct vsock_sock *vsk) 675 { 676 struct hvsock *hvs = vsk->trans; 677 s64 ret; 678 679 if (hvs->recv_data_len > 0) 680 return 1; 681 682 switch (hvs_channel_readable_payload(hvs->chan)) { 683 case 1: 684 ret = 1; 685 break; 686 case 0: 687 vsk->peer_shutdown |= SEND_SHUTDOWN; 688 ret = 0; 689 break; 690 default: /* -1 */ 691 ret = 0; 692 break; 693 } 694 695 return ret; 696 } 697 698 static s64 hvs_stream_has_space(struct vsock_sock *vsk) 699 { 700 struct hvsock *hvs = vsk->trans; 701 702 return hvs_channel_writable_bytes(hvs->chan); 703 } 704 705 static u64 hvs_stream_rcvhiwat(struct vsock_sock *vsk) 706 { 707 return HVS_MTU_SIZE + 1; 708 } 709 710 static bool hvs_stream_is_active(struct vsock_sock *vsk) 711 { 712 struct hvsock *hvs = vsk->trans; 713 714 return hvs->chan != NULL; 715 } 716 717 static bool hvs_stream_allow(u32 cid, u32 port) 718 { 719 if (cid == VMADDR_CID_HOST) 720 return true; 721 722 return false; 723 } 724 725 static 726 int hvs_notify_poll_in(struct vsock_sock *vsk, size_t target, bool *readable) 727 { 728 struct hvsock *hvs = vsk->trans; 729 730 *readable = hvs_channel_readable(hvs->chan); 731 return 0; 732 } 733 734 static 735 int hvs_notify_poll_out(struct vsock_sock *vsk, size_t target, bool *writable) 736 { 737 *writable = hvs_stream_has_space(vsk) > 0; 738 739 return 0; 740 } 741 742 static 743 int hvs_notify_recv_init(struct vsock_sock *vsk, size_t target, 744 struct vsock_transport_recv_notify_data *d) 745 { 746 return 0; 747 } 748 749 static 750 int hvs_notify_recv_pre_block(struct vsock_sock *vsk, size_t target, 751 struct vsock_transport_recv_notify_data *d) 752 { 753 return 0; 754 } 755 756 static 757 int hvs_notify_recv_pre_dequeue(struct vsock_sock *vsk, size_t target, 758 struct vsock_transport_recv_notify_data *d) 759 { 760 return 0; 761 } 762 763 static 764 int hvs_notify_recv_post_dequeue(struct vsock_sock *vsk, size_t target, 765 ssize_t copied, bool data_read, 766 struct vsock_transport_recv_notify_data *d) 767 { 768 return 0; 769 } 770 771 static 772 int hvs_notify_send_init(struct vsock_sock *vsk, 773 struct vsock_transport_send_notify_data *d) 774 { 775 return 0; 776 } 777 778 static 779 int hvs_notify_send_pre_block(struct vsock_sock *vsk, 780 struct vsock_transport_send_notify_data *d) 781 { 782 return 0; 783 } 784 785 static 786 int hvs_notify_send_pre_enqueue(struct vsock_sock *vsk, 787 struct vsock_transport_send_notify_data *d) 788 { 789 return 0; 790 } 791 792 static 793 int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written, 794 struct vsock_transport_send_notify_data *d) 795 { 796 return 0; 797 } 798 799 static struct vsock_transport hvs_transport = { 800 .module = THIS_MODULE, 801 802 .get_local_cid = hvs_get_local_cid, 803 804 .init = hvs_sock_init, 805 .destruct = hvs_destruct, 806 .release = hvs_release, 807 .connect = hvs_connect, 808 .shutdown = hvs_shutdown, 809 810 .dgram_bind = hvs_dgram_bind, 811 .dgram_dequeue = hvs_dgram_dequeue, 812 .dgram_enqueue = hvs_dgram_enqueue, 813 .dgram_allow = hvs_dgram_allow, 814 815 .stream_dequeue = hvs_stream_dequeue, 816 .stream_enqueue = hvs_stream_enqueue, 817 .stream_has_data = hvs_stream_has_data, 818 .stream_has_space = hvs_stream_has_space, 819 .stream_rcvhiwat = hvs_stream_rcvhiwat, 820 .stream_is_active = hvs_stream_is_active, 821 .stream_allow = hvs_stream_allow, 822 823 .notify_poll_in = hvs_notify_poll_in, 824 .notify_poll_out = hvs_notify_poll_out, 825 .notify_recv_init = hvs_notify_recv_init, 826 .notify_recv_pre_block = hvs_notify_recv_pre_block, 827 .notify_recv_pre_dequeue = hvs_notify_recv_pre_dequeue, 828 .notify_recv_post_dequeue = hvs_notify_recv_post_dequeue, 829 .notify_send_init = hvs_notify_send_init, 830 .notify_send_pre_block = hvs_notify_send_pre_block, 831 .notify_send_pre_enqueue = hvs_notify_send_pre_enqueue, 832 .notify_send_post_enqueue = hvs_notify_send_post_enqueue, 833 834 }; 835 836 static bool hvs_check_transport(struct vsock_sock *vsk) 837 { 838 return vsk->transport == &hvs_transport; 839 } 840 841 static int hvs_probe(struct hv_device *hdev, 842 const struct hv_vmbus_device_id *dev_id) 843 { 844 struct vmbus_channel *chan = hdev->channel; 845 846 hvs_open_connection(chan); 847 848 /* Always return success to suppress the unnecessary error message 849 * in vmbus_probe(): on error the host will rescind the device in 850 * 30 seconds and we can do cleanup at that time in 851 * vmbus_onoffer_rescind(). 852 */ 853 return 0; 854 } 855 856 static int hvs_remove(struct hv_device *hdev) 857 { 858 struct vmbus_channel *chan = hdev->channel; 859 860 vmbus_close(chan); 861 862 return 0; 863 } 864 865 /* hv_sock connections can not persist across hibernation, and all the hv_sock 866 * channels are forced to be rescinded before hibernation: see 867 * vmbus_bus_suspend(). Here the dummy hvs_suspend() and hvs_resume() 868 * are only needed because hibernation requires that every vmbus device's 869 * driver should have a .suspend and .resume callback: see vmbus_suspend(). 870 */ 871 static int hvs_suspend(struct hv_device *hv_dev) 872 { 873 /* Dummy */ 874 return 0; 875 } 876 877 static int hvs_resume(struct hv_device *dev) 878 { 879 /* Dummy */ 880 return 0; 881 } 882 883 /* This isn't really used. See vmbus_match() and vmbus_probe() */ 884 static const struct hv_vmbus_device_id id_table[] = { 885 {}, 886 }; 887 888 static struct hv_driver hvs_drv = { 889 .name = "hv_sock", 890 .hvsock = true, 891 .id_table = id_table, 892 .probe = hvs_probe, 893 .remove = hvs_remove, 894 .suspend = hvs_suspend, 895 .resume = hvs_resume, 896 }; 897 898 static int __init hvs_init(void) 899 { 900 int ret; 901 902 if (vmbus_proto_version < VERSION_WIN10) 903 return -ENODEV; 904 905 ret = vmbus_driver_register(&hvs_drv); 906 if (ret != 0) 907 return ret; 908 909 ret = vsock_core_register(&hvs_transport, VSOCK_TRANSPORT_F_G2H); 910 if (ret) { 911 vmbus_driver_unregister(&hvs_drv); 912 return ret; 913 } 914 915 return 0; 916 } 917 918 static void __exit hvs_exit(void) 919 { 920 vsock_core_unregister(&hvs_transport); 921 vmbus_driver_unregister(&hvs_drv); 922 } 923 924 module_init(hvs_init); 925 module_exit(hvs_exit); 926 927 MODULE_DESCRIPTION("Hyper-V Sockets"); 928 MODULE_VERSION("1.0.0"); 929 MODULE_LICENSE("GPL"); 930 MODULE_ALIAS_NETPROTO(PF_VSOCK); 931