net/vmw_vsock/vmci_transport_notify.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * VMware vSockets Driver
   4  *
   5  * Copyright (C) 2009-2013 VMware, Inc. All rights reserved.
   6  */
   7
   8 #include <linux/types.h>
   9 #include <linux/socket.h>
  10 #include <linux/stddef.h>
  11 #include <net/sock.h>
  12
  13 #include "vmci_transport_notify.h"
  14
  15 #define PKT_FIELD(vsk, field_name) (vmci_trans(vsk)->notify.pkt.field_name)
  16
  17 static bool vmci_transport_notify_waiting_write(struct vsock_sock *vsk)
  18 {
  19 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
  20         bool retval;
  21         u64 notify_limit;
  22
  23         if (!PKT_FIELD(vsk, peer_waiting_write))
  24                 return false;
  25
  26 #ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
  27         /* When the sender blocks, we take that as a sign that the sender is
  28          * faster than the receiver. To reduce the transmit rate of the sender,
  29          * we delay the sending of the read notification by decreasing the
  30          * write_notify_window. The notification is delayed until the number of
  31          * bytes used in the queue drops below the write_notify_window.
  32          */
  33
  34         if (!PKT_FIELD(vsk, peer_waiting_write_detected)) {
  35                 PKT_FIELD(vsk, peer_waiting_write_detected) = true;
  36                 if (PKT_FIELD(vsk, write_notify_window) < PAGE_SIZE) {
  37                         PKT_FIELD(vsk, write_notify_window) =
  38                             PKT_FIELD(vsk, write_notify_min_window);
  39                 } else {
  40                         PKT_FIELD(vsk, write_notify_window) -= PAGE_SIZE;
  41                         if (PKT_FIELD(vsk, write_notify_window) <
  42                             PKT_FIELD(vsk, write_notify_min_window))
  43                                 PKT_FIELD(vsk, write_notify_window) =
  44                                     PKT_FIELD(vsk, write_notify_min_window);
  45
  46                 }
  47         }
  48         notify_limit = vmci_trans(vsk)->consume_size -
  49                 PKT_FIELD(vsk, write_notify_window);
  50 #else
  51         notify_limit = 0;
  52 #endif
  53
  54         /* For now we ignore the wait information and just see if the free
  55          * space exceeds the notify limit.  Note that improving this function
  56          * to be more intelligent will not require a protocol change and will
  57          * retain compatibility between endpoints with mixed versions of this
  58          * function.
  59          *
  60          * The notify_limit is used to delay notifications in the case where
  61          * flow control is enabled. Below the test is expressed in terms of
  62          * free space in the queue: if free_space > ConsumeSize -
  63          * write_notify_window then notify An alternate way of expressing this
  64          * is to rewrite the expression to use the data ready in the receive
  65          * queue: if write_notify_window > bufferReady then notify as
  66          * free_space == ConsumeSize - bufferReady.
  67          */
  68         retval = vmci_qpair_consume_free_space(vmci_trans(vsk)->qpair) >
  69                 notify_limit;
  70 #ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
  71         if (retval) {
  72                 /*
  73                  * Once we notify the peer, we reset the detected flag so the
  74                  * next wait will again cause a decrease in the window size.
  75                  */
  76
  77                 PKT_FIELD(vsk, peer_waiting_write_detected) = false;
  78         }
  79 #endif
  80         return retval;
  81 #else
  82         return true;
  83 #endif
  84 }
  85
  86 static bool vmci_transport_notify_waiting_read(struct vsock_sock *vsk)
  87 {
  88 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
  89         if (!PKT_FIELD(vsk, peer_waiting_read))
  90                 return false;
  91
  92         /* For now we ignore the wait information and just see if there is any
  93          * data for our peer to read.  Note that improving this function to be
  94          * more intelligent will not require a protocol change and will retain
  95          * compatibility between endpoints with mixed versions of this
  96          * function.
  97          */
  98         return vmci_qpair_produce_buf_ready(vmci_trans(vsk)->qpair) > 0;
  99 #else
 100         return true;
 101 #endif
 102 }
 103
 104 static void
 105 vmci_transport_handle_waiting_read(struct sock *sk,
 106                                    struct vmci_transport_packet *pkt,
 107                                    bool bottom_half,
 108                                    struct sockaddr_vm *dst,
 109                                    struct sockaddr_vm *src)
 110 {
 111 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 112         struct vsock_sock *vsk;
 113
 114         vsk = vsock_sk(sk);
 115
 116         PKT_FIELD(vsk, peer_waiting_read) = true;
 117         memcpy(&PKT_FIELD(vsk, peer_waiting_read_info), &pkt->u.wait,
 118                sizeof(PKT_FIELD(vsk, peer_waiting_read_info)));
 119
 120         if (vmci_transport_notify_waiting_read(vsk)) {
 121                 bool sent;
 122
 123                 if (bottom_half)
 124                         sent = vmci_transport_send_wrote_bh(dst, src) > 0;
 125                 else
 126                         sent = vmci_transport_send_wrote(sk) > 0;
 127
 128                 if (sent)
 129                         PKT_FIELD(vsk, peer_waiting_read) = false;
 130         }
 131 #endif
 132 }
 133
 134 static void
 135 vmci_transport_handle_waiting_write(struct sock *sk,
 136                                     struct vmci_transport_packet *pkt,
 137                                     bool bottom_half,
 138                                     struct sockaddr_vm *dst,
 139                                     struct sockaddr_vm *src)
 140 {
 141 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 142         struct vsock_sock *vsk;
 143
 144         vsk = vsock_sk(sk);
 145
 146         PKT_FIELD(vsk, peer_waiting_write) = true;
 147         memcpy(&PKT_FIELD(vsk, peer_waiting_write_info), &pkt->u.wait,
 148                sizeof(PKT_FIELD(vsk, peer_waiting_write_info)));
 149
 150         if (vmci_transport_notify_waiting_write(vsk)) {
 151                 bool sent;
 152
 153                 if (bottom_half)
 154                         sent = vmci_transport_send_read_bh(dst, src) > 0;
 155                 else
 156                         sent = vmci_transport_send_read(sk) > 0;
 157
 158                 if (sent)
 159                         PKT_FIELD(vsk, peer_waiting_write) = false;
 160         }
 161 #endif
 162 }
 163
 164 static void
 165 vmci_transport_handle_read(struct sock *sk,
 166                            struct vmci_transport_packet *pkt,
 167                            bool bottom_half,
 168                            struct sockaddr_vm *dst, struct sockaddr_vm *src)
 169 {
 170 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 171         struct vsock_sock *vsk;
 172
 173         vsk = vsock_sk(sk);
 174         PKT_FIELD(vsk, sent_waiting_write) = false;
 175 #endif
 176
 177         sk->sk_write_space(sk);
 178 }
 179
 180 static bool send_waiting_read(struct sock *sk, u64 room_needed)
 181 {
 182 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 183         struct vsock_sock *vsk;
 184         struct vmci_transport_waiting_info waiting_info;
 185         u64 tail;
 186         u64 head;
 187         u64 room_left;
 188         bool ret;
 189
 190         vsk = vsock_sk(sk);
 191
 192         if (PKT_FIELD(vsk, sent_waiting_read))
 193                 return true;
 194
 195         if (PKT_FIELD(vsk, write_notify_window) <
 196                         vmci_trans(vsk)->consume_size)
 197                 PKT_FIELD(vsk, write_notify_window) =
 198                     min(PKT_FIELD(vsk, write_notify_window) + PAGE_SIZE,
 199                         vmci_trans(vsk)->consume_size);
 200
 201         vmci_qpair_get_consume_indexes(vmci_trans(vsk)->qpair, &tail, &head);
 202         room_left = vmci_trans(vsk)->consume_size - head;
 203         if (room_needed >= room_left) {
 204                 waiting_info.offset = room_needed - room_left;
 205                 waiting_info.generation =
 206                     PKT_FIELD(vsk, consume_q_generation) + 1;
 207         } else {
 208                 waiting_info.offset = head + room_needed;
 209                 waiting_info.generation = PKT_FIELD(vsk, consume_q_generation);
 210         }
 211
 212         ret = vmci_transport_send_waiting_read(sk, &waiting_info) > 0;
 213         if (ret)
 214                 PKT_FIELD(vsk, sent_waiting_read) = true;
 215
 216         return ret;
 217 #else
 218         return true;
 219 #endif
 220 }
 221
 222 static bool send_waiting_write(struct sock *sk, u64 room_needed)
 223 {
 224 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 225         struct vsock_sock *vsk;
 226         struct vmci_transport_waiting_info waiting_info;
 227         u64 tail;
 228         u64 head;
 229         u64 room_left;
 230         bool ret;
 231
 232         vsk = vsock_sk(sk);
 233
 234         if (PKT_FIELD(vsk, sent_waiting_write))
 235                 return true;
 236
 237         vmci_qpair_get_produce_indexes(vmci_trans(vsk)->qpair, &tail, &head);
 238         room_left = vmci_trans(vsk)->produce_size - tail;
 239         if (room_needed + 1 >= room_left) {
 240                 /* Wraps around to current generation. */
 241                 waiting_info.offset = room_needed + 1 - room_left;
 242                 waiting_info.generation = PKT_FIELD(vsk, produce_q_generation);
 243         } else {
 244                 waiting_info.offset = tail + room_needed + 1;
 245                 waiting_info.generation =
 246                     PKT_FIELD(vsk, produce_q_generation) - 1;
 247         }
 248
 249         ret = vmci_transport_send_waiting_write(sk, &waiting_info) > 0;
 250         if (ret)
 251                 PKT_FIELD(vsk, sent_waiting_write) = true;
 252
 253         return ret;
 254 #else
 255         return true;
 256 #endif
 257 }
 258
 259 static int vmci_transport_send_read_notification(struct sock *sk)
 260 {
 261         struct vsock_sock *vsk;
 262         bool sent_read;
 263         unsigned int retries;
 264         int err;
 265
 266         vsk = vsock_sk(sk);
 267         sent_read = false;
 268         retries = 0;
 269         err = 0;
 270
 271         if (vmci_transport_notify_waiting_write(vsk)) {
 272                 /* Notify the peer that we have read, retrying the send on
 273                  * failure up to our maximum value.  XXX For now we just log
 274                  * the failure, but later we should schedule a work item to
 275                  * handle the resend until it succeeds.  That would require
 276                  * keeping track of work items in the vsk and cleaning them up
 277                  * upon socket close.
 278                  */
 279                 while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
 280                        !sent_read &&
 281                        retries < VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
 282                         err = vmci_transport_send_read(sk);
 283                         if (err >= 0)
 284                                 sent_read = true;
 285
 286                         retries++;
 287                 }
 288
 289                 if (retries >= VMCI_TRANSPORT_MAX_DGRAM_RESENDS)
 290                         pr_err("%p unable to send read notify to peer\n", sk);
 291                 else
 292 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 293                         PKT_FIELD(vsk, peer_waiting_write) = false;
 294 #endif
 295
 296         }
 297         return err;
 298 }
 299
 300 static void
 301 vmci_transport_handle_wrote(struct sock *sk,
 302                             struct vmci_transport_packet *pkt,
 303                             bool bottom_half,
 304                             struct sockaddr_vm *dst, struct sockaddr_vm *src)
 305 {
 306 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 307         struct vsock_sock *vsk = vsock_sk(sk);
 308         PKT_FIELD(vsk, sent_waiting_read) = false;
 309 #endif
 310         sk->sk_data_ready(sk);
 311 }
 312
 313 static void vmci_transport_notify_pkt_socket_init(struct sock *sk)
 314 {
 315         struct vsock_sock *vsk = vsock_sk(sk);
 316
 317         PKT_FIELD(vsk, write_notify_window) = PAGE_SIZE;
 318         PKT_FIELD(vsk, write_notify_min_window) = PAGE_SIZE;
 319         PKT_FIELD(vsk, peer_waiting_read) = false;
 320         PKT_FIELD(vsk, peer_waiting_write) = false;
 321         PKT_FIELD(vsk, peer_waiting_write_detected) = false;
 322         PKT_FIELD(vsk, sent_waiting_read) = false;
 323         PKT_FIELD(vsk, sent_waiting_write) = false;
 324         PKT_FIELD(vsk, produce_q_generation) = 0;
 325         PKT_FIELD(vsk, consume_q_generation) = 0;
 326
 327         memset(&PKT_FIELD(vsk, peer_waiting_read_info), 0,
 328                sizeof(PKT_FIELD(vsk, peer_waiting_read_info)));
 329         memset(&PKT_FIELD(vsk, peer_waiting_write_info), 0,
 330                sizeof(PKT_FIELD(vsk, peer_waiting_write_info)));
 331 }
 332
 333 static void vmci_transport_notify_pkt_socket_destruct(struct vsock_sock *vsk)
 334 {
 335 }
 336
 337 static int
 338 vmci_transport_notify_pkt_poll_in(struct sock *sk,
 339                                   size_t target, bool *data_ready_now)
 340 {
 341         struct vsock_sock *vsk = vsock_sk(sk);
 342
 343         if (vsock_stream_has_data(vsk)) {
 344                 *data_ready_now = true;
 345         } else {
 346                 /* We can't read right now because there is nothing in the
 347                  * queue. Ask for notifications when there is something to
 348                  * read.
 349                  */
 350                 if (sk->sk_state == TCP_ESTABLISHED) {
 351                         if (!send_waiting_read(sk, 1))
 352                                 return -1;
 353
 354                 }
 355                 *data_ready_now = false;
 356         }
 357
 358         return 0;
 359 }
 360
 361 static int
 362 vmci_transport_notify_pkt_poll_out(struct sock *sk,
 363                                    size_t target, bool *space_avail_now)
 364 {
 365         s64 produce_q_free_space;
 366         struct vsock_sock *vsk = vsock_sk(sk);
 367
 368         produce_q_free_space = vsock_stream_has_space(vsk);
 369         if (produce_q_free_space > 0) {
 370                 *space_avail_now = true;
 371                 return 0;
 372         } else if (produce_q_free_space == 0) {
 373                 /* This is a connected socket but we can't currently send data.
 374                  * Notify the peer that we are waiting if the queue is full. We
 375                  * only send a waiting write if the queue is full because
 376                  * otherwise we end up in an infinite WAITING_WRITE, READ,
 377                  * WAITING_WRITE, READ, etc. loop. Treat failing to send the
 378                  * notification as a socket error, passing that back through
 379                  * the mask.
 380                  */
 381                 if (!send_waiting_write(sk, 1))
 382                         return -1;
 383
 384                 *space_avail_now = false;
 385         }
 386
 387         return 0;
 388 }
 389
 390 static int
 391 vmci_transport_notify_pkt_recv_init(
 392                         struct sock *sk,
 393                         size_t target,
 394                         struct vmci_transport_recv_notify_data *data)
 395 {
 396         struct vsock_sock *vsk = vsock_sk(sk);
 397
 398 #ifdef VSOCK_OPTIMIZATION_WAITING_NOTIFY
 399         data->consume_head = 0;
 400         data->produce_tail = 0;
 401 #ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
 402         data->notify_on_block = false;
 403
 404         if (PKT_FIELD(vsk, write_notify_min_window) < target + 1) {
 405                 PKT_FIELD(vsk, write_notify_min_window) = target + 1;
 406                 if (PKT_FIELD(vsk, write_notify_window) <
 407                     PKT_FIELD(vsk, write_notify_min_window)) {
 408                         /* If the current window is smaller than the new
 409                          * minimal window size, we need to reevaluate whether
 410                          * we need to notify the sender. If the number of ready
 411                          * bytes are smaller than the new window, we need to
 412                          * send a notification to the sender before we block.
 413                          */
 414
 415                         PKT_FIELD(vsk, write_notify_window) =
 416                             PKT_FIELD(vsk, write_notify_min_window);
 417                         data->notify_on_block = true;
 418                 }
 419         }
 420 #endif
 421 #endif
 422
 423         return 0;
 424 }
 425
 426 static int
 427 vmci_transport_notify_pkt_recv_pre_block(
 428                                 struct sock *sk,
 429                                 size_t target,
 430                                 struct vmci_transport_recv_notify_data *data)
 431 {
 432         int err = 0;
 433
 434         /* Notify our peer that we are waiting for data to read. */
 435         if (!send_waiting_read(sk, target)) {
 436                 err = -EHOSTUNREACH;
 437                 return err;
 438         }
 439 #ifdef VSOCK_OPTIMIZATION_FLOW_CONTROL
 440         if (data->notify_on_block) {
 441                 err = vmci_transport_send_read_notification(sk);
 442                 if (err < 0)
 443                         return err;
 444
 445                 data->notify_on_block = false;
 446         }
 447 #endif
 448
 449         return err;
 450 }
 451
 452 static int
 453 vmci_transport_notify_pkt_recv_pre_dequeue(
 454                                 struct sock *sk,
 455                                 size_t target,
 456                                 struct vmci_transport_recv_notify_data *data)
 457 {
 458         struct vsock_sock *vsk = vsock_sk(sk);
 459
 460         /* Now consume up to len bytes from the queue.  Note that since we have
 461          * the socket locked we should copy at least ready bytes.
 462          */
 463 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 464         vmci_qpair_get_consume_indexes(vmci_trans(vsk)->qpair,
 465                                        &data->produce_tail,
 466                                        &data->consume_head);
 467 #endif
 468
 469         return 0;
 470 }
 471
 472 static int
 473 vmci_transport_notify_pkt_recv_post_dequeue(
 474                                 struct sock *sk,
 475                                 size_t target,
 476                                 ssize_t copied,
 477                                 bool data_read,
 478                                 struct vmci_transport_recv_notify_data *data)
 479 {
 480         struct vsock_sock *vsk;
 481         int err;
 482
 483         vsk = vsock_sk(sk);
 484         err = 0;
 485
 486         if (data_read) {
 487 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 488                 /* Detect a wrap-around to maintain queue generation.  Note
 489                  * that this is safe since we hold the socket lock across the
 490                  * two queue pair operations.
 491                  */
 492                 if (copied >=
 493                         vmci_trans(vsk)->consume_size - data->consume_head)
 494                         PKT_FIELD(vsk, consume_q_generation)++;
 495 #endif
 496
 497                 err = vmci_transport_send_read_notification(sk);
 498                 if (err < 0)
 499                         return err;
 500
 501         }
 502         return err;
 503 }
 504
 505 static int
 506 vmci_transport_notify_pkt_send_init(
 507                         struct sock *sk,
 508                         struct vmci_transport_send_notify_data *data)
 509 {
 510 #ifdef VSOCK_OPTIMIZATION_WAITING_NOTIFY
 511         data->consume_head = 0;
 512         data->produce_tail = 0;
 513 #endif
 514
 515         return 0;
 516 }
 517
 518 static int
 519 vmci_transport_notify_pkt_send_pre_block(
 520                                 struct sock *sk,
 521                                 struct vmci_transport_send_notify_data *data)
 522 {
 523         /* Notify our peer that we are waiting for room to write. */
 524         if (!send_waiting_write(sk, 1))
 525                 return -EHOSTUNREACH;
 526
 527         return 0;
 528 }
 529
 530 static int
 531 vmci_transport_notify_pkt_send_pre_enqueue(
 532                                 struct sock *sk,
 533                                 struct vmci_transport_send_notify_data *data)
 534 {
 535         struct vsock_sock *vsk = vsock_sk(sk);
 536
 537 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 538         vmci_qpair_get_produce_indexes(vmci_trans(vsk)->qpair,
 539                                        &data->produce_tail,
 540                                        &data->consume_head);
 541 #endif
 542
 543         return 0;
 544 }
 545
 546 static int
 547 vmci_transport_notify_pkt_send_post_enqueue(
 548                                 struct sock *sk,
 549                                 ssize_t written,
 550                                 struct vmci_transport_send_notify_data *data)
 551 {
 552         int err = 0;
 553         struct vsock_sock *vsk;
 554         bool sent_wrote = false;
 555         int retries = 0;
 556
 557         vsk = vsock_sk(sk);
 558
 559 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 560         /* Detect a wrap-around to maintain queue generation.  Note that this
 561          * is safe since we hold the socket lock across the two queue pair
 562          * operations.
 563          */
 564         if (written >= vmci_trans(vsk)->produce_size - data->produce_tail)
 565                 PKT_FIELD(vsk, produce_q_generation)++;
 566
 567 #endif
 568
 569         if (vmci_transport_notify_waiting_read(vsk)) {
 570                 /* Notify the peer that we have written, retrying the send on
 571                  * failure up to our maximum value. See the XXX comment for the
 572                  * corresponding piece of code in StreamRecvmsg() for potential
 573                  * improvements.
 574                  */
 575                 while (!(vsk->peer_shutdown & RCV_SHUTDOWN) &&
 576                        !sent_wrote &&
 577                        retries < VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
 578                         err = vmci_transport_send_wrote(sk);
 579                         if (err >= 0)
 580                                 sent_wrote = true;
 581
 582                         retries++;
 583                 }
 584
 585                 if (retries >= VMCI_TRANSPORT_MAX_DGRAM_RESENDS) {
 586                         pr_err("%p unable to send wrote notify to peer\n", sk);
 587                         return err;
 588                 } else {
 589 #if defined(VSOCK_OPTIMIZATION_WAITING_NOTIFY)
 590                         PKT_FIELD(vsk, peer_waiting_read) = false;
 591 #endif
 592                 }
 593         }
 594         return err;
 595 }
 596
 597 static void
 598 vmci_transport_notify_pkt_handle_pkt(
 599                         struct sock *sk,
 600                         struct vmci_transport_packet *pkt,
 601                         bool bottom_half,
 602                         struct sockaddr_vm *dst,
 603                         struct sockaddr_vm *src, bool *pkt_processed)
 604 {
 605         bool processed = false;
 606
 607         switch (pkt->type) {
 608         case VMCI_TRANSPORT_PACKET_TYPE_WROTE:
 609                 vmci_transport_handle_wrote(sk, pkt, bottom_half, dst, src);
 610                 processed = true;
 611                 break;
 612         case VMCI_TRANSPORT_PACKET_TYPE_READ:
 613                 vmci_transport_handle_read(sk, pkt, bottom_half, dst, src);
 614                 processed = true;
 615                 break;
 616         case VMCI_TRANSPORT_PACKET_TYPE_WAITING_WRITE:
 617                 vmci_transport_handle_waiting_write(sk, pkt, bottom_half,
 618                                                     dst, src);
 619                 processed = true;
 620                 break;
 621
 622         case VMCI_TRANSPORT_PACKET_TYPE_WAITING_READ:
 623                 vmci_transport_handle_waiting_read(sk, pkt, bottom_half,
 624                                                    dst, src);
 625                 processed = true;
 626                 break;
 627         }
 628
 629         if (pkt_processed)
 630                 *pkt_processed = processed;
 631 }
 632
 633 static void vmci_transport_notify_pkt_process_request(struct sock *sk)
 634 {
 635         struct vsock_sock *vsk = vsock_sk(sk);
 636
 637         PKT_FIELD(vsk, write_notify_window) = vmci_trans(vsk)->consume_size;
 638         if (vmci_trans(vsk)->consume_size <
 639                 PKT_FIELD(vsk, write_notify_min_window))
 640                 PKT_FIELD(vsk, write_notify_min_window) =
 641                         vmci_trans(vsk)->consume_size;
 642 }
 643
 644 static void vmci_transport_notify_pkt_process_negotiate(struct sock *sk)
 645 {
 646         struct vsock_sock *vsk = vsock_sk(sk);
 647
 648         PKT_FIELD(vsk, write_notify_window) = vmci_trans(vsk)->consume_size;
 649         if (vmci_trans(vsk)->consume_size <
 650                 PKT_FIELD(vsk, write_notify_min_window))
 651                 PKT_FIELD(vsk, write_notify_min_window) =
 652                         vmci_trans(vsk)->consume_size;
 653 }
 654
 655 /* Socket control packet based operations. */
 656 const struct vmci_transport_notify_ops vmci_transport_notify_pkt_ops = {
 657         .socket_init = vmci_transport_notify_pkt_socket_init,
 658         .socket_destruct = vmci_transport_notify_pkt_socket_destruct,
 659         .poll_in = vmci_transport_notify_pkt_poll_in,
 660         .poll_out = vmci_transport_notify_pkt_poll_out,
 661         .handle_notify_pkt = vmci_transport_notify_pkt_handle_pkt,
 662         .recv_init = vmci_transport_notify_pkt_recv_init,
 663         .recv_pre_block = vmci_transport_notify_pkt_recv_pre_block,
 664         .recv_pre_dequeue = vmci_transport_notify_pkt_recv_pre_dequeue,
 665         .recv_post_dequeue = vmci_transport_notify_pkt_recv_post_dequeue,
 666         .send_init = vmci_transport_notify_pkt_send_init,
 667         .send_pre_block = vmci_transport_notify_pkt_send_pre_block,
 668         .send_pre_enqueue = vmci_transport_notify_pkt_send_pre_enqueue,
 669         .send_post_enqueue = vmci_transport_notify_pkt_send_post_enqueue,
 670         .process_request = vmci_transport_notify_pkt_process_request,
 671         .process_negotiate = vmci_transport_notify_pkt_process_negotiate,
 672 };