drivers/hv/channel.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/wait.h>
  26 #include <linux/mm.h>
  27 #include <linux/slab.h>
  28 #include <linux/module.h>
  29 #include <linux/hyperv.h>
  30 #include <linux/uio.h>
  31 #include <linux/interrupt.h>
  32
  33 #include "hyperv_vmbus.h"
  34
  35 #define NUM_PAGES_SPANNED(addr, len) \
  36 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
  37
  38 /*
  39  * vmbus_setevent- Trigger an event notification on the specified
  40  * channel.
  41  */
  42 static void vmbus_setevent(struct vmbus_channel *channel)
  43 {
  44         struct hv_monitor_page *monitorpage;
  45
  46         if (channel->offermsg.monitor_allocated) {
  47                 /* Each u32 represents 32 channels */
  48                 sync_set_bit(channel->offermsg.child_relid & 31,
  49                         (unsigned long *) vmbus_connection.send_int_page +
  50                         (channel->offermsg.child_relid >> 5));
  51
  52                 /* Get the child to parent monitor page */
  53                 monitorpage = vmbus_connection.monitor_pages[1];
  54
  55                 sync_set_bit(channel->monitor_bit,
  56                         (unsigned long *)&monitorpage->trigger_group
  57                                         [channel->monitor_grp].pending);
  58
  59         } else {
  60                 vmbus_set_event(channel);
  61         }
  62 }
  63
  64 /*
  65  * vmbus_open - Open the specified channel.
  66  */
  67 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
  68                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
  69                      void (*onchannelcallback)(void *context), void *context)
  70 {
  71         struct vmbus_channel_open_channel *open_msg;
  72         struct vmbus_channel_msginfo *open_info = NULL;
  73         void *in, *out;
  74         unsigned long flags;
  75         int ret, err = 0;
  76         struct page *page;
  77
  78         spin_lock_irqsave(&newchannel->lock, flags);
  79         if (newchannel->state == CHANNEL_OPEN_STATE) {
  80                 newchannel->state = CHANNEL_OPENING_STATE;
  81         } else {
  82                 spin_unlock_irqrestore(&newchannel->lock, flags);
  83                 return -EINVAL;
  84         }
  85         spin_unlock_irqrestore(&newchannel->lock, flags);
  86
  87         newchannel->onchannel_callback = onchannelcallback;
  88         newchannel->channel_callback_context = context;
  89
  90         /* Allocate the ring buffer */
  91         page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
  92                                 GFP_KERNEL|__GFP_ZERO,
  93                                 get_order(send_ringbuffer_size +
  94                                 recv_ringbuffer_size));
  95
  96         if (!page)
  97                 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
  98                                                get_order(send_ringbuffer_size +
  99                                                recv_ringbuffer_size));
 100         else
 101                 out = (void *)page_address(page);
 102
 103         if (!out) {
 104                 err = -ENOMEM;
 105                 goto error0;
 106         }
 107
 108         in = (void *)((unsigned long)out + send_ringbuffer_size);
 109
 110         newchannel->ringbuffer_pages = out;
 111         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 112                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 113
 114         ret = hv_ringbuffer_init(
 115                 &newchannel->outbound, out, send_ringbuffer_size);
 116
 117         if (ret != 0) {
 118                 err = ret;
 119                 goto error0;
 120         }
 121
 122         ret = hv_ringbuffer_init(
 123                 &newchannel->inbound, in, recv_ringbuffer_size);
 124         if (ret != 0) {
 125                 err = ret;
 126                 goto error0;
 127         }
 128
 129
 130         /* Establish the gpadl for the ring buffer */
 131         newchannel->ringbuffer_gpadlhandle = 0;
 132
 133         ret = vmbus_establish_gpadl(newchannel,
 134                                          newchannel->outbound.ring_buffer,
 135                                          send_ringbuffer_size +
 136                                          recv_ringbuffer_size,
 137                                          &newchannel->ringbuffer_gpadlhandle);
 138
 139         if (ret != 0) {
 140                 err = ret;
 141                 goto error0;
 142         }
 143
 144         /* Create and init the channel open message */
 145         open_info = kmalloc(sizeof(*open_info) +
 146                            sizeof(struct vmbus_channel_open_channel),
 147                            GFP_KERNEL);
 148         if (!open_info) {
 149                 err = -ENOMEM;
 150                 goto error_gpadl;
 151         }
 152
 153         init_completion(&open_info->waitevent);
 154
 155         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 156         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 157         open_msg->openid = newchannel->offermsg.child_relid;
 158         open_msg->child_relid = newchannel->offermsg.child_relid;
 159         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 160         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 161                                                   PAGE_SHIFT;
 162         open_msg->target_vp = newchannel->target_vp;
 163
 164         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 165                 err = -EINVAL;
 166                 goto error_gpadl;
 167         }
 168
 169         if (userdatalen)
 170                 memcpy(open_msg->userdata, userdata, userdatalen);
 171
 172         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 173         list_add_tail(&open_info->msglistentry,
 174                       &vmbus_connection.chn_msg_list);
 175         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 176
 177         ret = vmbus_post_msg(open_msg,
 178                                sizeof(struct vmbus_channel_open_channel));
 179
 180         if (ret != 0) {
 181                 err = ret;
 182                 goto error1;
 183         }
 184
 185         wait_for_completion(&open_info->waitevent);
 186
 187         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 188         list_del(&open_info->msglistentry);
 189         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 190
 191         if (open_info->response.open_result.status) {
 192                 err = -EAGAIN;
 193                 goto error_gpadl;
 194         }
 195
 196         newchannel->state = CHANNEL_OPENED_STATE;
 197         kfree(open_info);
 198         return 0;
 199
 200 error1:
 201         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 202         list_del(&open_info->msglistentry);
 203         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 204
 205 error_gpadl:
 206         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 207
 208 error0:
 209         free_pages((unsigned long)out,
 210                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 211         kfree(open_info);
 212         newchannel->state = CHANNEL_OPEN_STATE;
 213         return err;
 214 }
 215 EXPORT_SYMBOL_GPL(vmbus_open);
 216
 217 /* Used for Hyper-V Socket: a guest client's connect() to the host */
 218 int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
 219                                   const uuid_le *shv_host_servie_id)
 220 {
 221         struct vmbus_channel_tl_connect_request conn_msg;
 222
 223         memset(&conn_msg, 0, sizeof(conn_msg));
 224         conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
 225         conn_msg.guest_endpoint_id = *shv_guest_servie_id;
 226         conn_msg.host_service_id = *shv_host_servie_id;
 227
 228         return vmbus_post_msg(&conn_msg, sizeof(conn_msg));
 229 }
 230 EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
 231
 232 /*
 233  * create_gpadl_header - Creates a gpadl for the specified buffer
 234  */
 235 static int create_gpadl_header(void *kbuffer, u32 size,
 236                                struct vmbus_channel_msginfo **msginfo)
 237 {
 238         int i;
 239         int pagecount;
 240         struct vmbus_channel_gpadl_header *gpadl_header;
 241         struct vmbus_channel_gpadl_body *gpadl_body;
 242         struct vmbus_channel_msginfo *msgheader;
 243         struct vmbus_channel_msginfo *msgbody = NULL;
 244         u32 msgsize;
 245
 246         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 247
 248         pagecount = size >> PAGE_SHIFT;
 249
 250         /* do we need a gpadl body msg */
 251         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 252                   sizeof(struct vmbus_channel_gpadl_header) -
 253                   sizeof(struct gpa_range);
 254         pfncount = pfnsize / sizeof(u64);
 255
 256         if (pagecount > pfncount) {
 257                 /* we need a gpadl body */
 258                 /* fill in the header */
 259                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 260                           sizeof(struct vmbus_channel_gpadl_header) +
 261                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 262                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 263                 if (!msgheader)
 264                         goto nomem;
 265
 266                 INIT_LIST_HEAD(&msgheader->submsglist);
 267                 msgheader->msgsize = msgsize;
 268
 269                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 270                         msgheader->msg;
 271                 gpadl_header->rangecount = 1;
 272                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 273                                          pagecount * sizeof(u64);
 274                 gpadl_header->range[0].byte_offset = 0;
 275                 gpadl_header->range[0].byte_count = size;
 276                 for (i = 0; i < pfncount; i++)
 277                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 278                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 279                 *msginfo = msgheader;
 280
 281                 pfnsum = pfncount;
 282                 pfnleft = pagecount - pfncount;
 283
 284                 /* how many pfns can we fit */
 285                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 286                           sizeof(struct vmbus_channel_gpadl_body);
 287                 pfncount = pfnsize / sizeof(u64);
 288
 289                 /* fill in the body */
 290                 while (pfnleft) {
 291                         if (pfnleft > pfncount)
 292                                 pfncurr = pfncount;
 293                         else
 294                                 pfncurr = pfnleft;
 295
 296                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 297                                   sizeof(struct vmbus_channel_gpadl_body) +
 298                                   pfncurr * sizeof(u64);
 299                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 300
 301                         if (!msgbody) {
 302                                 struct vmbus_channel_msginfo *pos = NULL;
 303                                 struct vmbus_channel_msginfo *tmp = NULL;
 304                                 /*
 305                                  * Free up all the allocated messages.
 306                                  */
 307                                 list_for_each_entry_safe(pos, tmp,
 308                                         &msgheader->submsglist,
 309                                         msglistentry) {
 310
 311                                         list_del(&pos->msglistentry);
 312                                         kfree(pos);
 313                                 }
 314
 315                                 goto nomem;
 316                         }
 317
 318                         msgbody->msgsize = msgsize;
 319                         gpadl_body =
 320                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 321
 322                         /*
 323                          * Gpadl is u32 and we are using a pointer which could
 324                          * be 64-bit
 325                          * This is governed by the guest/host protocol and
 326                          * so the hypervisor gurantees that this is ok.
 327                          */
 328                         for (i = 0; i < pfncurr; i++)
 329                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 330                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 331                                         PAGE_SHIFT;
 332
 333                         /* add to msg header */
 334                         list_add_tail(&msgbody->msglistentry,
 335                                       &msgheader->submsglist);
 336                         pfnsum += pfncurr;
 337                         pfnleft -= pfncurr;
 338                 }
 339         } else {
 340                 /* everything fits in a header */
 341                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 342                           sizeof(struct vmbus_channel_gpadl_header) +
 343                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 344                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 345                 if (msgheader == NULL)
 346                         goto nomem;
 347
 348                 INIT_LIST_HEAD(&msgheader->submsglist);
 349                 msgheader->msgsize = msgsize;
 350
 351                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 352                         msgheader->msg;
 353                 gpadl_header->rangecount = 1;
 354                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 355                                          pagecount * sizeof(u64);
 356                 gpadl_header->range[0].byte_offset = 0;
 357                 gpadl_header->range[0].byte_count = size;
 358                 for (i = 0; i < pagecount; i++)
 359                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 360                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 361
 362                 *msginfo = msgheader;
 363         }
 364
 365         return 0;
 366 nomem:
 367         kfree(msgheader);
 368         kfree(msgbody);
 369         return -ENOMEM;
 370 }
 371
 372 /*
 373  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 374  *
 375  * @channel: a channel
 376  * @kbuffer: from kmalloc or vmalloc
 377  * @size: page-size multiple
 378  * @gpadl_handle: some funky thing
 379  */
 380 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 381                                u32 size, u32 *gpadl_handle)
 382 {
 383         struct vmbus_channel_gpadl_header *gpadlmsg;
 384         struct vmbus_channel_gpadl_body *gpadl_body;
 385         struct vmbus_channel_msginfo *msginfo = NULL;
 386         struct vmbus_channel_msginfo *submsginfo, *tmp;
 387         struct list_head *curr;
 388         u32 next_gpadl_handle;
 389         unsigned long flags;
 390         int ret = 0;
 391
 392         next_gpadl_handle =
 393                 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 394
 395         ret = create_gpadl_header(kbuffer, size, &msginfo);
 396         if (ret)
 397                 return ret;
 398
 399         init_completion(&msginfo->waitevent);
 400
 401         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 402         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 403         gpadlmsg->child_relid = channel->offermsg.child_relid;
 404         gpadlmsg->gpadl = next_gpadl_handle;
 405
 406
 407         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 408         list_add_tail(&msginfo->msglistentry,
 409                       &vmbus_connection.chn_msg_list);
 410
 411         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 412
 413         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 414                                sizeof(*msginfo));
 415         if (ret != 0)
 416                 goto cleanup;
 417
 418         list_for_each(curr, &msginfo->submsglist) {
 419                 submsginfo = (struct vmbus_channel_msginfo *)curr;
 420                 gpadl_body =
 421                         (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 422
 423                 gpadl_body->header.msgtype =
 424                         CHANNELMSG_GPADL_BODY;
 425                 gpadl_body->gpadl = next_gpadl_handle;
 426
 427                 ret = vmbus_post_msg(gpadl_body,
 428                                      submsginfo->msgsize -
 429                                      sizeof(*submsginfo));
 430                 if (ret != 0)
 431                         goto cleanup;
 432
 433         }
 434         wait_for_completion(&msginfo->waitevent);
 435
 436         /* At this point, we received the gpadl created msg */
 437         *gpadl_handle = gpadlmsg->gpadl;
 438
 439 cleanup:
 440         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 441         list_del(&msginfo->msglistentry);
 442         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 443         list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
 444                                  msglistentry) {
 445                 kfree(submsginfo);
 446         }
 447
 448         kfree(msginfo);
 449         return ret;
 450 }
 451 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 452
 453 /*
 454  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 455  */
 456 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 457 {
 458         struct vmbus_channel_gpadl_teardown *msg;
 459         struct vmbus_channel_msginfo *info;
 460         unsigned long flags;
 461         int ret;
 462
 463         info = kmalloc(sizeof(*info) +
 464                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 465         if (!info)
 466                 return -ENOMEM;
 467
 468         init_completion(&info->waitevent);
 469
 470         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 471
 472         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 473         msg->child_relid = channel->offermsg.child_relid;
 474         msg->gpadl = gpadl_handle;
 475
 476         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 477         list_add_tail(&info->msglistentry,
 478                       &vmbus_connection.chn_msg_list);
 479         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 480         ret = vmbus_post_msg(msg,
 481                                sizeof(struct vmbus_channel_gpadl_teardown));
 482
 483         if (ret)
 484                 goto post_msg_err;
 485
 486         wait_for_completion(&info->waitevent);
 487
 488 post_msg_err:
 489         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 490         list_del(&info->msglistentry);
 491         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 492
 493         kfree(info);
 494         return ret;
 495 }
 496 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 497
 498 static void reset_channel_cb(void *arg)
 499 {
 500         struct vmbus_channel *channel = arg;
 501
 502         channel->onchannel_callback = NULL;
 503 }
 504
 505 static int vmbus_close_internal(struct vmbus_channel *channel)
 506 {
 507         struct vmbus_channel_close_channel *msg;
 508         int ret;
 509
 510         /*
 511          * process_chn_event(), running in the tasklet, can race
 512          * with vmbus_close_internal() in the case of SMP guest, e.g., when
 513          * the former is accessing channel->inbound.ring_buffer, the latter
 514          * could be freeing the ring_buffer pages.
 515          *
 516          * To resolve the race, we can serialize them by disabling the
 517          * tasklet when the latter is running here.
 518          */
 519         hv_event_tasklet_disable(channel);
 520
 521         /*
 522          * In case a device driver's probe() fails (e.g.,
 523          * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
 524          * rescinded later (e.g., we dynamically disble an Integrated Service
 525          * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
 526          * here we should skip most of the below cleanup work.
 527          */
 528         if (channel->state != CHANNEL_OPENED_STATE) {
 529                 ret = -EINVAL;
 530                 goto out;
 531         }
 532
 533         channel->state = CHANNEL_OPEN_STATE;
 534         channel->sc_creation_callback = NULL;
 535         /* Stop callback and cancel the timer asap */
 536         if (channel->target_cpu != get_cpu()) {
 537                 put_cpu();
 538                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 539                                          channel, true);
 540         } else {
 541                 reset_channel_cb(channel);
 542                 put_cpu();
 543         }
 544
 545         /* Send a closing message */
 546
 547         msg = &channel->close_msg.msg;
 548
 549         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 550         msg->child_relid = channel->offermsg.child_relid;
 551
 552         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 553
 554         if (ret) {
 555                 pr_err("Close failed: close post msg return is %d\n", ret);
 556                 /*
 557                  * If we failed to post the close msg,
 558                  * it is perhaps better to leak memory.
 559                  */
 560                 goto out;
 561         }
 562
 563         /* Tear down the gpadl for the channel's ring buffer */
 564         if (channel->ringbuffer_gpadlhandle) {
 565                 ret = vmbus_teardown_gpadl(channel,
 566                                            channel->ringbuffer_gpadlhandle);
 567                 if (ret) {
 568                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 569                         /*
 570                          * If we failed to teardown gpadl,
 571                          * it is perhaps better to leak memory.
 572                          */
 573                         goto out;
 574                 }
 575         }
 576
 577         /* Cleanup the ring buffers for this channel */
 578         hv_ringbuffer_cleanup(&channel->outbound);
 579         hv_ringbuffer_cleanup(&channel->inbound);
 580
 581         free_pages((unsigned long)channel->ringbuffer_pages,
 582                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 583
 584 out:
 585         hv_event_tasklet_enable(channel);
 586
 587         return ret;
 588 }
 589
 590 /*
 591  * vmbus_close - Close the specified channel
 592  */
 593 void vmbus_close(struct vmbus_channel *channel)
 594 {
 595         struct list_head *cur, *tmp;
 596         struct vmbus_channel *cur_channel;
 597
 598         if (channel->primary_channel != NULL) {
 599                 /*
 600                  * We will only close sub-channels when
 601                  * the primary is closed.
 602                  */
 603                 return;
 604         }
 605         /*
 606          * Close all the sub-channels first and then close the
 607          * primary channel.
 608          */
 609         list_for_each_safe(cur, tmp, &channel->sc_list) {
 610                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 611                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 612                         continue;
 613                 vmbus_close_internal(cur_channel);
 614         }
 615         /*
 616          * Now close the primary.
 617          */
 618         vmbus_close_internal(channel);
 619 }
 620 EXPORT_SYMBOL_GPL(vmbus_close);
 621
 622 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 623                            u32 bufferlen, u64 requestid,
 624                            enum vmbus_packet_type type, u32 flags, bool kick_q)
 625 {
 626         struct vmpacket_descriptor desc;
 627         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 628         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 629         struct kvec bufferlist[3];
 630         u64 aligned_data = 0;
 631         int ret;
 632         bool signal = false;
 633         bool lock = channel->acquire_ring_lock;
 634         int num_vecs = ((bufferlen != 0) ? 3 : 1);
 635
 636
 637         /* Setup the descriptor */
 638         desc.type = type; /* VmbusPacketTypeDataInBand; */
 639         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 640         /* in 8-bytes granularity */
 641         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 642         desc.len8 = (u16)(packetlen_aligned >> 3);
 643         desc.trans_id = requestid;
 644
 645         bufferlist[0].iov_base = &desc;
 646         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 647         bufferlist[1].iov_base = buffer;
 648         bufferlist[1].iov_len = bufferlen;
 649         bufferlist[2].iov_base = &aligned_data;
 650         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 651
 652         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
 653                                   &signal, lock);
 654
 655         /*
 656          * Signalling the host is conditional on many factors:
 657          * 1. The ring state changed from being empty to non-empty.
 658          *    This is tracked by the variable "signal".
 659          * 2. The variable kick_q tracks if more data will be placed
 660          *    on the ring. We will not signal if more data is
 661          *    to be placed.
 662          *
 663          * Based on the channel signal state, we will decide
 664          * which signaling policy will be applied.
 665          *
 666          * If we cannot write to the ring-buffer; signal the host
 667          * even if we may not have written anything. This is a rare
 668          * enough condition that it should not matter.
 669          * NOTE: in this case, the hvsock channel is an exception, because
 670          * it looks the host side's hvsock implementation has a throttling
 671          * mechanism which can hurt the performance otherwise.
 672          */
 673
 674         if (channel->signal_policy)
 675                 signal = true;
 676         else
 677                 kick_q = true;
 678
 679         if (((ret == 0) && kick_q && signal) ||
 680             (ret && !is_hvsock_channel(channel)))
 681                 vmbus_setevent(channel);
 682
 683         return ret;
 684 }
 685 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 686
 687 /**
 688  * vmbus_sendpacket() - Send the specified buffer on the given channel
 689  * @channel: Pointer to vmbus_channel structure.
 690  * @buffer: Pointer to the buffer you want to receive the data into.
 691  * @bufferlen: Maximum size of what the the buffer will hold
 692  * @requestid: Identifier of the request
 693  * @type: Type of packet that is being send e.g. negotiate, time
 694  * packet etc.
 695  *
 696  * Sends data in @buffer directly to hyper-v via the vmbus
 697  * This will send the data unparsed to hyper-v.
 698  *
 699  * Mainly used by Hyper-V drivers.
 700  */
 701 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 702                            u32 bufferlen, u64 requestid,
 703                            enum vmbus_packet_type type, u32 flags)
 704 {
 705         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 706                                     type, flags, true);
 707 }
 708 EXPORT_SYMBOL(vmbus_sendpacket);
 709
 710 /*
 711  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 712  * packets using a GPADL Direct packet type. This interface allows you
 713  * to control notifying the host. This will be useful for sending
 714  * batched data. Also the sender can control the send flags
 715  * explicitly.
 716  */
 717 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 718                                      struct hv_page_buffer pagebuffers[],
 719                                      u32 pagecount, void *buffer, u32 bufferlen,
 720                                      u64 requestid,
 721                                      u32 flags,
 722                                      bool kick_q)
 723 {
 724         int ret;
 725         int i;
 726         struct vmbus_channel_packet_page_buffer desc;
 727         u32 descsize;
 728         u32 packetlen;
 729         u32 packetlen_aligned;
 730         struct kvec bufferlist[3];
 731         u64 aligned_data = 0;
 732         bool signal = false;
 733         bool lock = channel->acquire_ring_lock;
 734
 735         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 736                 return -EINVAL;
 737
 738
 739         /*
 740          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 741          * largest size we support
 742          */
 743         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 744                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 745                           sizeof(struct hv_page_buffer));
 746         packetlen = descsize + bufferlen;
 747         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 748
 749         /* Setup the descriptor */
 750         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 751         desc.flags = flags;
 752         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 753         desc.length8 = (u16)(packetlen_aligned >> 3);
 754         desc.transactionid = requestid;
 755         desc.rangecount = pagecount;
 756
 757         for (i = 0; i < pagecount; i++) {
 758                 desc.range[i].len = pagebuffers[i].len;
 759                 desc.range[i].offset = pagebuffers[i].offset;
 760                 desc.range[i].pfn        = pagebuffers[i].pfn;
 761         }
 762
 763         bufferlist[0].iov_base = &desc;
 764         bufferlist[0].iov_len = descsize;
 765         bufferlist[1].iov_base = buffer;
 766         bufferlist[1].iov_len = bufferlen;
 767         bufferlist[2].iov_base = &aligned_data;
 768         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 769
 770         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
 771                                   &signal, lock);
 772
 773         /*
 774          * Signalling the host is conditional on many factors:
 775          * 1. The ring state changed from being empty to non-empty.
 776          *    This is tracked by the variable "signal".
 777          * 2. The variable kick_q tracks if more data will be placed
 778          *    on the ring. We will not signal if more data is
 779          *    to be placed.
 780          *
 781          * Based on the channel signal state, we will decide
 782          * which signaling policy will be applied.
 783          *
 784          * If we cannot write to the ring-buffer; signal the host
 785          * even if we may not have written anything. This is a rare
 786          * enough condition that it should not matter.
 787          */
 788
 789         if (channel->signal_policy)
 790                 signal = true;
 791         else
 792                 kick_q = true;
 793
 794         if (((ret == 0) && kick_q && signal) || (ret))
 795                 vmbus_setevent(channel);
 796
 797         return ret;
 798 }
 799 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 800
 801 /*
 802  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 803  * packets using a GPADL Direct packet type.
 804  */
 805 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 806                                      struct hv_page_buffer pagebuffers[],
 807                                      u32 pagecount, void *buffer, u32 bufferlen,
 808                                      u64 requestid)
 809 {
 810         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 811         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 812                                                buffer, bufferlen, requestid,
 813                                                flags, true);
 814
 815 }
 816 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 817
 818 /*
 819  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 820  * using a GPADL Direct packet type.
 821  * The buffer includes the vmbus descriptor.
 822  */
 823 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 824                               struct vmbus_packet_mpb_array *desc,
 825                               u32 desc_size,
 826                               void *buffer, u32 bufferlen, u64 requestid)
 827 {
 828         int ret;
 829         u32 packetlen;
 830         u32 packetlen_aligned;
 831         struct kvec bufferlist[3];
 832         u64 aligned_data = 0;
 833         bool signal = false;
 834         bool lock = channel->acquire_ring_lock;
 835
 836         packetlen = desc_size + bufferlen;
 837         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 838
 839         /* Setup the descriptor */
 840         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 841         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 842         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
 843         desc->length8 = (u16)(packetlen_aligned >> 3);
 844         desc->transactionid = requestid;
 845         desc->rangecount = 1;
 846
 847         bufferlist[0].iov_base = desc;
 848         bufferlist[0].iov_len = desc_size;
 849         bufferlist[1].iov_base = buffer;
 850         bufferlist[1].iov_len = bufferlen;
 851         bufferlist[2].iov_base = &aligned_data;
 852         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 853
 854         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
 855                                   &signal, lock);
 856
 857         if (ret == 0 && signal)
 858                 vmbus_setevent(channel);
 859
 860         return ret;
 861 }
 862 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 863
 864 /*
 865  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 866  * using a GPADL Direct packet type.
 867  */
 868 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 869                                 struct hv_multipage_buffer *multi_pagebuffer,
 870                                 void *buffer, u32 bufferlen, u64 requestid)
 871 {
 872         int ret;
 873         struct vmbus_channel_packet_multipage_buffer desc;
 874         u32 descsize;
 875         u32 packetlen;
 876         u32 packetlen_aligned;
 877         struct kvec bufferlist[3];
 878         u64 aligned_data = 0;
 879         bool signal = false;
 880         bool lock = channel->acquire_ring_lock;
 881         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 882                                          multi_pagebuffer->len);
 883
 884         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 885                 return -EINVAL;
 886
 887         /*
 888          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 889          * the largest size we support
 890          */
 891         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 892                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 893                           sizeof(u64));
 894         packetlen = descsize + bufferlen;
 895         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 896
 897
 898         /* Setup the descriptor */
 899         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 900         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 901         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 902         desc.length8 = (u16)(packetlen_aligned >> 3);
 903         desc.transactionid = requestid;
 904         desc.rangecount = 1;
 905
 906         desc.range.len = multi_pagebuffer->len;
 907         desc.range.offset = multi_pagebuffer->offset;
 908
 909         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 910                pfncount * sizeof(u64));
 911
 912         bufferlist[0].iov_base = &desc;
 913         bufferlist[0].iov_len = descsize;
 914         bufferlist[1].iov_base = buffer;
 915         bufferlist[1].iov_len = bufferlen;
 916         bufferlist[2].iov_base = &aligned_data;
 917         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 918
 919         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
 920                                   &signal, lock);
 921
 922         if (ret == 0 && signal)
 923                 vmbus_setevent(channel);
 924
 925         return ret;
 926 }
 927 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 928
 929 /**
 930  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 931  * @channel: Pointer to vmbus_channel structure.
 932  * @buffer: Pointer to the buffer you want to receive the data into.
 933  * @bufferlen: Maximum size of what the the buffer will hold
 934  * @buffer_actual_len: The actual size of the data after it was received
 935  * @requestid: Identifier of the request
 936  *
 937  * Receives directly from the hyper-v vmbus and puts the data it received
 938  * into Buffer. This will receive the data unparsed from hyper-v.
 939  *
 940  * Mainly used by Hyper-V drivers.
 941  */
 942 static inline int
 943 __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 944                    u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
 945                    bool raw)
 946 {
 947         int ret;
 948         bool signal = false;
 949
 950         ret = hv_ringbuffer_read(&channel->inbound, buffer, bufferlen,
 951                                  buffer_actual_len, requestid, &signal, raw);
 952
 953         if (signal)
 954                 vmbus_setevent(channel);
 955
 956         return ret;
 957 }
 958
 959 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 960                      u32 bufferlen, u32 *buffer_actual_len,
 961                      u64 *requestid)
 962 {
 963         return __vmbus_recvpacket(channel, buffer, bufferlen,
 964                                   buffer_actual_len, requestid, false);
 965 }
 966 EXPORT_SYMBOL(vmbus_recvpacket);
 967
 968 /*
 969  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 970  */
 971 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 972                               u32 bufferlen, u32 *buffer_actual_len,
 973                               u64 *requestid)
 974 {
 975         return __vmbus_recvpacket(channel, buffer, bufferlen,
 976                                   buffer_actual_len, requestid, true);
 977 }
 978 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);