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         unsigned long t;
  77         struct page *page;
  78
  79         spin_lock_irqsave(&newchannel->lock, flags);
  80         if (newchannel->state == CHANNEL_OPEN_STATE) {
  81                 newchannel->state = CHANNEL_OPENING_STATE;
  82         } else {
  83                 spin_unlock_irqrestore(&newchannel->lock, flags);
  84                 return -EINVAL;
  85         }
  86         spin_unlock_irqrestore(&newchannel->lock, flags);
  87
  88         newchannel->onchannel_callback = onchannelcallback;
  89         newchannel->channel_callback_context = context;
  90
  91         /* Allocate the ring buffer */
  92         page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
  93                                 GFP_KERNEL|__GFP_ZERO,
  94                                 get_order(send_ringbuffer_size +
  95                                 recv_ringbuffer_size));
  96
  97         if (!page)
  98                 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
  99                                                get_order(send_ringbuffer_size +
 100                                                recv_ringbuffer_size));
 101         else
 102                 out = (void *)page_address(page);
 103
 104         if (!out) {
 105                 err = -ENOMEM;
 106                 goto error0;
 107         }
 108
 109         in = (void *)((unsigned long)out + send_ringbuffer_size);
 110
 111         newchannel->ringbuffer_pages = out;
 112         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 113                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 114
 115         ret = hv_ringbuffer_init(
 116                 &newchannel->outbound, out, send_ringbuffer_size);
 117
 118         if (ret != 0) {
 119                 err = ret;
 120                 goto error0;
 121         }
 122
 123         ret = hv_ringbuffer_init(
 124                 &newchannel->inbound, in, recv_ringbuffer_size);
 125         if (ret != 0) {
 126                 err = ret;
 127                 goto error0;
 128         }
 129
 130
 131         /* Establish the gpadl for the ring buffer */
 132         newchannel->ringbuffer_gpadlhandle = 0;
 133
 134         ret = vmbus_establish_gpadl(newchannel,
 135                                          newchannel->outbound.ring_buffer,
 136                                          send_ringbuffer_size +
 137                                          recv_ringbuffer_size,
 138                                          &newchannel->ringbuffer_gpadlhandle);
 139
 140         if (ret != 0) {
 141                 err = ret;
 142                 goto error0;
 143         }
 144
 145         /* Create and init the channel open message */
 146         open_info = kmalloc(sizeof(*open_info) +
 147                            sizeof(struct vmbus_channel_open_channel),
 148                            GFP_KERNEL);
 149         if (!open_info) {
 150                 err = -ENOMEM;
 151                 goto error_gpadl;
 152         }
 153
 154         init_completion(&open_info->waitevent);
 155
 156         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 157         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 158         open_msg->openid = newchannel->offermsg.child_relid;
 159         open_msg->child_relid = newchannel->offermsg.child_relid;
 160         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 161         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 162                                                   PAGE_SHIFT;
 163         open_msg->target_vp = newchannel->target_vp;
 164
 165         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 166                 err = -EINVAL;
 167                 goto error_gpadl;
 168         }
 169
 170         if (userdatalen)
 171                 memcpy(open_msg->userdata, userdata, userdatalen);
 172
 173         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 174         list_add_tail(&open_info->msglistentry,
 175                       &vmbus_connection.chn_msg_list);
 176         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 177
 178         ret = vmbus_post_msg(open_msg,
 179                                sizeof(struct vmbus_channel_open_channel));
 180
 181         if (ret != 0) {
 182                 err = ret;
 183                 goto error1;
 184         }
 185
 186         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 187         if (t == 0) {
 188                 err = -ETIMEDOUT;
 189                 goto error1;
 190         }
 191
 192         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 193         list_del(&open_info->msglistentry);
 194         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 195
 196         if (open_info->response.open_result.status) {
 197                 err = -EAGAIN;
 198                 goto error_gpadl;
 199         }
 200
 201         newchannel->state = CHANNEL_OPENED_STATE;
 202         kfree(open_info);
 203         return 0;
 204
 205 error1:
 206         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 207         list_del(&open_info->msglistentry);
 208         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 209
 210 error_gpadl:
 211         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 212
 213 error0:
 214         free_pages((unsigned long)out,
 215                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 216         kfree(open_info);
 217         newchannel->state = CHANNEL_OPEN_STATE;
 218         return err;
 219 }
 220 EXPORT_SYMBOL_GPL(vmbus_open);
 221
 222 /* Used for Hyper-V Socket: a guest client's connect() to the host */
 223 int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
 224                                   const uuid_le *shv_host_servie_id)
 225 {
 226         struct vmbus_channel_tl_connect_request conn_msg;
 227
 228         memset(&conn_msg, 0, sizeof(conn_msg));
 229         conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
 230         conn_msg.guest_endpoint_id = *shv_guest_servie_id;
 231         conn_msg.host_service_id = *shv_host_servie_id;
 232
 233         return vmbus_post_msg(&conn_msg, sizeof(conn_msg));
 234 }
 235 EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
 236
 237 /*
 238  * create_gpadl_header - Creates a gpadl for the specified buffer
 239  */
 240 static int create_gpadl_header(void *kbuffer, u32 size,
 241                                          struct vmbus_channel_msginfo **msginfo,
 242                                          u32 *messagecount)
 243 {
 244         int i;
 245         int pagecount;
 246         struct vmbus_channel_gpadl_header *gpadl_header;
 247         struct vmbus_channel_gpadl_body *gpadl_body;
 248         struct vmbus_channel_msginfo *msgheader;
 249         struct vmbus_channel_msginfo *msgbody = NULL;
 250         u32 msgsize;
 251
 252         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 253
 254         pagecount = size >> PAGE_SHIFT;
 255
 256         /* do we need a gpadl body msg */
 257         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 258                   sizeof(struct vmbus_channel_gpadl_header) -
 259                   sizeof(struct gpa_range);
 260         pfncount = pfnsize / sizeof(u64);
 261
 262         if (pagecount > pfncount) {
 263                 /* we need a gpadl body */
 264                 /* fill in the header */
 265                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 266                           sizeof(struct vmbus_channel_gpadl_header) +
 267                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 268                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 269                 if (!msgheader)
 270                         goto nomem;
 271
 272                 INIT_LIST_HEAD(&msgheader->submsglist);
 273                 msgheader->msgsize = msgsize;
 274
 275                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 276                         msgheader->msg;
 277                 gpadl_header->rangecount = 1;
 278                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 279                                          pagecount * sizeof(u64);
 280                 gpadl_header->range[0].byte_offset = 0;
 281                 gpadl_header->range[0].byte_count = size;
 282                 for (i = 0; i < pfncount; i++)
 283                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 284                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 285                 *msginfo = msgheader;
 286                 *messagecount = 1;
 287
 288                 pfnsum = pfncount;
 289                 pfnleft = pagecount - pfncount;
 290
 291                 /* how many pfns can we fit */
 292                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 293                           sizeof(struct vmbus_channel_gpadl_body);
 294                 pfncount = pfnsize / sizeof(u64);
 295
 296                 /* fill in the body */
 297                 while (pfnleft) {
 298                         if (pfnleft > pfncount)
 299                                 pfncurr = pfncount;
 300                         else
 301                                 pfncurr = pfnleft;
 302
 303                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 304                                   sizeof(struct vmbus_channel_gpadl_body) +
 305                                   pfncurr * sizeof(u64);
 306                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 307
 308                         if (!msgbody) {
 309                                 struct vmbus_channel_msginfo *pos = NULL;
 310                                 struct vmbus_channel_msginfo *tmp = NULL;
 311                                 /*
 312                                  * Free up all the allocated messages.
 313                                  */
 314                                 list_for_each_entry_safe(pos, tmp,
 315                                         &msgheader->submsglist,
 316                                         msglistentry) {
 317
 318                                         list_del(&pos->msglistentry);
 319                                         kfree(pos);
 320                                 }
 321
 322                                 goto nomem;
 323                         }
 324
 325                         msgbody->msgsize = msgsize;
 326                         (*messagecount)++;
 327                         gpadl_body =
 328                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 329
 330                         /*
 331                          * Gpadl is u32 and we are using a pointer which could
 332                          * be 64-bit
 333                          * This is governed by the guest/host protocol and
 334                          * so the hypervisor gurantees that this is ok.
 335                          */
 336                         for (i = 0; i < pfncurr; i++)
 337                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 338                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 339                                         PAGE_SHIFT;
 340
 341                         /* add to msg header */
 342                         list_add_tail(&msgbody->msglistentry,
 343                                       &msgheader->submsglist);
 344                         pfnsum += pfncurr;
 345                         pfnleft -= pfncurr;
 346                 }
 347         } else {
 348                 /* everything fits in a header */
 349                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 350                           sizeof(struct vmbus_channel_gpadl_header) +
 351                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 352                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 353                 if (msgheader == NULL)
 354                         goto nomem;
 355                 msgheader->msgsize = msgsize;
 356
 357                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 358                         msgheader->msg;
 359                 gpadl_header->rangecount = 1;
 360                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 361                                          pagecount * sizeof(u64);
 362                 gpadl_header->range[0].byte_offset = 0;
 363                 gpadl_header->range[0].byte_count = size;
 364                 for (i = 0; i < pagecount; i++)
 365                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 366                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 367
 368                 *msginfo = msgheader;
 369                 *messagecount = 1;
 370         }
 371
 372         return 0;
 373 nomem:
 374         kfree(msgheader);
 375         kfree(msgbody);
 376         return -ENOMEM;
 377 }
 378
 379 /*
 380  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 381  *
 382  * @channel: a channel
 383  * @kbuffer: from kmalloc or vmalloc
 384  * @size: page-size multiple
 385  * @gpadl_handle: some funky thing
 386  */
 387 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 388                                u32 size, u32 *gpadl_handle)
 389 {
 390         struct vmbus_channel_gpadl_header *gpadlmsg;
 391         struct vmbus_channel_gpadl_body *gpadl_body;
 392         struct vmbus_channel_msginfo *msginfo = NULL;
 393         struct vmbus_channel_msginfo *submsginfo;
 394         u32 msgcount;
 395         struct list_head *curr;
 396         u32 next_gpadl_handle;
 397         unsigned long flags;
 398         int ret = 0;
 399
 400         next_gpadl_handle =
 401                 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 402
 403         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 404         if (ret)
 405                 return ret;
 406
 407         init_completion(&msginfo->waitevent);
 408
 409         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 410         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 411         gpadlmsg->child_relid = channel->offermsg.child_relid;
 412         gpadlmsg->gpadl = next_gpadl_handle;
 413
 414
 415         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 416         list_add_tail(&msginfo->msglistentry,
 417                       &vmbus_connection.chn_msg_list);
 418
 419         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 420
 421         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 422                                sizeof(*msginfo));
 423         if (ret != 0)
 424                 goto cleanup;
 425
 426         if (msgcount > 1) {
 427                 list_for_each(curr, &msginfo->submsglist) {
 428
 429                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 430                         gpadl_body =
 431                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 432
 433                         gpadl_body->header.msgtype =
 434                                 CHANNELMSG_GPADL_BODY;
 435                         gpadl_body->gpadl = next_gpadl_handle;
 436
 437                         ret = vmbus_post_msg(gpadl_body,
 438                                                submsginfo->msgsize -
 439                                                sizeof(*submsginfo));
 440                         if (ret != 0)
 441                                 goto cleanup;
 442
 443                 }
 444         }
 445         wait_for_completion(&msginfo->waitevent);
 446
 447         /* At this point, we received the gpadl created msg */
 448         *gpadl_handle = gpadlmsg->gpadl;
 449
 450 cleanup:
 451         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 452         list_del(&msginfo->msglistentry);
 453         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 454
 455         kfree(msginfo);
 456         return ret;
 457 }
 458 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 459
 460 /*
 461  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 462  */
 463 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 464 {
 465         struct vmbus_channel_gpadl_teardown *msg;
 466         struct vmbus_channel_msginfo *info;
 467         unsigned long flags;
 468         int ret;
 469
 470         info = kmalloc(sizeof(*info) +
 471                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 472         if (!info)
 473                 return -ENOMEM;
 474
 475         init_completion(&info->waitevent);
 476
 477         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 478
 479         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 480         msg->child_relid = channel->offermsg.child_relid;
 481         msg->gpadl = gpadl_handle;
 482
 483         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 484         list_add_tail(&info->msglistentry,
 485                       &vmbus_connection.chn_msg_list);
 486         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 487         ret = vmbus_post_msg(msg,
 488                                sizeof(struct vmbus_channel_gpadl_teardown));
 489
 490         if (ret)
 491                 goto post_msg_err;
 492
 493         wait_for_completion(&info->waitevent);
 494
 495 post_msg_err:
 496         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 497         list_del(&info->msglistentry);
 498         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 499
 500         kfree(info);
 501         return ret;
 502 }
 503 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 504
 505 static void reset_channel_cb(void *arg)
 506 {
 507         struct vmbus_channel *channel = arg;
 508
 509         channel->onchannel_callback = NULL;
 510 }
 511
 512 static int vmbus_close_internal(struct vmbus_channel *channel)
 513 {
 514         struct vmbus_channel_close_channel *msg;
 515         struct tasklet_struct *tasklet;
 516         int ret;
 517
 518         /*
 519          * process_chn_event(), running in the tasklet, can race
 520          * with vmbus_close_internal() in the case of SMP guest, e.g., when
 521          * the former is accessing channel->inbound.ring_buffer, the latter
 522          * could be freeing the ring_buffer pages.
 523          *
 524          * To resolve the race, we can serialize them by disabling the
 525          * tasklet when the latter is running here.
 526          */
 527         tasklet = hv_context.event_dpc[channel->target_cpu];
 528         tasklet_disable(tasklet);
 529
 530         /*
 531          * In case a device driver's probe() fails (e.g.,
 532          * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
 533          * rescinded later (e.g., we dynamically disble an Integrated Service
 534          * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
 535          * here we should skip most of the below cleanup work.
 536          */
 537         if (channel->state != CHANNEL_OPENED_STATE) {
 538                 ret = -EINVAL;
 539                 goto out;
 540         }
 541
 542         channel->state = CHANNEL_OPEN_STATE;
 543         channel->sc_creation_callback = NULL;
 544         /* Stop callback and cancel the timer asap */
 545         if (channel->target_cpu != get_cpu()) {
 546                 put_cpu();
 547                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 548                                          channel, true);
 549         } else {
 550                 reset_channel_cb(channel);
 551                 put_cpu();
 552         }
 553
 554         /* Send a closing message */
 555
 556         msg = &channel->close_msg.msg;
 557
 558         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 559         msg->child_relid = channel->offermsg.child_relid;
 560
 561         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 562
 563         if (ret) {
 564                 pr_err("Close failed: close post msg return is %d\n", ret);
 565                 /*
 566                  * If we failed to post the close msg,
 567                  * it is perhaps better to leak memory.
 568                  */
 569                 goto out;
 570         }
 571
 572         /* Tear down the gpadl for the channel's ring buffer */
 573         if (channel->ringbuffer_gpadlhandle) {
 574                 ret = vmbus_teardown_gpadl(channel,
 575                                            channel->ringbuffer_gpadlhandle);
 576                 if (ret) {
 577                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 578                         /*
 579                          * If we failed to teardown gpadl,
 580                          * it is perhaps better to leak memory.
 581                          */
 582                         goto out;
 583                 }
 584         }
 585
 586         /* Cleanup the ring buffers for this channel */
 587         hv_ringbuffer_cleanup(&channel->outbound);
 588         hv_ringbuffer_cleanup(&channel->inbound);
 589
 590         free_pages((unsigned long)channel->ringbuffer_pages,
 591                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 592
 593 out:
 594         tasklet_enable(tasklet);
 595
 596         return ret;
 597 }
 598
 599 /*
 600  * vmbus_close - Close the specified channel
 601  */
 602 void vmbus_close(struct vmbus_channel *channel)
 603 {
 604         struct list_head *cur, *tmp;
 605         struct vmbus_channel *cur_channel;
 606
 607         if (channel->primary_channel != NULL) {
 608                 /*
 609                  * We will only close sub-channels when
 610                  * the primary is closed.
 611                  */
 612                 return;
 613         }
 614         /*
 615          * Close all the sub-channels first and then close the
 616          * primary channel.
 617          */
 618         list_for_each_safe(cur, tmp, &channel->sc_list) {
 619                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 620                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 621                         continue;
 622                 vmbus_close_internal(cur_channel);
 623         }
 624         /*
 625          * Now close the primary.
 626          */
 627         vmbus_close_internal(channel);
 628 }
 629 EXPORT_SYMBOL_GPL(vmbus_close);
 630
 631 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 632                            u32 bufferlen, u64 requestid,
 633                            enum vmbus_packet_type type, u32 flags, bool kick_q)
 634 {
 635         struct vmpacket_descriptor desc;
 636         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 637         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 638         struct kvec bufferlist[3];
 639         u64 aligned_data = 0;
 640         int ret;
 641         bool signal = false;
 642         bool lock = channel->acquire_ring_lock;
 643         int num_vecs = ((bufferlen != 0) ? 3 : 1);
 644
 645
 646         /* Setup the descriptor */
 647         desc.type = type; /* VmbusPacketTypeDataInBand; */
 648         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 649         /* in 8-bytes granularity */
 650         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 651         desc.len8 = (u16)(packetlen_aligned >> 3);
 652         desc.trans_id = requestid;
 653
 654         bufferlist[0].iov_base = &desc;
 655         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 656         bufferlist[1].iov_base = buffer;
 657         bufferlist[1].iov_len = bufferlen;
 658         bufferlist[2].iov_base = &aligned_data;
 659         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 660
 661         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
 662                                   &signal, lock);
 663
 664         /*
 665          * Signalling the host is conditional on many factors:
 666          * 1. The ring state changed from being empty to non-empty.
 667          *    This is tracked by the variable "signal".
 668          * 2. The variable kick_q tracks if more data will be placed
 669          *    on the ring. We will not signal if more data is
 670          *    to be placed.
 671          *
 672          * Based on the channel signal state, we will decide
 673          * which signaling policy will be applied.
 674          *
 675          * If we cannot write to the ring-buffer; signal the host
 676          * even if we may not have written anything. This is a rare
 677          * enough condition that it should not matter.
 678          * NOTE: in this case, the hvsock channel is an exception, because
 679          * it looks the host side's hvsock implementation has a throttling
 680          * mechanism which can hurt the performance otherwise.
 681          */
 682
 683         if (channel->signal_policy)
 684                 signal = true;
 685         else
 686                 kick_q = true;
 687
 688         if (((ret == 0) && kick_q && signal) ||
 689             (ret && !is_hvsock_channel(channel)))
 690                 vmbus_setevent(channel);
 691
 692         return ret;
 693 }
 694 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 695
 696 /**
 697  * vmbus_sendpacket() - Send the specified buffer on the given channel
 698  * @channel: Pointer to vmbus_channel structure.
 699  * @buffer: Pointer to the buffer you want to receive the data into.
 700  * @bufferlen: Maximum size of what the the buffer will hold
 701  * @requestid: Identifier of the request
 702  * @type: Type of packet that is being send e.g. negotiate, time
 703  * packet etc.
 704  *
 705  * Sends data in @buffer directly to hyper-v via the vmbus
 706  * This will send the data unparsed to hyper-v.
 707  *
 708  * Mainly used by Hyper-V drivers.
 709  */
 710 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 711                            u32 bufferlen, u64 requestid,
 712                            enum vmbus_packet_type type, u32 flags)
 713 {
 714         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 715                                     type, flags, true);
 716 }
 717 EXPORT_SYMBOL(vmbus_sendpacket);
 718
 719 /*
 720  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 721  * packets using a GPADL Direct packet type. This interface allows you
 722  * to control notifying the host. This will be useful for sending
 723  * batched data. Also the sender can control the send flags
 724  * explicitly.
 725  */
 726 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 727                                      struct hv_page_buffer pagebuffers[],
 728                                      u32 pagecount, void *buffer, u32 bufferlen,
 729                                      u64 requestid,
 730                                      u32 flags,
 731                                      bool kick_q)
 732 {
 733         int ret;
 734         int i;
 735         struct vmbus_channel_packet_page_buffer desc;
 736         u32 descsize;
 737         u32 packetlen;
 738         u32 packetlen_aligned;
 739         struct kvec bufferlist[3];
 740         u64 aligned_data = 0;
 741         bool signal = false;
 742         bool lock = channel->acquire_ring_lock;
 743
 744         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 745                 return -EINVAL;
 746
 747
 748         /*
 749          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 750          * largest size we support
 751          */
 752         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 753                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 754                           sizeof(struct hv_page_buffer));
 755         packetlen = descsize + bufferlen;
 756         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 757
 758         /* Setup the descriptor */
 759         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 760         desc.flags = flags;
 761         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 762         desc.length8 = (u16)(packetlen_aligned >> 3);
 763         desc.transactionid = requestid;
 764         desc.rangecount = pagecount;
 765
 766         for (i = 0; i < pagecount; i++) {
 767                 desc.range[i].len = pagebuffers[i].len;
 768                 desc.range[i].offset = pagebuffers[i].offset;
 769                 desc.range[i].pfn        = pagebuffers[i].pfn;
 770         }
 771
 772         bufferlist[0].iov_base = &desc;
 773         bufferlist[0].iov_len = descsize;
 774         bufferlist[1].iov_base = buffer;
 775         bufferlist[1].iov_len = bufferlen;
 776         bufferlist[2].iov_base = &aligned_data;
 777         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 778
 779         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
 780                                   &signal, lock);
 781
 782         /*
 783          * Signalling the host is conditional on many factors:
 784          * 1. The ring state changed from being empty to non-empty.
 785          *    This is tracked by the variable "signal".
 786          * 2. The variable kick_q tracks if more data will be placed
 787          *    on the ring. We will not signal if more data is
 788          *    to be placed.
 789          *
 790          * Based on the channel signal state, we will decide
 791          * which signaling policy will be applied.
 792          *
 793          * If we cannot write to the ring-buffer; signal the host
 794          * even if we may not have written anything. This is a rare
 795          * enough condition that it should not matter.
 796          */
 797
 798         if (channel->signal_policy)
 799                 signal = true;
 800         else
 801                 kick_q = true;
 802
 803         if (((ret == 0) && kick_q && signal) || (ret))
 804                 vmbus_setevent(channel);
 805
 806         return ret;
 807 }
 808 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 809
 810 /*
 811  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 812  * packets using a GPADL Direct packet type.
 813  */
 814 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 815                                      struct hv_page_buffer pagebuffers[],
 816                                      u32 pagecount, void *buffer, u32 bufferlen,
 817                                      u64 requestid)
 818 {
 819         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 820         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 821                                                buffer, bufferlen, requestid,
 822                                                flags, true);
 823
 824 }
 825 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 826
 827 /*
 828  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 829  * using a GPADL Direct packet type.
 830  * The buffer includes the vmbus descriptor.
 831  */
 832 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 833                               struct vmbus_packet_mpb_array *desc,
 834                               u32 desc_size,
 835                               void *buffer, u32 bufferlen, u64 requestid)
 836 {
 837         int ret;
 838         u32 packetlen;
 839         u32 packetlen_aligned;
 840         struct kvec bufferlist[3];
 841         u64 aligned_data = 0;
 842         bool signal = false;
 843         bool lock = channel->acquire_ring_lock;
 844
 845         packetlen = desc_size + bufferlen;
 846         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 847
 848         /* Setup the descriptor */
 849         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 850         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 851         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
 852         desc->length8 = (u16)(packetlen_aligned >> 3);
 853         desc->transactionid = requestid;
 854         desc->rangecount = 1;
 855
 856         bufferlist[0].iov_base = desc;
 857         bufferlist[0].iov_len = desc_size;
 858         bufferlist[1].iov_base = buffer;
 859         bufferlist[1].iov_len = bufferlen;
 860         bufferlist[2].iov_base = &aligned_data;
 861         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 862
 863         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
 864                                   &signal, lock);
 865
 866         if (ret == 0 && signal)
 867                 vmbus_setevent(channel);
 868
 869         return ret;
 870 }
 871 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 872
 873 /*
 874  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 875  * using a GPADL Direct packet type.
 876  */
 877 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 878                                 struct hv_multipage_buffer *multi_pagebuffer,
 879                                 void *buffer, u32 bufferlen, u64 requestid)
 880 {
 881         int ret;
 882         struct vmbus_channel_packet_multipage_buffer desc;
 883         u32 descsize;
 884         u32 packetlen;
 885         u32 packetlen_aligned;
 886         struct kvec bufferlist[3];
 887         u64 aligned_data = 0;
 888         bool signal = false;
 889         bool lock = channel->acquire_ring_lock;
 890         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 891                                          multi_pagebuffer->len);
 892
 893         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 894                 return -EINVAL;
 895
 896         /*
 897          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 898          * the largest size we support
 899          */
 900         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 901                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 902                           sizeof(u64));
 903         packetlen = descsize + bufferlen;
 904         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 905
 906
 907         /* Setup the descriptor */
 908         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 909         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 910         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 911         desc.length8 = (u16)(packetlen_aligned >> 3);
 912         desc.transactionid = requestid;
 913         desc.rangecount = 1;
 914
 915         desc.range.len = multi_pagebuffer->len;
 916         desc.range.offset = multi_pagebuffer->offset;
 917
 918         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 919                pfncount * sizeof(u64));
 920
 921         bufferlist[0].iov_base = &desc;
 922         bufferlist[0].iov_len = descsize;
 923         bufferlist[1].iov_base = buffer;
 924         bufferlist[1].iov_len = bufferlen;
 925         bufferlist[2].iov_base = &aligned_data;
 926         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 927
 928         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
 929                                   &signal, lock);
 930
 931         if (ret == 0 && signal)
 932                 vmbus_setevent(channel);
 933
 934         return ret;
 935 }
 936 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 937
 938 /**
 939  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 940  * @channel: Pointer to vmbus_channel structure.
 941  * @buffer: Pointer to the buffer you want to receive the data into.
 942  * @bufferlen: Maximum size of what the the buffer will hold
 943  * @buffer_actual_len: The actual size of the data after it was received
 944  * @requestid: Identifier of the request
 945  *
 946  * Receives directly from the hyper-v vmbus and puts the data it received
 947  * into Buffer. This will receive the data unparsed from hyper-v.
 948  *
 949  * Mainly used by Hyper-V drivers.
 950  */
 951 static inline int
 952 __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 953                    u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
 954                    bool raw)
 955 {
 956         int ret;
 957         bool signal = false;
 958
 959         ret = hv_ringbuffer_read(&channel->inbound, buffer, bufferlen,
 960                                  buffer_actual_len, requestid, &signal, raw);
 961
 962         if (signal)
 963                 vmbus_setevent(channel);
 964
 965         return ret;
 966 }
 967
 968 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 969                      u32 bufferlen, u32 *buffer_actual_len,
 970                      u64 *requestid)
 971 {
 972         return __vmbus_recvpacket(channel, buffer, bufferlen,
 973                                   buffer_actual_len, requestid, false);
 974 }
 975 EXPORT_SYMBOL(vmbus_recvpacket);
 976
 977 /*
 978  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 979  */
 980 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 981                               u32 bufferlen, u32 *buffer_actual_len,
 982                               u64 *requestid)
 983 {
 984         return __vmbus_recvpacket(channel, buffer, bufferlen,
 985                                   buffer_actual_len, requestid, true);
 986 }
 987 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);