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