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 /*
 218  * create_gpadl_header - Creates a gpadl for the specified buffer
 219  */
 220 static int create_gpadl_header(void *kbuffer, u32 size,
 221                                          struct vmbus_channel_msginfo **msginfo,
 222                                          u32 *messagecount)
 223 {
 224         int i;
 225         int pagecount;
 226         struct vmbus_channel_gpadl_header *gpadl_header;
 227         struct vmbus_channel_gpadl_body *gpadl_body;
 228         struct vmbus_channel_msginfo *msgheader;
 229         struct vmbus_channel_msginfo *msgbody = NULL;
 230         u32 msgsize;
 231
 232         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 233
 234         pagecount = size >> PAGE_SHIFT;
 235
 236         /* do we need a gpadl body msg */
 237         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 238                   sizeof(struct vmbus_channel_gpadl_header) -
 239                   sizeof(struct gpa_range);
 240         pfncount = pfnsize / sizeof(u64);
 241
 242         if (pagecount > pfncount) {
 243                 /* we need a gpadl body */
 244                 /* fill in the header */
 245                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 246                           sizeof(struct vmbus_channel_gpadl_header) +
 247                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 248                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 249                 if (!msgheader)
 250                         goto nomem;
 251
 252                 INIT_LIST_HEAD(&msgheader->submsglist);
 253                 msgheader->msgsize = msgsize;
 254
 255                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 256                         msgheader->msg;
 257                 gpadl_header->rangecount = 1;
 258                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 259                                          pagecount * sizeof(u64);
 260                 gpadl_header->range[0].byte_offset = 0;
 261                 gpadl_header->range[0].byte_count = size;
 262                 for (i = 0; i < pfncount; i++)
 263                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 264                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 265                 *msginfo = msgheader;
 266                 *messagecount = 1;
 267
 268                 pfnsum = pfncount;
 269                 pfnleft = pagecount - pfncount;
 270
 271                 /* how many pfns can we fit */
 272                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 273                           sizeof(struct vmbus_channel_gpadl_body);
 274                 pfncount = pfnsize / sizeof(u64);
 275
 276                 /* fill in the body */
 277                 while (pfnleft) {
 278                         if (pfnleft > pfncount)
 279                                 pfncurr = pfncount;
 280                         else
 281                                 pfncurr = pfnleft;
 282
 283                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 284                                   sizeof(struct vmbus_channel_gpadl_body) +
 285                                   pfncurr * sizeof(u64);
 286                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 287
 288                         if (!msgbody) {
 289                                 struct vmbus_channel_msginfo *pos = NULL;
 290                                 struct vmbus_channel_msginfo *tmp = NULL;
 291                                 /*
 292                                  * Free up all the allocated messages.
 293                                  */
 294                                 list_for_each_entry_safe(pos, tmp,
 295                                         &msgheader->submsglist,
 296                                         msglistentry) {
 297
 298                                         list_del(&pos->msglistentry);
 299                                         kfree(pos);
 300                                 }
 301
 302                                 goto nomem;
 303                         }
 304
 305                         msgbody->msgsize = msgsize;
 306                         (*messagecount)++;
 307                         gpadl_body =
 308                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 309
 310                         /*
 311                          * Gpadl is u32 and we are using a pointer which could
 312                          * be 64-bit
 313                          * This is governed by the guest/host protocol and
 314                          * so the hypervisor gurantees that this is ok.
 315                          */
 316                         for (i = 0; i < pfncurr; i++)
 317                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 318                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 319                                         PAGE_SHIFT;
 320
 321                         /* add to msg header */
 322                         list_add_tail(&msgbody->msglistentry,
 323                                       &msgheader->submsglist);
 324                         pfnsum += pfncurr;
 325                         pfnleft -= pfncurr;
 326                 }
 327         } else {
 328                 /* everything fits in a header */
 329                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 330                           sizeof(struct vmbus_channel_gpadl_header) +
 331                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 332                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 333                 if (msgheader == NULL)
 334                         goto nomem;
 335                 msgheader->msgsize = msgsize;
 336
 337                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 338                         msgheader->msg;
 339                 gpadl_header->rangecount = 1;
 340                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 341                                          pagecount * sizeof(u64);
 342                 gpadl_header->range[0].byte_offset = 0;
 343                 gpadl_header->range[0].byte_count = size;
 344                 for (i = 0; i < pagecount; i++)
 345                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 346                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 347
 348                 *msginfo = msgheader;
 349                 *messagecount = 1;
 350         }
 351
 352         return 0;
 353 nomem:
 354         kfree(msgheader);
 355         kfree(msgbody);
 356         return -ENOMEM;
 357 }
 358
 359 /*
 360  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 361  *
 362  * @channel: a channel
 363  * @kbuffer: from kmalloc or vmalloc
 364  * @size: page-size multiple
 365  * @gpadl_handle: some funky thing
 366  */
 367 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 368                                u32 size, u32 *gpadl_handle)
 369 {
 370         struct vmbus_channel_gpadl_header *gpadlmsg;
 371         struct vmbus_channel_gpadl_body *gpadl_body;
 372         struct vmbus_channel_msginfo *msginfo = NULL;
 373         struct vmbus_channel_msginfo *submsginfo, *tmp;
 374         u32 msgcount;
 375         struct list_head *curr;
 376         u32 next_gpadl_handle;
 377         unsigned long flags;
 378         int ret = 0;
 379
 380         next_gpadl_handle =
 381                 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 382
 383         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 384         if (ret)
 385                 return ret;
 386
 387         init_completion(&msginfo->waitevent);
 388
 389         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 390         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 391         gpadlmsg->child_relid = channel->offermsg.child_relid;
 392         gpadlmsg->gpadl = next_gpadl_handle;
 393
 394
 395         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 396         list_add_tail(&msginfo->msglistentry,
 397                       &vmbus_connection.chn_msg_list);
 398
 399         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 400
 401         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 402                                sizeof(*msginfo));
 403         if (ret != 0)
 404                 goto cleanup;
 405
 406         if (msgcount > 1) {
 407                 list_for_each(curr, &msginfo->submsglist) {
 408
 409                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 410                         gpadl_body =
 411                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 412
 413                         gpadl_body->header.msgtype =
 414                                 CHANNELMSG_GPADL_BODY;
 415                         gpadl_body->gpadl = next_gpadl_handle;
 416
 417                         ret = vmbus_post_msg(gpadl_body,
 418                                                submsginfo->msgsize -
 419                                                sizeof(*submsginfo));
 420                         if (ret != 0)
 421                                 goto cleanup;
 422
 423                 }
 424         }
 425         wait_for_completion(&msginfo->waitevent);
 426
 427         /* At this point, we received the gpadl created msg */
 428         *gpadl_handle = gpadlmsg->gpadl;
 429
 430 cleanup:
 431         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 432         list_del(&msginfo->msglistentry);
 433         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 434
 435         if (msgcount > 1) {
 436                 list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
 437                          msglistentry) {
 438                         kfree(submsginfo);
 439                 }
 440         }
 441
 442         kfree(msginfo);
 443         return ret;
 444 }
 445 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 446
 447 /*
 448  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 449  */
 450 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 451 {
 452         struct vmbus_channel_gpadl_teardown *msg;
 453         struct vmbus_channel_msginfo *info;
 454         unsigned long flags;
 455         int ret;
 456
 457         info = kmalloc(sizeof(*info) +
 458                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 459         if (!info)
 460                 return -ENOMEM;
 461
 462         init_completion(&info->waitevent);
 463
 464         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 465
 466         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 467         msg->child_relid = channel->offermsg.child_relid;
 468         msg->gpadl = gpadl_handle;
 469
 470         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 471         list_add_tail(&info->msglistentry,
 472                       &vmbus_connection.chn_msg_list);
 473         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 474         ret = vmbus_post_msg(msg,
 475                                sizeof(struct vmbus_channel_gpadl_teardown));
 476
 477         if (ret)
 478                 goto post_msg_err;
 479
 480         wait_for_completion(&info->waitevent);
 481
 482 post_msg_err:
 483         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 484         list_del(&info->msglistentry);
 485         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 486
 487         kfree(info);
 488         return ret;
 489 }
 490 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 491
 492 static void reset_channel_cb(void *arg)
 493 {
 494         struct vmbus_channel *channel = arg;
 495
 496         channel->onchannel_callback = NULL;
 497 }
 498
 499 static int vmbus_close_internal(struct vmbus_channel *channel)
 500 {
 501         struct vmbus_channel_close_channel *msg;
 502         struct tasklet_struct *tasklet;
 503         int ret;
 504
 505         /*
 506          * process_chn_event(), running in the tasklet, can race
 507          * with vmbus_close_internal() in the case of SMP guest, e.g., when
 508          * the former is accessing channel->inbound.ring_buffer, the latter
 509          * could be freeing the ring_buffer pages.
 510          *
 511          * To resolve the race, we can serialize them by disabling the
 512          * tasklet when the latter is running here.
 513          */
 514         tasklet = hv_context.event_dpc[channel->target_cpu];
 515         tasklet_disable(tasklet);
 516
 517         channel->state = CHANNEL_OPEN_STATE;
 518         channel->sc_creation_callback = NULL;
 519         /* Stop callback and cancel the timer asap */
 520         if (channel->target_cpu != get_cpu()) {
 521                 put_cpu();
 522                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 523                                          channel, true);
 524         } else {
 525                 reset_channel_cb(channel);
 526                 put_cpu();
 527         }
 528
 529         /* Send a closing message */
 530
 531         msg = &channel->close_msg.msg;
 532
 533         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 534         msg->child_relid = channel->offermsg.child_relid;
 535
 536         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 537
 538         if (ret) {
 539                 pr_err("Close failed: close post msg return is %d\n", ret);
 540                 /*
 541                  * If we failed to post the close msg,
 542                  * it is perhaps better to leak memory.
 543                  */
 544                 goto out;
 545         }
 546
 547         /* Tear down the gpadl for the channel's ring buffer */
 548         if (channel->ringbuffer_gpadlhandle) {
 549                 ret = vmbus_teardown_gpadl(channel,
 550                                            channel->ringbuffer_gpadlhandle);
 551                 if (ret) {
 552                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 553                         /*
 554                          * If we failed to teardown gpadl,
 555                          * it is perhaps better to leak memory.
 556                          */
 557                         goto out;
 558                 }
 559         }
 560
 561         /* Cleanup the ring buffers for this channel */
 562         hv_ringbuffer_cleanup(&channel->outbound);
 563         hv_ringbuffer_cleanup(&channel->inbound);
 564
 565         free_pages((unsigned long)channel->ringbuffer_pages,
 566                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 567
 568 out:
 569         tasklet_enable(tasklet);
 570
 571         return ret;
 572 }
 573
 574 /*
 575  * vmbus_close - Close the specified channel
 576  */
 577 void vmbus_close(struct vmbus_channel *channel)
 578 {
 579         struct list_head *cur, *tmp;
 580         struct vmbus_channel *cur_channel;
 581
 582         if (channel->primary_channel != NULL) {
 583                 /*
 584                  * We will only close sub-channels when
 585                  * the primary is closed.
 586                  */
 587                 return;
 588         }
 589         /*
 590          * Close all the sub-channels first and then close the
 591          * primary channel.
 592          */
 593         list_for_each_safe(cur, tmp, &channel->sc_list) {
 594                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 595                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 596                         continue;
 597                 vmbus_close_internal(cur_channel);
 598         }
 599         /*
 600          * Now close the primary.
 601          */
 602         vmbus_close_internal(channel);
 603 }
 604 EXPORT_SYMBOL_GPL(vmbus_close);
 605
 606 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 607                            u32 bufferlen, u64 requestid,
 608                            enum vmbus_packet_type type, u32 flags, bool kick_q)
 609 {
 610         struct vmpacket_descriptor desc;
 611         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 612         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 613         struct kvec bufferlist[3];
 614         u64 aligned_data = 0;
 615         int ret;
 616         bool signal = false;
 617         int num_vecs = ((bufferlen != 0) ? 3 : 1);
 618
 619
 620         /* Setup the descriptor */
 621         desc.type = type; /* VmbusPacketTypeDataInBand; */
 622         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 623         /* in 8-bytes granularity */
 624         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 625         desc.len8 = (u16)(packetlen_aligned >> 3);
 626         desc.trans_id = requestid;
 627
 628         bufferlist[0].iov_base = &desc;
 629         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 630         bufferlist[1].iov_base = buffer;
 631         bufferlist[1].iov_len = bufferlen;
 632         bufferlist[2].iov_base = &aligned_data;
 633         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 634
 635         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
 636                                   &signal);
 637
 638         /*
 639          * Signalling the host is conditional on many factors:
 640          * 1. The ring state changed from being empty to non-empty.
 641          *    This is tracked by the variable "signal".
 642          * 2. The variable kick_q tracks if more data will be placed
 643          *    on the ring. We will not signal if more data is
 644          *    to be placed.
 645          *
 646          * Based on the channel signal state, we will decide
 647          * which signaling policy will be applied.
 648          *
 649          * If we cannot write to the ring-buffer; signal the host
 650          * even if we may not have written anything. This is a rare
 651          * enough condition that it should not matter.
 652          */
 653
 654         if (channel->signal_policy)
 655                 signal = true;
 656         else
 657                 kick_q = true;
 658
 659         if (((ret == 0) && kick_q && signal) || (ret))
 660                 vmbus_setevent(channel);
 661
 662         return ret;
 663 }
 664 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 665
 666 /**
 667  * vmbus_sendpacket() - Send the specified buffer on the given channel
 668  * @channel: Pointer to vmbus_channel structure.
 669  * @buffer: Pointer to the buffer you want to receive the data into.
 670  * @bufferlen: Maximum size of what the the buffer will hold
 671  * @requestid: Identifier of the request
 672  * @type: Type of packet that is being send e.g. negotiate, time
 673  * packet etc.
 674  *
 675  * Sends data in @buffer directly to hyper-v via the vmbus
 676  * This will send the data unparsed to hyper-v.
 677  *
 678  * Mainly used by Hyper-V drivers.
 679  */
 680 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 681                            u32 bufferlen, u64 requestid,
 682                            enum vmbus_packet_type type, u32 flags)
 683 {
 684         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 685                                     type, flags, true);
 686 }
 687 EXPORT_SYMBOL(vmbus_sendpacket);
 688
 689 /*
 690  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 691  * packets using a GPADL Direct packet type. This interface allows you
 692  * to control notifying the host. This will be useful for sending
 693  * batched data. Also the sender can control the send flags
 694  * explicitly.
 695  */
 696 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 697                                      struct hv_page_buffer pagebuffers[],
 698                                      u32 pagecount, void *buffer, u32 bufferlen,
 699                                      u64 requestid,
 700                                      u32 flags,
 701                                      bool kick_q)
 702 {
 703         int ret;
 704         int i;
 705         struct vmbus_channel_packet_page_buffer desc;
 706         u32 descsize;
 707         u32 packetlen;
 708         u32 packetlen_aligned;
 709         struct kvec bufferlist[3];
 710         u64 aligned_data = 0;
 711         bool signal = false;
 712
 713         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 714                 return -EINVAL;
 715
 716
 717         /*
 718          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 719          * largest size we support
 720          */
 721         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 722                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 723                           sizeof(struct hv_page_buffer));
 724         packetlen = descsize + bufferlen;
 725         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 726
 727         /* Setup the descriptor */
 728         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 729         desc.flags = flags;
 730         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 731         desc.length8 = (u16)(packetlen_aligned >> 3);
 732         desc.transactionid = requestid;
 733         desc.rangecount = pagecount;
 734
 735         for (i = 0; i < pagecount; i++) {
 736                 desc.range[i].len = pagebuffers[i].len;
 737                 desc.range[i].offset = pagebuffers[i].offset;
 738                 desc.range[i].pfn        = pagebuffers[i].pfn;
 739         }
 740
 741         bufferlist[0].iov_base = &desc;
 742         bufferlist[0].iov_len = descsize;
 743         bufferlist[1].iov_base = buffer;
 744         bufferlist[1].iov_len = bufferlen;
 745         bufferlist[2].iov_base = &aligned_data;
 746         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 747
 748         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 749
 750         /*
 751          * Signalling the host is conditional on many factors:
 752          * 1. The ring state changed from being empty to non-empty.
 753          *    This is tracked by the variable "signal".
 754          * 2. The variable kick_q tracks if more data will be placed
 755          *    on the ring. We will not signal if more data is
 756          *    to be placed.
 757          *
 758          * Based on the channel signal state, we will decide
 759          * which signaling policy will be applied.
 760          *
 761          * If we cannot write to the ring-buffer; signal the host
 762          * even if we may not have written anything. This is a rare
 763          * enough condition that it should not matter.
 764          */
 765
 766         if (channel->signal_policy)
 767                 signal = true;
 768         else
 769                 kick_q = true;
 770
 771         if (((ret == 0) && kick_q && signal) || (ret))
 772                 vmbus_setevent(channel);
 773
 774         return ret;
 775 }
 776 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 777
 778 /*
 779  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 780  * packets using a GPADL Direct packet type.
 781  */
 782 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 783                                      struct hv_page_buffer pagebuffers[],
 784                                      u32 pagecount, void *buffer, u32 bufferlen,
 785                                      u64 requestid)
 786 {
 787         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 788         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 789                                                buffer, bufferlen, requestid,
 790                                                flags, true);
 791
 792 }
 793 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 794
 795 /*
 796  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 797  * using a GPADL Direct packet type.
 798  * The buffer includes the vmbus descriptor.
 799  */
 800 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 801                               struct vmbus_packet_mpb_array *desc,
 802                               u32 desc_size,
 803                               void *buffer, u32 bufferlen, u64 requestid)
 804 {
 805         int ret;
 806         u32 packetlen;
 807         u32 packetlen_aligned;
 808         struct kvec bufferlist[3];
 809         u64 aligned_data = 0;
 810         bool signal = false;
 811
 812         packetlen = desc_size + bufferlen;
 813         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 814
 815         /* Setup the descriptor */
 816         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 817         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 818         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
 819         desc->length8 = (u16)(packetlen_aligned >> 3);
 820         desc->transactionid = requestid;
 821         desc->rangecount = 1;
 822
 823         bufferlist[0].iov_base = desc;
 824         bufferlist[0].iov_len = desc_size;
 825         bufferlist[1].iov_base = buffer;
 826         bufferlist[1].iov_len = bufferlen;
 827         bufferlist[2].iov_base = &aligned_data;
 828         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 829
 830         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 831
 832         if (ret == 0 && signal)
 833                 vmbus_setevent(channel);
 834
 835         return ret;
 836 }
 837 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 838
 839 /*
 840  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 841  * using a GPADL Direct packet type.
 842  */
 843 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 844                                 struct hv_multipage_buffer *multi_pagebuffer,
 845                                 void *buffer, u32 bufferlen, u64 requestid)
 846 {
 847         int ret;
 848         struct vmbus_channel_packet_multipage_buffer desc;
 849         u32 descsize;
 850         u32 packetlen;
 851         u32 packetlen_aligned;
 852         struct kvec bufferlist[3];
 853         u64 aligned_data = 0;
 854         bool signal = false;
 855         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 856                                          multi_pagebuffer->len);
 857
 858         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 859                 return -EINVAL;
 860
 861         /*
 862          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 863          * the largest size we support
 864          */
 865         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 866                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 867                           sizeof(u64));
 868         packetlen = descsize + bufferlen;
 869         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 870
 871
 872         /* Setup the descriptor */
 873         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 874         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 875         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 876         desc.length8 = (u16)(packetlen_aligned >> 3);
 877         desc.transactionid = requestid;
 878         desc.rangecount = 1;
 879
 880         desc.range.len = multi_pagebuffer->len;
 881         desc.range.offset = multi_pagebuffer->offset;
 882
 883         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 884                pfncount * sizeof(u64));
 885
 886         bufferlist[0].iov_base = &desc;
 887         bufferlist[0].iov_len = descsize;
 888         bufferlist[1].iov_base = buffer;
 889         bufferlist[1].iov_len = bufferlen;
 890         bufferlist[2].iov_base = &aligned_data;
 891         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 892
 893         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 894
 895         if (ret == 0 && signal)
 896                 vmbus_setevent(channel);
 897
 898         return ret;
 899 }
 900 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 901
 902 /**
 903  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 904  * @channel: Pointer to vmbus_channel structure.
 905  * @buffer: Pointer to the buffer you want to receive the data into.
 906  * @bufferlen: Maximum size of what the the buffer will hold
 907  * @buffer_actual_len: The actual size of the data after it was received
 908  * @requestid: Identifier of the request
 909  *
 910  * Receives directly from the hyper-v vmbus and puts the data it received
 911  * into Buffer. This will receive the data unparsed from hyper-v.
 912  *
 913  * Mainly used by Hyper-V drivers.
 914  */
 915 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 916                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 917 {
 918         struct vmpacket_descriptor desc;
 919         u32 packetlen;
 920         u32 userlen;
 921         int ret;
 922         bool signal = false;
 923
 924         *buffer_actual_len = 0;
 925         *requestid = 0;
 926
 927
 928         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 929                              sizeof(struct vmpacket_descriptor));
 930         if (ret != 0)
 931                 return 0;
 932
 933         packetlen = desc.len8 << 3;
 934         userlen = packetlen - (desc.offset8 << 3);
 935
 936         *buffer_actual_len = userlen;
 937
 938         if (userlen > bufferlen) {
 939
 940                 pr_err("Buffer too small - got %d needs %d\n",
 941                            bufferlen, userlen);
 942                 return -ETOOSMALL;
 943         }
 944
 945         *requestid = desc.trans_id;
 946
 947         /* Copy over the packet to the user buffer */
 948         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 949                              (desc.offset8 << 3), &signal);
 950
 951         if (signal)
 952                 vmbus_setevent(channel);
 953
 954         return 0;
 955 }
 956 EXPORT_SYMBOL(vmbus_recvpacket);
 957
 958 /*
 959  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 960  */
 961 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 962                               u32 bufferlen, u32 *buffer_actual_len,
 963                               u64 *requestid)
 964 {
 965         struct vmpacket_descriptor desc;
 966         u32 packetlen;
 967         int ret;
 968         bool signal = false;
 969
 970         *buffer_actual_len = 0;
 971         *requestid = 0;
 972
 973
 974         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 975                              sizeof(struct vmpacket_descriptor));
 976         if (ret != 0)
 977                 return 0;
 978
 979
 980         packetlen = desc.len8 << 3;
 981
 982         *buffer_actual_len = packetlen;
 983
 984         if (packetlen > bufferlen)
 985                 return -ENOBUFS;
 986
 987         *requestid = desc.trans_id;
 988
 989         /* Copy over the entire packet to the user buffer */
 990         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 991                                  &signal);
 992
 993         if (signal)
 994                 vmbus_setevent(channel);
 995
 996         return ret;
 997 }
 998 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);