1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2009, Microsoft Corporation. 4 * 5 * Authors: 6 * Haiyang Zhang <haiyangz@microsoft.com> 7 * Hank Janssen <hjanssen@microsoft.com> 8 */ 9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 10 11 #include <linux/kernel.h> 12 #include <linux/sched.h> 13 #include <linux/wait.h> 14 #include <linux/mm.h> 15 #include <linux/slab.h> 16 #include <linux/module.h> 17 #include <linux/hyperv.h> 18 #include <linux/uio.h> 19 #include <linux/interrupt.h> 20 #include <asm/page.h> 21 22 #include "hyperv_vmbus.h" 23 24 #define NUM_PAGES_SPANNED(addr, len) \ 25 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT)) 26 27 static unsigned long virt_to_hvpfn(void *addr) 28 { 29 phys_addr_t paddr; 30 31 if (is_vmalloc_addr(addr)) 32 paddr = page_to_phys(vmalloc_to_page(addr)) + 33 offset_in_page(addr); 34 else 35 paddr = __pa(addr); 36 37 return paddr >> PAGE_SHIFT; 38 } 39 40 /* 41 * vmbus_setevent- Trigger an event notification on the specified 42 * channel. 43 */ 44 void vmbus_setevent(struct vmbus_channel *channel) 45 { 46 struct hv_monitor_page *monitorpage; 47 48 trace_vmbus_setevent(channel); 49 50 /* 51 * For channels marked as in "low latency" mode 52 * bypass the monitor page mechanism. 53 */ 54 if (channel->offermsg.monitor_allocated && !channel->low_latency) { 55 vmbus_send_interrupt(channel->offermsg.child_relid); 56 57 /* Get the child to parent monitor page */ 58 monitorpage = vmbus_connection.monitor_pages[1]; 59 60 sync_set_bit(channel->monitor_bit, 61 (unsigned long *)&monitorpage->trigger_group 62 [channel->monitor_grp].pending); 63 64 } else { 65 vmbus_set_event(channel); 66 } 67 } 68 EXPORT_SYMBOL_GPL(vmbus_setevent); 69 70 /* vmbus_free_ring - drop mapping of ring buffer */ 71 void vmbus_free_ring(struct vmbus_channel *channel) 72 { 73 hv_ringbuffer_cleanup(&channel->outbound); 74 hv_ringbuffer_cleanup(&channel->inbound); 75 76 if (channel->ringbuffer_page) { 77 __free_pages(channel->ringbuffer_page, 78 get_order(channel->ringbuffer_pagecount 79 << PAGE_SHIFT)); 80 channel->ringbuffer_page = NULL; 81 } 82 } 83 EXPORT_SYMBOL_GPL(vmbus_free_ring); 84 85 /* vmbus_alloc_ring - allocate and map pages for ring buffer */ 86 int vmbus_alloc_ring(struct vmbus_channel *newchannel, 87 u32 send_size, u32 recv_size) 88 { 89 struct page *page; 90 int order; 91 92 if (send_size % PAGE_SIZE || recv_size % PAGE_SIZE) 93 return -EINVAL; 94 95 /* Allocate the ring buffer */ 96 order = get_order(send_size + recv_size); 97 page = alloc_pages_node(cpu_to_node(newchannel->target_cpu), 98 GFP_KERNEL|__GFP_ZERO, order); 99 100 if (!page) 101 page = alloc_pages(GFP_KERNEL|__GFP_ZERO, order); 102 103 if (!page) 104 return -ENOMEM; 105 106 newchannel->ringbuffer_page = page; 107 newchannel->ringbuffer_pagecount = (send_size + recv_size) >> PAGE_SHIFT; 108 newchannel->ringbuffer_send_offset = send_size >> PAGE_SHIFT; 109 110 return 0; 111 } 112 EXPORT_SYMBOL_GPL(vmbus_alloc_ring); 113 114 static int __vmbus_open(struct vmbus_channel *newchannel, 115 void *userdata, u32 userdatalen, 116 void (*onchannelcallback)(void *context), void *context) 117 { 118 struct vmbus_channel_open_channel *open_msg; 119 struct vmbus_channel_msginfo *open_info = NULL; 120 struct page *page = newchannel->ringbuffer_page; 121 u32 send_pages, recv_pages; 122 unsigned long flags; 123 int err; 124 125 if (userdatalen > MAX_USER_DEFINED_BYTES) 126 return -EINVAL; 127 128 send_pages = newchannel->ringbuffer_send_offset; 129 recv_pages = newchannel->ringbuffer_pagecount - send_pages; 130 131 spin_lock_irqsave(&newchannel->lock, flags); 132 if (newchannel->state != CHANNEL_OPEN_STATE) { 133 spin_unlock_irqrestore(&newchannel->lock, flags); 134 return -EINVAL; 135 } 136 spin_unlock_irqrestore(&newchannel->lock, flags); 137 138 newchannel->state = CHANNEL_OPENING_STATE; 139 newchannel->onchannel_callback = onchannelcallback; 140 newchannel->channel_callback_context = context; 141 142 err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages); 143 if (err) 144 goto error_clean_ring; 145 146 err = hv_ringbuffer_init(&newchannel->inbound, 147 &page[send_pages], recv_pages); 148 if (err) 149 goto error_clean_ring; 150 151 /* Establish the gpadl for the ring buffer */ 152 newchannel->ringbuffer_gpadlhandle = 0; 153 154 err = vmbus_establish_gpadl(newchannel, 155 page_address(newchannel->ringbuffer_page), 156 (send_pages + recv_pages) << PAGE_SHIFT, 157 &newchannel->ringbuffer_gpadlhandle); 158 if (err) 159 goto error_clean_ring; 160 161 /* Create and init the channel open message */ 162 open_info = kmalloc(sizeof(*open_info) + 163 sizeof(struct vmbus_channel_open_channel), 164 GFP_KERNEL); 165 if (!open_info) { 166 err = -ENOMEM; 167 goto error_free_gpadl; 168 } 169 170 init_completion(&open_info->waitevent); 171 open_info->waiting_channel = newchannel; 172 173 open_msg = (struct vmbus_channel_open_channel *)open_info->msg; 174 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL; 175 open_msg->openid = newchannel->offermsg.child_relid; 176 open_msg->child_relid = newchannel->offermsg.child_relid; 177 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle; 178 open_msg->downstream_ringbuffer_pageoffset = newchannel->ringbuffer_send_offset; 179 open_msg->target_vp = newchannel->target_vp; 180 181 if (userdatalen) 182 memcpy(open_msg->userdata, userdata, userdatalen); 183 184 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 185 list_add_tail(&open_info->msglistentry, 186 &vmbus_connection.chn_msg_list); 187 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 188 189 if (newchannel->rescind) { 190 err = -ENODEV; 191 goto error_free_info; 192 } 193 194 err = vmbus_post_msg(open_msg, 195 sizeof(struct vmbus_channel_open_channel), true); 196 197 trace_vmbus_open(open_msg, err); 198 199 if (err != 0) 200 goto error_clean_msglist; 201 202 wait_for_completion(&open_info->waitevent); 203 204 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 205 list_del(&open_info->msglistentry); 206 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 207 208 if (newchannel->rescind) { 209 err = -ENODEV; 210 goto error_free_info; 211 } 212 213 if (open_info->response.open_result.status) { 214 err = -EAGAIN; 215 goto error_free_info; 216 } 217 218 newchannel->state = CHANNEL_OPENED_STATE; 219 kfree(open_info); 220 return 0; 221 222 error_clean_msglist: 223 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 224 list_del(&open_info->msglistentry); 225 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 226 error_free_info: 227 kfree(open_info); 228 error_free_gpadl: 229 vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle); 230 newchannel->ringbuffer_gpadlhandle = 0; 231 error_clean_ring: 232 hv_ringbuffer_cleanup(&newchannel->outbound); 233 hv_ringbuffer_cleanup(&newchannel->inbound); 234 newchannel->state = CHANNEL_OPEN_STATE; 235 return err; 236 } 237 238 /* 239 * vmbus_connect_ring - Open the channel but reuse ring buffer 240 */ 241 int vmbus_connect_ring(struct vmbus_channel *newchannel, 242 void (*onchannelcallback)(void *context), void *context) 243 { 244 return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context); 245 } 246 EXPORT_SYMBOL_GPL(vmbus_connect_ring); 247 248 /* 249 * vmbus_open - Open the specified channel. 250 */ 251 int vmbus_open(struct vmbus_channel *newchannel, 252 u32 send_ringbuffer_size, u32 recv_ringbuffer_size, 253 void *userdata, u32 userdatalen, 254 void (*onchannelcallback)(void *context), void *context) 255 { 256 int err; 257 258 err = vmbus_alloc_ring(newchannel, send_ringbuffer_size, 259 recv_ringbuffer_size); 260 if (err) 261 return err; 262 263 err = __vmbus_open(newchannel, userdata, userdatalen, 264 onchannelcallback, context); 265 if (err) 266 vmbus_free_ring(newchannel); 267 268 return err; 269 } 270 EXPORT_SYMBOL_GPL(vmbus_open); 271 272 /* Used for Hyper-V Socket: a guest client's connect() to the host */ 273 int vmbus_send_tl_connect_request(const guid_t *shv_guest_servie_id, 274 const guid_t *shv_host_servie_id) 275 { 276 struct vmbus_channel_tl_connect_request conn_msg; 277 int ret; 278 279 memset(&conn_msg, 0, sizeof(conn_msg)); 280 conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST; 281 conn_msg.guest_endpoint_id = *shv_guest_servie_id; 282 conn_msg.host_service_id = *shv_host_servie_id; 283 284 ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true); 285 286 trace_vmbus_send_tl_connect_request(&conn_msg, ret); 287 288 return ret; 289 } 290 EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request); 291 292 /* 293 * create_gpadl_header - Creates a gpadl for the specified buffer 294 */ 295 static int create_gpadl_header(void *kbuffer, u32 size, 296 struct vmbus_channel_msginfo **msginfo) 297 { 298 int i; 299 int pagecount; 300 struct vmbus_channel_gpadl_header *gpadl_header; 301 struct vmbus_channel_gpadl_body *gpadl_body; 302 struct vmbus_channel_msginfo *msgheader; 303 struct vmbus_channel_msginfo *msgbody = NULL; 304 u32 msgsize; 305 306 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize; 307 308 pagecount = size >> PAGE_SHIFT; 309 310 /* do we need a gpadl body msg */ 311 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 312 sizeof(struct vmbus_channel_gpadl_header) - 313 sizeof(struct gpa_range); 314 pfncount = pfnsize / sizeof(u64); 315 316 if (pagecount > pfncount) { 317 /* we need a gpadl body */ 318 /* fill in the header */ 319 msgsize = sizeof(struct vmbus_channel_msginfo) + 320 sizeof(struct vmbus_channel_gpadl_header) + 321 sizeof(struct gpa_range) + pfncount * sizeof(u64); 322 msgheader = kzalloc(msgsize, GFP_KERNEL); 323 if (!msgheader) 324 goto nomem; 325 326 INIT_LIST_HEAD(&msgheader->submsglist); 327 msgheader->msgsize = msgsize; 328 329 gpadl_header = (struct vmbus_channel_gpadl_header *) 330 msgheader->msg; 331 gpadl_header->rangecount = 1; 332 gpadl_header->range_buflen = sizeof(struct gpa_range) + 333 pagecount * sizeof(u64); 334 gpadl_header->range[0].byte_offset = 0; 335 gpadl_header->range[0].byte_count = size; 336 for (i = 0; i < pfncount; i++) 337 gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn( 338 kbuffer + PAGE_SIZE * i); 339 *msginfo = msgheader; 340 341 pfnsum = pfncount; 342 pfnleft = pagecount - pfncount; 343 344 /* how many pfns can we fit */ 345 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 346 sizeof(struct vmbus_channel_gpadl_body); 347 pfncount = pfnsize / sizeof(u64); 348 349 /* fill in the body */ 350 while (pfnleft) { 351 if (pfnleft > pfncount) 352 pfncurr = pfncount; 353 else 354 pfncurr = pfnleft; 355 356 msgsize = sizeof(struct vmbus_channel_msginfo) + 357 sizeof(struct vmbus_channel_gpadl_body) + 358 pfncurr * sizeof(u64); 359 msgbody = kzalloc(msgsize, GFP_KERNEL); 360 361 if (!msgbody) { 362 struct vmbus_channel_msginfo *pos = NULL; 363 struct vmbus_channel_msginfo *tmp = NULL; 364 /* 365 * Free up all the allocated messages. 366 */ 367 list_for_each_entry_safe(pos, tmp, 368 &msgheader->submsglist, 369 msglistentry) { 370 371 list_del(&pos->msglistentry); 372 kfree(pos); 373 } 374 375 goto nomem; 376 } 377 378 msgbody->msgsize = msgsize; 379 gpadl_body = 380 (struct vmbus_channel_gpadl_body *)msgbody->msg; 381 382 /* 383 * Gpadl is u32 and we are using a pointer which could 384 * be 64-bit 385 * This is governed by the guest/host protocol and 386 * so the hypervisor guarantees that this is ok. 387 */ 388 for (i = 0; i < pfncurr; i++) 389 gpadl_body->pfn[i] = virt_to_hvpfn( 390 kbuffer + PAGE_SIZE * (pfnsum + i)); 391 392 /* add to msg header */ 393 list_add_tail(&msgbody->msglistentry, 394 &msgheader->submsglist); 395 pfnsum += pfncurr; 396 pfnleft -= pfncurr; 397 } 398 } else { 399 /* everything fits in a header */ 400 msgsize = sizeof(struct vmbus_channel_msginfo) + 401 sizeof(struct vmbus_channel_gpadl_header) + 402 sizeof(struct gpa_range) + pagecount * sizeof(u64); 403 msgheader = kzalloc(msgsize, GFP_KERNEL); 404 if (msgheader == NULL) 405 goto nomem; 406 407 INIT_LIST_HEAD(&msgheader->submsglist); 408 msgheader->msgsize = msgsize; 409 410 gpadl_header = (struct vmbus_channel_gpadl_header *) 411 msgheader->msg; 412 gpadl_header->rangecount = 1; 413 gpadl_header->range_buflen = sizeof(struct gpa_range) + 414 pagecount * sizeof(u64); 415 gpadl_header->range[0].byte_offset = 0; 416 gpadl_header->range[0].byte_count = size; 417 for (i = 0; i < pagecount; i++) 418 gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn( 419 kbuffer + PAGE_SIZE * i); 420 421 *msginfo = msgheader; 422 } 423 424 return 0; 425 nomem: 426 kfree(msgheader); 427 kfree(msgbody); 428 return -ENOMEM; 429 } 430 431 /* 432 * vmbus_establish_gpadl - Establish a GPADL for the specified buffer 433 * 434 * @channel: a channel 435 * @kbuffer: from kmalloc or vmalloc 436 * @size: page-size multiple 437 * @gpadl_handle: some funky thing 438 */ 439 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer, 440 u32 size, u32 *gpadl_handle) 441 { 442 struct vmbus_channel_gpadl_header *gpadlmsg; 443 struct vmbus_channel_gpadl_body *gpadl_body; 444 struct vmbus_channel_msginfo *msginfo = NULL; 445 struct vmbus_channel_msginfo *submsginfo, *tmp; 446 struct list_head *curr; 447 u32 next_gpadl_handle; 448 unsigned long flags; 449 int ret = 0; 450 451 next_gpadl_handle = 452 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1); 453 454 ret = create_gpadl_header(kbuffer, size, &msginfo); 455 if (ret) 456 return ret; 457 458 init_completion(&msginfo->waitevent); 459 msginfo->waiting_channel = channel; 460 461 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg; 462 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER; 463 gpadlmsg->child_relid = channel->offermsg.child_relid; 464 gpadlmsg->gpadl = next_gpadl_handle; 465 466 467 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 468 list_add_tail(&msginfo->msglistentry, 469 &vmbus_connection.chn_msg_list); 470 471 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 472 473 if (channel->rescind) { 474 ret = -ENODEV; 475 goto cleanup; 476 } 477 478 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize - 479 sizeof(*msginfo), true); 480 481 trace_vmbus_establish_gpadl_header(gpadlmsg, ret); 482 483 if (ret != 0) 484 goto cleanup; 485 486 list_for_each(curr, &msginfo->submsglist) { 487 submsginfo = (struct vmbus_channel_msginfo *)curr; 488 gpadl_body = 489 (struct vmbus_channel_gpadl_body *)submsginfo->msg; 490 491 gpadl_body->header.msgtype = 492 CHANNELMSG_GPADL_BODY; 493 gpadl_body->gpadl = next_gpadl_handle; 494 495 ret = vmbus_post_msg(gpadl_body, 496 submsginfo->msgsize - sizeof(*submsginfo), 497 true); 498 499 trace_vmbus_establish_gpadl_body(gpadl_body, ret); 500 501 if (ret != 0) 502 goto cleanup; 503 504 } 505 wait_for_completion(&msginfo->waitevent); 506 507 if (msginfo->response.gpadl_created.creation_status != 0) { 508 pr_err("Failed to establish GPADL: err = 0x%x\n", 509 msginfo->response.gpadl_created.creation_status); 510 511 ret = -EDQUOT; 512 goto cleanup; 513 } 514 515 if (channel->rescind) { 516 ret = -ENODEV; 517 goto cleanup; 518 } 519 520 /* At this point, we received the gpadl created msg */ 521 *gpadl_handle = gpadlmsg->gpadl; 522 523 cleanup: 524 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 525 list_del(&msginfo->msglistentry); 526 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 527 list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist, 528 msglistentry) { 529 kfree(submsginfo); 530 } 531 532 kfree(msginfo); 533 return ret; 534 } 535 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl); 536 537 /* 538 * vmbus_teardown_gpadl -Teardown the specified GPADL handle 539 */ 540 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle) 541 { 542 struct vmbus_channel_gpadl_teardown *msg; 543 struct vmbus_channel_msginfo *info; 544 unsigned long flags; 545 int ret; 546 547 info = kmalloc(sizeof(*info) + 548 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL); 549 if (!info) 550 return -ENOMEM; 551 552 init_completion(&info->waitevent); 553 info->waiting_channel = channel; 554 555 msg = (struct vmbus_channel_gpadl_teardown *)info->msg; 556 557 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN; 558 msg->child_relid = channel->offermsg.child_relid; 559 msg->gpadl = gpadl_handle; 560 561 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 562 list_add_tail(&info->msglistentry, 563 &vmbus_connection.chn_msg_list); 564 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 565 566 if (channel->rescind) 567 goto post_msg_err; 568 569 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown), 570 true); 571 572 trace_vmbus_teardown_gpadl(msg, ret); 573 574 if (ret) 575 goto post_msg_err; 576 577 wait_for_completion(&info->waitevent); 578 579 post_msg_err: 580 /* 581 * If the channel has been rescinded; 582 * we will be awakened by the rescind 583 * handler; set the error code to zero so we don't leak memory. 584 */ 585 if (channel->rescind) 586 ret = 0; 587 588 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 589 list_del(&info->msglistentry); 590 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 591 592 kfree(info); 593 return ret; 594 } 595 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl); 596 597 static void reset_channel_cb(void *arg) 598 { 599 struct vmbus_channel *channel = arg; 600 601 channel->onchannel_callback = NULL; 602 } 603 604 void vmbus_reset_channel_cb(struct vmbus_channel *channel) 605 { 606 /* 607 * vmbus_on_event(), running in the per-channel tasklet, can race 608 * with vmbus_close_internal() in the case of SMP guest, e.g., when 609 * the former is accessing channel->inbound.ring_buffer, the latter 610 * could be freeing the ring_buffer pages, so here we must stop it 611 * first. 612 */ 613 tasklet_disable(&channel->callback_event); 614 615 channel->sc_creation_callback = NULL; 616 617 /* Stop the callback asap */ 618 if (channel->target_cpu != get_cpu()) { 619 put_cpu(); 620 smp_call_function_single(channel->target_cpu, reset_channel_cb, 621 channel, true); 622 } else { 623 reset_channel_cb(channel); 624 put_cpu(); 625 } 626 627 /* Re-enable tasklet for use on re-open */ 628 tasklet_enable(&channel->callback_event); 629 } 630 631 static int vmbus_close_internal(struct vmbus_channel *channel) 632 { 633 struct vmbus_channel_close_channel *msg; 634 int ret; 635 636 vmbus_reset_channel_cb(channel); 637 638 /* 639 * In case a device driver's probe() fails (e.g., 640 * util_probe() -> vmbus_open() returns -ENOMEM) and the device is 641 * rescinded later (e.g., we dynamically disable an Integrated Service 642 * in Hyper-V Manager), the driver's remove() invokes vmbus_close(): 643 * here we should skip most of the below cleanup work. 644 */ 645 if (channel->state != CHANNEL_OPENED_STATE) 646 return -EINVAL; 647 648 channel->state = CHANNEL_OPEN_STATE; 649 650 /* Send a closing message */ 651 652 msg = &channel->close_msg.msg; 653 654 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL; 655 msg->child_relid = channel->offermsg.child_relid; 656 657 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel), 658 true); 659 660 trace_vmbus_close_internal(msg, ret); 661 662 if (ret) { 663 pr_err("Close failed: close post msg return is %d\n", ret); 664 /* 665 * If we failed to post the close msg, 666 * it is perhaps better to leak memory. 667 */ 668 } 669 670 /* Tear down the gpadl for the channel's ring buffer */ 671 else if (channel->ringbuffer_gpadlhandle) { 672 ret = vmbus_teardown_gpadl(channel, 673 channel->ringbuffer_gpadlhandle); 674 if (ret) { 675 pr_err("Close failed: teardown gpadl return %d\n", ret); 676 /* 677 * If we failed to teardown gpadl, 678 * it is perhaps better to leak memory. 679 */ 680 } 681 682 channel->ringbuffer_gpadlhandle = 0; 683 } 684 685 return ret; 686 } 687 688 /* disconnect ring - close all channels */ 689 int vmbus_disconnect_ring(struct vmbus_channel *channel) 690 { 691 struct vmbus_channel *cur_channel, *tmp; 692 int ret; 693 694 if (channel->primary_channel != NULL) 695 return -EINVAL; 696 697 list_for_each_entry_safe(cur_channel, tmp, &channel->sc_list, sc_list) { 698 if (cur_channel->rescind) 699 wait_for_completion(&cur_channel->rescind_event); 700 701 mutex_lock(&vmbus_connection.channel_mutex); 702 if (vmbus_close_internal(cur_channel) == 0) { 703 vmbus_free_ring(cur_channel); 704 705 if (cur_channel->rescind) 706 hv_process_channel_removal(cur_channel); 707 } 708 mutex_unlock(&vmbus_connection.channel_mutex); 709 } 710 711 /* 712 * Now close the primary. 713 */ 714 mutex_lock(&vmbus_connection.channel_mutex); 715 ret = vmbus_close_internal(channel); 716 mutex_unlock(&vmbus_connection.channel_mutex); 717 718 return ret; 719 } 720 EXPORT_SYMBOL_GPL(vmbus_disconnect_ring); 721 722 /* 723 * vmbus_close - Close the specified channel 724 */ 725 void vmbus_close(struct vmbus_channel *channel) 726 { 727 if (vmbus_disconnect_ring(channel) == 0) 728 vmbus_free_ring(channel); 729 } 730 EXPORT_SYMBOL_GPL(vmbus_close); 731 732 /** 733 * vmbus_sendpacket() - Send the specified buffer on the given channel 734 * @channel: Pointer to vmbus_channel structure 735 * @buffer: Pointer to the buffer you want to send the data from. 736 * @bufferlen: Maximum size of what the buffer holds. 737 * @requestid: Identifier of the request 738 * @type: Type of packet that is being sent e.g. negotiate, time 739 * packet etc. 740 * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED 741 * 742 * Sends data in @buffer directly to Hyper-V via the vmbus. 743 * This will send the data unparsed to Hyper-V. 744 * 745 * Mainly used by Hyper-V drivers. 746 */ 747 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer, 748 u32 bufferlen, u64 requestid, 749 enum vmbus_packet_type type, u32 flags) 750 { 751 struct vmpacket_descriptor desc; 752 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen; 753 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 754 struct kvec bufferlist[3]; 755 u64 aligned_data = 0; 756 int num_vecs = ((bufferlen != 0) ? 3 : 1); 757 758 759 /* Setup the descriptor */ 760 desc.type = type; /* VmbusPacketTypeDataInBand; */ 761 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */ 762 /* in 8-bytes granularity */ 763 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3; 764 desc.len8 = (u16)(packetlen_aligned >> 3); 765 desc.trans_id = requestid; 766 767 bufferlist[0].iov_base = &desc; 768 bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor); 769 bufferlist[1].iov_base = buffer; 770 bufferlist[1].iov_len = bufferlen; 771 bufferlist[2].iov_base = &aligned_data; 772 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 773 774 return hv_ringbuffer_write(channel, bufferlist, num_vecs); 775 } 776 EXPORT_SYMBOL(vmbus_sendpacket); 777 778 /* 779 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer 780 * packets using a GPADL Direct packet type. This interface allows you 781 * to control notifying the host. This will be useful for sending 782 * batched data. Also the sender can control the send flags 783 * explicitly. 784 */ 785 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, 786 struct hv_page_buffer pagebuffers[], 787 u32 pagecount, void *buffer, u32 bufferlen, 788 u64 requestid) 789 { 790 int i; 791 struct vmbus_channel_packet_page_buffer desc; 792 u32 descsize; 793 u32 packetlen; 794 u32 packetlen_aligned; 795 struct kvec bufferlist[3]; 796 u64 aligned_data = 0; 797 798 if (pagecount > MAX_PAGE_BUFFER_COUNT) 799 return -EINVAL; 800 801 /* 802 * Adjust the size down since vmbus_channel_packet_page_buffer is the 803 * largest size we support 804 */ 805 descsize = sizeof(struct vmbus_channel_packet_page_buffer) - 806 ((MAX_PAGE_BUFFER_COUNT - pagecount) * 807 sizeof(struct hv_page_buffer)); 808 packetlen = descsize + bufferlen; 809 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 810 811 /* Setup the descriptor */ 812 desc.type = VM_PKT_DATA_USING_GPA_DIRECT; 813 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 814 desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */ 815 desc.length8 = (u16)(packetlen_aligned >> 3); 816 desc.transactionid = requestid; 817 desc.reserved = 0; 818 desc.rangecount = pagecount; 819 820 for (i = 0; i < pagecount; i++) { 821 desc.range[i].len = pagebuffers[i].len; 822 desc.range[i].offset = pagebuffers[i].offset; 823 desc.range[i].pfn = pagebuffers[i].pfn; 824 } 825 826 bufferlist[0].iov_base = &desc; 827 bufferlist[0].iov_len = descsize; 828 bufferlist[1].iov_base = buffer; 829 bufferlist[1].iov_len = bufferlen; 830 bufferlist[2].iov_base = &aligned_data; 831 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 832 833 return hv_ringbuffer_write(channel, bufferlist, 3); 834 } 835 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer); 836 837 /* 838 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet 839 * using a GPADL Direct packet type. 840 * The buffer includes the vmbus descriptor. 841 */ 842 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel, 843 struct vmbus_packet_mpb_array *desc, 844 u32 desc_size, 845 void *buffer, u32 bufferlen, u64 requestid) 846 { 847 u32 packetlen; 848 u32 packetlen_aligned; 849 struct kvec bufferlist[3]; 850 u64 aligned_data = 0; 851 852 packetlen = desc_size + bufferlen; 853 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 854 855 /* Setup the descriptor */ 856 desc->type = VM_PKT_DATA_USING_GPA_DIRECT; 857 desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 858 desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */ 859 desc->length8 = (u16)(packetlen_aligned >> 3); 860 desc->transactionid = requestid; 861 desc->reserved = 0; 862 desc->rangecount = 1; 863 864 bufferlist[0].iov_base = desc; 865 bufferlist[0].iov_len = desc_size; 866 bufferlist[1].iov_base = buffer; 867 bufferlist[1].iov_len = bufferlen; 868 bufferlist[2].iov_base = &aligned_data; 869 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 870 871 return hv_ringbuffer_write(channel, bufferlist, 3); 872 } 873 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc); 874 875 /** 876 * __vmbus_recvpacket() - Retrieve the user packet on the specified channel 877 * @channel: Pointer to vmbus_channel structure 878 * @buffer: Pointer to the buffer you want to receive the data into. 879 * @bufferlen: Maximum size of what the buffer can hold. 880 * @buffer_actual_len: The actual size of the data after it was received. 881 * @requestid: Identifier of the request 882 * @raw: true means keep the vmpacket_descriptor header in the received data. 883 * 884 * Receives directly from the hyper-v vmbus and puts the data it received 885 * into Buffer. This will receive the data unparsed from hyper-v. 886 * 887 * Mainly used by Hyper-V drivers. 888 */ 889 static inline int 890 __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, 891 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid, 892 bool raw) 893 { 894 return hv_ringbuffer_read(channel, buffer, bufferlen, 895 buffer_actual_len, requestid, raw); 896 897 } 898 899 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, 900 u32 bufferlen, u32 *buffer_actual_len, 901 u64 *requestid) 902 { 903 return __vmbus_recvpacket(channel, buffer, bufferlen, 904 buffer_actual_len, requestid, false); 905 } 906 EXPORT_SYMBOL(vmbus_recvpacket); 907 908 /* 909 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel 910 */ 911 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer, 912 u32 bufferlen, u32 *buffer_actual_len, 913 u64 *requestid) 914 { 915 return __vmbus_recvpacket(channel, buffer, bufferlen, 916 buffer_actual_len, requestid, true); 917 } 918 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); 919