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 * Set/change the vCPU (@target_vp) the channel (@child_relid) will interrupt. 294 * 295 * CHANNELMSG_MODIFYCHANNEL messages are aynchronous. Also, Hyper-V does not 296 * ACK such messages. IOW we can't know when the host will stop interrupting 297 * the "old" vCPU and start interrupting the "new" vCPU for the given channel. 298 * 299 * The CHANNELMSG_MODIFYCHANNEL message type is supported since VMBus version 300 * VERSION_WIN10_V4_1. 301 */ 302 int vmbus_send_modifychannel(u32 child_relid, u32 target_vp) 303 { 304 struct vmbus_channel_modifychannel conn_msg; 305 int ret; 306 307 memset(&conn_msg, 0, sizeof(conn_msg)); 308 conn_msg.header.msgtype = CHANNELMSG_MODIFYCHANNEL; 309 conn_msg.child_relid = child_relid; 310 conn_msg.target_vp = target_vp; 311 312 ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true); 313 314 trace_vmbus_send_modifychannel(&conn_msg, ret); 315 316 return ret; 317 } 318 EXPORT_SYMBOL_GPL(vmbus_send_modifychannel); 319 320 /* 321 * create_gpadl_header - Creates a gpadl for the specified buffer 322 */ 323 static int create_gpadl_header(void *kbuffer, u32 size, 324 struct vmbus_channel_msginfo **msginfo) 325 { 326 int i; 327 int pagecount; 328 struct vmbus_channel_gpadl_header *gpadl_header; 329 struct vmbus_channel_gpadl_body *gpadl_body; 330 struct vmbus_channel_msginfo *msgheader; 331 struct vmbus_channel_msginfo *msgbody = NULL; 332 u32 msgsize; 333 334 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize; 335 336 pagecount = size >> PAGE_SHIFT; 337 338 /* do we need a gpadl body msg */ 339 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 340 sizeof(struct vmbus_channel_gpadl_header) - 341 sizeof(struct gpa_range); 342 pfncount = pfnsize / sizeof(u64); 343 344 if (pagecount > pfncount) { 345 /* we need a gpadl body */ 346 /* fill in the header */ 347 msgsize = sizeof(struct vmbus_channel_msginfo) + 348 sizeof(struct vmbus_channel_gpadl_header) + 349 sizeof(struct gpa_range) + pfncount * sizeof(u64); 350 msgheader = kzalloc(msgsize, GFP_KERNEL); 351 if (!msgheader) 352 goto nomem; 353 354 INIT_LIST_HEAD(&msgheader->submsglist); 355 msgheader->msgsize = msgsize; 356 357 gpadl_header = (struct vmbus_channel_gpadl_header *) 358 msgheader->msg; 359 gpadl_header->rangecount = 1; 360 gpadl_header->range_buflen = sizeof(struct gpa_range) + 361 pagecount * sizeof(u64); 362 gpadl_header->range[0].byte_offset = 0; 363 gpadl_header->range[0].byte_count = size; 364 for (i = 0; i < pfncount; i++) 365 gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn( 366 kbuffer + PAGE_SIZE * i); 367 *msginfo = msgheader; 368 369 pfnsum = pfncount; 370 pfnleft = pagecount - pfncount; 371 372 /* how many pfns can we fit */ 373 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 374 sizeof(struct vmbus_channel_gpadl_body); 375 pfncount = pfnsize / sizeof(u64); 376 377 /* fill in the body */ 378 while (pfnleft) { 379 if (pfnleft > pfncount) 380 pfncurr = pfncount; 381 else 382 pfncurr = pfnleft; 383 384 msgsize = sizeof(struct vmbus_channel_msginfo) + 385 sizeof(struct vmbus_channel_gpadl_body) + 386 pfncurr * sizeof(u64); 387 msgbody = kzalloc(msgsize, GFP_KERNEL); 388 389 if (!msgbody) { 390 struct vmbus_channel_msginfo *pos = NULL; 391 struct vmbus_channel_msginfo *tmp = NULL; 392 /* 393 * Free up all the allocated messages. 394 */ 395 list_for_each_entry_safe(pos, tmp, 396 &msgheader->submsglist, 397 msglistentry) { 398 399 list_del(&pos->msglistentry); 400 kfree(pos); 401 } 402 403 goto nomem; 404 } 405 406 msgbody->msgsize = msgsize; 407 gpadl_body = 408 (struct vmbus_channel_gpadl_body *)msgbody->msg; 409 410 /* 411 * Gpadl is u32 and we are using a pointer which could 412 * be 64-bit 413 * This is governed by the guest/host protocol and 414 * so the hypervisor guarantees that this is ok. 415 */ 416 for (i = 0; i < pfncurr; i++) 417 gpadl_body->pfn[i] = virt_to_hvpfn( 418 kbuffer + PAGE_SIZE * (pfnsum + i)); 419 420 /* add to msg header */ 421 list_add_tail(&msgbody->msglistentry, 422 &msgheader->submsglist); 423 pfnsum += pfncurr; 424 pfnleft -= pfncurr; 425 } 426 } else { 427 /* everything fits in a header */ 428 msgsize = sizeof(struct vmbus_channel_msginfo) + 429 sizeof(struct vmbus_channel_gpadl_header) + 430 sizeof(struct gpa_range) + pagecount * sizeof(u64); 431 msgheader = kzalloc(msgsize, GFP_KERNEL); 432 if (msgheader == NULL) 433 goto nomem; 434 435 INIT_LIST_HEAD(&msgheader->submsglist); 436 msgheader->msgsize = msgsize; 437 438 gpadl_header = (struct vmbus_channel_gpadl_header *) 439 msgheader->msg; 440 gpadl_header->rangecount = 1; 441 gpadl_header->range_buflen = sizeof(struct gpa_range) + 442 pagecount * sizeof(u64); 443 gpadl_header->range[0].byte_offset = 0; 444 gpadl_header->range[0].byte_count = size; 445 for (i = 0; i < pagecount; i++) 446 gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn( 447 kbuffer + PAGE_SIZE * i); 448 449 *msginfo = msgheader; 450 } 451 452 return 0; 453 nomem: 454 kfree(msgheader); 455 kfree(msgbody); 456 return -ENOMEM; 457 } 458 459 /* 460 * vmbus_establish_gpadl - Establish a GPADL for the specified buffer 461 * 462 * @channel: a channel 463 * @kbuffer: from kmalloc or vmalloc 464 * @size: page-size multiple 465 * @gpadl_handle: some funky thing 466 */ 467 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer, 468 u32 size, u32 *gpadl_handle) 469 { 470 struct vmbus_channel_gpadl_header *gpadlmsg; 471 struct vmbus_channel_gpadl_body *gpadl_body; 472 struct vmbus_channel_msginfo *msginfo = NULL; 473 struct vmbus_channel_msginfo *submsginfo, *tmp; 474 struct list_head *curr; 475 u32 next_gpadl_handle; 476 unsigned long flags; 477 int ret = 0; 478 479 next_gpadl_handle = 480 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1); 481 482 ret = create_gpadl_header(kbuffer, size, &msginfo); 483 if (ret) 484 return ret; 485 486 init_completion(&msginfo->waitevent); 487 msginfo->waiting_channel = channel; 488 489 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg; 490 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER; 491 gpadlmsg->child_relid = channel->offermsg.child_relid; 492 gpadlmsg->gpadl = next_gpadl_handle; 493 494 495 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 496 list_add_tail(&msginfo->msglistentry, 497 &vmbus_connection.chn_msg_list); 498 499 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 500 501 if (channel->rescind) { 502 ret = -ENODEV; 503 goto cleanup; 504 } 505 506 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize - 507 sizeof(*msginfo), true); 508 509 trace_vmbus_establish_gpadl_header(gpadlmsg, ret); 510 511 if (ret != 0) 512 goto cleanup; 513 514 list_for_each(curr, &msginfo->submsglist) { 515 submsginfo = (struct vmbus_channel_msginfo *)curr; 516 gpadl_body = 517 (struct vmbus_channel_gpadl_body *)submsginfo->msg; 518 519 gpadl_body->header.msgtype = 520 CHANNELMSG_GPADL_BODY; 521 gpadl_body->gpadl = next_gpadl_handle; 522 523 ret = vmbus_post_msg(gpadl_body, 524 submsginfo->msgsize - sizeof(*submsginfo), 525 true); 526 527 trace_vmbus_establish_gpadl_body(gpadl_body, ret); 528 529 if (ret != 0) 530 goto cleanup; 531 532 } 533 wait_for_completion(&msginfo->waitevent); 534 535 if (msginfo->response.gpadl_created.creation_status != 0) { 536 pr_err("Failed to establish GPADL: err = 0x%x\n", 537 msginfo->response.gpadl_created.creation_status); 538 539 ret = -EDQUOT; 540 goto cleanup; 541 } 542 543 if (channel->rescind) { 544 ret = -ENODEV; 545 goto cleanup; 546 } 547 548 /* At this point, we received the gpadl created msg */ 549 *gpadl_handle = gpadlmsg->gpadl; 550 551 cleanup: 552 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 553 list_del(&msginfo->msglistentry); 554 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 555 list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist, 556 msglistentry) { 557 kfree(submsginfo); 558 } 559 560 kfree(msginfo); 561 return ret; 562 } 563 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl); 564 565 /* 566 * vmbus_teardown_gpadl -Teardown the specified GPADL handle 567 */ 568 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle) 569 { 570 struct vmbus_channel_gpadl_teardown *msg; 571 struct vmbus_channel_msginfo *info; 572 unsigned long flags; 573 int ret; 574 575 info = kmalloc(sizeof(*info) + 576 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL); 577 if (!info) 578 return -ENOMEM; 579 580 init_completion(&info->waitevent); 581 info->waiting_channel = channel; 582 583 msg = (struct vmbus_channel_gpadl_teardown *)info->msg; 584 585 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN; 586 msg->child_relid = channel->offermsg.child_relid; 587 msg->gpadl = gpadl_handle; 588 589 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 590 list_add_tail(&info->msglistentry, 591 &vmbus_connection.chn_msg_list); 592 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 593 594 if (channel->rescind) 595 goto post_msg_err; 596 597 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown), 598 true); 599 600 trace_vmbus_teardown_gpadl(msg, ret); 601 602 if (ret) 603 goto post_msg_err; 604 605 wait_for_completion(&info->waitevent); 606 607 post_msg_err: 608 /* 609 * If the channel has been rescinded; 610 * we will be awakened by the rescind 611 * handler; set the error code to zero so we don't leak memory. 612 */ 613 if (channel->rescind) 614 ret = 0; 615 616 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 617 list_del(&info->msglistentry); 618 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 619 620 kfree(info); 621 return ret; 622 } 623 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl); 624 625 void vmbus_reset_channel_cb(struct vmbus_channel *channel) 626 { 627 unsigned long flags; 628 629 /* 630 * vmbus_on_event(), running in the per-channel tasklet, can race 631 * with vmbus_close_internal() in the case of SMP guest, e.g., when 632 * the former is accessing channel->inbound.ring_buffer, the latter 633 * could be freeing the ring_buffer pages, so here we must stop it 634 * first. 635 * 636 * vmbus_chan_sched() might call the netvsc driver callback function 637 * that ends up scheduling NAPI work that accesses the ring buffer. 638 * At this point, we have to ensure that any such work is completed 639 * and that the channel ring buffer is no longer being accessed, cf. 640 * the calls to napi_disable() in netvsc_device_remove(). 641 */ 642 tasklet_disable(&channel->callback_event); 643 644 /* See the inline comments in vmbus_chan_sched(). */ 645 spin_lock_irqsave(&channel->sched_lock, flags); 646 channel->onchannel_callback = NULL; 647 spin_unlock_irqrestore(&channel->sched_lock, flags); 648 649 channel->sc_creation_callback = NULL; 650 651 /* Re-enable tasklet for use on re-open */ 652 tasklet_enable(&channel->callback_event); 653 } 654 655 static int vmbus_close_internal(struct vmbus_channel *channel) 656 { 657 struct vmbus_channel_close_channel *msg; 658 int ret; 659 660 vmbus_reset_channel_cb(channel); 661 662 /* 663 * In case a device driver's probe() fails (e.g., 664 * util_probe() -> vmbus_open() returns -ENOMEM) and the device is 665 * rescinded later (e.g., we dynamically disable an Integrated Service 666 * in Hyper-V Manager), the driver's remove() invokes vmbus_close(): 667 * here we should skip most of the below cleanup work. 668 */ 669 if (channel->state != CHANNEL_OPENED_STATE) 670 return -EINVAL; 671 672 channel->state = CHANNEL_OPEN_STATE; 673 674 /* Send a closing message */ 675 676 msg = &channel->close_msg.msg; 677 678 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL; 679 msg->child_relid = channel->offermsg.child_relid; 680 681 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel), 682 true); 683 684 trace_vmbus_close_internal(msg, ret); 685 686 if (ret) { 687 pr_err("Close failed: close post msg return is %d\n", ret); 688 /* 689 * If we failed to post the close msg, 690 * it is perhaps better to leak memory. 691 */ 692 } 693 694 /* Tear down the gpadl for the channel's ring buffer */ 695 else if (channel->ringbuffer_gpadlhandle) { 696 ret = vmbus_teardown_gpadl(channel, 697 channel->ringbuffer_gpadlhandle); 698 if (ret) { 699 pr_err("Close failed: teardown gpadl return %d\n", ret); 700 /* 701 * If we failed to teardown gpadl, 702 * it is perhaps better to leak memory. 703 */ 704 } 705 706 channel->ringbuffer_gpadlhandle = 0; 707 } 708 709 return ret; 710 } 711 712 /* disconnect ring - close all channels */ 713 int vmbus_disconnect_ring(struct vmbus_channel *channel) 714 { 715 struct vmbus_channel *cur_channel, *tmp; 716 int ret; 717 718 if (channel->primary_channel != NULL) 719 return -EINVAL; 720 721 list_for_each_entry_safe(cur_channel, tmp, &channel->sc_list, sc_list) { 722 if (cur_channel->rescind) 723 wait_for_completion(&cur_channel->rescind_event); 724 725 mutex_lock(&vmbus_connection.channel_mutex); 726 if (vmbus_close_internal(cur_channel) == 0) { 727 vmbus_free_ring(cur_channel); 728 729 if (cur_channel->rescind) 730 hv_process_channel_removal(cur_channel); 731 } 732 mutex_unlock(&vmbus_connection.channel_mutex); 733 } 734 735 /* 736 * Now close the primary. 737 */ 738 mutex_lock(&vmbus_connection.channel_mutex); 739 ret = vmbus_close_internal(channel); 740 mutex_unlock(&vmbus_connection.channel_mutex); 741 742 return ret; 743 } 744 EXPORT_SYMBOL_GPL(vmbus_disconnect_ring); 745 746 /* 747 * vmbus_close - Close the specified channel 748 */ 749 void vmbus_close(struct vmbus_channel *channel) 750 { 751 if (vmbus_disconnect_ring(channel) == 0) 752 vmbus_free_ring(channel); 753 } 754 EXPORT_SYMBOL_GPL(vmbus_close); 755 756 /** 757 * vmbus_sendpacket() - Send the specified buffer on the given channel 758 * @channel: Pointer to vmbus_channel structure 759 * @buffer: Pointer to the buffer you want to send the data from. 760 * @bufferlen: Maximum size of what the buffer holds. 761 * @requestid: Identifier of the request 762 * @type: Type of packet that is being sent e.g. negotiate, time 763 * packet etc. 764 * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED 765 * 766 * Sends data in @buffer directly to Hyper-V via the vmbus. 767 * This will send the data unparsed to Hyper-V. 768 * 769 * Mainly used by Hyper-V drivers. 770 */ 771 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer, 772 u32 bufferlen, u64 requestid, 773 enum vmbus_packet_type type, u32 flags) 774 { 775 struct vmpacket_descriptor desc; 776 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen; 777 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 778 struct kvec bufferlist[3]; 779 u64 aligned_data = 0; 780 int num_vecs = ((bufferlen != 0) ? 3 : 1); 781 782 783 /* Setup the descriptor */ 784 desc.type = type; /* VmbusPacketTypeDataInBand; */ 785 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */ 786 /* in 8-bytes granularity */ 787 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3; 788 desc.len8 = (u16)(packetlen_aligned >> 3); 789 desc.trans_id = requestid; 790 791 bufferlist[0].iov_base = &desc; 792 bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor); 793 bufferlist[1].iov_base = buffer; 794 bufferlist[1].iov_len = bufferlen; 795 bufferlist[2].iov_base = &aligned_data; 796 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 797 798 return hv_ringbuffer_write(channel, bufferlist, num_vecs); 799 } 800 EXPORT_SYMBOL(vmbus_sendpacket); 801 802 /* 803 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer 804 * packets using a GPADL Direct packet type. This interface allows you 805 * to control notifying the host. This will be useful for sending 806 * batched data. Also the sender can control the send flags 807 * explicitly. 808 */ 809 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, 810 struct hv_page_buffer pagebuffers[], 811 u32 pagecount, void *buffer, u32 bufferlen, 812 u64 requestid) 813 { 814 int i; 815 struct vmbus_channel_packet_page_buffer desc; 816 u32 descsize; 817 u32 packetlen; 818 u32 packetlen_aligned; 819 struct kvec bufferlist[3]; 820 u64 aligned_data = 0; 821 822 if (pagecount > MAX_PAGE_BUFFER_COUNT) 823 return -EINVAL; 824 825 /* 826 * Adjust the size down since vmbus_channel_packet_page_buffer is the 827 * largest size we support 828 */ 829 descsize = sizeof(struct vmbus_channel_packet_page_buffer) - 830 ((MAX_PAGE_BUFFER_COUNT - pagecount) * 831 sizeof(struct hv_page_buffer)); 832 packetlen = descsize + bufferlen; 833 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 834 835 /* Setup the descriptor */ 836 desc.type = VM_PKT_DATA_USING_GPA_DIRECT; 837 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 838 desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */ 839 desc.length8 = (u16)(packetlen_aligned >> 3); 840 desc.transactionid = requestid; 841 desc.reserved = 0; 842 desc.rangecount = pagecount; 843 844 for (i = 0; i < pagecount; i++) { 845 desc.range[i].len = pagebuffers[i].len; 846 desc.range[i].offset = pagebuffers[i].offset; 847 desc.range[i].pfn = pagebuffers[i].pfn; 848 } 849 850 bufferlist[0].iov_base = &desc; 851 bufferlist[0].iov_len = descsize; 852 bufferlist[1].iov_base = buffer; 853 bufferlist[1].iov_len = bufferlen; 854 bufferlist[2].iov_base = &aligned_data; 855 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 856 857 return hv_ringbuffer_write(channel, bufferlist, 3); 858 } 859 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer); 860 861 /* 862 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet 863 * using a GPADL Direct packet type. 864 * The buffer includes the vmbus descriptor. 865 */ 866 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel, 867 struct vmbus_packet_mpb_array *desc, 868 u32 desc_size, 869 void *buffer, u32 bufferlen, u64 requestid) 870 { 871 u32 packetlen; 872 u32 packetlen_aligned; 873 struct kvec bufferlist[3]; 874 u64 aligned_data = 0; 875 876 packetlen = desc_size + bufferlen; 877 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 878 879 /* Setup the descriptor */ 880 desc->type = VM_PKT_DATA_USING_GPA_DIRECT; 881 desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 882 desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */ 883 desc->length8 = (u16)(packetlen_aligned >> 3); 884 desc->transactionid = requestid; 885 desc->reserved = 0; 886 desc->rangecount = 1; 887 888 bufferlist[0].iov_base = desc; 889 bufferlist[0].iov_len = desc_size; 890 bufferlist[1].iov_base = buffer; 891 bufferlist[1].iov_len = bufferlen; 892 bufferlist[2].iov_base = &aligned_data; 893 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 894 895 return hv_ringbuffer_write(channel, bufferlist, 3); 896 } 897 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc); 898 899 /** 900 * __vmbus_recvpacket() - Retrieve the user packet on the specified channel 901 * @channel: Pointer to vmbus_channel structure 902 * @buffer: Pointer to the buffer you want to receive the data into. 903 * @bufferlen: Maximum size of what the buffer can hold. 904 * @buffer_actual_len: The actual size of the data after it was received. 905 * @requestid: Identifier of the request 906 * @raw: true means keep the vmpacket_descriptor header in the received data. 907 * 908 * Receives directly from the hyper-v vmbus and puts the data it received 909 * into Buffer. This will receive the data unparsed from hyper-v. 910 * 911 * Mainly used by Hyper-V drivers. 912 */ 913 static inline int 914 __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, 915 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid, 916 bool raw) 917 { 918 return hv_ringbuffer_read(channel, buffer, bufferlen, 919 buffer_actual_len, requestid, raw); 920 921 } 922 923 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, 924 u32 bufferlen, u32 *buffer_actual_len, 925 u64 *requestid) 926 { 927 return __vmbus_recvpacket(channel, buffer, bufferlen, 928 buffer_actual_len, requestid, false); 929 } 930 EXPORT_SYMBOL(vmbus_recvpacket); 931 932 /* 933 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel 934 */ 935 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer, 936 u32 bufferlen, u32 *buffer_actual_len, 937 u64 *requestid) 938 { 939 return __vmbus_recvpacket(channel, buffer, bufferlen, 940 buffer_actual_len, requestid, true); 941 } 942 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); 943