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 <linux/set_memory.h> 21#include <asm/page.h> 22#include <asm/mshyperv.h> 23 24#include "hyperv_vmbus.h" 25 26/* 27 * hv_gpadl_size - Return the real size of a gpadl, the size that Hyper-V uses 28 * 29 * For BUFFER gpadl, Hyper-V uses the exact same size as the guest does. 30 * 31 * For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the header 32 * (because of the alignment requirement), however, the hypervisor only 33 * uses the first HV_HYP_PAGE_SIZE as the header, therefore leaving a 34 * (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap. And since there are two rings in a 35 * ringbuffer, the total size for a RING gpadl that Hyper-V uses is the 36 * total size that the guest uses minus twice of the gap size. 37 */ 38static inline u32 hv_gpadl_size(enum hv_gpadl_type type, u32 size) 39{ 40 switch (type) { 41 case HV_GPADL_BUFFER: 42 return size; 43 case HV_GPADL_RING: 44 /* The size of a ringbuffer must be page-aligned */ 45 BUG_ON(size % PAGE_SIZE); 46 /* 47 * Two things to notice here: 48 * 1) We're processing two ring buffers as a unit 49 * 2) We're skipping any space larger than HV_HYP_PAGE_SIZE in 50 * the first guest-size page of each of the two ring buffers. 51 * So we effectively subtract out two guest-size pages, and add 52 * back two Hyper-V size pages. 53 */ 54 return size - 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE); 55 } 56 BUG(); 57 return 0; 58} 59 60/* 61 * hv_ring_gpadl_send_hvpgoffset - Calculate the send offset (in unit of 62 * HV_HYP_PAGE) in a ring gpadl based on the 63 * offset in the guest 64 * 65 * @offset: the offset (in bytes) where the send ringbuffer starts in the 66 * virtual address space of the guest 67 */ 68static inline u32 hv_ring_gpadl_send_hvpgoffset(u32 offset) 69{ 70 71 /* 72 * For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the 73 * header (because of the alignment requirement), however, the 74 * hypervisor only uses the first HV_HYP_PAGE_SIZE as the header, 75 * therefore leaving a (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap. 76 * 77 * And to calculate the effective send offset in gpadl, we need to 78 * substract this gap. 79 */ 80 return (offset - (PAGE_SIZE - HV_HYP_PAGE_SIZE)) >> HV_HYP_PAGE_SHIFT; 81} 82 83/* 84 * hv_gpadl_hvpfn - Return the Hyper-V page PFN of the @i th Hyper-V page in 85 * the gpadl 86 * 87 * @type: the type of the gpadl 88 * @kbuffer: the pointer to the gpadl in the guest 89 * @size: the total size (in bytes) of the gpadl 90 * @send_offset: the offset (in bytes) where the send ringbuffer starts in the 91 * virtual address space of the guest 92 * @i: the index 93 */ 94static inline u64 hv_gpadl_hvpfn(enum hv_gpadl_type type, void *kbuffer, 95 u32 size, u32 send_offset, int i) 96{ 97 int send_idx = hv_ring_gpadl_send_hvpgoffset(send_offset); 98 unsigned long delta = 0UL; 99 100 switch (type) { 101 case HV_GPADL_BUFFER: 102 break; 103 case HV_GPADL_RING: 104 if (i == 0) 105 delta = 0; 106 else if (i <= send_idx) 107 delta = PAGE_SIZE - HV_HYP_PAGE_SIZE; 108 else 109 delta = 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE); 110 break; 111 default: 112 BUG(); 113 break; 114 } 115 116 return virt_to_hvpfn(kbuffer + delta + (HV_HYP_PAGE_SIZE * i)); 117} 118 119/* 120 * vmbus_setevent- Trigger an event notification on the specified 121 * channel. 122 */ 123void vmbus_setevent(struct vmbus_channel *channel) 124{ 125 struct hv_monitor_page *monitorpage; 126 127 trace_vmbus_setevent(channel); 128 129 /* 130 * For channels marked as in "low latency" mode 131 * bypass the monitor page mechanism. 132 */ 133 if (channel->offermsg.monitor_allocated && !channel->low_latency) { 134 vmbus_send_interrupt(channel->offermsg.child_relid); 135 136 /* Get the child to parent monitor page */ 137 monitorpage = vmbus_connection.monitor_pages[1]; 138 139 sync_set_bit(channel->monitor_bit, 140 (unsigned long *)&monitorpage->trigger_group 141 [channel->monitor_grp].pending); 142 143 } else { 144 vmbus_set_event(channel); 145 } 146} 147EXPORT_SYMBOL_GPL(vmbus_setevent); 148 149/* vmbus_free_ring - drop mapping of ring buffer */ 150void vmbus_free_ring(struct vmbus_channel *channel) 151{ 152 hv_ringbuffer_cleanup(&channel->outbound); 153 hv_ringbuffer_cleanup(&channel->inbound); 154 155 if (channel->ringbuffer_page) { 156 /* In a CoCo VM leak the memory if it didn't get re-encrypted */ 157 if (!channel->ringbuffer_gpadlhandle.decrypted) 158 __free_pages(channel->ringbuffer_page, 159 get_order(channel->ringbuffer_pagecount 160 << PAGE_SHIFT)); 161 channel->ringbuffer_page = NULL; 162 } 163} 164EXPORT_SYMBOL_GPL(vmbus_free_ring); 165 166/* vmbus_alloc_ring - allocate and map pages for ring buffer */ 167int vmbus_alloc_ring(struct vmbus_channel *newchannel, 168 u32 send_size, u32 recv_size) 169{ 170 struct page *page; 171 int order; 172 173 if (send_size % PAGE_SIZE || recv_size % PAGE_SIZE) 174 return -EINVAL; 175 176 /* Allocate the ring buffer */ 177 order = get_order(send_size + recv_size); 178 page = alloc_pages_node(cpu_to_node(newchannel->target_cpu), 179 GFP_KERNEL|__GFP_ZERO, order); 180 181 if (!page) 182 page = alloc_pages(GFP_KERNEL|__GFP_ZERO, order); 183 184 if (!page) 185 return -ENOMEM; 186 187 newchannel->ringbuffer_page = page; 188 newchannel->ringbuffer_pagecount = (send_size + recv_size) >> PAGE_SHIFT; 189 newchannel->ringbuffer_send_offset = send_size >> PAGE_SHIFT; 190 191 return 0; 192} 193EXPORT_SYMBOL_GPL(vmbus_alloc_ring); 194 195/* Used for Hyper-V Socket: a guest client's connect() to the host */ 196int vmbus_send_tl_connect_request(const guid_t *shv_guest_servie_id, 197 const guid_t *shv_host_servie_id) 198{ 199 struct vmbus_channel_tl_connect_request conn_msg; 200 int ret; 201 202 memset(&conn_msg, 0, sizeof(conn_msg)); 203 conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST; 204 conn_msg.guest_endpoint_id = *shv_guest_servie_id; 205 conn_msg.host_service_id = *shv_host_servie_id; 206 207 ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true); 208 209 trace_vmbus_send_tl_connect_request(&conn_msg, ret); 210 211 return ret; 212} 213EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request); 214 215static int send_modifychannel_without_ack(struct vmbus_channel *channel, u32 target_vp) 216{ 217 struct vmbus_channel_modifychannel msg; 218 int ret; 219 220 memset(&msg, 0, sizeof(msg)); 221 msg.header.msgtype = CHANNELMSG_MODIFYCHANNEL; 222 msg.child_relid = channel->offermsg.child_relid; 223 msg.target_vp = target_vp; 224 225 ret = vmbus_post_msg(&msg, sizeof(msg), true); 226 trace_vmbus_send_modifychannel(&msg, ret); 227 228 return ret; 229} 230 231static int send_modifychannel_with_ack(struct vmbus_channel *channel, u32 target_vp) 232{ 233 struct vmbus_channel_modifychannel *msg; 234 struct vmbus_channel_msginfo *info; 235 unsigned long flags; 236 int ret; 237 238 info = kzalloc(sizeof(struct vmbus_channel_msginfo) + 239 sizeof(struct vmbus_channel_modifychannel), 240 GFP_KERNEL); 241 if (!info) 242 return -ENOMEM; 243 244 init_completion(&info->waitevent); 245 info->waiting_channel = channel; 246 247 msg = (struct vmbus_channel_modifychannel *)info->msg; 248 msg->header.msgtype = CHANNELMSG_MODIFYCHANNEL; 249 msg->child_relid = channel->offermsg.child_relid; 250 msg->target_vp = target_vp; 251 252 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 253 list_add_tail(&info->msglistentry, &vmbus_connection.chn_msg_list); 254 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 255 256 ret = vmbus_post_msg(msg, sizeof(*msg), true); 257 trace_vmbus_send_modifychannel(msg, ret); 258 if (ret != 0) { 259 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 260 list_del(&info->msglistentry); 261 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 262 goto free_info; 263 } 264 265 /* 266 * Release channel_mutex; otherwise, vmbus_onoffer_rescind() could block on 267 * the mutex and be unable to signal the completion. 268 * 269 * See the caller target_cpu_store() for information about the usage of the 270 * mutex. 271 */ 272 mutex_unlock(&vmbus_connection.channel_mutex); 273 wait_for_completion(&info->waitevent); 274 mutex_lock(&vmbus_connection.channel_mutex); 275 276 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 277 list_del(&info->msglistentry); 278 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 279 280 if (info->response.modify_response.status) 281 ret = -EAGAIN; 282 283free_info: 284 kfree(info); 285 return ret; 286} 287 288/* 289 * Set/change the vCPU (@target_vp) the channel (@child_relid) will interrupt. 290 * 291 * CHANNELMSG_MODIFYCHANNEL messages are aynchronous. When VMbus version 5.3 292 * or later is negotiated, Hyper-V always sends an ACK in response to such a 293 * message. For VMbus version 5.2 and earlier, it never sends an ACK. With- 294 * out an ACK, we can not know when the host will stop interrupting the "old" 295 * vCPU and start interrupting the "new" vCPU for the given channel. 296 * 297 * The CHANNELMSG_MODIFYCHANNEL message type is supported since VMBus version 298 * VERSION_WIN10_V4_1. 299 */ 300int vmbus_send_modifychannel(struct vmbus_channel *channel, u32 target_vp) 301{ 302 if (vmbus_proto_version >= VERSION_WIN10_V5_3) 303 return send_modifychannel_with_ack(channel, target_vp); 304 return send_modifychannel_without_ack(channel, target_vp); 305} 306EXPORT_SYMBOL_GPL(vmbus_send_modifychannel); 307 308/* 309 * create_gpadl_header - Creates a gpadl for the specified buffer 310 */ 311static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer, 312 u32 size, u32 send_offset, 313 struct vmbus_channel_msginfo **msginfo) 314{ 315 int i; 316 int pagecount; 317 struct vmbus_channel_gpadl_header *gpadl_header; 318 struct vmbus_channel_gpadl_body *gpadl_body; 319 struct vmbus_channel_msginfo *msgheader; 320 struct vmbus_channel_msginfo *msgbody = NULL; 321 u32 msgsize; 322 323 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize; 324 325 pagecount = hv_gpadl_size(type, size) >> HV_HYP_PAGE_SHIFT; 326 327 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 328 sizeof(struct vmbus_channel_gpadl_header) - 329 sizeof(struct gpa_range); 330 pfncount = umin(pagecount, pfnsize / sizeof(u64)); 331 332 msgsize = sizeof(struct vmbus_channel_msginfo) + 333 sizeof(struct vmbus_channel_gpadl_header) + 334 sizeof(struct gpa_range) + pfncount * sizeof(u64); 335 msgheader = kzalloc(msgsize, GFP_KERNEL); 336 if (!msgheader) 337 return -ENOMEM; 338 339 INIT_LIST_HEAD(&msgheader->submsglist); 340 msgheader->msgsize = msgsize; 341 342 gpadl_header = (struct vmbus_channel_gpadl_header *) 343 msgheader->msg; 344 gpadl_header->rangecount = 1; 345 gpadl_header->range_buflen = sizeof(struct gpa_range) + 346 pagecount * sizeof(u64); 347 gpadl_header->range[0].byte_offset = 0; 348 gpadl_header->range[0].byte_count = hv_gpadl_size(type, size); 349 for (i = 0; i < pfncount; i++) 350 gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn( 351 type, kbuffer, size, send_offset, i); 352 *msginfo = msgheader; 353 354 pfnsum = pfncount; 355 pfnleft = pagecount - pfncount; 356 357 /* how many pfns can we fit in a body message */ 358 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 359 sizeof(struct vmbus_channel_gpadl_body); 360 pfncount = pfnsize / sizeof(u64); 361 362 /* 363 * If pfnleft is zero, everything fits in the header and no body 364 * messages are needed 365 */ 366 while (pfnleft) { 367 pfncurr = umin(pfncount, pfnleft); 368 msgsize = sizeof(struct vmbus_channel_msginfo) + 369 sizeof(struct vmbus_channel_gpadl_body) + 370 pfncurr * sizeof(u64); 371 msgbody = kzalloc(msgsize, GFP_KERNEL); 372 373 if (!msgbody) { 374 struct vmbus_channel_msginfo *pos = NULL; 375 struct vmbus_channel_msginfo *tmp = NULL; 376 /* 377 * Free up all the allocated messages. 378 */ 379 list_for_each_entry_safe(pos, tmp, 380 &msgheader->submsglist, 381 msglistentry) { 382 383 list_del(&pos->msglistentry); 384 kfree(pos); 385 } 386 kfree(msgheader); 387 return -ENOMEM; 388 } 389 390 msgbody->msgsize = msgsize; 391 gpadl_body = (struct vmbus_channel_gpadl_body *)msgbody->msg; 392 393 /* 394 * Gpadl is u32 and we are using a pointer which could 395 * be 64-bit 396 * This is governed by the guest/host protocol and 397 * so the hypervisor guarantees that this is ok. 398 */ 399 for (i = 0; i < pfncurr; i++) 400 gpadl_body->pfn[i] = hv_gpadl_hvpfn(type, 401 kbuffer, size, send_offset, pfnsum + i); 402 403 /* add to msg header */ 404 list_add_tail(&msgbody->msglistentry, &msgheader->submsglist); 405 pfnsum += pfncurr; 406 pfnleft -= pfncurr; 407 } 408 409 return 0; 410} 411 412/* 413 * __vmbus_establish_gpadl - Establish a GPADL for a buffer or ringbuffer 414 * 415 * @channel: a channel 416 * @type: the type of the corresponding GPADL, only meaningful for the guest. 417 * @kbuffer: from kmalloc or vmalloc 418 * @size: page-size multiple 419 * @send_offset: the offset (in bytes) where the send ring buffer starts, 420 * should be 0 for BUFFER type gpadl 421 * @gpadl_handle: some funky thing 422 */ 423static int __vmbus_establish_gpadl(struct vmbus_channel *channel, 424 enum hv_gpadl_type type, void *kbuffer, 425 u32 size, u32 send_offset, 426 struct vmbus_gpadl *gpadl) 427{ 428 struct vmbus_channel_gpadl_header *gpadlmsg; 429 struct vmbus_channel_gpadl_body *gpadl_body; 430 struct vmbus_channel_msginfo *msginfo = NULL; 431 struct vmbus_channel_msginfo *submsginfo, *tmp; 432 struct list_head *curr; 433 u32 next_gpadl_handle; 434 unsigned long flags; 435 int ret = 0; 436 437 next_gpadl_handle = 438 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1); 439 440 ret = create_gpadl_header(type, kbuffer, size, send_offset, &msginfo); 441 if (ret) { 442 gpadl->decrypted = false; 443 return ret; 444 } 445 446 /* 447 * Set the "decrypted" flag to true for the set_memory_decrypted() 448 * success case. In the failure case, the encryption state of the 449 * memory is unknown. Leave "decrypted" as true to ensure the 450 * memory will be leaked instead of going back on the free list. 451 */ 452 gpadl->decrypted = true; 453 ret = set_memory_decrypted((unsigned long)kbuffer, 454 PFN_UP(size)); 455 if (ret) { 456 dev_warn(&channel->device_obj->device, 457 "Failed to set host visibility for new GPADL %d.\n", 458 ret); 459 return ret; 460 } 461 462 init_completion(&msginfo->waitevent); 463 msginfo->waiting_channel = channel; 464 465 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg; 466 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER; 467 gpadlmsg->child_relid = channel->offermsg.child_relid; 468 gpadlmsg->gpadl = next_gpadl_handle; 469 470 471 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 472 list_add_tail(&msginfo->msglistentry, 473 &vmbus_connection.chn_msg_list); 474 475 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 476 477 if (channel->rescind) { 478 ret = -ENODEV; 479 goto cleanup; 480 } 481 482 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize - 483 sizeof(*msginfo), true); 484 485 trace_vmbus_establish_gpadl_header(gpadlmsg, ret); 486 487 if (ret != 0) 488 goto cleanup; 489 490 list_for_each(curr, &msginfo->submsglist) { 491 submsginfo = (struct vmbus_channel_msginfo *)curr; 492 gpadl_body = 493 (struct vmbus_channel_gpadl_body *)submsginfo->msg; 494 495 gpadl_body->header.msgtype = 496 CHANNELMSG_GPADL_BODY; 497 gpadl_body->gpadl = next_gpadl_handle; 498 499 ret = vmbus_post_msg(gpadl_body, 500 submsginfo->msgsize - sizeof(*submsginfo), 501 true); 502 503 trace_vmbus_establish_gpadl_body(gpadl_body, ret); 504 505 if (ret != 0) 506 goto cleanup; 507 508 } 509 wait_for_completion(&msginfo->waitevent); 510 511 if (msginfo->response.gpadl_created.creation_status != 0) { 512 pr_err("Failed to establish GPADL: err = 0x%x\n", 513 msginfo->response.gpadl_created.creation_status); 514 515 ret = -EDQUOT; 516 goto cleanup; 517 } 518 519 if (channel->rescind) { 520 ret = -ENODEV; 521 goto cleanup; 522 } 523 524 /* At this point, we received the gpadl created msg */ 525 gpadl->gpadl_handle = gpadlmsg->gpadl; 526 gpadl->buffer = kbuffer; 527 gpadl->size = size; 528 529 530cleanup: 531 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 532 list_del(&msginfo->msglistentry); 533 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 534 list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist, 535 msglistentry) { 536 kfree(submsginfo); 537 } 538 539 kfree(msginfo); 540 541 if (ret) { 542 /* 543 * If set_memory_encrypted() fails, the decrypted flag is 544 * left as true so the memory is leaked instead of being 545 * put back on the free list. 546 */ 547 if (!set_memory_encrypted((unsigned long)kbuffer, PFN_UP(size))) 548 gpadl->decrypted = false; 549 } 550 551 return ret; 552} 553 554/* 555 * vmbus_establish_gpadl - Establish a GPADL for the specified buffer 556 * 557 * @channel: a channel 558 * @kbuffer: from kmalloc or vmalloc 559 * @size: page-size multiple 560 * @gpadl_handle: some funky thing 561 */ 562int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer, 563 u32 size, struct vmbus_gpadl *gpadl) 564{ 565 return __vmbus_establish_gpadl(channel, HV_GPADL_BUFFER, kbuffer, size, 566 0U, gpadl); 567} 568EXPORT_SYMBOL_GPL(vmbus_establish_gpadl); 569 570/** 571 * request_arr_init - Allocates memory for the requestor array. Each slot 572 * keeps track of the next available slot in the array. Initially, each 573 * slot points to the next one (as in a Linked List). The last slot 574 * does not point to anything, so its value is U64_MAX by default. 575 * @size The size of the array 576 */ 577static u64 *request_arr_init(u32 size) 578{ 579 int i; 580 u64 *req_arr; 581 582 req_arr = kcalloc(size, sizeof(u64), GFP_KERNEL); 583 if (!req_arr) 584 return NULL; 585 586 for (i = 0; i < size - 1; i++) 587 req_arr[i] = i + 1; 588 589 /* Last slot (no more available slots) */ 590 req_arr[i] = U64_MAX; 591 592 return req_arr; 593} 594 595/* 596 * vmbus_alloc_requestor - Initializes @rqstor's fields. 597 * Index 0 is the first free slot 598 * @size: Size of the requestor array 599 */ 600static int vmbus_alloc_requestor(struct vmbus_requestor *rqstor, u32 size) 601{ 602 u64 *rqst_arr; 603 unsigned long *bitmap; 604 605 rqst_arr = request_arr_init(size); 606 if (!rqst_arr) 607 return -ENOMEM; 608 609 bitmap = bitmap_zalloc(size, GFP_KERNEL); 610 if (!bitmap) { 611 kfree(rqst_arr); 612 return -ENOMEM; 613 } 614 615 rqstor->req_arr = rqst_arr; 616 rqstor->req_bitmap = bitmap; 617 rqstor->size = size; 618 rqstor->next_request_id = 0; 619 spin_lock_init(&rqstor->req_lock); 620 621 return 0; 622} 623 624/* 625 * vmbus_free_requestor - Frees memory allocated for @rqstor 626 * @rqstor: Pointer to the requestor struct 627 */ 628static void vmbus_free_requestor(struct vmbus_requestor *rqstor) 629{ 630 kfree(rqstor->req_arr); 631 bitmap_free(rqstor->req_bitmap); 632} 633 634static int __vmbus_open(struct vmbus_channel *newchannel, 635 void *userdata, u32 userdatalen, 636 void (*onchannelcallback)(void *context), void *context) 637{ 638 struct vmbus_channel_open_channel *open_msg; 639 struct vmbus_channel_msginfo *open_info = NULL; 640 struct page *page = newchannel->ringbuffer_page; 641 u32 send_pages, recv_pages; 642 unsigned long flags; 643 int err; 644 645 if (userdatalen > MAX_USER_DEFINED_BYTES) 646 return -EINVAL; 647 648 send_pages = newchannel->ringbuffer_send_offset; 649 recv_pages = newchannel->ringbuffer_pagecount - send_pages; 650 651 if (newchannel->state != CHANNEL_OPEN_STATE) 652 return -EINVAL; 653 654 /* Create and init requestor */ 655 if (newchannel->rqstor_size) { 656 if (vmbus_alloc_requestor(&newchannel->requestor, newchannel->rqstor_size)) 657 return -ENOMEM; 658 } 659 660 newchannel->state = CHANNEL_OPENING_STATE; 661 newchannel->onchannel_callback = onchannelcallback; 662 newchannel->channel_callback_context = context; 663 664 if (!newchannel->max_pkt_size) 665 newchannel->max_pkt_size = VMBUS_DEFAULT_MAX_PKT_SIZE; 666 667 /* Establish the gpadl for the ring buffer */ 668 newchannel->ringbuffer_gpadlhandle.gpadl_handle = 0; 669 670 err = __vmbus_establish_gpadl(newchannel, HV_GPADL_RING, 671 page_address(newchannel->ringbuffer_page), 672 (send_pages + recv_pages) << PAGE_SHIFT, 673 newchannel->ringbuffer_send_offset << PAGE_SHIFT, 674 &newchannel->ringbuffer_gpadlhandle); 675 if (err) 676 goto error_clean_ring; 677 678 err = hv_ringbuffer_init(&newchannel->outbound, 679 page, send_pages, 0); 680 if (err) 681 goto error_free_gpadl; 682 683 err = hv_ringbuffer_init(&newchannel->inbound, &page[send_pages], 684 recv_pages, newchannel->max_pkt_size); 685 if (err) 686 goto error_free_gpadl; 687 688 /* Create and init the channel open message */ 689 open_info = kzalloc(sizeof(*open_info) + 690 sizeof(struct vmbus_channel_open_channel), 691 GFP_KERNEL); 692 if (!open_info) { 693 err = -ENOMEM; 694 goto error_free_gpadl; 695 } 696 697 init_completion(&open_info->waitevent); 698 open_info->waiting_channel = newchannel; 699 700 open_msg = (struct vmbus_channel_open_channel *)open_info->msg; 701 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL; 702 open_msg->openid = newchannel->offermsg.child_relid; 703 open_msg->child_relid = newchannel->offermsg.child_relid; 704 open_msg->ringbuffer_gpadlhandle 705 = newchannel->ringbuffer_gpadlhandle.gpadl_handle; 706 /* 707 * The unit of ->downstream_ringbuffer_pageoffset is HV_HYP_PAGE and 708 * the unit of ->ringbuffer_send_offset (i.e. send_pages) is PAGE, so 709 * here we calculate it into HV_HYP_PAGE. 710 */ 711 open_msg->downstream_ringbuffer_pageoffset = 712 hv_ring_gpadl_send_hvpgoffset(send_pages << PAGE_SHIFT); 713 open_msg->target_vp = hv_cpu_number_to_vp_number(newchannel->target_cpu); 714 715 if (userdatalen) 716 memcpy(open_msg->userdata, userdata, userdatalen); 717 718 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 719 list_add_tail(&open_info->msglistentry, 720 &vmbus_connection.chn_msg_list); 721 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 722 723 if (newchannel->rescind) { 724 err = -ENODEV; 725 goto error_clean_msglist; 726 } 727 728 err = vmbus_post_msg(open_msg, 729 sizeof(struct vmbus_channel_open_channel), true); 730 731 trace_vmbus_open(open_msg, err); 732 733 if (err != 0) 734 goto error_clean_msglist; 735 736 wait_for_completion(&open_info->waitevent); 737 738 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 739 list_del(&open_info->msglistentry); 740 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 741 742 if (newchannel->rescind) { 743 err = -ENODEV; 744 goto error_free_info; 745 } 746 747 if (open_info->response.open_result.status) { 748 err = -EAGAIN; 749 goto error_free_info; 750 } 751 752 newchannel->state = CHANNEL_OPENED_STATE; 753 kfree(open_info); 754 return 0; 755 756error_clean_msglist: 757 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 758 list_del(&open_info->msglistentry); 759 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 760error_free_info: 761 kfree(open_info); 762error_free_gpadl: 763 vmbus_teardown_gpadl(newchannel, &newchannel->ringbuffer_gpadlhandle); 764error_clean_ring: 765 hv_ringbuffer_cleanup(&newchannel->outbound); 766 hv_ringbuffer_cleanup(&newchannel->inbound); 767 vmbus_free_requestor(&newchannel->requestor); 768 newchannel->state = CHANNEL_OPEN_STATE; 769 return err; 770} 771 772/* 773 * vmbus_connect_ring - Open the channel but reuse ring buffer 774 */ 775int vmbus_connect_ring(struct vmbus_channel *newchannel, 776 void (*onchannelcallback)(void *context), void *context) 777{ 778 return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context); 779} 780EXPORT_SYMBOL_GPL(vmbus_connect_ring); 781 782/* 783 * vmbus_open - Open the specified channel. 784 */ 785int vmbus_open(struct vmbus_channel *newchannel, 786 u32 send_ringbuffer_size, u32 recv_ringbuffer_size, 787 void *userdata, u32 userdatalen, 788 void (*onchannelcallback)(void *context), void *context) 789{ 790 int err; 791 792 err = vmbus_alloc_ring(newchannel, send_ringbuffer_size, 793 recv_ringbuffer_size); 794 if (err) 795 return err; 796 797 err = __vmbus_open(newchannel, userdata, userdatalen, 798 onchannelcallback, context); 799 if (err) 800 vmbus_free_ring(newchannel); 801 802 return err; 803} 804EXPORT_SYMBOL_GPL(vmbus_open); 805 806/* 807 * vmbus_teardown_gpadl -Teardown the specified GPADL handle 808 */ 809int vmbus_teardown_gpadl(struct vmbus_channel *channel, struct vmbus_gpadl *gpadl) 810{ 811 struct vmbus_channel_gpadl_teardown *msg; 812 struct vmbus_channel_msginfo *info; 813 unsigned long flags; 814 int ret; 815 816 info = kzalloc(sizeof(*info) + 817 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL); 818 if (!info) 819 return -ENOMEM; 820 821 init_completion(&info->waitevent); 822 info->waiting_channel = channel; 823 824 msg = (struct vmbus_channel_gpadl_teardown *)info->msg; 825 826 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN; 827 msg->child_relid = channel->offermsg.child_relid; 828 msg->gpadl = gpadl->gpadl_handle; 829 830 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 831 list_add_tail(&info->msglistentry, 832 &vmbus_connection.chn_msg_list); 833 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 834 835 if (channel->rescind) 836 goto post_msg_err; 837 838 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown), 839 true); 840 841 trace_vmbus_teardown_gpadl(msg, ret); 842 843 if (ret) 844 goto post_msg_err; 845 846 wait_for_completion(&info->waitevent); 847 848 gpadl->gpadl_handle = 0; 849 850post_msg_err: 851 /* 852 * If the channel has been rescinded; 853 * we will be awakened by the rescind 854 * handler; set the error code to zero so we don't leak memory. 855 */ 856 if (channel->rescind) 857 ret = 0; 858 859 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 860 list_del(&info->msglistentry); 861 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 862 863 kfree(info); 864 865 ret = set_memory_encrypted((unsigned long)gpadl->buffer, 866 PFN_UP(gpadl->size)); 867 if (ret) 868 pr_warn("Fail to set mem host visibility in GPADL teardown %d.\n", ret); 869 870 gpadl->decrypted = ret; 871 872 return ret; 873} 874EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl); 875 876void vmbus_reset_channel_cb(struct vmbus_channel *channel) 877{ 878 unsigned long flags; 879 880 /* 881 * vmbus_on_event(), running in the per-channel tasklet, can race 882 * with vmbus_close_internal() in the case of SMP guest, e.g., when 883 * the former is accessing channel->inbound.ring_buffer, the latter 884 * could be freeing the ring_buffer pages, so here we must stop it 885 * first. 886 * 887 * vmbus_chan_sched() might call the netvsc driver callback function 888 * that ends up scheduling NAPI work that accesses the ring buffer. 889 * At this point, we have to ensure that any such work is completed 890 * and that the channel ring buffer is no longer being accessed, cf. 891 * the calls to napi_disable() in netvsc_device_remove(). 892 */ 893 tasklet_disable(&channel->callback_event); 894 895 /* See the inline comments in vmbus_chan_sched(). */ 896 spin_lock_irqsave(&channel->sched_lock, flags); 897 channel->onchannel_callback = NULL; 898 spin_unlock_irqrestore(&channel->sched_lock, flags); 899 900 channel->sc_creation_callback = NULL; 901 902 /* Re-enable tasklet for use on re-open */ 903 tasklet_enable(&channel->callback_event); 904} 905 906static int vmbus_close_internal(struct vmbus_channel *channel) 907{ 908 struct vmbus_channel_close_channel *msg; 909 int ret; 910 911 vmbus_reset_channel_cb(channel); 912 913 /* 914 * In case a device driver's probe() fails (e.g., 915 * util_probe() -> vmbus_open() returns -ENOMEM) and the device is 916 * rescinded later (e.g., we dynamically disable an Integrated Service 917 * in Hyper-V Manager), the driver's remove() invokes vmbus_close(): 918 * here we should skip most of the below cleanup work. 919 */ 920 if (channel->state != CHANNEL_OPENED_STATE) 921 return -EINVAL; 922 923 channel->state = CHANNEL_OPEN_STATE; 924 925 /* Send a closing message */ 926 927 msg = &channel->close_msg.msg; 928 929 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL; 930 msg->child_relid = channel->offermsg.child_relid; 931 932 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel), 933 true); 934 935 trace_vmbus_close_internal(msg, ret); 936 937 if (ret) { 938 pr_err("Close failed: close post msg return is %d\n", ret); 939 /* 940 * If we failed to post the close msg, 941 * it is perhaps better to leak memory. 942 */ 943 } 944 945 /* Tear down the gpadl for the channel's ring buffer */ 946 else if (channel->ringbuffer_gpadlhandle.gpadl_handle) { 947 ret = vmbus_teardown_gpadl(channel, &channel->ringbuffer_gpadlhandle); 948 if (ret) { 949 pr_err("Close failed: teardown gpadl return %d\n", ret); 950 /* 951 * If we failed to teardown gpadl, 952 * it is perhaps better to leak memory. 953 */ 954 } 955 } 956 957 if (!ret) 958 vmbus_free_requestor(&channel->requestor); 959 960 return ret; 961} 962 963/* disconnect ring - close all channels */ 964int vmbus_disconnect_ring(struct vmbus_channel *channel) 965{ 966 struct vmbus_channel *cur_channel, *tmp; 967 int ret; 968 969 if (channel->primary_channel != NULL) 970 return -EINVAL; 971 972 list_for_each_entry_safe(cur_channel, tmp, &channel->sc_list, sc_list) { 973 if (cur_channel->rescind) 974 wait_for_completion(&cur_channel->rescind_event); 975 976 mutex_lock(&vmbus_connection.channel_mutex); 977 if (vmbus_close_internal(cur_channel) == 0) { 978 vmbus_free_ring(cur_channel); 979 980 if (cur_channel->rescind) 981 hv_process_channel_removal(cur_channel); 982 } 983 mutex_unlock(&vmbus_connection.channel_mutex); 984 } 985 986 /* 987 * Now close the primary. 988 */ 989 mutex_lock(&vmbus_connection.channel_mutex); 990 ret = vmbus_close_internal(channel); 991 mutex_unlock(&vmbus_connection.channel_mutex); 992 993 return ret; 994} 995EXPORT_SYMBOL_GPL(vmbus_disconnect_ring); 996 997/* 998 * vmbus_close - Close the specified channel 999 */ 1000void vmbus_close(struct vmbus_channel *channel) 1001{ 1002 if (vmbus_disconnect_ring(channel) == 0) 1003 vmbus_free_ring(channel); 1004} 1005EXPORT_SYMBOL_GPL(vmbus_close); 1006 1007/** 1008 * vmbus_sendpacket_getid() - Send the specified buffer on the given channel 1009 * @channel: Pointer to vmbus_channel structure 1010 * @buffer: Pointer to the buffer you want to send the data from. 1011 * @bufferlen: Maximum size of what the buffer holds. 1012 * @requestid: Identifier of the request 1013 * @trans_id: Identifier of the transaction associated to this request, if 1014 * the send is successful; undefined, otherwise. 1015 * @type: Type of packet that is being sent e.g. negotiate, time 1016 * packet etc. 1017 * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED 1018 * 1019 * Sends data in @buffer directly to Hyper-V via the vmbus. 1020 * This will send the data unparsed to Hyper-V. 1021 * 1022 * Mainly used by Hyper-V drivers. 1023 */ 1024int vmbus_sendpacket_getid(struct vmbus_channel *channel, void *buffer, 1025 u32 bufferlen, u64 requestid, u64 *trans_id, 1026 enum vmbus_packet_type type, u32 flags) 1027{ 1028 struct vmpacket_descriptor desc; 1029 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen; 1030 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 1031 struct kvec bufferlist[3]; 1032 u64 aligned_data = 0; 1033 int num_vecs = ((bufferlen != 0) ? 3 : 1); 1034 1035 1036 /* Setup the descriptor */ 1037 desc.type = type; /* VmbusPacketTypeDataInBand; */ 1038 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */ 1039 /* in 8-bytes granularity */ 1040 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3; 1041 desc.len8 = (u16)(packetlen_aligned >> 3); 1042 desc.trans_id = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */ 1043 1044 bufferlist[0].iov_base = &desc; 1045 bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor); 1046 bufferlist[1].iov_base = buffer; 1047 bufferlist[1].iov_len = bufferlen; 1048 bufferlist[2].iov_base = &aligned_data; 1049 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 1050 1051 return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid, trans_id); 1052} 1053EXPORT_SYMBOL(vmbus_sendpacket_getid); 1054 1055/** 1056 * vmbus_sendpacket() - Send the specified buffer on the given channel 1057 * @channel: Pointer to vmbus_channel structure 1058 * @buffer: Pointer to the buffer you want to send the data from. 1059 * @bufferlen: Maximum size of what the buffer holds. 1060 * @requestid: Identifier of the request 1061 * @type: Type of packet that is being sent e.g. negotiate, time 1062 * packet etc. 1063 * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED 1064 * 1065 * Sends data in @buffer directly to Hyper-V via the vmbus. 1066 * This will send the data unparsed to Hyper-V. 1067 * 1068 * Mainly used by Hyper-V drivers. 1069 */ 1070int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer, 1071 u32 bufferlen, u64 requestid, 1072 enum vmbus_packet_type type, u32 flags) 1073{ 1074 return vmbus_sendpacket_getid(channel, buffer, bufferlen, 1075 requestid, NULL, type, flags); 1076} 1077EXPORT_SYMBOL(vmbus_sendpacket); 1078 1079/* 1080 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer 1081 * packets using a GPADL Direct packet type. This interface allows you 1082 * to control notifying the host. This will be useful for sending 1083 * batched data. Also the sender can control the send flags 1084 * explicitly. 1085 */ 1086int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, 1087 struct hv_page_buffer pagebuffers[], 1088 u32 pagecount, void *buffer, u32 bufferlen, 1089 u64 requestid) 1090{ 1091 int i; 1092 struct vmbus_channel_packet_page_buffer desc; 1093 u32 descsize; 1094 u32 packetlen; 1095 u32 packetlen_aligned; 1096 struct kvec bufferlist[3]; 1097 u64 aligned_data = 0; 1098 1099 if (pagecount > MAX_PAGE_BUFFER_COUNT) 1100 return -EINVAL; 1101 1102 /* 1103 * Adjust the size down since vmbus_channel_packet_page_buffer is the 1104 * largest size we support 1105 */ 1106 descsize = sizeof(struct vmbus_channel_packet_page_buffer) - 1107 ((MAX_PAGE_BUFFER_COUNT - pagecount) * 1108 sizeof(struct hv_page_buffer)); 1109 packetlen = descsize + bufferlen; 1110 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 1111 1112 /* Setup the descriptor */ 1113 desc.type = VM_PKT_DATA_USING_GPA_DIRECT; 1114 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 1115 desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */ 1116 desc.length8 = (u16)(packetlen_aligned >> 3); 1117 desc.transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */ 1118 desc.reserved = 0; 1119 desc.rangecount = pagecount; 1120 1121 for (i = 0; i < pagecount; i++) { 1122 desc.range[i].len = pagebuffers[i].len; 1123 desc.range[i].offset = pagebuffers[i].offset; 1124 desc.range[i].pfn = pagebuffers[i].pfn; 1125 } 1126 1127 bufferlist[0].iov_base = &desc; 1128 bufferlist[0].iov_len = descsize; 1129 bufferlist[1].iov_base = buffer; 1130 bufferlist[1].iov_len = bufferlen; 1131 bufferlist[2].iov_base = &aligned_data; 1132 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 1133 1134 return hv_ringbuffer_write(channel, bufferlist, 3, requestid, NULL); 1135} 1136EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer); 1137 1138/* 1139 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet 1140 * using a GPADL Direct packet type. 1141 * The buffer includes the vmbus descriptor. 1142 */ 1143int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel, 1144 struct vmbus_packet_mpb_array *desc, 1145 u32 desc_size, 1146 void *buffer, u32 bufferlen, u64 requestid) 1147{ 1148 u32 packetlen; 1149 u32 packetlen_aligned; 1150 struct kvec bufferlist[3]; 1151 u64 aligned_data = 0; 1152 1153 packetlen = desc_size + bufferlen; 1154 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 1155 1156 /* Setup the descriptor */ 1157 desc->type = VM_PKT_DATA_USING_GPA_DIRECT; 1158 desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 1159 desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */ 1160 desc->length8 = (u16)(packetlen_aligned >> 3); 1161 desc->transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */ 1162 desc->reserved = 0; 1163 desc->rangecount = 1; 1164 1165 bufferlist[0].iov_base = desc; 1166 bufferlist[0].iov_len = desc_size; 1167 bufferlist[1].iov_base = buffer; 1168 bufferlist[1].iov_len = bufferlen; 1169 bufferlist[2].iov_base = &aligned_data; 1170 bufferlist[2].iov_len = (packetlen_aligned - packetlen); 1171 1172 return hv_ringbuffer_write(channel, bufferlist, 3, requestid, NULL); 1173} 1174EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc); 1175 1176/** 1177 * __vmbus_recvpacket() - Retrieve the user packet on the specified channel 1178 * @channel: Pointer to vmbus_channel structure 1179 * @buffer: Pointer to the buffer you want to receive the data into. 1180 * @bufferlen: Maximum size of what the buffer can hold. 1181 * @buffer_actual_len: The actual size of the data after it was received. 1182 * @requestid: Identifier of the request 1183 * @raw: true means keep the vmpacket_descriptor header in the received data. 1184 * 1185 * Receives directly from the hyper-v vmbus and puts the data it received 1186 * into Buffer. This will receive the data unparsed from hyper-v. 1187 * 1188 * Mainly used by Hyper-V drivers. 1189 */ 1190static inline int 1191__vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, 1192 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid, 1193 bool raw) 1194{ 1195 return hv_ringbuffer_read(channel, buffer, bufferlen, 1196 buffer_actual_len, requestid, raw); 1197 1198} 1199 1200int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, 1201 u32 bufferlen, u32 *buffer_actual_len, 1202 u64 *requestid) 1203{ 1204 return __vmbus_recvpacket(channel, buffer, bufferlen, 1205 buffer_actual_len, requestid, false); 1206} 1207EXPORT_SYMBOL(vmbus_recvpacket); 1208 1209/* 1210 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel 1211 */ 1212int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer, 1213 u32 bufferlen, u32 *buffer_actual_len, 1214 u64 *requestid) 1215{ 1216 return __vmbus_recvpacket(channel, buffer, bufferlen, 1217 buffer_actual_len, requestid, true); 1218} 1219EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); 1220 1221/* 1222 * vmbus_next_request_id - Returns a new request id. It is also 1223 * the index at which the guest memory address is stored. 1224 * Uses a spin lock to avoid race conditions. 1225 * @channel: Pointer to the VMbus channel struct 1226 * @rqst_add: Guest memory address to be stored in the array 1227 */ 1228u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr) 1229{ 1230 struct vmbus_requestor *rqstor = &channel->requestor; 1231 unsigned long flags; 1232 u64 current_id; 1233 1234 /* Check rqstor has been initialized */ 1235 if (!channel->rqstor_size) 1236 return VMBUS_NO_RQSTOR; 1237 1238 lock_requestor(channel, flags); 1239 current_id = rqstor->next_request_id; 1240 1241 /* Requestor array is full */ 1242 if (current_id >= rqstor->size) { 1243 unlock_requestor(channel, flags); 1244 return VMBUS_RQST_ERROR; 1245 } 1246 1247 rqstor->next_request_id = rqstor->req_arr[current_id]; 1248 rqstor->req_arr[current_id] = rqst_addr; 1249 1250 /* The already held spin lock provides atomicity */ 1251 bitmap_set(rqstor->req_bitmap, current_id, 1); 1252 1253 unlock_requestor(channel, flags); 1254 1255 /* 1256 * Cannot return an ID of 0, which is reserved for an unsolicited 1257 * message from Hyper-V; Hyper-V does not acknowledge (respond to) 1258 * VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED requests with ID of 1259 * 0 sent by the guest. 1260 */ 1261 return current_id + 1; 1262} 1263EXPORT_SYMBOL_GPL(vmbus_next_request_id); 1264 1265/* As in vmbus_request_addr_match() but without the requestor lock */ 1266u64 __vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id, 1267 u64 rqst_addr) 1268{ 1269 struct vmbus_requestor *rqstor = &channel->requestor; 1270 u64 req_addr; 1271 1272 /* Check rqstor has been initialized */ 1273 if (!channel->rqstor_size) 1274 return VMBUS_NO_RQSTOR; 1275 1276 /* Hyper-V can send an unsolicited message with ID of 0 */ 1277 if (!trans_id) 1278 return VMBUS_RQST_ERROR; 1279 1280 /* Data corresponding to trans_id is stored at trans_id - 1 */ 1281 trans_id--; 1282 1283 /* Invalid trans_id */ 1284 if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap)) 1285 return VMBUS_RQST_ERROR; 1286 1287 req_addr = rqstor->req_arr[trans_id]; 1288 if (rqst_addr == VMBUS_RQST_ADDR_ANY || req_addr == rqst_addr) { 1289 rqstor->req_arr[trans_id] = rqstor->next_request_id; 1290 rqstor->next_request_id = trans_id; 1291 1292 /* The already held spin lock provides atomicity */ 1293 bitmap_clear(rqstor->req_bitmap, trans_id, 1); 1294 } 1295 1296 return req_addr; 1297} 1298EXPORT_SYMBOL_GPL(__vmbus_request_addr_match); 1299 1300/* 1301 * vmbus_request_addr_match - Clears/removes @trans_id from the @channel's 1302 * requestor, provided the memory address stored at @trans_id equals @rqst_addr 1303 * (or provided @rqst_addr matches the sentinel value VMBUS_RQST_ADDR_ANY). 1304 * 1305 * Returns the memory address stored at @trans_id, or VMBUS_RQST_ERROR if 1306 * @trans_id is not contained in the requestor. 1307 * 1308 * Acquires and releases the requestor spin lock. 1309 */ 1310u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id, 1311 u64 rqst_addr) 1312{ 1313 unsigned long flags; 1314 u64 req_addr; 1315 1316 lock_requestor(channel, flags); 1317 req_addr = __vmbus_request_addr_match(channel, trans_id, rqst_addr); 1318 unlock_requestor(channel, flags); 1319 1320 return req_addr; 1321} 1322EXPORT_SYMBOL_GPL(vmbus_request_addr_match); 1323 1324/* 1325 * vmbus_request_addr - Returns the memory address stored at @trans_id 1326 * in @rqstor. Uses a spin lock to avoid race conditions. 1327 * @channel: Pointer to the VMbus channel struct 1328 * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's 1329 * next request id. 1330 */ 1331u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id) 1332{ 1333 return vmbus_request_addr_match(channel, trans_id, VMBUS_RQST_ADDR_ANY); 1334} 1335EXPORT_SYMBOL_GPL(vmbus_request_addr); 1336