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1// SPDX-License-Identifier: GPL-2.0-only2/*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 ": " fmt10 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 uses28 *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 header32 * (because of the alignment requirement), however, the hypervisor only33 * uses the first HV_HYP_PAGE_SIZE as the header, therefore leaving a34 * (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap. And since there are two rings in a35 * ringbuffer, the total size for a RING gpadl that Hyper-V uses is the36 * 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 unit49 * 2) We're skipping any space larger than HV_HYP_PAGE_SIZE in50 * the first guest-size page of each of the two ring buffers.51 * So we effectively subtract out two guest-size pages, and add52 * 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 of62 * HV_HYP_PAGE) in a ring gpadl based on the63 * offset in the guest64 *65 * @offset: the offset (in bytes) where the send ringbuffer starts in the66 * virtual address space of the guest67 */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 the73 * header (because of the alignment requirement), however, the74 * 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 to78 * 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 in85 * the gpadl86 *87 * @type: the type of the gpadl88 * @kbuffer: the pointer to the gpadl in the guest89 * @size: the total size (in bytes) of the gpadl90 * @send_offset: the offset (in bytes) where the send ringbuffer starts in the91 * virtual address space of the guest92 * @i: the index93 */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 else109 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 specified121 * 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" mode131 * 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_group141 [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_pagecount160 << 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 on267 * the mutex and be unable to signal the completion.268 *269 * See the caller target_cpu_store() for information about the usage of the270 * 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 5.3292 * or later is negotiated, Hyper-V always sends an ACK in response to such a293 * 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 version298 * 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 buffer310 */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 body364 * messages are needed365 */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 could395 * be 64-bit396 * This is governed by the guest/host protocol and397 * 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 ringbuffer414 *415 * @channel: a channel416 * @type: the type of the corresponding GPADL, only meaningful for the guest.417 * @kbuffer: from kmalloc or vmalloc418 * @size: page-size multiple419 * @send_offset: the offset (in bytes) where the send ring buffer starts,420 * should be 0 for BUFFER type gpadl421 * @gpadl_handle: some funky thing422 */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 the449 * memory is unknown. Leave "decrypted" as true to ensure the450 * 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 is544 * left as true so the memory is leaked instead of being545 * 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 buffer556 *557 * @channel: a channel558 * @kbuffer: from kmalloc or vmalloc559 * @size: page-size multiple560 * @gpadl_handle: some funky thing561 */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 slot572 * keeps track of the next available slot in the array. Initially, each573 * slot points to the next one (as in a Linked List). The last slot574 * does not point to anything, so its value is U64_MAX by default.575 * @size The size of the array576 */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 slot598 * @size: Size of the requestor array599 */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 @rqstor626 * @rqstor: Pointer to the requestor struct627 */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_gpadlhandle705 = newchannel->ringbuffer_gpadlhandle.gpadl_handle;706 /*707 * The unit of ->downstream_ringbuffer_pageoffset is HV_HYP_PAGE and708 * the unit of ->ringbuffer_send_offset (i.e. send_pages) is PAGE, so709 * 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 buffer774 */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 handle808 */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 rescind854 * 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 race882 * with vmbus_close_internal() in the case of SMP guest, e.g., when883 * the former is accessing channel->inbound.ring_buffer, the latter884 * could be freeing the ring_buffer pages, so here we must stop it885 * first.886 *887 * vmbus_chan_sched() might call the netvsc driver callback function888 * that ends up scheduling NAPI work that accesses the ring buffer.889 * At this point, we have to ensure that any such work is completed890 * 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 is916 * rescinded later (e.g., we dynamically disable an Integrated Service917 * 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 channel999 */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 channel1009 * @channel: Pointer to vmbus_channel structure1010 * @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 request1013 * @trans_id: Identifier of the transaction associated to this request, if1014 * the send is successful; undefined, otherwise.1015 * @type: Type of packet that is being sent e.g. negotiate, time1016 * packet etc.1017 * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED1018 *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 channel1057 * @channel: Pointer to vmbus_channel structure1058 * @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 request1061 * @type: Type of packet that is being sent e.g. negotiate, time1062 * packet etc.1063 * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED1064 *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 buffer1081 * packets using a GPADL Direct packet type. This interface allows you1082 * to control notifying the host. This will be useful for sending1083 * batched data. Also the sender can control the send flags1084 * 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 the1104 * largest size we support1105 */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 packet1140 * 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 channel1178 * @channel: Pointer to vmbus_channel structure1179 * @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 request1183 * @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 received1186 * into Buffer. This will receive the data unparsed from hyper-v.1187 *1188 * Mainly used by Hyper-V drivers.1189 */1190static inline int1191__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 channel1211 */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 also1223 * 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 struct1226 * @rqst_add: Guest memory address to be stored in the array1227 */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 unsolicited1257 * message from Hyper-V; Hyper-V does not acknowledge (respond to)1258 * VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED requests with ID of1259 * 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's1302 * requestor, provided the memory address stored at @trans_id equals @rqst_addr1303 * (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 if1306 * @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_id1326 * in @rqstor. Uses a spin lock to avoid race conditions.1327 * @channel: Pointer to the VMbus channel struct1328 * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's1329 * 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