2 * Copyright (c) 2009, Microsoft Corporation.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307 USA.
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/wait.h>
27 #include <linux/slab.h>
28 #include <linux/module.h>
29 #include <linux/hyperv.h>
31 #include "hyperv_vmbus.h"
33 #define NUM_PAGES_SPANNED(addr, len) \
34 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
37 * vmbus_setevent- Trigger an event notification on the specified
40 static void vmbus_setevent(struct vmbus_channel *channel)
42 struct hv_monitor_page *monitorpage;
44 if (channel->offermsg.monitor_allocated) {
45 /* Each u32 represents 32 channels */
46 sync_set_bit(channel->offermsg.child_relid & 31,
47 (unsigned long *) vmbus_connection.send_int_page +
48 (channel->offermsg.child_relid >> 5));
50 monitorpage = vmbus_connection.monitor_pages;
51 monitorpage++; /* Get the child to parent monitor page */
53 sync_set_bit(channel->monitor_bit,
54 (unsigned long *)&monitorpage->trigger_group
55 [channel->monitor_grp].pending);
58 vmbus_set_event(channel);
63 * vmbus_get_debug_info -Retrieve various channel debug info
65 void vmbus_get_debug_info(struct vmbus_channel *channel,
66 struct vmbus_channel_debug_info *debuginfo)
68 struct hv_monitor_page *monitorpage;
69 u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
70 u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
72 debuginfo->relid = channel->offermsg.child_relid;
73 debuginfo->state = channel->state;
74 memcpy(&debuginfo->interfacetype,
75 &channel->offermsg.offer.if_type, sizeof(uuid_le));
76 memcpy(&debuginfo->interface_instance,
77 &channel->offermsg.offer.if_instance,
80 monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
82 debuginfo->monitorid = channel->offermsg.monitorid;
84 debuginfo->servermonitor_pending =
85 monitorpage->trigger_group[monitor_group].pending;
86 debuginfo->servermonitor_latency =
87 monitorpage->latency[monitor_group][monitor_offset];
88 debuginfo->servermonitor_connectionid =
89 monitorpage->parameter[monitor_group]
90 [monitor_offset].connectionid.u.id;
94 debuginfo->clientmonitor_pending =
95 monitorpage->trigger_group[monitor_group].pending;
96 debuginfo->clientmonitor_latency =
97 monitorpage->latency[monitor_group][monitor_offset];
98 debuginfo->clientmonitor_connectionid =
99 monitorpage->parameter[monitor_group]
100 [monitor_offset].connectionid.u.id;
102 hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
103 hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
107 * vmbus_open - Open the specified channel.
109 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
110 u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
111 void (*onchannelcallback)(void *context), void *context)
113 struct vmbus_channel_open_channel *open_msg;
114 struct vmbus_channel_msginfo *open_info = NULL;
119 newchannel->onchannel_callback = onchannelcallback;
120 newchannel->channel_callback_context = context;
122 /* Allocate the ring buffer */
123 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
124 get_order(send_ringbuffer_size + recv_ringbuffer_size));
130 in = (void *)((unsigned long)out + send_ringbuffer_size);
132 newchannel->ringbuffer_pages = out;
133 newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
134 recv_ringbuffer_size) >> PAGE_SHIFT;
136 ret = hv_ringbuffer_init(
137 &newchannel->outbound, out, send_ringbuffer_size);
144 ret = hv_ringbuffer_init(
145 &newchannel->inbound, in, recv_ringbuffer_size);
152 /* Establish the gpadl for the ring buffer */
153 newchannel->ringbuffer_gpadlhandle = 0;
155 ret = vmbus_establish_gpadl(newchannel,
156 newchannel->outbound.ring_buffer,
157 send_ringbuffer_size +
158 recv_ringbuffer_size,
159 &newchannel->ringbuffer_gpadlhandle);
166 /* Create and init the channel open message */
167 open_info = kmalloc(sizeof(*open_info) +
168 sizeof(struct vmbus_channel_open_channel),
175 init_completion(&open_info->waitevent);
177 open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
178 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
179 open_msg->openid = newchannel->offermsg.child_relid;
180 open_msg->child_relid = newchannel->offermsg.child_relid;
181 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
182 open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
184 open_msg->target_vp = newchannel->target_vp;
186 if (userdatalen > MAX_USER_DEFINED_BYTES) {
192 memcpy(open_msg->userdata, userdata, userdatalen);
194 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
195 list_add_tail(&open_info->msglistentry,
196 &vmbus_connection.chn_msg_list);
197 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
199 ret = vmbus_post_msg(open_msg,
200 sizeof(struct vmbus_channel_open_channel));
207 t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
214 if (open_info->response.open_result.status)
215 err = open_info->response.open_result.status;
217 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
218 list_del(&open_info->msglistentry);
219 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
225 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
226 list_del(&open_info->msglistentry);
227 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
230 vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
233 free_pages((unsigned long)out,
234 get_order(send_ringbuffer_size + recv_ringbuffer_size));
238 EXPORT_SYMBOL_GPL(vmbus_open);
241 * create_gpadl_header - Creates a gpadl for the specified buffer
243 static int create_gpadl_header(void *kbuffer, u32 size,
244 struct vmbus_channel_msginfo **msginfo,
249 unsigned long long pfn;
250 struct vmbus_channel_gpadl_header *gpadl_header;
251 struct vmbus_channel_gpadl_body *gpadl_body;
252 struct vmbus_channel_msginfo *msgheader;
253 struct vmbus_channel_msginfo *msgbody = NULL;
256 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
258 pagecount = size >> PAGE_SHIFT;
259 pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
261 /* do we need a gpadl body msg */
262 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
263 sizeof(struct vmbus_channel_gpadl_header) -
264 sizeof(struct gpa_range);
265 pfncount = pfnsize / sizeof(u64);
267 if (pagecount > pfncount) {
268 /* we need a gpadl body */
269 /* fill in the header */
270 msgsize = sizeof(struct vmbus_channel_msginfo) +
271 sizeof(struct vmbus_channel_gpadl_header) +
272 sizeof(struct gpa_range) + pfncount * sizeof(u64);
273 msgheader = kzalloc(msgsize, GFP_KERNEL);
277 INIT_LIST_HEAD(&msgheader->submsglist);
278 msgheader->msgsize = msgsize;
280 gpadl_header = (struct vmbus_channel_gpadl_header *)
282 gpadl_header->rangecount = 1;
283 gpadl_header->range_buflen = sizeof(struct gpa_range) +
284 pagecount * sizeof(u64);
285 gpadl_header->range[0].byte_offset = 0;
286 gpadl_header->range[0].byte_count = size;
287 for (i = 0; i < pfncount; i++)
288 gpadl_header->range[0].pfn_array[i] = pfn+i;
289 *msginfo = msgheader;
293 pfnleft = pagecount - pfncount;
295 /* how many pfns can we fit */
296 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
297 sizeof(struct vmbus_channel_gpadl_body);
298 pfncount = pfnsize / sizeof(u64);
300 /* fill in the body */
302 if (pfnleft > pfncount)
307 msgsize = sizeof(struct vmbus_channel_msginfo) +
308 sizeof(struct vmbus_channel_gpadl_body) +
309 pfncurr * sizeof(u64);
310 msgbody = kzalloc(msgsize, GFP_KERNEL);
313 struct vmbus_channel_msginfo *pos = NULL;
314 struct vmbus_channel_msginfo *tmp = NULL;
316 * Free up all the allocated messages.
318 list_for_each_entry_safe(pos, tmp,
319 &msgheader->submsglist,
322 list_del(&pos->msglistentry);
329 msgbody->msgsize = msgsize;
332 (struct vmbus_channel_gpadl_body *)msgbody->msg;
335 * Gpadl is u32 and we are using a pointer which could
337 * This is governed by the guest/host protocol and
338 * so the hypervisor gurantees that this is ok.
340 for (i = 0; i < pfncurr; i++)
341 gpadl_body->pfn[i] = pfn + pfnsum + i;
343 /* add to msg header */
344 list_add_tail(&msgbody->msglistentry,
345 &msgheader->submsglist);
350 /* everything fits in a header */
351 msgsize = sizeof(struct vmbus_channel_msginfo) +
352 sizeof(struct vmbus_channel_gpadl_header) +
353 sizeof(struct gpa_range) + pagecount * sizeof(u64);
354 msgheader = kzalloc(msgsize, GFP_KERNEL);
355 if (msgheader == NULL)
357 msgheader->msgsize = msgsize;
359 gpadl_header = (struct vmbus_channel_gpadl_header *)
361 gpadl_header->rangecount = 1;
362 gpadl_header->range_buflen = sizeof(struct gpa_range) +
363 pagecount * sizeof(u64);
364 gpadl_header->range[0].byte_offset = 0;
365 gpadl_header->range[0].byte_count = size;
366 for (i = 0; i < pagecount; i++)
367 gpadl_header->range[0].pfn_array[i] = pfn+i;
369 *msginfo = msgheader;
381 * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
383 * @channel: a channel
384 * @kbuffer: from kmalloc
385 * @size: page-size multiple
386 * @gpadl_handle: some funky thing
388 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
389 u32 size, u32 *gpadl_handle)
391 struct vmbus_channel_gpadl_header *gpadlmsg;
392 struct vmbus_channel_gpadl_body *gpadl_body;
393 struct vmbus_channel_msginfo *msginfo = NULL;
394 struct vmbus_channel_msginfo *submsginfo;
396 struct list_head *curr;
397 u32 next_gpadl_handle;
401 next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
402 atomic_inc(&vmbus_connection.next_gpadl_handle);
404 ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
408 init_completion(&msginfo->waitevent);
410 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
411 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
412 gpadlmsg->child_relid = channel->offermsg.child_relid;
413 gpadlmsg->gpadl = next_gpadl_handle;
416 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
417 list_add_tail(&msginfo->msglistentry,
418 &vmbus_connection.chn_msg_list);
420 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
422 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
428 list_for_each(curr, &msginfo->submsglist) {
430 submsginfo = (struct vmbus_channel_msginfo *)curr;
432 (struct vmbus_channel_gpadl_body *)submsginfo->msg;
434 gpadl_body->header.msgtype =
435 CHANNELMSG_GPADL_BODY;
436 gpadl_body->gpadl = next_gpadl_handle;
438 ret = vmbus_post_msg(gpadl_body,
439 submsginfo->msgsize -
440 sizeof(*submsginfo));
446 wait_for_completion(&msginfo->waitevent);
448 /* At this point, we received the gpadl created msg */
449 *gpadl_handle = gpadlmsg->gpadl;
452 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
453 list_del(&msginfo->msglistentry);
454 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
459 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
462 * vmbus_teardown_gpadl -Teardown the specified GPADL handle
464 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
466 struct vmbus_channel_gpadl_teardown *msg;
467 struct vmbus_channel_msginfo *info;
471 info = kmalloc(sizeof(*info) +
472 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
476 init_completion(&info->waitevent);
478 msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
480 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
481 msg->child_relid = channel->offermsg.child_relid;
482 msg->gpadl = gpadl_handle;
484 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
485 list_add_tail(&info->msglistentry,
486 &vmbus_connection.chn_msg_list);
487 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
488 ret = vmbus_post_msg(msg,
489 sizeof(struct vmbus_channel_gpadl_teardown));
494 wait_for_completion(&info->waitevent);
497 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
498 list_del(&info->msglistentry);
499 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
504 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
507 * vmbus_close - Close the specified channel
509 void vmbus_close(struct vmbus_channel *channel)
511 struct vmbus_channel_close_channel *msg;
515 /* Stop callback and cancel the timer asap */
516 spin_lock_irqsave(&channel->inbound_lock, flags);
517 channel->onchannel_callback = NULL;
518 spin_unlock_irqrestore(&channel->inbound_lock, flags);
520 /* Send a closing message */
522 msg = &channel->close_msg.msg;
524 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
525 msg->child_relid = channel->offermsg.child_relid;
527 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
530 /* Tear down the gpadl for the channel's ring buffer */
531 if (channel->ringbuffer_gpadlhandle)
532 vmbus_teardown_gpadl(channel,
533 channel->ringbuffer_gpadlhandle);
535 /* Cleanup the ring buffers for this channel */
536 hv_ringbuffer_cleanup(&channel->outbound);
537 hv_ringbuffer_cleanup(&channel->inbound);
539 free_pages((unsigned long)channel->ringbuffer_pages,
540 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
544 EXPORT_SYMBOL_GPL(vmbus_close);
547 * vmbus_sendpacket() - Send the specified buffer on the given channel
548 * @channel: Pointer to vmbus_channel structure.
549 * @buffer: Pointer to the buffer you want to receive the data into.
550 * @bufferlen: Maximum size of what the the buffer will hold
551 * @requestid: Identifier of the request
552 * @type: Type of packet that is being send e.g. negotiate, time
555 * Sends data in @buffer directly to hyper-v via the vmbus
556 * This will send the data unparsed to hyper-v.
558 * Mainly used by Hyper-V drivers.
560 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
561 u32 bufferlen, u64 requestid,
562 enum vmbus_packet_type type, u32 flags)
564 struct vmpacket_descriptor desc;
565 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
566 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
567 struct scatterlist bufferlist[3];
568 u64 aligned_data = 0;
573 /* Setup the descriptor */
574 desc.type = type; /* VmbusPacketTypeDataInBand; */
575 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
576 /* in 8-bytes granularity */
577 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
578 desc.len8 = (u16)(packetlen_aligned >> 3);
579 desc.trans_id = requestid;
581 sg_init_table(bufferlist, 3);
582 sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
583 sg_set_buf(&bufferlist[1], buffer, bufferlen);
584 sg_set_buf(&bufferlist[2], &aligned_data,
585 packetlen_aligned - packetlen);
587 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
589 if (ret == 0 && signal)
590 vmbus_setevent(channel);
594 EXPORT_SYMBOL(vmbus_sendpacket);
597 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
598 * packets using a GPADL Direct packet type.
600 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
601 struct hv_page_buffer pagebuffers[],
602 u32 pagecount, void *buffer, u32 bufferlen,
607 struct vmbus_channel_packet_page_buffer desc;
610 u32 packetlen_aligned;
611 struct scatterlist bufferlist[3];
612 u64 aligned_data = 0;
615 if (pagecount > MAX_PAGE_BUFFER_COUNT)
620 * Adjust the size down since vmbus_channel_packet_page_buffer is the
621 * largest size we support
623 descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
624 ((MAX_PAGE_BUFFER_COUNT - pagecount) *
625 sizeof(struct hv_page_buffer));
626 packetlen = descsize + bufferlen;
627 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
629 /* Setup the descriptor */
630 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
631 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
632 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
633 desc.length8 = (u16)(packetlen_aligned >> 3);
634 desc.transactionid = requestid;
635 desc.rangecount = pagecount;
637 for (i = 0; i < pagecount; i++) {
638 desc.range[i].len = pagebuffers[i].len;
639 desc.range[i].offset = pagebuffers[i].offset;
640 desc.range[i].pfn = pagebuffers[i].pfn;
643 sg_init_table(bufferlist, 3);
644 sg_set_buf(&bufferlist[0], &desc, descsize);
645 sg_set_buf(&bufferlist[1], buffer, bufferlen);
646 sg_set_buf(&bufferlist[2], &aligned_data,
647 packetlen_aligned - packetlen);
649 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
651 if (ret == 0 && signal)
652 vmbus_setevent(channel);
656 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
659 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
660 * using a GPADL Direct packet type.
662 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
663 struct hv_multipage_buffer *multi_pagebuffer,
664 void *buffer, u32 bufferlen, u64 requestid)
667 struct vmbus_channel_packet_multipage_buffer desc;
670 u32 packetlen_aligned;
671 struct scatterlist bufferlist[3];
672 u64 aligned_data = 0;
674 u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
675 multi_pagebuffer->len);
678 if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
682 * Adjust the size down since vmbus_channel_packet_multipage_buffer is
683 * the largest size we support
685 descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
686 ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
688 packetlen = descsize + bufferlen;
689 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
692 /* Setup the descriptor */
693 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
694 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
695 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
696 desc.length8 = (u16)(packetlen_aligned >> 3);
697 desc.transactionid = requestid;
700 desc.range.len = multi_pagebuffer->len;
701 desc.range.offset = multi_pagebuffer->offset;
703 memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
704 pfncount * sizeof(u64));
706 sg_init_table(bufferlist, 3);
707 sg_set_buf(&bufferlist[0], &desc, descsize);
708 sg_set_buf(&bufferlist[1], buffer, bufferlen);
709 sg_set_buf(&bufferlist[2], &aligned_data,
710 packetlen_aligned - packetlen);
712 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
714 if (ret == 0 && signal)
715 vmbus_setevent(channel);
719 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
722 * vmbus_recvpacket() - Retrieve the user packet on the specified channel
723 * @channel: Pointer to vmbus_channel structure.
724 * @buffer: Pointer to the buffer you want to receive the data into.
725 * @bufferlen: Maximum size of what the the buffer will hold
726 * @buffer_actual_len: The actual size of the data after it was received
727 * @requestid: Identifier of the request
729 * Receives directly from the hyper-v vmbus and puts the data it received
730 * into Buffer. This will receive the data unparsed from hyper-v.
732 * Mainly used by Hyper-V drivers.
734 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
735 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
737 struct vmpacket_descriptor desc;
743 *buffer_actual_len = 0;
747 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
748 sizeof(struct vmpacket_descriptor));
752 packetlen = desc.len8 << 3;
753 userlen = packetlen - (desc.offset8 << 3);
755 *buffer_actual_len = userlen;
757 if (userlen > bufferlen) {
759 pr_err("Buffer too small - got %d needs %d\n",
764 *requestid = desc.trans_id;
766 /* Copy over the packet to the user buffer */
767 ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
768 (desc.offset8 << 3), &signal);
771 vmbus_setevent(channel);
775 EXPORT_SYMBOL(vmbus_recvpacket);
778 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
780 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
781 u32 bufferlen, u32 *buffer_actual_len,
784 struct vmpacket_descriptor desc;
789 *buffer_actual_len = 0;
793 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
794 sizeof(struct vmpacket_descriptor));
799 packetlen = desc.len8 << 3;
801 *buffer_actual_len = packetlen;
803 if (packetlen > bufferlen) {
804 pr_err("Buffer too small - needed %d bytes but "
805 "got space for only %d bytes\n",
806 packetlen, bufferlen);
810 *requestid = desc.trans_id;
812 /* Copy over the entire packet to the user buffer */
813 ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
817 vmbus_setevent(channel);
821 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);