1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/kernel.h>
24#include <linux/sched.h>
25#include <linux/wait.h>
26#include <linux/mm.h>
27#include <linux/slab.h>
28#include <linux/module.h>
29#include <linux/hyperv.h>
30
31#include "hyperv_vmbus.h"
32
33#define NUM_PAGES_SPANNED(addr, len) \
34((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
35
36
37
38
39
40static void vmbus_setevent(struct vmbus_channel *channel)
41{
42 struct hv_monitor_page *monitorpage;
43
44 if (channel->offermsg.monitor_allocated) {
45
46 sync_set_bit(channel->offermsg.child_relid & 31,
47 (unsigned long *) vmbus_connection.send_int_page +
48 (channel->offermsg.child_relid >> 5));
49
50 monitorpage = vmbus_connection.monitor_pages;
51 monitorpage++;
52
53 sync_set_bit(channel->monitor_bit,
54 (unsigned long *)&monitorpage->trigger_group
55 [channel->monitor_grp].pending);
56
57 } else {
58 vmbus_set_event(channel);
59 }
60}
61
62
63
64
65void vmbus_get_debug_info(struct vmbus_channel *channel,
66 struct vmbus_channel_debug_info *debuginfo)
67{
68 struct hv_monitor_page *monitorpage;
69 u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
70 u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
71
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,
78 sizeof(uuid_le));
79
80 monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
81
82 debuginfo->monitorid = channel->offermsg.monitorid;
83
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;
91
92 monitorpage++;
93
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;
101
102 hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
103 hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
104}
105
106
107
108
109int 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)
112{
113 struct vmbus_channel_open_channel *open_msg;
114 struct vmbus_channel_msginfo *open_info = NULL;
115 void *in, *out;
116 unsigned long flags;
117 int ret, t, err = 0;
118
119 newchannel->onchannel_callback = onchannelcallback;
120 newchannel->channel_callback_context = context;
121
122
123 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
124 get_order(send_ringbuffer_size + recv_ringbuffer_size));
125
126 if (!out)
127 return -ENOMEM;
128
129
130 in = (void *)((unsigned long)out + send_ringbuffer_size);
131
132 newchannel->ringbuffer_pages = out;
133 newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
134 recv_ringbuffer_size) >> PAGE_SHIFT;
135
136 ret = hv_ringbuffer_init(
137 &newchannel->outbound, out, send_ringbuffer_size);
138
139 if (ret != 0) {
140 err = ret;
141 goto error0;
142 }
143
144 ret = hv_ringbuffer_init(
145 &newchannel->inbound, in, recv_ringbuffer_size);
146 if (ret != 0) {
147 err = ret;
148 goto error0;
149 }
150
151
152
153 newchannel->ringbuffer_gpadlhandle = 0;
154
155 ret = vmbus_establish_gpadl(newchannel,
156 newchannel->outbound.ring_buffer,
157 send_ringbuffer_size +
158 recv_ringbuffer_size,
159 &newchannel->ringbuffer_gpadlhandle);
160
161 if (ret != 0) {
162 err = ret;
163 goto error0;
164 }
165
166
167 open_info = kmalloc(sizeof(*open_info) +
168 sizeof(struct vmbus_channel_open_channel),
169 GFP_KERNEL);
170 if (!open_info) {
171 err = -ENOMEM;
172 goto error0;
173 }
174
175 init_completion(&open_info->waitevent);
176
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 >>
183 PAGE_SHIFT;
184 open_msg->target_vp = newchannel->target_vp;
185
186 if (userdatalen > MAX_USER_DEFINED_BYTES) {
187 err = -EINVAL;
188 goto error0;
189 }
190
191 if (userdatalen)
192 memcpy(open_msg->userdata, userdata, userdatalen);
193
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);
198
199 ret = vmbus_post_msg(open_msg,
200 sizeof(struct vmbus_channel_open_channel));
201
202 if (ret != 0)
203 goto error1;
204
205 t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
206 if (t == 0) {
207 err = -ETIMEDOUT;
208 goto error1;
209 }
210
211
212 if (open_info->response.open_result.status)
213 err = open_info->response.open_result.status;
214
215 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
216 list_del(&open_info->msglistentry);
217 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
218
219 kfree(open_info);
220 return err;
221
222error1:
223 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
224 list_del(&open_info->msglistentry);
225 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
226
227error0:
228 free_pages((unsigned long)out,
229 get_order(send_ringbuffer_size + recv_ringbuffer_size));
230 kfree(open_info);
231 return err;
232}
233EXPORT_SYMBOL_GPL(vmbus_open);
234
235
236
237
238static int create_gpadl_header(void *kbuffer, u32 size,
239 struct vmbus_channel_msginfo **msginfo,
240 u32 *messagecount)
241{
242 int i;
243 int pagecount;
244 unsigned long long pfn;
245 struct vmbus_channel_gpadl_header *gpadl_header;
246 struct vmbus_channel_gpadl_body *gpadl_body;
247 struct vmbus_channel_msginfo *msgheader;
248 struct vmbus_channel_msginfo *msgbody = NULL;
249 u32 msgsize;
250
251 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
252
253 pagecount = size >> PAGE_SHIFT;
254 pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
255
256
257 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
258 sizeof(struct vmbus_channel_gpadl_header) -
259 sizeof(struct gpa_range);
260 pfncount = pfnsize / sizeof(u64);
261
262 if (pagecount > pfncount) {
263
264
265 msgsize = sizeof(struct vmbus_channel_msginfo) +
266 sizeof(struct vmbus_channel_gpadl_header) +
267 sizeof(struct gpa_range) + pfncount * sizeof(u64);
268 msgheader = kzalloc(msgsize, GFP_KERNEL);
269 if (!msgheader)
270 goto nomem;
271
272 INIT_LIST_HEAD(&msgheader->submsglist);
273 msgheader->msgsize = msgsize;
274
275 gpadl_header = (struct vmbus_channel_gpadl_header *)
276 msgheader->msg;
277 gpadl_header->rangecount = 1;
278 gpadl_header->range_buflen = sizeof(struct gpa_range) +
279 pagecount * sizeof(u64);
280 gpadl_header->range[0].byte_offset = 0;
281 gpadl_header->range[0].byte_count = size;
282 for (i = 0; i < pfncount; i++)
283 gpadl_header->range[0].pfn_array[i] = pfn+i;
284 *msginfo = msgheader;
285 *messagecount = 1;
286
287 pfnsum = pfncount;
288 pfnleft = pagecount - pfncount;
289
290
291 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
292 sizeof(struct vmbus_channel_gpadl_body);
293 pfncount = pfnsize / sizeof(u64);
294
295
296 while (pfnleft) {
297 if (pfnleft > pfncount)
298 pfncurr = pfncount;
299 else
300 pfncurr = pfnleft;
301
302 msgsize = sizeof(struct vmbus_channel_msginfo) +
303 sizeof(struct vmbus_channel_gpadl_body) +
304 pfncurr * sizeof(u64);
305 msgbody = kzalloc(msgsize, GFP_KERNEL);
306
307 if (!msgbody) {
308 struct vmbus_channel_msginfo *pos = NULL;
309 struct vmbus_channel_msginfo *tmp = NULL;
310
311
312
313 list_for_each_entry_safe(pos, tmp,
314 &msgheader->submsglist,
315 msglistentry) {
316
317 list_del(&pos->msglistentry);
318 kfree(pos);
319 }
320
321 goto nomem;
322 }
323
324 msgbody->msgsize = msgsize;
325 (*messagecount)++;
326 gpadl_body =
327 (struct vmbus_channel_gpadl_body *)msgbody->msg;
328
329
330
331
332
333
334
335 for (i = 0; i < pfncurr; i++)
336 gpadl_body->pfn[i] = pfn + pfnsum + i;
337
338
339 list_add_tail(&msgbody->msglistentry,
340 &msgheader->submsglist);
341 pfnsum += pfncurr;
342 pfnleft -= pfncurr;
343 }
344 } else {
345
346 msgsize = sizeof(struct vmbus_channel_msginfo) +
347 sizeof(struct vmbus_channel_gpadl_header) +
348 sizeof(struct gpa_range) + pagecount * sizeof(u64);
349 msgheader = kzalloc(msgsize, GFP_KERNEL);
350 if (msgheader == NULL)
351 goto nomem;
352 msgheader->msgsize = msgsize;
353
354 gpadl_header = (struct vmbus_channel_gpadl_header *)
355 msgheader->msg;
356 gpadl_header->rangecount = 1;
357 gpadl_header->range_buflen = sizeof(struct gpa_range) +
358 pagecount * sizeof(u64);
359 gpadl_header->range[0].byte_offset = 0;
360 gpadl_header->range[0].byte_count = size;
361 for (i = 0; i < pagecount; i++)
362 gpadl_header->range[0].pfn_array[i] = pfn+i;
363
364 *msginfo = msgheader;
365 *messagecount = 1;
366 }
367
368 return 0;
369nomem:
370 kfree(msgheader);
371 kfree(msgbody);
372 return -ENOMEM;
373}
374
375
376
377
378
379
380
381
382
383int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
384 u32 size, u32 *gpadl_handle)
385{
386 struct vmbus_channel_gpadl_header *gpadlmsg;
387 struct vmbus_channel_gpadl_body *gpadl_body;
388 struct vmbus_channel_msginfo *msginfo = NULL;
389 struct vmbus_channel_msginfo *submsginfo;
390 u32 msgcount;
391 struct list_head *curr;
392 u32 next_gpadl_handle;
393 unsigned long flags;
394 int ret = 0;
395 int t;
396
397 next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
398 atomic_inc(&vmbus_connection.next_gpadl_handle);
399
400 ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
401 if (ret)
402 return ret;
403
404 init_completion(&msginfo->waitevent);
405
406 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
407 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
408 gpadlmsg->child_relid = channel->offermsg.child_relid;
409 gpadlmsg->gpadl = next_gpadl_handle;
410
411
412 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
413 list_add_tail(&msginfo->msglistentry,
414 &vmbus_connection.chn_msg_list);
415
416 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
417
418 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
419 sizeof(*msginfo));
420 if (ret != 0)
421 goto cleanup;
422
423 if (msgcount > 1) {
424 list_for_each(curr, &msginfo->submsglist) {
425
426 submsginfo = (struct vmbus_channel_msginfo *)curr;
427 gpadl_body =
428 (struct vmbus_channel_gpadl_body *)submsginfo->msg;
429
430 gpadl_body->header.msgtype =
431 CHANNELMSG_GPADL_BODY;
432 gpadl_body->gpadl = next_gpadl_handle;
433
434 ret = vmbus_post_msg(gpadl_body,
435 submsginfo->msgsize -
436 sizeof(*submsginfo));
437 if (ret != 0)
438 goto cleanup;
439
440 }
441 }
442 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
443 BUG_ON(t == 0);
444
445
446
447 *gpadl_handle = gpadlmsg->gpadl;
448
449cleanup:
450 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
451 list_del(&msginfo->msglistentry);
452 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
453
454 kfree(msginfo);
455 return ret;
456}
457EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
458
459
460
461
462int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
463{
464 struct vmbus_channel_gpadl_teardown *msg;
465 struct vmbus_channel_msginfo *info;
466 unsigned long flags;
467 int ret, t;
468
469 info = kmalloc(sizeof(*info) +
470 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
471 if (!info)
472 return -ENOMEM;
473
474 init_completion(&info->waitevent);
475
476 msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
477
478 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
479 msg->child_relid = channel->offermsg.child_relid;
480 msg->gpadl = gpadl_handle;
481
482 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
483 list_add_tail(&info->msglistentry,
484 &vmbus_connection.chn_msg_list);
485 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
486 ret = vmbus_post_msg(msg,
487 sizeof(struct vmbus_channel_gpadl_teardown));
488
489 BUG_ON(ret != 0);
490 t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
491 BUG_ON(t == 0);
492
493
494 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
495 list_del(&info->msglistentry);
496 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
497
498 kfree(info);
499 return ret;
500}
501EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
502
503
504
505
506void vmbus_close(struct vmbus_channel *channel)
507{
508 struct vmbus_channel_close_channel *msg;
509 int ret;
510 unsigned long flags;
511
512
513 spin_lock_irqsave(&channel->inbound_lock, flags);
514 channel->onchannel_callback = NULL;
515 spin_unlock_irqrestore(&channel->inbound_lock, flags);
516
517
518
519 msg = &channel->close_msg.msg;
520
521 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
522 msg->child_relid = channel->offermsg.child_relid;
523
524 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
525
526 BUG_ON(ret != 0);
527
528 if (channel->ringbuffer_gpadlhandle)
529 vmbus_teardown_gpadl(channel,
530 channel->ringbuffer_gpadlhandle);
531
532
533 hv_ringbuffer_cleanup(&channel->outbound);
534 hv_ringbuffer_cleanup(&channel->inbound);
535
536 free_pages((unsigned long)channel->ringbuffer_pages,
537 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
538
539
540}
541EXPORT_SYMBOL_GPL(vmbus_close);
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
558 u32 bufferlen, u64 requestid,
559 enum vmbus_packet_type type, u32 flags)
560{
561 struct vmpacket_descriptor desc;
562 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
563 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
564 struct scatterlist bufferlist[3];
565 u64 aligned_data = 0;
566 int ret;
567 bool signal = false;
568
569
570
571 desc.type = type;
572 desc.flags = flags;
573
574 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
575 desc.len8 = (u16)(packetlen_aligned >> 3);
576 desc.trans_id = requestid;
577
578 sg_init_table(bufferlist, 3);
579 sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
580 sg_set_buf(&bufferlist[1], buffer, bufferlen);
581 sg_set_buf(&bufferlist[2], &aligned_data,
582 packetlen_aligned - packetlen);
583
584 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
585
586 if (ret == 0 && signal)
587 vmbus_setevent(channel);
588
589 return ret;
590}
591EXPORT_SYMBOL(vmbus_sendpacket);
592
593
594
595
596
597int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
598 struct hv_page_buffer pagebuffers[],
599 u32 pagecount, void *buffer, u32 bufferlen,
600 u64 requestid)
601{
602 int ret;
603 int i;
604 struct vmbus_channel_packet_page_buffer desc;
605 u32 descsize;
606 u32 packetlen;
607 u32 packetlen_aligned;
608 struct scatterlist bufferlist[3];
609 u64 aligned_data = 0;
610 bool signal = false;
611
612 if (pagecount > MAX_PAGE_BUFFER_COUNT)
613 return -EINVAL;
614
615
616
617
618
619
620 descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
621 ((MAX_PAGE_BUFFER_COUNT - pagecount) *
622 sizeof(struct hv_page_buffer));
623 packetlen = descsize + bufferlen;
624 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
625
626
627 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
628 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
629 desc.dataoffset8 = descsize >> 3;
630 desc.length8 = (u16)(packetlen_aligned >> 3);
631 desc.transactionid = requestid;
632 desc.rangecount = pagecount;
633
634 for (i = 0; i < pagecount; i++) {
635 desc.range[i].len = pagebuffers[i].len;
636 desc.range[i].offset = pagebuffers[i].offset;
637 desc.range[i].pfn = pagebuffers[i].pfn;
638 }
639
640 sg_init_table(bufferlist, 3);
641 sg_set_buf(&bufferlist[0], &desc, descsize);
642 sg_set_buf(&bufferlist[1], buffer, bufferlen);
643 sg_set_buf(&bufferlist[2], &aligned_data,
644 packetlen_aligned - packetlen);
645
646 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
647
648 if (ret == 0 && signal)
649 vmbus_setevent(channel);
650
651 return ret;
652}
653EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
654
655
656
657
658
659int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
660 struct hv_multipage_buffer *multi_pagebuffer,
661 void *buffer, u32 bufferlen, u64 requestid)
662{
663 int ret;
664 struct vmbus_channel_packet_multipage_buffer desc;
665 u32 descsize;
666 u32 packetlen;
667 u32 packetlen_aligned;
668 struct scatterlist bufferlist[3];
669 u64 aligned_data = 0;
670 bool signal = false;
671 u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
672 multi_pagebuffer->len);
673
674
675 if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
676 return -EINVAL;
677
678
679
680
681
682 descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
683 ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
684 sizeof(u64));
685 packetlen = descsize + bufferlen;
686 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
687
688
689
690 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
691 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
692 desc.dataoffset8 = descsize >> 3;
693 desc.length8 = (u16)(packetlen_aligned >> 3);
694 desc.transactionid = requestid;
695 desc.rangecount = 1;
696
697 desc.range.len = multi_pagebuffer->len;
698 desc.range.offset = multi_pagebuffer->offset;
699
700 memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
701 pfncount * sizeof(u64));
702
703 sg_init_table(bufferlist, 3);
704 sg_set_buf(&bufferlist[0], &desc, descsize);
705 sg_set_buf(&bufferlist[1], buffer, bufferlen);
706 sg_set_buf(&bufferlist[2], &aligned_data,
707 packetlen_aligned - packetlen);
708
709 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
710
711 if (ret == 0 && signal)
712 vmbus_setevent(channel);
713
714 return ret;
715}
716EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
732 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
733{
734 struct vmpacket_descriptor desc;
735 u32 packetlen;
736 u32 userlen;
737 int ret;
738 bool signal = false;
739
740 *buffer_actual_len = 0;
741 *requestid = 0;
742
743
744 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
745 sizeof(struct vmpacket_descriptor));
746 if (ret != 0)
747 return 0;
748
749 packetlen = desc.len8 << 3;
750 userlen = packetlen - (desc.offset8 << 3);
751
752 *buffer_actual_len = userlen;
753
754 if (userlen > bufferlen) {
755
756 pr_err("Buffer too small - got %d needs %d\n",
757 bufferlen, userlen);
758 return -ETOOSMALL;
759 }
760
761 *requestid = desc.trans_id;
762
763
764 ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
765 (desc.offset8 << 3), &signal);
766
767 if (signal)
768 vmbus_setevent(channel);
769
770 return 0;
771}
772EXPORT_SYMBOL(vmbus_recvpacket);
773
774
775
776
777int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
778 u32 bufferlen, u32 *buffer_actual_len,
779 u64 *requestid)
780{
781 struct vmpacket_descriptor desc;
782 u32 packetlen;
783 int ret;
784 bool signal = false;
785
786 *buffer_actual_len = 0;
787 *requestid = 0;
788
789
790 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
791 sizeof(struct vmpacket_descriptor));
792 if (ret != 0)
793 return 0;
794
795
796 packetlen = desc.len8 << 3;
797
798 *buffer_actual_len = packetlen;
799
800 if (packetlen > bufferlen) {
801 pr_err("Buffer too small - needed %d bytes but "
802 "got space for only %d bytes\n",
803 packetlen, bufferlen);
804 return -ENOBUFS;
805 }
806
807 *requestid = desc.trans_id;
808
809
810 ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
811 &signal);
812
813 if (signal)
814 vmbus_setevent(channel);
815
816 return 0;
817}
818EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
819