1 /*
2 * Copyright (c) 2009, Microsoft Corporation.
3 *
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.
7 *
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
11 * more details.
12 *
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.
16 *
17 * Authors:
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
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 #include <linux/uio.h>
31
32 #include "hyperv_vmbus.h"
33
34 #define NUM_PAGES_SPANNED(addr, len) \
35 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
36
37 /*
38 * vmbus_setevent- Trigger an event notification on the specified
39 * channel.
40 */
vmbus_setevent(struct vmbus_channel * channel)41 static void vmbus_setevent(struct vmbus_channel *channel)
42 {
43 struct hv_monitor_page *monitorpage;
44
45 if (channel->offermsg.monitor_allocated) {
46 /* Each u32 represents 32 channels */
47 sync_set_bit(channel->offermsg.child_relid & 31,
48 (unsigned long *) vmbus_connection.send_int_page +
49 (channel->offermsg.child_relid >> 5));
50
51 /* Get the child to parent monitor page */
52 monitorpage = vmbus_connection.monitor_pages[1];
53
54 sync_set_bit(channel->monitor_bit,
55 (unsigned long *)&monitorpage->trigger_group
56 [channel->monitor_grp].pending);
57
58 } else {
59 vmbus_set_event(channel);
60 }
61 }
62
63 /*
64 * vmbus_open - Open the specified channel.
65 */
vmbus_open(struct vmbus_channel * newchannel,u32 send_ringbuffer_size,u32 recv_ringbuffer_size,void * userdata,u32 userdatalen,void (* onchannelcallback)(void * context),void * context)66 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
67 u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
68 void (*onchannelcallback)(void *context), void *context)
69 {
70 struct vmbus_channel_open_channel *open_msg;
71 struct vmbus_channel_msginfo *open_info = NULL;
72 void *in, *out;
73 unsigned long flags;
74 int ret, err = 0;
75 unsigned long t;
76 struct page *page;
77
78 spin_lock_irqsave(&newchannel->lock, flags);
79 if (newchannel->state == CHANNEL_OPEN_STATE) {
80 newchannel->state = CHANNEL_OPENING_STATE;
81 } else {
82 spin_unlock_irqrestore(&newchannel->lock, flags);
83 return -EINVAL;
84 }
85 spin_unlock_irqrestore(&newchannel->lock, flags);
86
87 newchannel->onchannel_callback = onchannelcallback;
88 newchannel->channel_callback_context = context;
89
90 /* Allocate the ring buffer */
91 page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
92 GFP_KERNEL|__GFP_ZERO,
93 get_order(send_ringbuffer_size +
94 recv_ringbuffer_size));
95
96 if (!page)
97 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
98 get_order(send_ringbuffer_size +
99 recv_ringbuffer_size));
100 else
101 out = (void *)page_address(page);
102
103 if (!out) {
104 err = -ENOMEM;
105 goto error0;
106 }
107
108 in = (void *)((unsigned long)out + send_ringbuffer_size);
109
110 newchannel->ringbuffer_pages = out;
111 newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
112 recv_ringbuffer_size) >> PAGE_SHIFT;
113
114 ret = hv_ringbuffer_init(
115 &newchannel->outbound, out, send_ringbuffer_size);
116
117 if (ret != 0) {
118 err = ret;
119 goto error0;
120 }
121
122 ret = hv_ringbuffer_init(
123 &newchannel->inbound, in, recv_ringbuffer_size);
124 if (ret != 0) {
125 err = ret;
126 goto error0;
127 }
128
129
130 /* Establish the gpadl for the ring buffer */
131 newchannel->ringbuffer_gpadlhandle = 0;
132
133 ret = vmbus_establish_gpadl(newchannel,
134 newchannel->outbound.ring_buffer,
135 send_ringbuffer_size +
136 recv_ringbuffer_size,
137 &newchannel->ringbuffer_gpadlhandle);
138
139 if (ret != 0) {
140 err = ret;
141 goto error0;
142 }
143
144 /* Create and init the channel open message */
145 open_info = kmalloc(sizeof(*open_info) +
146 sizeof(struct vmbus_channel_open_channel),
147 GFP_KERNEL);
148 if (!open_info) {
149 err = -ENOMEM;
150 goto error_gpadl;
151 }
152
153 init_completion(&open_info->waitevent);
154
155 open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
156 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
157 open_msg->openid = newchannel->offermsg.child_relid;
158 open_msg->child_relid = newchannel->offermsg.child_relid;
159 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
160 open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
161 PAGE_SHIFT;
162 open_msg->target_vp = newchannel->target_vp;
163
164 if (userdatalen > MAX_USER_DEFINED_BYTES) {
165 err = -EINVAL;
166 goto error_gpadl;
167 }
168
169 if (userdatalen)
170 memcpy(open_msg->userdata, userdata, userdatalen);
171
172 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
173 list_add_tail(&open_info->msglistentry,
174 &vmbus_connection.chn_msg_list);
175 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
176
177 ret = vmbus_post_msg(open_msg,
178 sizeof(struct vmbus_channel_open_channel));
179
180 if (ret != 0) {
181 err = ret;
182 goto error1;
183 }
184
185 t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
186 if (t == 0) {
187 err = -ETIMEDOUT;
188 goto error1;
189 }
190
191 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
192 list_del(&open_info->msglistentry);
193 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
194
195 if (open_info->response.open_result.status) {
196 err = -EAGAIN;
197 goto error_gpadl;
198 }
199
200 newchannel->state = CHANNEL_OPENED_STATE;
201 kfree(open_info);
202 return 0;
203
204 error1:
205 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
206 list_del(&open_info->msglistentry);
207 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
208
209 error_gpadl:
210 vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
211
212 error0:
213 free_pages((unsigned long)out,
214 get_order(send_ringbuffer_size + recv_ringbuffer_size));
215 kfree(open_info);
216 newchannel->state = CHANNEL_OPEN_STATE;
217 return err;
218 }
219 EXPORT_SYMBOL_GPL(vmbus_open);
220
221 /*
222 * create_gpadl_header - Creates a gpadl for the specified buffer
223 */
create_gpadl_header(void * kbuffer,u32 size,struct vmbus_channel_msginfo ** msginfo,u32 * messagecount)224 static int create_gpadl_header(void *kbuffer, u32 size,
225 struct vmbus_channel_msginfo **msginfo,
226 u32 *messagecount)
227 {
228 int i;
229 int pagecount;
230 struct vmbus_channel_gpadl_header *gpadl_header;
231 struct vmbus_channel_gpadl_body *gpadl_body;
232 struct vmbus_channel_msginfo *msgheader;
233 struct vmbus_channel_msginfo *msgbody = NULL;
234 u32 msgsize;
235
236 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
237
238 pagecount = size >> PAGE_SHIFT;
239
240 /* do we need a gpadl body msg */
241 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
242 sizeof(struct vmbus_channel_gpadl_header) -
243 sizeof(struct gpa_range);
244 pfncount = pfnsize / sizeof(u64);
245
246 if (pagecount > pfncount) {
247 /* we need a gpadl body */
248 /* fill in the header */
249 msgsize = sizeof(struct vmbus_channel_msginfo) +
250 sizeof(struct vmbus_channel_gpadl_header) +
251 sizeof(struct gpa_range) + pfncount * sizeof(u64);
252 msgheader = kzalloc(msgsize, GFP_KERNEL);
253 if (!msgheader)
254 goto nomem;
255
256 INIT_LIST_HEAD(&msgheader->submsglist);
257 msgheader->msgsize = msgsize;
258
259 gpadl_header = (struct vmbus_channel_gpadl_header *)
260 msgheader->msg;
261 gpadl_header->rangecount = 1;
262 gpadl_header->range_buflen = sizeof(struct gpa_range) +
263 pagecount * sizeof(u64);
264 gpadl_header->range[0].byte_offset = 0;
265 gpadl_header->range[0].byte_count = size;
266 for (i = 0; i < pfncount; i++)
267 gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
268 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
269 *msginfo = msgheader;
270 *messagecount = 1;
271
272 pfnsum = pfncount;
273 pfnleft = pagecount - pfncount;
274
275 /* how many pfns can we fit */
276 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
277 sizeof(struct vmbus_channel_gpadl_body);
278 pfncount = pfnsize / sizeof(u64);
279
280 /* fill in the body */
281 while (pfnleft) {
282 if (pfnleft > pfncount)
283 pfncurr = pfncount;
284 else
285 pfncurr = pfnleft;
286
287 msgsize = sizeof(struct vmbus_channel_msginfo) +
288 sizeof(struct vmbus_channel_gpadl_body) +
289 pfncurr * sizeof(u64);
290 msgbody = kzalloc(msgsize, GFP_KERNEL);
291
292 if (!msgbody) {
293 struct vmbus_channel_msginfo *pos = NULL;
294 struct vmbus_channel_msginfo *tmp = NULL;
295 /*
296 * Free up all the allocated messages.
297 */
298 list_for_each_entry_safe(pos, tmp,
299 &msgheader->submsglist,
300 msglistentry) {
301
302 list_del(&pos->msglistentry);
303 kfree(pos);
304 }
305
306 goto nomem;
307 }
308
309 msgbody->msgsize = msgsize;
310 (*messagecount)++;
311 gpadl_body =
312 (struct vmbus_channel_gpadl_body *)msgbody->msg;
313
314 /*
315 * Gpadl is u32 and we are using a pointer which could
316 * be 64-bit
317 * This is governed by the guest/host protocol and
318 * so the hypervisor gurantees that this is ok.
319 */
320 for (i = 0; i < pfncurr; i++)
321 gpadl_body->pfn[i] = slow_virt_to_phys(
322 kbuffer + PAGE_SIZE * (pfnsum + i)) >>
323 PAGE_SHIFT;
324
325 /* add to msg header */
326 list_add_tail(&msgbody->msglistentry,
327 &msgheader->submsglist);
328 pfnsum += pfncurr;
329 pfnleft -= pfncurr;
330 }
331 } else {
332 /* everything fits in a header */
333 msgsize = sizeof(struct vmbus_channel_msginfo) +
334 sizeof(struct vmbus_channel_gpadl_header) +
335 sizeof(struct gpa_range) + pagecount * sizeof(u64);
336 msgheader = kzalloc(msgsize, GFP_KERNEL);
337 if (msgheader == NULL)
338 goto nomem;
339 msgheader->msgsize = msgsize;
340
341 gpadl_header = (struct vmbus_channel_gpadl_header *)
342 msgheader->msg;
343 gpadl_header->rangecount = 1;
344 gpadl_header->range_buflen = sizeof(struct gpa_range) +
345 pagecount * sizeof(u64);
346 gpadl_header->range[0].byte_offset = 0;
347 gpadl_header->range[0].byte_count = size;
348 for (i = 0; i < pagecount; i++)
349 gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
350 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
351
352 *msginfo = msgheader;
353 *messagecount = 1;
354 }
355
356 return 0;
357 nomem:
358 kfree(msgheader);
359 kfree(msgbody);
360 return -ENOMEM;
361 }
362
363 /*
364 * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
365 *
366 * @channel: a channel
367 * @kbuffer: from kmalloc or vmalloc
368 * @size: page-size multiple
369 * @gpadl_handle: some funky thing
370 */
vmbus_establish_gpadl(struct vmbus_channel * channel,void * kbuffer,u32 size,u32 * gpadl_handle)371 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
372 u32 size, u32 *gpadl_handle)
373 {
374 struct vmbus_channel_gpadl_header *gpadlmsg;
375 struct vmbus_channel_gpadl_body *gpadl_body;
376 struct vmbus_channel_msginfo *msginfo = NULL;
377 struct vmbus_channel_msginfo *submsginfo;
378 u32 msgcount;
379 struct list_head *curr;
380 u32 next_gpadl_handle;
381 unsigned long flags;
382 int ret = 0;
383
384 next_gpadl_handle =
385 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
386
387 ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
388 if (ret)
389 return ret;
390
391 init_completion(&msginfo->waitevent);
392
393 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
394 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
395 gpadlmsg->child_relid = channel->offermsg.child_relid;
396 gpadlmsg->gpadl = next_gpadl_handle;
397
398
399 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
400 list_add_tail(&msginfo->msglistentry,
401 &vmbus_connection.chn_msg_list);
402
403 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
404
405 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
406 sizeof(*msginfo));
407 if (ret != 0)
408 goto cleanup;
409
410 if (msgcount > 1) {
411 list_for_each(curr, &msginfo->submsglist) {
412
413 submsginfo = (struct vmbus_channel_msginfo *)curr;
414 gpadl_body =
415 (struct vmbus_channel_gpadl_body *)submsginfo->msg;
416
417 gpadl_body->header.msgtype =
418 CHANNELMSG_GPADL_BODY;
419 gpadl_body->gpadl = next_gpadl_handle;
420
421 ret = vmbus_post_msg(gpadl_body,
422 submsginfo->msgsize -
423 sizeof(*submsginfo));
424 if (ret != 0)
425 goto cleanup;
426
427 }
428 }
429 wait_for_completion(&msginfo->waitevent);
430
431 /* At this point, we received the gpadl created msg */
432 *gpadl_handle = gpadlmsg->gpadl;
433
434 cleanup:
435 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
436 list_del(&msginfo->msglistentry);
437 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
438
439 kfree(msginfo);
440 return ret;
441 }
442 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
443
444 /*
445 * vmbus_teardown_gpadl -Teardown the specified GPADL handle
446 */
vmbus_teardown_gpadl(struct vmbus_channel * channel,u32 gpadl_handle)447 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
448 {
449 struct vmbus_channel_gpadl_teardown *msg;
450 struct vmbus_channel_msginfo *info;
451 unsigned long flags;
452 int ret;
453
454 info = kmalloc(sizeof(*info) +
455 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
456 if (!info)
457 return -ENOMEM;
458
459 init_completion(&info->waitevent);
460
461 msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
462
463 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
464 msg->child_relid = channel->offermsg.child_relid;
465 msg->gpadl = gpadl_handle;
466
467 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
468 list_add_tail(&info->msglistentry,
469 &vmbus_connection.chn_msg_list);
470 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
471 ret = vmbus_post_msg(msg,
472 sizeof(struct vmbus_channel_gpadl_teardown));
473
474 if (ret)
475 goto post_msg_err;
476
477 wait_for_completion(&info->waitevent);
478
479 post_msg_err:
480 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
481 list_del(&info->msglistentry);
482 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
483
484 kfree(info);
485 return ret;
486 }
487 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
488
reset_channel_cb(void * arg)489 static void reset_channel_cb(void *arg)
490 {
491 struct vmbus_channel *channel = arg;
492
493 channel->onchannel_callback = NULL;
494 }
495
vmbus_close_internal(struct vmbus_channel * channel)496 static int vmbus_close_internal(struct vmbus_channel *channel)
497 {
498 struct vmbus_channel_close_channel *msg;
499 int ret;
500
501 channel->state = CHANNEL_OPEN_STATE;
502 channel->sc_creation_callback = NULL;
503 /* Stop callback and cancel the timer asap */
504 if (channel->target_cpu != get_cpu()) {
505 put_cpu();
506 smp_call_function_single(channel->target_cpu, reset_channel_cb,
507 channel, true);
508 } else {
509 reset_channel_cb(channel);
510 put_cpu();
511 }
512
513 /* Send a closing message */
514
515 msg = &channel->close_msg.msg;
516
517 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
518 msg->child_relid = channel->offermsg.child_relid;
519
520 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
521
522 if (ret) {
523 pr_err("Close failed: close post msg return is %d\n", ret);
524 /*
525 * If we failed to post the close msg,
526 * it is perhaps better to leak memory.
527 */
528 return ret;
529 }
530
531 /* Tear down the gpadl for the channel's ring buffer */
532 if (channel->ringbuffer_gpadlhandle) {
533 ret = vmbus_teardown_gpadl(channel,
534 channel->ringbuffer_gpadlhandle);
535 if (ret) {
536 pr_err("Close failed: teardown gpadl return %d\n", ret);
537 /*
538 * If we failed to teardown gpadl,
539 * it is perhaps better to leak memory.
540 */
541 return ret;
542 }
543 }
544
545 /* Cleanup the ring buffers for this channel */
546 hv_ringbuffer_cleanup(&channel->outbound);
547 hv_ringbuffer_cleanup(&channel->inbound);
548
549 free_pages((unsigned long)channel->ringbuffer_pages,
550 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
551
552 /*
553 * If the channel has been rescinded; process device removal.
554 */
555 if (channel->rescind)
556 hv_process_channel_removal(channel,
557 channel->offermsg.child_relid);
558 return ret;
559 }
560
561 /*
562 * vmbus_close - Close the specified channel
563 */
vmbus_close(struct vmbus_channel * channel)564 void vmbus_close(struct vmbus_channel *channel)
565 {
566 struct list_head *cur, *tmp;
567 struct vmbus_channel *cur_channel;
568
569 if (channel->primary_channel != NULL) {
570 /*
571 * We will only close sub-channels when
572 * the primary is closed.
573 */
574 return;
575 }
576 /*
577 * Close all the sub-channels first and then close the
578 * primary channel.
579 */
580 list_for_each_safe(cur, tmp, &channel->sc_list) {
581 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
582 if (cur_channel->state != CHANNEL_OPENED_STATE)
583 continue;
584 vmbus_close_internal(cur_channel);
585 }
586 /*
587 * Now close the primary.
588 */
589 vmbus_close_internal(channel);
590 }
591 EXPORT_SYMBOL_GPL(vmbus_close);
592
vmbus_sendpacket_ctl(struct vmbus_channel * channel,void * buffer,u32 bufferlen,u64 requestid,enum vmbus_packet_type type,u32 flags,bool kick_q)593 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
594 u32 bufferlen, u64 requestid,
595 enum vmbus_packet_type type, u32 flags, bool kick_q)
596 {
597 struct vmpacket_descriptor desc;
598 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
599 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
600 struct kvec bufferlist[3];
601 u64 aligned_data = 0;
602 int ret;
603 bool signal = false;
604 int num_vecs = ((bufferlen != 0) ? 3 : 1);
605
606
607 /* Setup the descriptor */
608 desc.type = type; /* VmbusPacketTypeDataInBand; */
609 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
610 /* in 8-bytes granularity */
611 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
612 desc.len8 = (u16)(packetlen_aligned >> 3);
613 desc.trans_id = requestid;
614
615 bufferlist[0].iov_base = &desc;
616 bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
617 bufferlist[1].iov_base = buffer;
618 bufferlist[1].iov_len = bufferlen;
619 bufferlist[2].iov_base = &aligned_data;
620 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
621
622 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
623 &signal);
624
625 /*
626 * Signalling the host is conditional on many factors:
627 * 1. The ring state changed from being empty to non-empty.
628 * This is tracked by the variable "signal".
629 * 2. The variable kick_q tracks if more data will be placed
630 * on the ring. We will not signal if more data is
631 * to be placed.
632 *
633 * Based on the channel signal state, we will decide
634 * which signaling policy will be applied.
635 *
636 * If we cannot write to the ring-buffer; signal the host
637 * even if we may not have written anything. This is a rare
638 * enough condition that it should not matter.
639 */
640
641 if (channel->signal_policy)
642 signal = true;
643 else
644 kick_q = true;
645
646 if (((ret == 0) && kick_q && signal) || (ret))
647 vmbus_setevent(channel);
648
649 return ret;
650 }
651 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
652
653 /**
654 * vmbus_sendpacket() - Send the specified buffer on the given channel
655 * @channel: Pointer to vmbus_channel structure.
656 * @buffer: Pointer to the buffer you want to receive the data into.
657 * @bufferlen: Maximum size of what the the buffer will hold
658 * @requestid: Identifier of the request
659 * @type: Type of packet that is being send e.g. negotiate, time
660 * packet etc.
661 *
662 * Sends data in @buffer directly to hyper-v via the vmbus
663 * This will send the data unparsed to hyper-v.
664 *
665 * Mainly used by Hyper-V drivers.
666 */
vmbus_sendpacket(struct vmbus_channel * channel,void * buffer,u32 bufferlen,u64 requestid,enum vmbus_packet_type type,u32 flags)667 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
668 u32 bufferlen, u64 requestid,
669 enum vmbus_packet_type type, u32 flags)
670 {
671 return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
672 type, flags, true);
673 }
674 EXPORT_SYMBOL(vmbus_sendpacket);
675
676 /*
677 * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
678 * packets using a GPADL Direct packet type. This interface allows you
679 * to control notifying the host. This will be useful for sending
680 * batched data. Also the sender can control the send flags
681 * explicitly.
682 */
vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel * channel,struct hv_page_buffer pagebuffers[],u32 pagecount,void * buffer,u32 bufferlen,u64 requestid,u32 flags,bool kick_q)683 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
684 struct hv_page_buffer pagebuffers[],
685 u32 pagecount, void *buffer, u32 bufferlen,
686 u64 requestid,
687 u32 flags,
688 bool kick_q)
689 {
690 int ret;
691 int i;
692 struct vmbus_channel_packet_page_buffer desc;
693 u32 descsize;
694 u32 packetlen;
695 u32 packetlen_aligned;
696 struct kvec bufferlist[3];
697 u64 aligned_data = 0;
698 bool signal = false;
699
700 if (pagecount > MAX_PAGE_BUFFER_COUNT)
701 return -EINVAL;
702
703
704 /*
705 * Adjust the size down since vmbus_channel_packet_page_buffer is the
706 * largest size we support
707 */
708 descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
709 ((MAX_PAGE_BUFFER_COUNT - pagecount) *
710 sizeof(struct hv_page_buffer));
711 packetlen = descsize + bufferlen;
712 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
713
714 /* Setup the descriptor */
715 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
716 desc.flags = flags;
717 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
718 desc.length8 = (u16)(packetlen_aligned >> 3);
719 desc.transactionid = requestid;
720 desc.rangecount = pagecount;
721
722 for (i = 0; i < pagecount; i++) {
723 desc.range[i].len = pagebuffers[i].len;
724 desc.range[i].offset = pagebuffers[i].offset;
725 desc.range[i].pfn = pagebuffers[i].pfn;
726 }
727
728 bufferlist[0].iov_base = &desc;
729 bufferlist[0].iov_len = descsize;
730 bufferlist[1].iov_base = buffer;
731 bufferlist[1].iov_len = bufferlen;
732 bufferlist[2].iov_base = &aligned_data;
733 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
734
735 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
736
737 /*
738 * Signalling the host is conditional on many factors:
739 * 1. The ring state changed from being empty to non-empty.
740 * This is tracked by the variable "signal".
741 * 2. The variable kick_q tracks if more data will be placed
742 * on the ring. We will not signal if more data is
743 * to be placed.
744 *
745 * Based on the channel signal state, we will decide
746 * which signaling policy will be applied.
747 *
748 * If we cannot write to the ring-buffer; signal the host
749 * even if we may not have written anything. This is a rare
750 * enough condition that it should not matter.
751 */
752
753 if (channel->signal_policy)
754 signal = true;
755 else
756 kick_q = true;
757
758 if (((ret == 0) && kick_q && signal) || (ret))
759 vmbus_setevent(channel);
760
761 return ret;
762 }
763 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
764
765 /*
766 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
767 * packets using a GPADL Direct packet type.
768 */
vmbus_sendpacket_pagebuffer(struct vmbus_channel * channel,struct hv_page_buffer pagebuffers[],u32 pagecount,void * buffer,u32 bufferlen,u64 requestid)769 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
770 struct hv_page_buffer pagebuffers[],
771 u32 pagecount, void *buffer, u32 bufferlen,
772 u64 requestid)
773 {
774 u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
775 return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
776 buffer, bufferlen, requestid,
777 flags, true);
778
779 }
780 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
781
782 /*
783 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
784 * using a GPADL Direct packet type.
785 * The buffer includes the vmbus descriptor.
786 */
vmbus_sendpacket_mpb_desc(struct vmbus_channel * channel,struct vmbus_packet_mpb_array * desc,u32 desc_size,void * buffer,u32 bufferlen,u64 requestid)787 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
788 struct vmbus_packet_mpb_array *desc,
789 u32 desc_size,
790 void *buffer, u32 bufferlen, u64 requestid)
791 {
792 int ret;
793 u32 packetlen;
794 u32 packetlen_aligned;
795 struct kvec bufferlist[3];
796 u64 aligned_data = 0;
797 bool signal = false;
798
799 packetlen = desc_size + bufferlen;
800 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
801
802 /* Setup the descriptor */
803 desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
804 desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
805 desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
806 desc->length8 = (u16)(packetlen_aligned >> 3);
807 desc->transactionid = requestid;
808 desc->rangecount = 1;
809
810 bufferlist[0].iov_base = desc;
811 bufferlist[0].iov_len = desc_size;
812 bufferlist[1].iov_base = buffer;
813 bufferlist[1].iov_len = bufferlen;
814 bufferlist[2].iov_base = &aligned_data;
815 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
816
817 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
818
819 if (ret == 0 && signal)
820 vmbus_setevent(channel);
821
822 return ret;
823 }
824 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
825
826 /*
827 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
828 * using a GPADL Direct packet type.
829 */
vmbus_sendpacket_multipagebuffer(struct vmbus_channel * channel,struct hv_multipage_buffer * multi_pagebuffer,void * buffer,u32 bufferlen,u64 requestid)830 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
831 struct hv_multipage_buffer *multi_pagebuffer,
832 void *buffer, u32 bufferlen, u64 requestid)
833 {
834 int ret;
835 struct vmbus_channel_packet_multipage_buffer desc;
836 u32 descsize;
837 u32 packetlen;
838 u32 packetlen_aligned;
839 struct kvec bufferlist[3];
840 u64 aligned_data = 0;
841 bool signal = false;
842 u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
843 multi_pagebuffer->len);
844
845 if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
846 return -EINVAL;
847
848 /*
849 * Adjust the size down since vmbus_channel_packet_multipage_buffer is
850 * the largest size we support
851 */
852 descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
853 ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
854 sizeof(u64));
855 packetlen = descsize + bufferlen;
856 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
857
858
859 /* Setup the descriptor */
860 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
861 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
862 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
863 desc.length8 = (u16)(packetlen_aligned >> 3);
864 desc.transactionid = requestid;
865 desc.rangecount = 1;
866
867 desc.range.len = multi_pagebuffer->len;
868 desc.range.offset = multi_pagebuffer->offset;
869
870 memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
871 pfncount * sizeof(u64));
872
873 bufferlist[0].iov_base = &desc;
874 bufferlist[0].iov_len = descsize;
875 bufferlist[1].iov_base = buffer;
876 bufferlist[1].iov_len = bufferlen;
877 bufferlist[2].iov_base = &aligned_data;
878 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
879
880 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
881
882 if (ret == 0 && signal)
883 vmbus_setevent(channel);
884
885 return ret;
886 }
887 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
888
889 /**
890 * vmbus_recvpacket() - Retrieve the user packet on the specified channel
891 * @channel: Pointer to vmbus_channel structure.
892 * @buffer: Pointer to the buffer you want to receive the data into.
893 * @bufferlen: Maximum size of what the the buffer will hold
894 * @buffer_actual_len: The actual size of the data after it was received
895 * @requestid: Identifier of the request
896 *
897 * Receives directly from the hyper-v vmbus and puts the data it received
898 * into Buffer. This will receive the data unparsed from hyper-v.
899 *
900 * Mainly used by Hyper-V drivers.
901 */
vmbus_recvpacket(struct vmbus_channel * channel,void * buffer,u32 bufferlen,u32 * buffer_actual_len,u64 * requestid)902 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
903 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
904 {
905 struct vmpacket_descriptor desc;
906 u32 packetlen;
907 u32 userlen;
908 int ret;
909 bool signal = false;
910
911 *buffer_actual_len = 0;
912 *requestid = 0;
913
914
915 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
916 sizeof(struct vmpacket_descriptor));
917 if (ret != 0)
918 return 0;
919
920 packetlen = desc.len8 << 3;
921 userlen = packetlen - (desc.offset8 << 3);
922
923 *buffer_actual_len = userlen;
924
925 if (userlen > bufferlen) {
926
927 pr_err("Buffer too small - got %d needs %d\n",
928 bufferlen, userlen);
929 return -ETOOSMALL;
930 }
931
932 *requestid = desc.trans_id;
933
934 /* Copy over the packet to the user buffer */
935 ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
936 (desc.offset8 << 3), &signal);
937
938 if (signal)
939 vmbus_setevent(channel);
940
941 return 0;
942 }
943 EXPORT_SYMBOL(vmbus_recvpacket);
944
945 /*
946 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
947 */
vmbus_recvpacket_raw(struct vmbus_channel * channel,void * buffer,u32 bufferlen,u32 * buffer_actual_len,u64 * requestid)948 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
949 u32 bufferlen, u32 *buffer_actual_len,
950 u64 *requestid)
951 {
952 struct vmpacket_descriptor desc;
953 u32 packetlen;
954 int ret;
955 bool signal = false;
956
957 *buffer_actual_len = 0;
958 *requestid = 0;
959
960
961 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
962 sizeof(struct vmpacket_descriptor));
963 if (ret != 0)
964 return 0;
965
966
967 packetlen = desc.len8 << 3;
968
969 *buffer_actual_len = packetlen;
970
971 if (packetlen > bufferlen)
972 return -ENOBUFS;
973
974 *requestid = desc.trans_id;
975
976 /* Copy over the entire packet to the user buffer */
977 ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
978 &signal);
979
980 if (signal)
981 vmbus_setevent(channel);
982
983 return ret;
984 }
985 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
986