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/list.h>
29 #include <linux/module.h>
30 #include <linux/completion.h>
31 #include <linux/hyperv.h>
32
33 #include "hyperv_vmbus.h"
34
35 struct vmbus_channel_message_table_entry {
36 enum vmbus_channel_message_type message_type;
37 void (*message_handler)(struct vmbus_channel_message_header *msg);
38 };
39
40
41 /**
42 * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
43 * @icmsghdrp: Pointer to msg header structure
44 * @icmsg_negotiate: Pointer to negotiate message structure
45 * @buf: Raw buffer channel data
46 *
47 * @icmsghdrp is of type &struct icmsg_hdr.
48 * @negop is of type &struct icmsg_negotiate.
49 * Set up and fill in default negotiate response message.
50 *
51 * The fw_version specifies the framework version that
52 * we can support and srv_version specifies the service
53 * version we can support.
54 *
55 * Mainly used by Hyper-V drivers.
56 */
vmbus_prep_negotiate_resp(struct icmsg_hdr * icmsghdrp,struct icmsg_negotiate * negop,u8 * buf,int fw_version,int srv_version)57 bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp,
58 struct icmsg_negotiate *negop, u8 *buf,
59 int fw_version, int srv_version)
60 {
61 int icframe_major, icframe_minor;
62 int icmsg_major, icmsg_minor;
63 int fw_major, fw_minor;
64 int srv_major, srv_minor;
65 int i;
66 bool found_match = false;
67
68 icmsghdrp->icmsgsize = 0x10;
69 fw_major = (fw_version >> 16);
70 fw_minor = (fw_version & 0xFFFF);
71
72 srv_major = (srv_version >> 16);
73 srv_minor = (srv_version & 0xFFFF);
74
75 negop = (struct icmsg_negotiate *)&buf[
76 sizeof(struct vmbuspipe_hdr) +
77 sizeof(struct icmsg_hdr)];
78
79 icframe_major = negop->icframe_vercnt;
80 icframe_minor = 0;
81
82 icmsg_major = negop->icmsg_vercnt;
83 icmsg_minor = 0;
84
85 /*
86 * Select the framework version number we will
87 * support.
88 */
89
90 for (i = 0; i < negop->icframe_vercnt; i++) {
91 if ((negop->icversion_data[i].major == fw_major) &&
92 (negop->icversion_data[i].minor == fw_minor)) {
93 icframe_major = negop->icversion_data[i].major;
94 icframe_minor = negop->icversion_data[i].minor;
95 found_match = true;
96 }
97 }
98
99 if (!found_match)
100 goto fw_error;
101
102 found_match = false;
103
104 for (i = negop->icframe_vercnt;
105 (i < negop->icframe_vercnt + negop->icmsg_vercnt); i++) {
106 if ((negop->icversion_data[i].major == srv_major) &&
107 (negop->icversion_data[i].minor == srv_minor)) {
108 icmsg_major = negop->icversion_data[i].major;
109 icmsg_minor = negop->icversion_data[i].minor;
110 found_match = true;
111 }
112 }
113
114 /*
115 * Respond with the framework and service
116 * version numbers we can support.
117 */
118
119 fw_error:
120 if (!found_match) {
121 negop->icframe_vercnt = 0;
122 negop->icmsg_vercnt = 0;
123 } else {
124 negop->icframe_vercnt = 1;
125 negop->icmsg_vercnt = 1;
126 }
127
128 negop->icversion_data[0].major = icframe_major;
129 negop->icversion_data[0].minor = icframe_minor;
130 negop->icversion_data[1].major = icmsg_major;
131 negop->icversion_data[1].minor = icmsg_minor;
132 return found_match;
133 }
134
135 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
136
137 /*
138 * alloc_channel - Allocate and initialize a vmbus channel object
139 */
alloc_channel(void)140 static struct vmbus_channel *alloc_channel(void)
141 {
142 struct vmbus_channel *channel;
143
144 channel = kzalloc(sizeof(*channel), GFP_ATOMIC);
145 if (!channel)
146 return NULL;
147
148 spin_lock_init(&channel->inbound_lock);
149 spin_lock_init(&channel->sc_lock);
150
151 INIT_LIST_HEAD(&channel->sc_list);
152 INIT_LIST_HEAD(&channel->percpu_list);
153
154 channel->controlwq = create_workqueue("hv_vmbus_ctl");
155 if (!channel->controlwq) {
156 kfree(channel);
157 return NULL;
158 }
159
160 return channel;
161 }
162
163 /*
164 * release_hannel - Release the vmbus channel object itself
165 */
release_channel(struct work_struct * work)166 static void release_channel(struct work_struct *work)
167 {
168 struct vmbus_channel *channel = container_of(work,
169 struct vmbus_channel,
170 work);
171
172 destroy_workqueue(channel->controlwq);
173
174 kfree(channel);
175 }
176
177 /*
178 * free_channel - Release the resources used by the vmbus channel object
179 */
free_channel(struct vmbus_channel * channel)180 static void free_channel(struct vmbus_channel *channel)
181 {
182
183 /*
184 * We have to release the channel's workqueue/thread in the vmbus's
185 * workqueue/thread context
186 * ie we can't destroy ourselves.
187 */
188 INIT_WORK(&channel->work, release_channel);
189 queue_work(vmbus_connection.work_queue, &channel->work);
190 }
191
percpu_channel_enq(void * arg)192 static void percpu_channel_enq(void *arg)
193 {
194 struct vmbus_channel *channel = arg;
195 int cpu = smp_processor_id();
196
197 list_add_tail(&channel->percpu_list, &hv_context.percpu_list[cpu]);
198 }
199
percpu_channel_deq(void * arg)200 static void percpu_channel_deq(void *arg)
201 {
202 struct vmbus_channel *channel = arg;
203
204 list_del(&channel->percpu_list);
205 }
206
207 /*
208 * vmbus_process_rescind_offer -
209 * Rescind the offer by initiating a device removal
210 */
vmbus_process_rescind_offer(struct work_struct * work)211 static void vmbus_process_rescind_offer(struct work_struct *work)
212 {
213 struct vmbus_channel *channel = container_of(work,
214 struct vmbus_channel,
215 work);
216 unsigned long flags;
217 struct vmbus_channel *primary_channel;
218 struct vmbus_channel_relid_released msg;
219 struct device *dev;
220
221 if (channel->device_obj) {
222 dev = get_device(&channel->device_obj->device);
223 if (dev) {
224 vmbus_device_unregister(channel->device_obj);
225 put_device(dev);
226 }
227 }
228
229 memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
230 msg.child_relid = channel->offermsg.child_relid;
231 msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
232 vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
233
234 if (channel->target_cpu != get_cpu()) {
235 put_cpu();
236 smp_call_function_single(channel->target_cpu,
237 percpu_channel_deq, channel, true);
238 } else {
239 percpu_channel_deq(channel);
240 put_cpu();
241 }
242
243 if (channel->primary_channel == NULL) {
244 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
245 list_del(&channel->listentry);
246 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
247 } else {
248 primary_channel = channel->primary_channel;
249 spin_lock_irqsave(&primary_channel->sc_lock, flags);
250 list_del(&channel->sc_list);
251 spin_unlock_irqrestore(&primary_channel->sc_lock, flags);
252 }
253 free_channel(channel);
254 }
255
vmbus_free_channels(void)256 void vmbus_free_channels(void)
257 {
258 struct vmbus_channel *channel;
259
260 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
261 vmbus_device_unregister(channel->device_obj);
262 kfree(channel->device_obj);
263 free_channel(channel);
264 }
265 }
266
267 /*
268 * vmbus_process_offer - Process the offer by creating a channel/device
269 * associated with this offer
270 */
vmbus_process_offer(struct work_struct * work)271 static void vmbus_process_offer(struct work_struct *work)
272 {
273 struct vmbus_channel *newchannel = container_of(work,
274 struct vmbus_channel,
275 work);
276 struct vmbus_channel *channel;
277 bool fnew = true;
278 bool enq = false;
279 int ret;
280 unsigned long flags;
281
282 /* The next possible work is rescind handling */
283 INIT_WORK(&newchannel->work, vmbus_process_rescind_offer);
284
285 /* Make sure this is a new offer */
286 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
287
288 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
289 if (!uuid_le_cmp(channel->offermsg.offer.if_type,
290 newchannel->offermsg.offer.if_type) &&
291 !uuid_le_cmp(channel->offermsg.offer.if_instance,
292 newchannel->offermsg.offer.if_instance)) {
293 fnew = false;
294 break;
295 }
296 }
297
298 if (fnew) {
299 list_add_tail(&newchannel->listentry,
300 &vmbus_connection.chn_list);
301 enq = true;
302 }
303
304 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
305
306 if (enq) {
307 if (newchannel->target_cpu != get_cpu()) {
308 put_cpu();
309 smp_call_function_single(newchannel->target_cpu,
310 percpu_channel_enq,
311 newchannel, true);
312 } else {
313 percpu_channel_enq(newchannel);
314 put_cpu();
315 }
316 }
317 if (!fnew) {
318 /*
319 * Check to see if this is a sub-channel.
320 */
321 if (newchannel->offermsg.offer.sub_channel_index != 0) {
322 /*
323 * Process the sub-channel.
324 */
325 newchannel->primary_channel = channel;
326 spin_lock_irqsave(&channel->sc_lock, flags);
327 list_add_tail(&newchannel->sc_list, &channel->sc_list);
328 spin_unlock_irqrestore(&channel->sc_lock, flags);
329
330 if (newchannel->target_cpu != get_cpu()) {
331 put_cpu();
332 smp_call_function_single(newchannel->target_cpu,
333 percpu_channel_enq,
334 newchannel, true);
335 } else {
336 percpu_channel_enq(newchannel);
337 put_cpu();
338 }
339
340 newchannel->state = CHANNEL_OPEN_STATE;
341 if (channel->sc_creation_callback != NULL)
342 channel->sc_creation_callback(newchannel);
343
344 return;
345 }
346
347 free_channel(newchannel);
348 return;
349 }
350
351 /*
352 * This state is used to indicate a successful open
353 * so that when we do close the channel normally, we
354 * can cleanup properly
355 */
356 newchannel->state = CHANNEL_OPEN_STATE;
357
358 /*
359 * Start the process of binding this offer to the driver
360 * We need to set the DeviceObject field before calling
361 * vmbus_child_dev_add()
362 */
363 newchannel->device_obj = vmbus_device_create(
364 &newchannel->offermsg.offer.if_type,
365 &newchannel->offermsg.offer.if_instance,
366 newchannel);
367
368 /*
369 * Add the new device to the bus. This will kick off device-driver
370 * binding which eventually invokes the device driver's AddDevice()
371 * method.
372 */
373 ret = vmbus_device_register(newchannel->device_obj);
374 if (ret != 0) {
375 pr_err("unable to add child device object (relid %d)\n",
376 newchannel->offermsg.child_relid);
377
378 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
379 list_del(&newchannel->listentry);
380 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
381 kfree(newchannel->device_obj);
382
383 free_channel(newchannel);
384 }
385 }
386
387 enum {
388 IDE = 0,
389 SCSI,
390 NIC,
391 MAX_PERF_CHN,
392 };
393
394 /*
395 * This is an array of device_ids (device types) that are performance critical.
396 * We attempt to distribute the interrupt load for these devices across
397 * all available CPUs.
398 */
399 static const struct hv_vmbus_device_id hp_devs[] = {
400 /* IDE */
401 { HV_IDE_GUID, },
402 /* Storage - SCSI */
403 { HV_SCSI_GUID, },
404 /* Network */
405 { HV_NIC_GUID, },
406 };
407
408
409 /*
410 * We use this state to statically distribute the channel interrupt load.
411 */
412 static u32 next_vp;
413
414 /*
415 * Starting with Win8, we can statically distribute the incoming
416 * channel interrupt load by binding a channel to VCPU. We
417 * implement here a simple round robin scheme for distributing
418 * the interrupt load.
419 * We will bind channels that are not performance critical to cpu 0 and
420 * performance critical channels (IDE, SCSI and Network) will be uniformly
421 * distributed across all available CPUs.
422 */
init_vp_index(struct vmbus_channel * channel,const uuid_le * type_guid)423 static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid)
424 {
425 u32 cur_cpu;
426 int i;
427 bool perf_chn = false;
428 u32 max_cpus = num_online_cpus();
429
430 for (i = IDE; i < MAX_PERF_CHN; i++) {
431 if (!memcmp(type_guid->b, hp_devs[i].guid,
432 sizeof(uuid_le))) {
433 perf_chn = true;
434 break;
435 }
436 }
437 if ((vmbus_proto_version == VERSION_WS2008) ||
438 (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) {
439 /*
440 * Prior to win8, all channel interrupts are
441 * delivered on cpu 0.
442 * Also if the channel is not a performance critical
443 * channel, bind it to cpu 0.
444 */
445 channel->target_cpu = 0;
446 channel->target_vp = 0;
447 return;
448 }
449 cur_cpu = (++next_vp % max_cpus);
450 channel->target_cpu = cur_cpu;
451 channel->target_vp = hv_context.vp_index[cur_cpu];
452 }
453
454 /*
455 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
456 *
457 */
vmbus_onoffer(struct vmbus_channel_message_header * hdr)458 static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
459 {
460 struct vmbus_channel_offer_channel *offer;
461 struct vmbus_channel *newchannel;
462
463 offer = (struct vmbus_channel_offer_channel *)hdr;
464
465 /* Allocate the channel object and save this offer. */
466 newchannel = alloc_channel();
467 if (!newchannel) {
468 pr_err("Unable to allocate channel object\n");
469 return;
470 }
471
472 /*
473 * By default we setup state to enable batched
474 * reading. A specific service can choose to
475 * disable this prior to opening the channel.
476 */
477 newchannel->batched_reading = true;
478
479 /*
480 * Setup state for signalling the host.
481 */
482 newchannel->sig_event = (struct hv_input_signal_event *)
483 (ALIGN((unsigned long)
484 &newchannel->sig_buf,
485 HV_HYPERCALL_PARAM_ALIGN));
486
487 newchannel->sig_event->connectionid.asu32 = 0;
488 newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
489 newchannel->sig_event->flag_number = 0;
490 newchannel->sig_event->rsvdz = 0;
491
492 if (vmbus_proto_version != VERSION_WS2008) {
493 newchannel->is_dedicated_interrupt =
494 (offer->is_dedicated_interrupt != 0);
495 newchannel->sig_event->connectionid.u.id =
496 offer->connection_id;
497 }
498
499 init_vp_index(newchannel, &offer->offer.if_type);
500
501 memcpy(&newchannel->offermsg, offer,
502 sizeof(struct vmbus_channel_offer_channel));
503 newchannel->monitor_grp = (u8)offer->monitorid / 32;
504 newchannel->monitor_bit = (u8)offer->monitorid % 32;
505
506 INIT_WORK(&newchannel->work, vmbus_process_offer);
507 queue_work(newchannel->controlwq, &newchannel->work);
508 }
509
510 /*
511 * vmbus_onoffer_rescind - Rescind offer handler.
512 *
513 * We queue a work item to process this offer synchronously
514 */
vmbus_onoffer_rescind(struct vmbus_channel_message_header * hdr)515 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
516 {
517 struct vmbus_channel_rescind_offer *rescind;
518 struct vmbus_channel *channel;
519
520 rescind = (struct vmbus_channel_rescind_offer *)hdr;
521 channel = relid2channel(rescind->child_relid);
522
523 if (channel == NULL)
524 /* Just return here, no channel found */
525 return;
526
527 /* work is initialized for vmbus_process_rescind_offer() from
528 * vmbus_process_offer() where the channel got created */
529 queue_work(channel->controlwq, &channel->work);
530 }
531
532 /*
533 * vmbus_onoffers_delivered -
534 * This is invoked when all offers have been delivered.
535 *
536 * Nothing to do here.
537 */
vmbus_onoffers_delivered(struct vmbus_channel_message_header * hdr)538 static void vmbus_onoffers_delivered(
539 struct vmbus_channel_message_header *hdr)
540 {
541 }
542
543 /*
544 * vmbus_onopen_result - Open result handler.
545 *
546 * This is invoked when we received a response to our channel open request.
547 * Find the matching request, copy the response and signal the requesting
548 * thread.
549 */
vmbus_onopen_result(struct vmbus_channel_message_header * hdr)550 static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr)
551 {
552 struct vmbus_channel_open_result *result;
553 struct vmbus_channel_msginfo *msginfo;
554 struct vmbus_channel_message_header *requestheader;
555 struct vmbus_channel_open_channel *openmsg;
556 unsigned long flags;
557
558 result = (struct vmbus_channel_open_result *)hdr;
559
560 /*
561 * Find the open msg, copy the result and signal/unblock the wait event
562 */
563 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
564
565 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
566 msglistentry) {
567 requestheader =
568 (struct vmbus_channel_message_header *)msginfo->msg;
569
570 if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) {
571 openmsg =
572 (struct vmbus_channel_open_channel *)msginfo->msg;
573 if (openmsg->child_relid == result->child_relid &&
574 openmsg->openid == result->openid) {
575 memcpy(&msginfo->response.open_result,
576 result,
577 sizeof(
578 struct vmbus_channel_open_result));
579 complete(&msginfo->waitevent);
580 break;
581 }
582 }
583 }
584 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
585 }
586
587 /*
588 * vmbus_ongpadl_created - GPADL created handler.
589 *
590 * This is invoked when we received a response to our gpadl create request.
591 * Find the matching request, copy the response and signal the requesting
592 * thread.
593 */
vmbus_ongpadl_created(struct vmbus_channel_message_header * hdr)594 static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr)
595 {
596 struct vmbus_channel_gpadl_created *gpadlcreated;
597 struct vmbus_channel_msginfo *msginfo;
598 struct vmbus_channel_message_header *requestheader;
599 struct vmbus_channel_gpadl_header *gpadlheader;
600 unsigned long flags;
601
602 gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr;
603
604 /*
605 * Find the establish msg, copy the result and signal/unblock the wait
606 * event
607 */
608 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
609
610 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
611 msglistentry) {
612 requestheader =
613 (struct vmbus_channel_message_header *)msginfo->msg;
614
615 if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) {
616 gpadlheader =
617 (struct vmbus_channel_gpadl_header *)requestheader;
618
619 if ((gpadlcreated->child_relid ==
620 gpadlheader->child_relid) &&
621 (gpadlcreated->gpadl == gpadlheader->gpadl)) {
622 memcpy(&msginfo->response.gpadl_created,
623 gpadlcreated,
624 sizeof(
625 struct vmbus_channel_gpadl_created));
626 complete(&msginfo->waitevent);
627 break;
628 }
629 }
630 }
631 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
632 }
633
634 /*
635 * vmbus_ongpadl_torndown - GPADL torndown handler.
636 *
637 * This is invoked when we received a response to our gpadl teardown request.
638 * Find the matching request, copy the response and signal the requesting
639 * thread.
640 */
vmbus_ongpadl_torndown(struct vmbus_channel_message_header * hdr)641 static void vmbus_ongpadl_torndown(
642 struct vmbus_channel_message_header *hdr)
643 {
644 struct vmbus_channel_gpadl_torndown *gpadl_torndown;
645 struct vmbus_channel_msginfo *msginfo;
646 struct vmbus_channel_message_header *requestheader;
647 struct vmbus_channel_gpadl_teardown *gpadl_teardown;
648 unsigned long flags;
649
650 gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr;
651
652 /*
653 * Find the open msg, copy the result and signal/unblock the wait event
654 */
655 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
656
657 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
658 msglistentry) {
659 requestheader =
660 (struct vmbus_channel_message_header *)msginfo->msg;
661
662 if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) {
663 gpadl_teardown =
664 (struct vmbus_channel_gpadl_teardown *)requestheader;
665
666 if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) {
667 memcpy(&msginfo->response.gpadl_torndown,
668 gpadl_torndown,
669 sizeof(
670 struct vmbus_channel_gpadl_torndown));
671 complete(&msginfo->waitevent);
672 break;
673 }
674 }
675 }
676 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
677 }
678
679 /*
680 * vmbus_onversion_response - Version response handler
681 *
682 * This is invoked when we received a response to our initiate contact request.
683 * Find the matching request, copy the response and signal the requesting
684 * thread.
685 */
vmbus_onversion_response(struct vmbus_channel_message_header * hdr)686 static void vmbus_onversion_response(
687 struct vmbus_channel_message_header *hdr)
688 {
689 struct vmbus_channel_msginfo *msginfo;
690 struct vmbus_channel_message_header *requestheader;
691 struct vmbus_channel_version_response *version_response;
692 unsigned long flags;
693
694 version_response = (struct vmbus_channel_version_response *)hdr;
695 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
696
697 list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list,
698 msglistentry) {
699 requestheader =
700 (struct vmbus_channel_message_header *)msginfo->msg;
701
702 if (requestheader->msgtype ==
703 CHANNELMSG_INITIATE_CONTACT) {
704 memcpy(&msginfo->response.version_response,
705 version_response,
706 sizeof(struct vmbus_channel_version_response));
707 complete(&msginfo->waitevent);
708 }
709 }
710 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
711 }
712
713 /* Channel message dispatch table */
714 static struct vmbus_channel_message_table_entry
715 channel_message_table[CHANNELMSG_COUNT] = {
716 {CHANNELMSG_INVALID, NULL},
717 {CHANNELMSG_OFFERCHANNEL, vmbus_onoffer},
718 {CHANNELMSG_RESCIND_CHANNELOFFER, vmbus_onoffer_rescind},
719 {CHANNELMSG_REQUESTOFFERS, NULL},
720 {CHANNELMSG_ALLOFFERS_DELIVERED, vmbus_onoffers_delivered},
721 {CHANNELMSG_OPENCHANNEL, NULL},
722 {CHANNELMSG_OPENCHANNEL_RESULT, vmbus_onopen_result},
723 {CHANNELMSG_CLOSECHANNEL, NULL},
724 {CHANNELMSG_GPADL_HEADER, NULL},
725 {CHANNELMSG_GPADL_BODY, NULL},
726 {CHANNELMSG_GPADL_CREATED, vmbus_ongpadl_created},
727 {CHANNELMSG_GPADL_TEARDOWN, NULL},
728 {CHANNELMSG_GPADL_TORNDOWN, vmbus_ongpadl_torndown},
729 {CHANNELMSG_RELID_RELEASED, NULL},
730 {CHANNELMSG_INITIATE_CONTACT, NULL},
731 {CHANNELMSG_VERSION_RESPONSE, vmbus_onversion_response},
732 {CHANNELMSG_UNLOAD, NULL},
733 };
734
735 /*
736 * vmbus_onmessage - Handler for channel protocol messages.
737 *
738 * This is invoked in the vmbus worker thread context.
739 */
vmbus_onmessage(void * context)740 void vmbus_onmessage(void *context)
741 {
742 struct hv_message *msg = context;
743 struct vmbus_channel_message_header *hdr;
744 int size;
745
746 hdr = (struct vmbus_channel_message_header *)msg->u.payload;
747 size = msg->header.payload_size;
748
749 if (hdr->msgtype >= CHANNELMSG_COUNT) {
750 pr_err("Received invalid channel message type %d size %d\n",
751 hdr->msgtype, size);
752 print_hex_dump_bytes("", DUMP_PREFIX_NONE,
753 (unsigned char *)msg->u.payload, size);
754 return;
755 }
756
757 if (channel_message_table[hdr->msgtype].message_handler)
758 channel_message_table[hdr->msgtype].message_handler(hdr);
759 else
760 pr_err("Unhandled channel message type %d\n", hdr->msgtype);
761 }
762
763 /*
764 * vmbus_request_offers - Send a request to get all our pending offers.
765 */
vmbus_request_offers(void)766 int vmbus_request_offers(void)
767 {
768 struct vmbus_channel_message_header *msg;
769 struct vmbus_channel_msginfo *msginfo;
770 int ret;
771
772 msginfo = kmalloc(sizeof(*msginfo) +
773 sizeof(struct vmbus_channel_message_header),
774 GFP_KERNEL);
775 if (!msginfo)
776 return -ENOMEM;
777
778 msg = (struct vmbus_channel_message_header *)msginfo->msg;
779
780 msg->msgtype = CHANNELMSG_REQUESTOFFERS;
781
782
783 ret = vmbus_post_msg(msg,
784 sizeof(struct vmbus_channel_message_header));
785 if (ret != 0) {
786 pr_err("Unable to request offers - %d\n", ret);
787
788 goto cleanup;
789 }
790
791 cleanup:
792 kfree(msginfo);
793
794 return ret;
795 }
796
797 /*
798 * Retrieve the (sub) channel on which to send an outgoing request.
799 * When a primary channel has multiple sub-channels, we choose a
800 * channel whose VCPU binding is closest to the VCPU on which
801 * this call is being made.
802 */
vmbus_get_outgoing_channel(struct vmbus_channel * primary)803 struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
804 {
805 struct list_head *cur, *tmp;
806 int cur_cpu = hv_context.vp_index[smp_processor_id()];
807 struct vmbus_channel *cur_channel;
808 struct vmbus_channel *outgoing_channel = primary;
809 int cpu_distance, new_cpu_distance;
810
811 if (list_empty(&primary->sc_list))
812 return outgoing_channel;
813
814 list_for_each_safe(cur, tmp, &primary->sc_list) {
815 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
816 if (cur_channel->state != CHANNEL_OPENED_STATE)
817 continue;
818
819 if (cur_channel->target_vp == cur_cpu)
820 return cur_channel;
821
822 cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ?
823 (outgoing_channel->target_vp - cur_cpu) :
824 (cur_cpu - outgoing_channel->target_vp));
825
826 new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ?
827 (cur_channel->target_vp - cur_cpu) :
828 (cur_cpu - cur_channel->target_vp));
829
830 if (cpu_distance < new_cpu_distance)
831 continue;
832
833 outgoing_channel = cur_channel;
834 }
835
836 return outgoing_channel;
837 }
838 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel);
839
invoke_sc_cb(struct vmbus_channel * primary_channel)840 static void invoke_sc_cb(struct vmbus_channel *primary_channel)
841 {
842 struct list_head *cur, *tmp;
843 struct vmbus_channel *cur_channel;
844
845 if (primary_channel->sc_creation_callback == NULL)
846 return;
847
848 list_for_each_safe(cur, tmp, &primary_channel->sc_list) {
849 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
850
851 primary_channel->sc_creation_callback(cur_channel);
852 }
853 }
854
vmbus_set_sc_create_callback(struct vmbus_channel * primary_channel,void (* sc_cr_cb)(struct vmbus_channel * new_sc))855 void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
856 void (*sc_cr_cb)(struct vmbus_channel *new_sc))
857 {
858 primary_channel->sc_creation_callback = sc_cr_cb;
859 }
860 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback);
861
vmbus_are_subchannels_present(struct vmbus_channel * primary)862 bool vmbus_are_subchannels_present(struct vmbus_channel *primary)
863 {
864 bool ret;
865
866 ret = !list_empty(&primary->sc_list);
867
868 if (ret) {
869 /*
870 * Invoke the callback on sub-channel creation.
871 * This will present a uniform interface to the
872 * clients.
873 */
874 invoke_sc_cb(primary);
875 }
876
877 return ret;
878 }
879 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present);
880