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/list.h>
29 #include <linux/module.h>
30 #include <linux/completion.h>
31 #include <linux/hyperv.h>
33 #include "hyperv_vmbus.h"
35 static void init_vp_index(struct vmbus_channel
*channel
,
36 const uuid_le
*type_guid
);
39 * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
40 * @icmsghdrp: Pointer to msg header structure
41 * @icmsg_negotiate: Pointer to negotiate message structure
42 * @buf: Raw buffer channel data
44 * @icmsghdrp is of type &struct icmsg_hdr.
45 * @negop is of type &struct icmsg_negotiate.
46 * Set up and fill in default negotiate response message.
48 * The fw_version specifies the framework version that
49 * we can support and srv_version specifies the service
50 * version we can support.
52 * Mainly used by Hyper-V drivers.
54 bool vmbus_prep_negotiate_resp(struct icmsg_hdr
*icmsghdrp
,
55 struct icmsg_negotiate
*negop
, u8
*buf
,
56 int fw_version
, int srv_version
)
58 int icframe_major
, icframe_minor
;
59 int icmsg_major
, icmsg_minor
;
60 int fw_major
, fw_minor
;
61 int srv_major
, srv_minor
;
63 bool found_match
= false;
65 icmsghdrp
->icmsgsize
= 0x10;
66 fw_major
= (fw_version
>> 16);
67 fw_minor
= (fw_version
& 0xFFFF);
69 srv_major
= (srv_version
>> 16);
70 srv_minor
= (srv_version
& 0xFFFF);
72 negop
= (struct icmsg_negotiate
*)&buf
[
73 sizeof(struct vmbuspipe_hdr
) +
74 sizeof(struct icmsg_hdr
)];
76 icframe_major
= negop
->icframe_vercnt
;
79 icmsg_major
= negop
->icmsg_vercnt
;
83 * Select the framework version number we will
87 for (i
= 0; i
< negop
->icframe_vercnt
; i
++) {
88 if ((negop
->icversion_data
[i
].major
== fw_major
) &&
89 (negop
->icversion_data
[i
].minor
== fw_minor
)) {
90 icframe_major
= negop
->icversion_data
[i
].major
;
91 icframe_minor
= negop
->icversion_data
[i
].minor
;
101 for (i
= negop
->icframe_vercnt
;
102 (i
< negop
->icframe_vercnt
+ negop
->icmsg_vercnt
); i
++) {
103 if ((negop
->icversion_data
[i
].major
== srv_major
) &&
104 (negop
->icversion_data
[i
].minor
== srv_minor
)) {
105 icmsg_major
= negop
->icversion_data
[i
].major
;
106 icmsg_minor
= negop
->icversion_data
[i
].minor
;
112 * Respond with the framework and service
113 * version numbers we can support.
118 negop
->icframe_vercnt
= 0;
119 negop
->icmsg_vercnt
= 0;
121 negop
->icframe_vercnt
= 1;
122 negop
->icmsg_vercnt
= 1;
125 negop
->icversion_data
[0].major
= icframe_major
;
126 negop
->icversion_data
[0].minor
= icframe_minor
;
127 negop
->icversion_data
[1].major
= icmsg_major
;
128 negop
->icversion_data
[1].minor
= icmsg_minor
;
132 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp
);
135 * alloc_channel - Allocate and initialize a vmbus channel object
137 static struct vmbus_channel
*alloc_channel(void)
139 static atomic_t chan_num
= ATOMIC_INIT(0);
140 struct vmbus_channel
*channel
;
142 channel
= kzalloc(sizeof(*channel
), GFP_ATOMIC
);
146 channel
->id
= atomic_inc_return(&chan_num
);
147 spin_lock_init(&channel
->inbound_lock
);
148 spin_lock_init(&channel
->lock
);
150 INIT_LIST_HEAD(&channel
->sc_list
);
151 INIT_LIST_HEAD(&channel
->percpu_list
);
157 * free_channel - Release the resources used by the vmbus channel object
159 static void free_channel(struct vmbus_channel
*channel
)
164 static void percpu_channel_enq(void *arg
)
166 struct vmbus_channel
*channel
= arg
;
167 int cpu
= smp_processor_id();
169 list_add_tail(&channel
->percpu_list
, &hv_context
.percpu_list
[cpu
]);
172 static void percpu_channel_deq(void *arg
)
174 struct vmbus_channel
*channel
= arg
;
176 list_del(&channel
->percpu_list
);
180 void hv_process_channel_removal(struct vmbus_channel
*channel
, u32 relid
)
182 struct vmbus_channel_relid_released msg
;
184 struct vmbus_channel
*primary_channel
;
186 memset(&msg
, 0, sizeof(struct vmbus_channel_relid_released
));
187 msg
.child_relid
= relid
;
188 msg
.header
.msgtype
= CHANNELMSG_RELID_RELEASED
;
189 vmbus_post_msg(&msg
, sizeof(struct vmbus_channel_relid_released
));
194 if (channel
->target_cpu
!= get_cpu()) {
196 smp_call_function_single(channel
->target_cpu
,
197 percpu_channel_deq
, channel
, true);
199 percpu_channel_deq(channel
);
203 if (channel
->primary_channel
== NULL
) {
204 spin_lock_irqsave(&vmbus_connection
.channel_lock
, flags
);
205 list_del(&channel
->listentry
);
206 spin_unlock_irqrestore(&vmbus_connection
.channel_lock
, flags
);
208 primary_channel
= channel
->primary_channel
;
209 spin_lock_irqsave(&primary_channel
->lock
, flags
);
210 list_del(&channel
->sc_list
);
211 primary_channel
->num_sc
--;
212 spin_unlock_irqrestore(&primary_channel
->lock
, flags
);
214 free_channel(channel
);
217 void vmbus_free_channels(void)
219 struct vmbus_channel
*channel
, *tmp
;
221 list_for_each_entry_safe(channel
, tmp
, &vmbus_connection
.chn_list
,
223 /* if we don't set rescind to true, vmbus_close_internal()
224 * won't invoke hv_process_channel_removal().
226 channel
->rescind
= true;
228 vmbus_device_unregister(channel
->device_obj
);
233 * vmbus_process_offer - Process the offer by creating a channel/device
234 * associated with this offer
236 static void vmbus_process_offer(struct vmbus_channel
*newchannel
)
238 struct vmbus_channel
*channel
;
242 /* Make sure this is a new offer */
243 spin_lock_irqsave(&vmbus_connection
.channel_lock
, flags
);
245 list_for_each_entry(channel
, &vmbus_connection
.chn_list
, listentry
) {
246 if (!uuid_le_cmp(channel
->offermsg
.offer
.if_type
,
247 newchannel
->offermsg
.offer
.if_type
) &&
248 !uuid_le_cmp(channel
->offermsg
.offer
.if_instance
,
249 newchannel
->offermsg
.offer
.if_instance
)) {
256 list_add_tail(&newchannel
->listentry
,
257 &vmbus_connection
.chn_list
);
259 spin_unlock_irqrestore(&vmbus_connection
.channel_lock
, flags
);
263 * Check to see if this is a sub-channel.
265 if (newchannel
->offermsg
.offer
.sub_channel_index
!= 0) {
267 * Process the sub-channel.
269 newchannel
->primary_channel
= channel
;
270 spin_lock_irqsave(&channel
->lock
, flags
);
271 list_add_tail(&newchannel
->sc_list
, &channel
->sc_list
);
273 spin_unlock_irqrestore(&channel
->lock
, flags
);
278 init_vp_index(newchannel
, &newchannel
->offermsg
.offer
.if_type
);
280 if (newchannel
->target_cpu
!= get_cpu()) {
282 smp_call_function_single(newchannel
->target_cpu
,
286 percpu_channel_enq(newchannel
);
291 * This state is used to indicate a successful open
292 * so that when we do close the channel normally, we
293 * can cleanup properly
295 newchannel
->state
= CHANNEL_OPEN_STATE
;
298 if (channel
->sc_creation_callback
!= NULL
)
299 channel
->sc_creation_callback(newchannel
);
304 * Start the process of binding this offer to the driver
305 * We need to set the DeviceObject field before calling
306 * vmbus_child_dev_add()
308 newchannel
->device_obj
= vmbus_device_create(
309 &newchannel
->offermsg
.offer
.if_type
,
310 &newchannel
->offermsg
.offer
.if_instance
,
312 if (!newchannel
->device_obj
)
316 * Add the new device to the bus. This will kick off device-driver
317 * binding which eventually invokes the device driver's AddDevice()
320 if (vmbus_device_register(newchannel
->device_obj
) != 0) {
321 pr_err("unable to add child device object (relid %d)\n",
322 newchannel
->offermsg
.child_relid
);
323 kfree(newchannel
->device_obj
);
329 spin_lock_irqsave(&vmbus_connection
.channel_lock
, flags
);
330 list_del(&newchannel
->listentry
);
331 spin_unlock_irqrestore(&vmbus_connection
.channel_lock
, flags
);
333 if (newchannel
->target_cpu
!= get_cpu()) {
335 smp_call_function_single(newchannel
->target_cpu
,
336 percpu_channel_deq
, newchannel
, true);
338 percpu_channel_deq(newchannel
);
343 free_channel(newchannel
);
354 * This is an array of device_ids (device types) that are performance critical.
355 * We attempt to distribute the interrupt load for these devices across
356 * all available CPUs.
358 static const struct hv_vmbus_device_id hp_devs
[] = {
365 /* NetworkDirect Guest RDMA */
371 * We use this state to statically distribute the channel interrupt load.
373 static int next_numa_node_id
;
376 * Starting with Win8, we can statically distribute the incoming
377 * channel interrupt load by binding a channel to VCPU.
378 * We do this in a hierarchical fashion:
379 * First distribute the primary channels across available NUMA nodes
380 * and then distribute the subchannels amongst the CPUs in the NUMA
381 * node assigned to the primary channel.
383 * For pre-win8 hosts or non-performance critical channels we assign the
384 * first CPU in the first NUMA node.
386 static void init_vp_index(struct vmbus_channel
*channel
, const uuid_le
*type_guid
)
390 bool perf_chn
= false;
391 struct vmbus_channel
*primary
= channel
->primary_channel
;
393 struct cpumask available_mask
;
395 for (i
= IDE
; i
< MAX_PERF_CHN
; i
++) {
396 if (!memcmp(type_guid
->b
, hp_devs
[i
].guid
,
402 if ((vmbus_proto_version
== VERSION_WS2008
) ||
403 (vmbus_proto_version
== VERSION_WIN7
) || (!perf_chn
)) {
405 * Prior to win8, all channel interrupts are
406 * delivered on cpu 0.
407 * Also if the channel is not a performance critical
408 * channel, bind it to cpu 0.
410 channel
->numa_node
= 0;
411 cpumask_set_cpu(0, &channel
->alloced_cpus_in_node
);
412 channel
->target_cpu
= 0;
413 channel
->target_vp
= hv_context
.vp_index
[0];
418 * We distribute primary channels evenly across all the available
419 * NUMA nodes and within the assigned NUMA node we will assign the
420 * first available CPU to the primary channel.
421 * The sub-channels will be assigned to the CPUs available in the
426 next_node
= next_numa_node_id
++;
427 if (next_node
== nr_node_ids
)
428 next_node
= next_numa_node_id
= 0;
429 if (cpumask_empty(cpumask_of_node(next_node
)))
433 channel
->numa_node
= next_node
;
437 if (cpumask_weight(&primary
->alloced_cpus_in_node
) ==
438 cpumask_weight(cpumask_of_node(primary
->numa_node
))) {
440 * We have cycled through all the CPUs in the node;
441 * reset the alloced map.
443 cpumask_clear(&primary
->alloced_cpus_in_node
);
446 cpumask_xor(&available_mask
, &primary
->alloced_cpus_in_node
,
447 cpumask_of_node(primary
->numa_node
));
449 cur_cpu
= cpumask_next(-1, &available_mask
);
450 cpumask_set_cpu(cur_cpu
, &primary
->alloced_cpus_in_node
);
452 channel
->target_cpu
= cur_cpu
;
453 channel
->target_vp
= hv_context
.vp_index
[cur_cpu
];
457 * vmbus_unload_response - Handler for the unload response.
459 static void vmbus_unload_response(struct vmbus_channel_message_header
*hdr
)
462 * This is a global event; just wakeup the waiting thread.
463 * Once we successfully unload, we can cleanup the monitor state.
465 complete(&vmbus_connection
.unload_event
);
468 void vmbus_initiate_unload(void)
470 struct vmbus_channel_message_header hdr
;
472 init_completion(&vmbus_connection
.unload_event
);
473 memset(&hdr
, 0, sizeof(struct vmbus_channel_message_header
));
474 hdr
.msgtype
= CHANNELMSG_UNLOAD
;
475 vmbus_post_msg(&hdr
, sizeof(struct vmbus_channel_message_header
));
477 wait_for_completion(&vmbus_connection
.unload_event
);
481 * vmbus_onoffer - Handler for channel offers from vmbus in parent partition.
484 static void vmbus_onoffer(struct vmbus_channel_message_header
*hdr
)
486 struct vmbus_channel_offer_channel
*offer
;
487 struct vmbus_channel
*newchannel
;
489 offer
= (struct vmbus_channel_offer_channel
*)hdr
;
491 /* Allocate the channel object and save this offer. */
492 newchannel
= alloc_channel();
494 pr_err("Unable to allocate channel object\n");
499 * By default we setup state to enable batched
500 * reading. A specific service can choose to
501 * disable this prior to opening the channel.
503 newchannel
->batched_reading
= true;
506 * Setup state for signalling the host.
508 newchannel
->sig_event
= (struct hv_input_signal_event
*)
509 (ALIGN((unsigned long)
510 &newchannel
->sig_buf
,
511 HV_HYPERCALL_PARAM_ALIGN
));
513 newchannel
->sig_event
->connectionid
.asu32
= 0;
514 newchannel
->sig_event
->connectionid
.u
.id
= VMBUS_EVENT_CONNECTION_ID
;
515 newchannel
->sig_event
->flag_number
= 0;
516 newchannel
->sig_event
->rsvdz
= 0;
518 if (vmbus_proto_version
!= VERSION_WS2008
) {
519 newchannel
->is_dedicated_interrupt
=
520 (offer
->is_dedicated_interrupt
!= 0);
521 newchannel
->sig_event
->connectionid
.u
.id
=
522 offer
->connection_id
;
525 memcpy(&newchannel
->offermsg
, offer
,
526 sizeof(struct vmbus_channel_offer_channel
));
527 newchannel
->monitor_grp
= (u8
)offer
->monitorid
/ 32;
528 newchannel
->monitor_bit
= (u8
)offer
->monitorid
% 32;
530 vmbus_process_offer(newchannel
);
534 * vmbus_onoffer_rescind - Rescind offer handler.
536 * We queue a work item to process this offer synchronously
538 static void vmbus_onoffer_rescind(struct vmbus_channel_message_header
*hdr
)
540 struct vmbus_channel_rescind_offer
*rescind
;
541 struct vmbus_channel
*channel
;
545 rescind
= (struct vmbus_channel_rescind_offer
*)hdr
;
546 channel
= relid2channel(rescind
->child_relid
);
548 if (channel
== NULL
) {
549 hv_process_channel_removal(NULL
, rescind
->child_relid
);
553 spin_lock_irqsave(&channel
->lock
, flags
);
554 channel
->rescind
= true;
555 spin_unlock_irqrestore(&channel
->lock
, flags
);
557 if (channel
->device_obj
) {
559 * We will have to unregister this device from the
562 dev
= get_device(&channel
->device_obj
->device
);
564 vmbus_device_unregister(channel
->device_obj
);
568 hv_process_channel_removal(channel
,
569 channel
->offermsg
.child_relid
);
574 * vmbus_onoffers_delivered -
575 * This is invoked when all offers have been delivered.
577 * Nothing to do here.
579 static void vmbus_onoffers_delivered(
580 struct vmbus_channel_message_header
*hdr
)
585 * vmbus_onopen_result - Open result handler.
587 * This is invoked when we received a response to our channel open request.
588 * Find the matching request, copy the response and signal the requesting
591 static void vmbus_onopen_result(struct vmbus_channel_message_header
*hdr
)
593 struct vmbus_channel_open_result
*result
;
594 struct vmbus_channel_msginfo
*msginfo
;
595 struct vmbus_channel_message_header
*requestheader
;
596 struct vmbus_channel_open_channel
*openmsg
;
599 result
= (struct vmbus_channel_open_result
*)hdr
;
602 * Find the open msg, copy the result and signal/unblock the wait event
604 spin_lock_irqsave(&vmbus_connection
.channelmsg_lock
, flags
);
606 list_for_each_entry(msginfo
, &vmbus_connection
.chn_msg_list
,
609 (struct vmbus_channel_message_header
*)msginfo
->msg
;
611 if (requestheader
->msgtype
== CHANNELMSG_OPENCHANNEL
) {
613 (struct vmbus_channel_open_channel
*)msginfo
->msg
;
614 if (openmsg
->child_relid
== result
->child_relid
&&
615 openmsg
->openid
== result
->openid
) {
616 memcpy(&msginfo
->response
.open_result
,
619 struct vmbus_channel_open_result
));
620 complete(&msginfo
->waitevent
);
625 spin_unlock_irqrestore(&vmbus_connection
.channelmsg_lock
, flags
);
629 * vmbus_ongpadl_created - GPADL created handler.
631 * This is invoked when we received a response to our gpadl create request.
632 * Find the matching request, copy the response and signal the requesting
635 static void vmbus_ongpadl_created(struct vmbus_channel_message_header
*hdr
)
637 struct vmbus_channel_gpadl_created
*gpadlcreated
;
638 struct vmbus_channel_msginfo
*msginfo
;
639 struct vmbus_channel_message_header
*requestheader
;
640 struct vmbus_channel_gpadl_header
*gpadlheader
;
643 gpadlcreated
= (struct vmbus_channel_gpadl_created
*)hdr
;
646 * Find the establish msg, copy the result and signal/unblock the wait
649 spin_lock_irqsave(&vmbus_connection
.channelmsg_lock
, flags
);
651 list_for_each_entry(msginfo
, &vmbus_connection
.chn_msg_list
,
654 (struct vmbus_channel_message_header
*)msginfo
->msg
;
656 if (requestheader
->msgtype
== CHANNELMSG_GPADL_HEADER
) {
658 (struct vmbus_channel_gpadl_header
*)requestheader
;
660 if ((gpadlcreated
->child_relid
==
661 gpadlheader
->child_relid
) &&
662 (gpadlcreated
->gpadl
== gpadlheader
->gpadl
)) {
663 memcpy(&msginfo
->response
.gpadl_created
,
666 struct vmbus_channel_gpadl_created
));
667 complete(&msginfo
->waitevent
);
672 spin_unlock_irqrestore(&vmbus_connection
.channelmsg_lock
, flags
);
676 * vmbus_ongpadl_torndown - GPADL torndown handler.
678 * This is invoked when we received a response to our gpadl teardown request.
679 * Find the matching request, copy the response and signal the requesting
682 static void vmbus_ongpadl_torndown(
683 struct vmbus_channel_message_header
*hdr
)
685 struct vmbus_channel_gpadl_torndown
*gpadl_torndown
;
686 struct vmbus_channel_msginfo
*msginfo
;
687 struct vmbus_channel_message_header
*requestheader
;
688 struct vmbus_channel_gpadl_teardown
*gpadl_teardown
;
691 gpadl_torndown
= (struct vmbus_channel_gpadl_torndown
*)hdr
;
694 * Find the open msg, copy the result and signal/unblock the wait event
696 spin_lock_irqsave(&vmbus_connection
.channelmsg_lock
, flags
);
698 list_for_each_entry(msginfo
, &vmbus_connection
.chn_msg_list
,
701 (struct vmbus_channel_message_header
*)msginfo
->msg
;
703 if (requestheader
->msgtype
== CHANNELMSG_GPADL_TEARDOWN
) {
705 (struct vmbus_channel_gpadl_teardown
*)requestheader
;
707 if (gpadl_torndown
->gpadl
== gpadl_teardown
->gpadl
) {
708 memcpy(&msginfo
->response
.gpadl_torndown
,
711 struct vmbus_channel_gpadl_torndown
));
712 complete(&msginfo
->waitevent
);
717 spin_unlock_irqrestore(&vmbus_connection
.channelmsg_lock
, flags
);
721 * vmbus_onversion_response - Version response handler
723 * This is invoked when we received a response to our initiate contact request.
724 * Find the matching request, copy the response and signal the requesting
727 static void vmbus_onversion_response(
728 struct vmbus_channel_message_header
*hdr
)
730 struct vmbus_channel_msginfo
*msginfo
;
731 struct vmbus_channel_message_header
*requestheader
;
732 struct vmbus_channel_version_response
*version_response
;
735 version_response
= (struct vmbus_channel_version_response
*)hdr
;
736 spin_lock_irqsave(&vmbus_connection
.channelmsg_lock
, flags
);
738 list_for_each_entry(msginfo
, &vmbus_connection
.chn_msg_list
,
741 (struct vmbus_channel_message_header
*)msginfo
->msg
;
743 if (requestheader
->msgtype
==
744 CHANNELMSG_INITIATE_CONTACT
) {
745 memcpy(&msginfo
->response
.version_response
,
747 sizeof(struct vmbus_channel_version_response
));
748 complete(&msginfo
->waitevent
);
751 spin_unlock_irqrestore(&vmbus_connection
.channelmsg_lock
, flags
);
754 /* Channel message dispatch table */
755 struct vmbus_channel_message_table_entry
756 channel_message_table
[CHANNELMSG_COUNT
] = {
757 {CHANNELMSG_INVALID
, 0, NULL
},
758 {CHANNELMSG_OFFERCHANNEL
, 0, vmbus_onoffer
},
759 {CHANNELMSG_RESCIND_CHANNELOFFER
, 0, vmbus_onoffer_rescind
},
760 {CHANNELMSG_REQUESTOFFERS
, 0, NULL
},
761 {CHANNELMSG_ALLOFFERS_DELIVERED
, 1, vmbus_onoffers_delivered
},
762 {CHANNELMSG_OPENCHANNEL
, 0, NULL
},
763 {CHANNELMSG_OPENCHANNEL_RESULT
, 1, vmbus_onopen_result
},
764 {CHANNELMSG_CLOSECHANNEL
, 0, NULL
},
765 {CHANNELMSG_GPADL_HEADER
, 0, NULL
},
766 {CHANNELMSG_GPADL_BODY
, 0, NULL
},
767 {CHANNELMSG_GPADL_CREATED
, 1, vmbus_ongpadl_created
},
768 {CHANNELMSG_GPADL_TEARDOWN
, 0, NULL
},
769 {CHANNELMSG_GPADL_TORNDOWN
, 1, vmbus_ongpadl_torndown
},
770 {CHANNELMSG_RELID_RELEASED
, 0, NULL
},
771 {CHANNELMSG_INITIATE_CONTACT
, 0, NULL
},
772 {CHANNELMSG_VERSION_RESPONSE
, 1, vmbus_onversion_response
},
773 {CHANNELMSG_UNLOAD
, 0, NULL
},
774 {CHANNELMSG_UNLOAD_RESPONSE
, 1, vmbus_unload_response
},
778 * vmbus_onmessage - Handler for channel protocol messages.
780 * This is invoked in the vmbus worker thread context.
782 void vmbus_onmessage(void *context
)
784 struct hv_message
*msg
= context
;
785 struct vmbus_channel_message_header
*hdr
;
788 hdr
= (struct vmbus_channel_message_header
*)msg
->u
.payload
;
789 size
= msg
->header
.payload_size
;
791 if (hdr
->msgtype
>= CHANNELMSG_COUNT
) {
792 pr_err("Received invalid channel message type %d size %d\n",
794 print_hex_dump_bytes("", DUMP_PREFIX_NONE
,
795 (unsigned char *)msg
->u
.payload
, size
);
799 if (channel_message_table
[hdr
->msgtype
].message_handler
)
800 channel_message_table
[hdr
->msgtype
].message_handler(hdr
);
802 pr_err("Unhandled channel message type %d\n", hdr
->msgtype
);
806 * vmbus_request_offers - Send a request to get all our pending offers.
808 int vmbus_request_offers(void)
810 struct vmbus_channel_message_header
*msg
;
811 struct vmbus_channel_msginfo
*msginfo
;
814 msginfo
= kmalloc(sizeof(*msginfo
) +
815 sizeof(struct vmbus_channel_message_header
),
820 msg
= (struct vmbus_channel_message_header
*)msginfo
->msg
;
822 msg
->msgtype
= CHANNELMSG_REQUESTOFFERS
;
825 ret
= vmbus_post_msg(msg
,
826 sizeof(struct vmbus_channel_message_header
));
828 pr_err("Unable to request offers - %d\n", ret
);
840 * Retrieve the (sub) channel on which to send an outgoing request.
841 * When a primary channel has multiple sub-channels, we try to
842 * distribute the load equally amongst all available channels.
844 struct vmbus_channel
*vmbus_get_outgoing_channel(struct vmbus_channel
*primary
)
846 struct list_head
*cur
, *tmp
;
848 struct vmbus_channel
*cur_channel
;
849 struct vmbus_channel
*outgoing_channel
= primary
;
853 if (list_empty(&primary
->sc_list
))
854 return outgoing_channel
;
856 next_channel
= primary
->next_oc
++;
858 if (next_channel
> (primary
->num_sc
)) {
859 primary
->next_oc
= 0;
860 return outgoing_channel
;
863 cur_cpu
= hv_context
.vp_index
[get_cpu()];
865 list_for_each_safe(cur
, tmp
, &primary
->sc_list
) {
866 cur_channel
= list_entry(cur
, struct vmbus_channel
, sc_list
);
867 if (cur_channel
->state
!= CHANNEL_OPENED_STATE
)
870 if (cur_channel
->target_vp
== cur_cpu
)
873 if (i
== next_channel
)
879 return outgoing_channel
;
881 EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel
);
883 static void invoke_sc_cb(struct vmbus_channel
*primary_channel
)
885 struct list_head
*cur
, *tmp
;
886 struct vmbus_channel
*cur_channel
;
888 if (primary_channel
->sc_creation_callback
== NULL
)
891 list_for_each_safe(cur
, tmp
, &primary_channel
->sc_list
) {
892 cur_channel
= list_entry(cur
, struct vmbus_channel
, sc_list
);
894 primary_channel
->sc_creation_callback(cur_channel
);
898 void vmbus_set_sc_create_callback(struct vmbus_channel
*primary_channel
,
899 void (*sc_cr_cb
)(struct vmbus_channel
*new_sc
))
901 primary_channel
->sc_creation_callback
= sc_cr_cb
;
903 EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback
);
905 bool vmbus_are_subchannels_present(struct vmbus_channel
*primary
)
909 ret
= !list_empty(&primary
->sc_list
);
913 * Invoke the callback on sub-channel creation.
914 * This will present a uniform interface to the
917 invoke_sc_cb(primary
);
922 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present
);