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22
23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25#include <linux/kernel.h>
26#include <linux/sched.h>
27#include <linux/wait.h>
28#include <linux/delay.h>
29#include <linux/mm.h>
30#include <linux/slab.h>
31#include <linux/vmalloc.h>
32#include <linux/hyperv.h>
33#include <linux/export.h>
34#include <asm/hyperv.h>
35#include "hyperv_vmbus.h"
36
37
38struct vmbus_connection vmbus_connection = {
39 .conn_state = DISCONNECTED,
40 .next_gpadl_handle = ATOMIC_INIT(0xE1E10),
41};
42
43
44
45
46__u32 vmbus_proto_version;
47EXPORT_SYMBOL_GPL(vmbus_proto_version);
48
49static __u32 vmbus_get_next_version(__u32 current_version)
50{
51 switch (current_version) {
52 case (VERSION_WIN7):
53 return VERSION_WS2008;
54
55 case (VERSION_WIN8):
56 return VERSION_WIN7;
57
58 case (VERSION_WIN8_1):
59 return VERSION_WIN8;
60
61 case (VERSION_WIN10):
62 return VERSION_WIN8_1;
63
64 case (VERSION_WS2008):
65 default:
66 return VERSION_INVAL;
67 }
68}
69
70static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
71 __u32 version)
72{
73 int ret = 0;
74 struct vmbus_channel_initiate_contact *msg;
75 unsigned long flags;
76
77 init_completion(&msginfo->waitevent);
78
79 msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;
80
81 msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
82 msg->vmbus_version_requested = version;
83 msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
84 msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
85 msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
86
87
88
89
90
91
92
93
94
95 if (version >= VERSION_WIN8_1) {
96 msg->target_vcpu = hv_context.vp_index[get_cpu()];
97 put_cpu();
98 } else {
99 msg->target_vcpu = 0;
100 }
101
102
103
104
105
106 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
107 list_add_tail(&msginfo->msglistentry,
108 &vmbus_connection.chn_msg_list);
109
110 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
111
112 ret = vmbus_post_msg(msg,
113 sizeof(struct vmbus_channel_initiate_contact));
114 if (ret != 0) {
115 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
116 list_del(&msginfo->msglistentry);
117 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
118 flags);
119 return ret;
120 }
121
122
123 wait_for_completion(&msginfo->waitevent);
124
125 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
126 list_del(&msginfo->msglistentry);
127 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
128
129
130 if (msginfo->response.version_response.version_supported) {
131 vmbus_connection.conn_state = CONNECTED;
132 } else {
133 return -ECONNREFUSED;
134 }
135
136 return ret;
137}
138
139
140
141
142int vmbus_connect(void)
143{
144 int ret = 0;
145 struct vmbus_channel_msginfo *msginfo = NULL;
146 __u32 version;
147
148
149 vmbus_connection.conn_state = CONNECTING;
150 vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
151 if (!vmbus_connection.work_queue) {
152 ret = -ENOMEM;
153 goto cleanup;
154 }
155
156 INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
157 spin_lock_init(&vmbus_connection.channelmsg_lock);
158
159 INIT_LIST_HEAD(&vmbus_connection.chn_list);
160 mutex_init(&vmbus_connection.channel_mutex);
161
162
163
164
165
166 vmbus_connection.int_page =
167 (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
168 if (vmbus_connection.int_page == NULL) {
169 ret = -ENOMEM;
170 goto cleanup;
171 }
172
173 vmbus_connection.recv_int_page = vmbus_connection.int_page;
174 vmbus_connection.send_int_page =
175 (void *)((unsigned long)vmbus_connection.int_page +
176 (PAGE_SIZE >> 1));
177
178
179
180
181
182 vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
183 vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
184 if ((vmbus_connection.monitor_pages[0] == NULL) ||
185 (vmbus_connection.monitor_pages[1] == NULL)) {
186 ret = -ENOMEM;
187 goto cleanup;
188 }
189
190 msginfo = kzalloc(sizeof(*msginfo) +
191 sizeof(struct vmbus_channel_initiate_contact),
192 GFP_KERNEL);
193 if (msginfo == NULL) {
194 ret = -ENOMEM;
195 goto cleanup;
196 }
197
198
199
200
201
202
203
204
205 version = VERSION_CURRENT;
206
207 do {
208 ret = vmbus_negotiate_version(msginfo, version);
209 if (ret == -ETIMEDOUT)
210 goto cleanup;
211
212 if (vmbus_connection.conn_state == CONNECTED)
213 break;
214
215 version = vmbus_get_next_version(version);
216 } while (version != VERSION_INVAL);
217
218 if (version == VERSION_INVAL)
219 goto cleanup;
220
221 vmbus_proto_version = version;
222 pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n",
223 host_info_eax, host_info_ebx >> 16,
224 host_info_ebx & 0xFFFF, host_info_ecx,
225 host_info_edx >> 24, host_info_edx & 0xFFFFFF,
226 version >> 16, version & 0xFFFF);
227
228 kfree(msginfo);
229 return 0;
230
231cleanup:
232 pr_err("Unable to connect to host\n");
233
234 vmbus_connection.conn_state = DISCONNECTED;
235 vmbus_disconnect();
236
237 kfree(msginfo);
238
239 return ret;
240}
241
242void vmbus_disconnect(void)
243{
244
245
246
247 vmbus_initiate_unload(false);
248
249 if (vmbus_connection.work_queue) {
250 drain_workqueue(vmbus_connection.work_queue);
251 destroy_workqueue(vmbus_connection.work_queue);
252 }
253
254 if (vmbus_connection.int_page) {
255 free_pages((unsigned long)vmbus_connection.int_page, 0);
256 vmbus_connection.int_page = NULL;
257 }
258
259 free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0);
260 free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0);
261 vmbus_connection.monitor_pages[0] = NULL;
262 vmbus_connection.monitor_pages[1] = NULL;
263}
264
265
266
267
268
269
270
271static struct vmbus_channel *pcpu_relid2channel(u32 relid)
272{
273 struct vmbus_channel *channel;
274 struct vmbus_channel *found_channel = NULL;
275 int cpu = smp_processor_id();
276 struct list_head *pcpu_head = &hv_context.percpu_list[cpu];
277
278 list_for_each_entry(channel, pcpu_head, percpu_list) {
279 if (channel->offermsg.child_relid == relid) {
280 found_channel = channel;
281 break;
282 }
283 }
284
285 return found_channel;
286}
287
288
289
290
291
292struct vmbus_channel *relid2channel(u32 relid)
293{
294 struct vmbus_channel *channel;
295 struct vmbus_channel *found_channel = NULL;
296 struct list_head *cur, *tmp;
297 struct vmbus_channel *cur_sc;
298
299 BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex));
300
301 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
302 if (channel->offermsg.child_relid == relid) {
303 found_channel = channel;
304 break;
305 } else if (!list_empty(&channel->sc_list)) {
306
307
308
309 list_for_each_safe(cur, tmp, &channel->sc_list) {
310 cur_sc = list_entry(cur, struct vmbus_channel,
311 sc_list);
312 if (cur_sc->offermsg.child_relid == relid) {
313 found_channel = cur_sc;
314 break;
315 }
316 }
317 }
318 }
319
320 return found_channel;
321}
322
323
324
325
326static void process_chn_event(u32 relid)
327{
328 struct vmbus_channel *channel;
329 void *arg;
330 bool read_state;
331 u32 bytes_to_read;
332
333
334
335
336
337 channel = pcpu_relid2channel(relid);
338
339 if (!channel)
340 return;
341
342
343
344
345
346
347
348
349
350
351 if (channel->onchannel_callback != NULL) {
352 arg = channel->channel_callback_context;
353 read_state = channel->batched_reading;
354
355
356
357
358
359
360
361
362
363
364
365
366 do {
367 if (read_state)
368 hv_begin_read(&channel->inbound);
369 channel->onchannel_callback(arg);
370 if (read_state)
371 bytes_to_read = hv_end_read(&channel->inbound);
372 else
373 bytes_to_read = 0;
374 } while (read_state && (bytes_to_read != 0));
375 }
376}
377
378
379
380
381void vmbus_on_event(unsigned long data)
382{
383 u32 dword;
384 u32 maxdword;
385 int bit;
386 u32 relid;
387 u32 *recv_int_page = NULL;
388 void *page_addr;
389 int cpu = smp_processor_id();
390 union hv_synic_event_flags *event;
391
392 if (vmbus_proto_version < VERSION_WIN8) {
393 maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
394 recv_int_page = vmbus_connection.recv_int_page;
395 } else {
396
397
398
399
400
401 maxdword = HV_EVENT_FLAGS_DWORD_COUNT;
402 page_addr = hv_context.synic_event_page[cpu];
403 event = (union hv_synic_event_flags *)page_addr +
404 VMBUS_MESSAGE_SINT;
405 recv_int_page = event->flags32;
406 }
407
408
409
410
411 if (!recv_int_page)
412 return;
413 for (dword = 0; dword < maxdword; dword++) {
414 if (!recv_int_page[dword])
415 continue;
416 for (bit = 0; bit < 32; bit++) {
417 if (sync_test_and_clear_bit(bit,
418 (unsigned long *)&recv_int_page[dword])) {
419 relid = (dword << 5) + bit;
420
421 if (relid == 0)
422
423
424
425
426 continue;
427
428 process_chn_event(relid);
429 }
430 }
431 }
432}
433
434
435
436
437int vmbus_post_msg(void *buffer, size_t buflen)
438{
439 union hv_connection_id conn_id;
440 int ret = 0;
441 int retries = 0;
442 u32 usec = 1;
443
444 conn_id.asu32 = 0;
445 conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
446
447
448
449
450
451
452 while (retries < 20) {
453 ret = hv_post_message(conn_id, 1, buffer, buflen);
454
455 switch (ret) {
456 case HV_STATUS_INVALID_CONNECTION_ID:
457
458
459
460
461 ret = -EAGAIN;
462 break;
463 case HV_STATUS_INSUFFICIENT_MEMORY:
464 case HV_STATUS_INSUFFICIENT_BUFFERS:
465 ret = -ENOMEM;
466 break;
467 case HV_STATUS_SUCCESS:
468 return ret;
469 default:
470 pr_err("hv_post_msg() failed; error code:%d\n", ret);
471 return -EINVAL;
472 }
473
474 retries++;
475 udelay(usec);
476 if (usec < 2048)
477 usec *= 2;
478 }
479 return ret;
480}
481
482
483
484
485void vmbus_set_event(struct vmbus_channel *channel)
486{
487 u32 child_relid = channel->offermsg.child_relid;
488
489 if (!channel->is_dedicated_interrupt) {
490
491 sync_set_bit(child_relid & 31,
492 (unsigned long *)vmbus_connection.send_int_page +
493 (child_relid >> 5));
494 }
495
496 hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL);
497}
498EXPORT_SYMBOL_GPL(vmbus_set_event);
499