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Commit | Line | Data |
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3e7ee490 HJ |
1 | /* |
2 | * | |
3 | * Copyright (c) 2009, Microsoft Corporation. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms and conditions of the GNU General Public License, | |
7 | * version 2, as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope it will be useful, but WITHOUT | |
10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along with | |
15 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple | |
16 | * Place - Suite 330, Boston, MA 02111-1307 USA. | |
17 | * | |
18 | * Authors: | |
19 | * Haiyang Zhang <haiyangz@microsoft.com> | |
20 | * Hank Janssen <hjanssen@microsoft.com> | |
21 | * | |
22 | */ | |
0a46618d HJ |
23 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
24 | ||
a0086dc5 | 25 | #include <linux/kernel.h> |
0c3b7b2f S |
26 | #include <linux/sched.h> |
27 | #include <linux/wait.h> | |
5289d3d1 | 28 | #include <linux/delay.h> |
a0086dc5 | 29 | #include <linux/mm.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
a0086dc5 | 31 | #include <linux/vmalloc.h> |
46a97191 | 32 | #include <linux/hyperv.h> |
37f7278b | 33 | #include <linux/export.h> |
407dd164 | 34 | #include <asm/hyperv.h> |
0f2a6619 | 35 | #include "hyperv_vmbus.h" |
3e7ee490 | 36 | |
3e7ee490 | 37 | |
da9fcb72 HZ |
38 | struct vmbus_connection vmbus_connection = { |
39 | .conn_state = DISCONNECTED, | |
40 | .next_gpadl_handle = ATOMIC_INIT(0xE1E10), | |
3e7ee490 HJ |
41 | }; |
42 | ||
37f7278b S |
43 | /* |
44 | * Negotiated protocol version with the host. | |
45 | */ | |
46 | __u32 vmbus_proto_version; | |
47 | EXPORT_SYMBOL_GPL(vmbus_proto_version); | |
48 | ||
610071c3 S |
49 | static __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 | ||
03367ef5 S |
58 | case (VERSION_WIN8_1): |
59 | return VERSION_WIN8; | |
60 | ||
6c4e5f9c KM |
61 | case (VERSION_WIN10): |
62 | return VERSION_WIN8_1; | |
63 | ||
610071c3 S |
64 | case (VERSION_WS2008): |
65 | default: | |
66 | return VERSION_INVAL; | |
67 | } | |
68 | } | |
69 | ||
70 | static 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; | |
610071c3 S |
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); | |
8681db44 GKH |
84 | msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]); |
85 | msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]); | |
b282e4c0 S |
86 | /* |
87 | * We want all channel messages to be delivered on CPU 0. | |
88 | * This has been the behavior pre-win8. This is not | |
89 | * perf issue and having all channel messages delivered on CPU 0 | |
90 | * would be ok. | |
91 | */ | |
92 | msg->target_vcpu = 0; | |
610071c3 S |
93 | |
94 | /* | |
95 | * Add to list before we send the request since we may | |
96 | * receive the response before returning from this routine | |
97 | */ | |
98 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
99 | list_add_tail(&msginfo->msglistentry, | |
100 | &vmbus_connection.chn_msg_list); | |
101 | ||
102 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
103 | ||
104 | ret = vmbus_post_msg(msg, | |
105 | sizeof(struct vmbus_channel_initiate_contact)); | |
106 | if (ret != 0) { | |
107 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
108 | list_del(&msginfo->msglistentry); | |
109 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, | |
110 | flags); | |
111 | return ret; | |
112 | } | |
113 | ||
114 | /* Wait for the connection response */ | |
269f9794 | 115 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
116 | |
117 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
118 | list_del(&msginfo->msglistentry); | |
119 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
120 | ||
121 | /* Check if successful */ | |
122 | if (msginfo->response.version_response.version_supported) { | |
123 | vmbus_connection.conn_state = CONNECTED; | |
124 | } else { | |
610071c3 S |
125 | return -ECONNREFUSED; |
126 | } | |
127 | ||
128 | return ret; | |
129 | } | |
130 | ||
3e189519 | 131 | /* |
c6977677 | 132 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 133 | */ |
c6977677 | 134 | int vmbus_connect(void) |
3e7ee490 | 135 | { |
fd8b85ea | 136 | int ret = 0; |
15b2f647 | 137 | struct vmbus_channel_msginfo *msginfo = NULL; |
610071c3 | 138 | __u32 version; |
3e7ee490 | 139 | |
454f18a9 | 140 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
141 | vmbus_connection.conn_state = CONNECTING; |
142 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
143 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 144 | ret = -ENOMEM; |
b0043863 | 145 | goto cleanup; |
de65a384 | 146 | } |
3e7ee490 | 147 | |
da9fcb72 | 148 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 149 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 150 | |
da9fcb72 | 151 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
d6f591e3 | 152 | mutex_init(&vmbus_connection.channel_mutex); |
3e7ee490 | 153 | |
454f18a9 BP |
154 | /* |
155 | * Setup the vmbus event connection for channel interrupt | |
156 | * abstraction stuff | |
157 | */ | |
df3493e0 S |
158 | vmbus_connection.int_page = |
159 | (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); | |
da9fcb72 | 160 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 161 | ret = -ENOMEM; |
b0043863 | 162 | goto cleanup; |
3e7ee490 HJ |
163 | } |
164 | ||
da9fcb72 HZ |
165 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
166 | vmbus_connection.send_int_page = | |
167 | (void *)((unsigned long)vmbus_connection.int_page + | |
fd8b85ea | 168 | (PAGE_SIZE >> 1)); |
3e7ee490 | 169 | |
fd8b85ea GKH |
170 | /* |
171 | * Setup the monitor notification facility. The 1st page for | |
172 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 173 | */ |
8681db44 GKH |
174 | vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); |
175 | vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); | |
176 | if ((vmbus_connection.monitor_pages[0] == NULL) || | |
177 | (vmbus_connection.monitor_pages[1] == NULL)) { | |
3a7546d9 | 178 | ret = -ENOMEM; |
b0043863 | 179 | goto cleanup; |
3e7ee490 HJ |
180 | } |
181 | ||
15b2f647 | 182 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
183 | sizeof(struct vmbus_channel_initiate_contact), |
184 | GFP_KERNEL); | |
15b2f647 | 185 | if (msginfo == NULL) { |
8cad0af9 | 186 | ret = -ENOMEM; |
b0043863 | 187 | goto cleanup; |
3e7ee490 HJ |
188 | } |
189 | ||
454f18a9 | 190 | /* |
610071c3 S |
191 | * Negotiate a compatible VMBUS version number with the |
192 | * host. We start with the highest number we can support | |
193 | * and work our way down until we negotiate a compatible | |
194 | * version. | |
454f18a9 | 195 | */ |
3e7ee490 | 196 | |
2a5c43a8 | 197 | version = VERSION_CURRENT; |
3e7ee490 | 198 | |
610071c3 S |
199 | do { |
200 | ret = vmbus_negotiate_version(msginfo, version); | |
8bbf9f44 | 201 | if (ret == -ETIMEDOUT) |
666b9adc S |
202 | goto cleanup; |
203 | ||
204 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 205 | break; |
3e7ee490 | 206 | |
610071c3 S |
207 | version = vmbus_get_next_version(version); |
208 | } while (version != VERSION_INVAL); | |
3e7ee490 | 209 | |
610071c3 | 210 | if (version == VERSION_INVAL) |
b0043863 | 211 | goto cleanup; |
3e7ee490 | 212 | |
37f7278b | 213 | vmbus_proto_version = version; |
3bacaf0c S |
214 | pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n", |
215 | host_info_eax, host_info_ebx >> 16, | |
216 | host_info_ebx & 0xFFFF, host_info_ecx, | |
217 | host_info_edx >> 24, host_info_edx & 0xFFFFFF, | |
218 | version >> 16, version & 0xFFFF); | |
219 | ||
15b2f647 | 220 | kfree(msginfo); |
3e7ee490 HJ |
221 | return 0; |
222 | ||
b0043863 | 223 | cleanup: |
3bacaf0c | 224 | pr_err("Unable to connect to host\n"); |
09a19628 | 225 | |
da9fcb72 | 226 | vmbus_connection.conn_state = DISCONNECTED; |
09a19628 VK |
227 | vmbus_disconnect(); |
228 | ||
229 | kfree(msginfo); | |
230 | ||
231 | return ret; | |
232 | } | |
3e7ee490 | 233 | |
09a19628 VK |
234 | void vmbus_disconnect(void) |
235 | { | |
2db84eff S |
236 | /* |
237 | * First send the unload request to the host. | |
238 | */ | |
75ff3a8a | 239 | vmbus_initiate_unload(false); |
2db84eff | 240 | |
09a19628 VK |
241 | if (vmbus_connection.work_queue) { |
242 | drain_workqueue(vmbus_connection.work_queue); | |
da9fcb72 | 243 | destroy_workqueue(vmbus_connection.work_queue); |
09a19628 | 244 | } |
3e7ee490 | 245 | |
da9fcb72 | 246 | if (vmbus_connection.int_page) { |
df3493e0 | 247 | free_pages((unsigned long)vmbus_connection.int_page, 0); |
da9fcb72 | 248 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
249 | } |
250 | ||
a100d88d RK |
251 | free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0); |
252 | free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); | |
8681db44 GKH |
253 | vmbus_connection.monitor_pages[0] = NULL; |
254 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 HJ |
255 | } |
256 | ||
3a28fa35 S |
257 | /* |
258 | * Map the given relid to the corresponding channel based on the | |
259 | * per-cpu list of channels that have been affinitized to this CPU. | |
260 | * This will be used in the channel callback path as we can do this | |
261 | * mapping in a lock-free fashion. | |
262 | */ | |
263 | static struct vmbus_channel *pcpu_relid2channel(u32 relid) | |
264 | { | |
265 | struct vmbus_channel *channel; | |
266 | struct vmbus_channel *found_channel = NULL; | |
267 | int cpu = smp_processor_id(); | |
268 | struct list_head *pcpu_head = &hv_context.percpu_list[cpu]; | |
269 | ||
270 | list_for_each_entry(channel, pcpu_head, percpu_list) { | |
271 | if (channel->offermsg.child_relid == relid) { | |
272 | found_channel = channel; | |
273 | break; | |
274 | } | |
275 | } | |
276 | ||
277 | return found_channel; | |
278 | } | |
3e7ee490 | 279 | |
3e189519 | 280 | /* |
c6977677 HZ |
281 | * relid2channel - Get the channel object given its |
282 | * child relative id (ie channel id) | |
fd8b85ea | 283 | */ |
d43e2fe7 | 284 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 285 | { |
aded7165 | 286 | struct vmbus_channel *channel; |
15b2f647 | 287 | struct vmbus_channel *found_channel = NULL; |
e68d2971 S |
288 | struct list_head *cur, *tmp; |
289 | struct vmbus_channel *cur_sc; | |
3e7ee490 | 290 | |
85d9aa70 DC |
291 | BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); |
292 | ||
da9fcb72 | 293 | list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |
15b2f647 HZ |
294 | if (channel->offermsg.child_relid == relid) { |
295 | found_channel = channel; | |
3e7ee490 | 296 | break; |
e68d2971 S |
297 | } else if (!list_empty(&channel->sc_list)) { |
298 | /* | |
299 | * Deal with sub-channels. | |
300 | */ | |
301 | list_for_each_safe(cur, tmp, &channel->sc_list) { | |
302 | cur_sc = list_entry(cur, struct vmbus_channel, | |
303 | sc_list); | |
304 | if (cur_sc->offermsg.child_relid == relid) { | |
305 | found_channel = cur_sc; | |
306 | break; | |
307 | } | |
308 | } | |
3e7ee490 HJ |
309 | } |
310 | } | |
3e7ee490 | 311 | |
15b2f647 | 312 | return found_channel; |
3e7ee490 HJ |
313 | } |
314 | ||
3e189519 | 315 | /* |
c6977677 | 316 | * process_chn_event - Process a channel event notification |
fd8b85ea | 317 | */ |
35436487 | 318 | static void process_chn_event(u32 relid) |
3e7ee490 | 319 | { |
aded7165 | 320 | struct vmbus_channel *channel; |
f878f3d5 S |
321 | void *arg; |
322 | bool read_state; | |
323 | u32 bytes_to_read; | |
3e7ee490 | 324 | |
454f18a9 BP |
325 | /* |
326 | * Find the channel based on this relid and invokes the | |
327 | * channel callback to process the event | |
328 | */ | |
3a28fa35 | 329 | channel = pcpu_relid2channel(relid); |
3e7ee490 | 330 | |
37f492ce | 331 | if (!channel) |
24326039 | 332 | return; |
24326039 S |
333 | |
334 | /* | |
335 | * A channel once created is persistent even when there | |
336 | * is no driver handling the device. An unloading driver | |
d3ba720d S |
337 | * sets the onchannel_callback to NULL on the same CPU |
338 | * as where this interrupt is handled (in an interrupt context). | |
339 | * Thus, checking and invoking the driver specific callback takes | |
340 | * care of orderly unloading of the driver. | |
24326039 S |
341 | */ |
342 | ||
f878f3d5 S |
343 | if (channel->onchannel_callback != NULL) { |
344 | arg = channel->channel_callback_context; | |
345 | read_state = channel->batched_reading; | |
346 | /* | |
347 | * This callback reads the messages sent by the host. | |
348 | * We can optimize host to guest signaling by ensuring: | |
349 | * 1. While reading the channel, we disable interrupts from | |
350 | * host. | |
351 | * 2. Ensure that we process all posted messages from the host | |
352 | * before returning from this callback. | |
353 | * 3. Once we return, enable signaling from the host. Once this | |
354 | * state is set we check to see if additional packets are | |
355 | * available to read. In this case we repeat the process. | |
356 | */ | |
357 | ||
358 | do { | |
affb1aff S |
359 | if (read_state) |
360 | hv_begin_read(&channel->inbound); | |
f878f3d5 | 361 | channel->onchannel_callback(arg); |
affb1aff S |
362 | if (read_state) |
363 | bytes_to_read = hv_end_read(&channel->inbound); | |
364 | else | |
365 | bytes_to_read = 0; | |
f878f3d5 | 366 | } while (read_state && (bytes_to_read != 0)); |
f878f3d5 | 367 | } |
3e7ee490 HJ |
368 | } |
369 | ||
3e189519 | 370 | /* |
c6977677 | 371 | * vmbus_on_event - Handler for events |
fd8b85ea | 372 | */ |
6de3d6aa | 373 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 374 | { |
35436487 | 375 | u32 dword; |
6552ecd7 | 376 | u32 maxdword; |
3e7ee490 | 377 | int bit; |
35436487 | 378 | u32 relid; |
6552ecd7 S |
379 | u32 *recv_int_page = NULL; |
380 | void *page_addr; | |
381 | int cpu = smp_processor_id(); | |
382 | union hv_synic_event_flags *event; | |
383 | ||
6c4e5f9c | 384 | if (vmbus_proto_version < VERSION_WIN8) { |
6552ecd7 S |
385 | maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5; |
386 | recv_int_page = vmbus_connection.recv_int_page; | |
387 | } else { | |
388 | /* | |
389 | * When the host is win8 and beyond, the event page | |
390 | * can be directly checked to get the id of the channel | |
391 | * that has the interrupt pending. | |
392 | */ | |
393 | maxdword = HV_EVENT_FLAGS_DWORD_COUNT; | |
394 | page_addr = hv_context.synic_event_page[cpu]; | |
395 | event = (union hv_synic_event_flags *)page_addr + | |
396 | VMBUS_MESSAGE_SINT; | |
397 | recv_int_page = event->flags32; | |
398 | } | |
399 | ||
400 | ||
3e7ee490 | 401 | |
454f18a9 | 402 | /* Check events */ |
242b45aa OH |
403 | if (!recv_int_page) |
404 | return; | |
405 | for (dword = 0; dword < maxdword; dword++) { | |
406 | if (!recv_int_page[dword]) | |
407 | continue; | |
408 | for (bit = 0; bit < 32; bit++) { | |
d9add43b S |
409 | if (sync_test_and_clear_bit(bit, |
410 | (unsigned long *)&recv_int_page[dword])) { | |
242b45aa OH |
411 | relid = (dword << 5) + bit; |
412 | ||
d9add43b | 413 | if (relid == 0) |
6d81d330 S |
414 | /* |
415 | * Special case - vmbus | |
416 | * channel protocol msg | |
417 | */ | |
242b45aa | 418 | continue; |
d9add43b | 419 | |
35436487 | 420 | process_chn_event(relid); |
3e7ee490 | 421 | } |
242b45aa | 422 | } |
3e7ee490 | 423 | } |
3e7ee490 HJ |
424 | } |
425 | ||
3e189519 | 426 | /* |
c6977677 | 427 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 428 | */ |
c6977677 | 429 | int vmbus_post_msg(void *buffer, size_t buflen) |
3e7ee490 | 430 | { |
15b2f647 | 431 | union hv_connection_id conn_id; |
5289d3d1 S |
432 | int ret = 0; |
433 | int retries = 0; | |
e1c0d82d | 434 | u32 msec = 1; |
3e7ee490 | 435 | |
15b2f647 HZ |
436 | conn_id.asu32 = 0; |
437 | conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID; | |
5289d3d1 S |
438 | |
439 | /* | |
440 | * hv_post_message() can have transient failures because of | |
441 | * insufficient resources. Retry the operation a couple of | |
442 | * times before giving up. | |
443 | */ | |
e1c0d82d | 444 | while (retries < 20) { |
fdeebcc6 S |
445 | ret = hv_post_message(conn_id, 1, buffer, buflen); |
446 | ||
447 | switch (ret) { | |
89f9f679 DC |
448 | case HV_STATUS_INVALID_CONNECTION_ID: |
449 | /* | |
450 | * We could get this if we send messages too | |
451 | * frequently. | |
452 | */ | |
453 | ret = -EAGAIN; | |
454 | break; | |
455 | case HV_STATUS_INSUFFICIENT_MEMORY: | |
fdeebcc6 S |
456 | case HV_STATUS_INSUFFICIENT_BUFFERS: |
457 | ret = -ENOMEM; | |
fdeebcc6 S |
458 | break; |
459 | case HV_STATUS_SUCCESS: | |
5289d3d1 | 460 | return ret; |
fdeebcc6 S |
461 | default: |
462 | pr_err("hv_post_msg() failed; error code:%d\n", ret); | |
463 | return -EINVAL; | |
464 | } | |
465 | ||
5289d3d1 | 466 | retries++; |
e1c0d82d HZ |
467 | msleep(msec); |
468 | if (msec < 2048) | |
469 | msec *= 2; | |
5289d3d1 S |
470 | } |
471 | return ret; | |
3e7ee490 HJ |
472 | } |
473 | ||
3e189519 | 474 | /* |
c6977677 | 475 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 476 | */ |
1b807e10 | 477 | void vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 478 | { |
21c3bef5 | 479 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 480 | |
3be77774 S |
481 | if (!channel->is_dedicated_interrupt) { |
482 | /* Each u32 represents 32 channels */ | |
483 | sync_set_bit(child_relid & 31, | |
484 | (unsigned long *)vmbus_connection.send_int_page + | |
485 | (child_relid >> 5)); | |
486 | } | |
487 | ||
1b807e10 | 488 | hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL); |
3e7ee490 | 489 | } |