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 | 41 | }; |
95096f2f | 42 | EXPORT_SYMBOL_GPL(vmbus_connection); |
3e7ee490 | 43 | |
37f7278b S |
44 | /* |
45 | * Negotiated protocol version with the host. | |
46 | */ | |
47 | __u32 vmbus_proto_version; | |
48 | EXPORT_SYMBOL_GPL(vmbus_proto_version); | |
49 | ||
610071c3 S |
50 | static __u32 vmbus_get_next_version(__u32 current_version) |
51 | { | |
52 | switch (current_version) { | |
53 | case (VERSION_WIN7): | |
54 | return VERSION_WS2008; | |
55 | ||
56 | case (VERSION_WIN8): | |
57 | return VERSION_WIN7; | |
58 | ||
03367ef5 S |
59 | case (VERSION_WIN8_1): |
60 | return VERSION_WIN8; | |
61 | ||
6c4e5f9c KM |
62 | case (VERSION_WIN10): |
63 | return VERSION_WIN8_1; | |
64 | ||
610071c3 S |
65 | case (VERSION_WS2008): |
66 | default: | |
67 | return VERSION_INVAL; | |
68 | } | |
69 | } | |
70 | ||
71 | static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, | |
72 | __u32 version) | |
73 | { | |
74 | int ret = 0; | |
75 | struct vmbus_channel_initiate_contact *msg; | |
76 | unsigned long flags; | |
610071c3 S |
77 | |
78 | init_completion(&msginfo->waitevent); | |
79 | ||
80 | msg = (struct vmbus_channel_initiate_contact *)msginfo->msg; | |
81 | ||
82 | msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; | |
83 | msg->vmbus_version_requested = version; | |
84 | msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); | |
8681db44 GKH |
85 | msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]); |
86 | msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]); | |
b282e4c0 S |
87 | /* |
88 | * We want all channel messages to be delivered on CPU 0. | |
89 | * This has been the behavior pre-win8. This is not | |
90 | * perf issue and having all channel messages delivered on CPU 0 | |
91 | * would be ok. | |
72686447 AN |
92 | * For post win8 hosts, we support receiving channel messagges on |
93 | * all the CPUs. This is needed for kexec to work correctly where | |
94 | * the CPU attempting to connect may not be CPU 0. | |
b282e4c0 | 95 | */ |
72686447 AN |
96 | if (version >= VERSION_WIN8_1) { |
97 | msg->target_vcpu = hv_context.vp_index[get_cpu()]; | |
98 | put_cpu(); | |
99 | } else { | |
100 | msg->target_vcpu = 0; | |
101 | } | |
610071c3 S |
102 | |
103 | /* | |
104 | * Add to list before we send the request since we may | |
105 | * receive the response before returning from this routine | |
106 | */ | |
107 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
108 | list_add_tail(&msginfo->msglistentry, | |
109 | &vmbus_connection.chn_msg_list); | |
110 | ||
111 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
112 | ||
113 | ret = vmbus_post_msg(msg, | |
114 | sizeof(struct vmbus_channel_initiate_contact)); | |
115 | if (ret != 0) { | |
116 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
117 | list_del(&msginfo->msglistentry); | |
118 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, | |
119 | flags); | |
120 | return ret; | |
121 | } | |
122 | ||
123 | /* Wait for the connection response */ | |
269f9794 | 124 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
125 | |
126 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
127 | list_del(&msginfo->msglistentry); | |
128 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
129 | ||
130 | /* Check if successful */ | |
131 | if (msginfo->response.version_response.version_supported) { | |
132 | vmbus_connection.conn_state = CONNECTED; | |
133 | } else { | |
610071c3 S |
134 | return -ECONNREFUSED; |
135 | } | |
136 | ||
137 | return ret; | |
138 | } | |
139 | ||
3e189519 | 140 | /* |
c6977677 | 141 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 142 | */ |
c6977677 | 143 | int vmbus_connect(void) |
3e7ee490 | 144 | { |
fd8b85ea | 145 | int ret = 0; |
15b2f647 | 146 | struct vmbus_channel_msginfo *msginfo = NULL; |
610071c3 | 147 | __u32 version; |
3e7ee490 | 148 | |
454f18a9 | 149 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
150 | vmbus_connection.conn_state = CONNECTING; |
151 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
152 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 153 | ret = -ENOMEM; |
b0043863 | 154 | goto cleanup; |
de65a384 | 155 | } |
3e7ee490 | 156 | |
da9fcb72 | 157 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 158 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 159 | |
da9fcb72 | 160 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
d6f591e3 | 161 | mutex_init(&vmbus_connection.channel_mutex); |
3e7ee490 | 162 | |
454f18a9 BP |
163 | /* |
164 | * Setup the vmbus event connection for channel interrupt | |
165 | * abstraction stuff | |
166 | */ | |
df3493e0 S |
167 | vmbus_connection.int_page = |
168 | (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); | |
da9fcb72 | 169 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 170 | ret = -ENOMEM; |
b0043863 | 171 | goto cleanup; |
3e7ee490 HJ |
172 | } |
173 | ||
da9fcb72 HZ |
174 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
175 | vmbus_connection.send_int_page = | |
176 | (void *)((unsigned long)vmbus_connection.int_page + | |
fd8b85ea | 177 | (PAGE_SIZE >> 1)); |
3e7ee490 | 178 | |
fd8b85ea GKH |
179 | /* |
180 | * Setup the monitor notification facility. The 1st page for | |
181 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 182 | */ |
8681db44 GKH |
183 | vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); |
184 | vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); | |
185 | if ((vmbus_connection.monitor_pages[0] == NULL) || | |
186 | (vmbus_connection.monitor_pages[1] == NULL)) { | |
3a7546d9 | 187 | ret = -ENOMEM; |
b0043863 | 188 | goto cleanup; |
3e7ee490 HJ |
189 | } |
190 | ||
15b2f647 | 191 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
192 | sizeof(struct vmbus_channel_initiate_contact), |
193 | GFP_KERNEL); | |
15b2f647 | 194 | if (msginfo == NULL) { |
8cad0af9 | 195 | ret = -ENOMEM; |
b0043863 | 196 | goto cleanup; |
3e7ee490 HJ |
197 | } |
198 | ||
454f18a9 | 199 | /* |
610071c3 S |
200 | * Negotiate a compatible VMBUS version number with the |
201 | * host. We start with the highest number we can support | |
202 | * and work our way down until we negotiate a compatible | |
203 | * version. | |
454f18a9 | 204 | */ |
3e7ee490 | 205 | |
2a5c43a8 | 206 | version = VERSION_CURRENT; |
3e7ee490 | 207 | |
610071c3 S |
208 | do { |
209 | ret = vmbus_negotiate_version(msginfo, version); | |
8bbf9f44 | 210 | if (ret == -ETIMEDOUT) |
666b9adc S |
211 | goto cleanup; |
212 | ||
213 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 214 | break; |
3e7ee490 | 215 | |
610071c3 S |
216 | version = vmbus_get_next_version(version); |
217 | } while (version != VERSION_INVAL); | |
3e7ee490 | 218 | |
610071c3 | 219 | if (version == VERSION_INVAL) |
b0043863 | 220 | goto cleanup; |
3e7ee490 | 221 | |
37f7278b | 222 | vmbus_proto_version = version; |
3bacaf0c S |
223 | pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n", |
224 | host_info_eax, host_info_ebx >> 16, | |
225 | host_info_ebx & 0xFFFF, host_info_ecx, | |
226 | host_info_edx >> 24, host_info_edx & 0xFFFFFF, | |
227 | version >> 16, version & 0xFFFF); | |
228 | ||
15b2f647 | 229 | kfree(msginfo); |
3e7ee490 HJ |
230 | return 0; |
231 | ||
b0043863 | 232 | cleanup: |
3bacaf0c | 233 | pr_err("Unable to connect to host\n"); |
09a19628 | 234 | |
da9fcb72 | 235 | vmbus_connection.conn_state = DISCONNECTED; |
09a19628 VK |
236 | vmbus_disconnect(); |
237 | ||
238 | kfree(msginfo); | |
239 | ||
240 | return ret; | |
241 | } | |
3e7ee490 | 242 | |
09a19628 VK |
243 | void vmbus_disconnect(void) |
244 | { | |
2db84eff S |
245 | /* |
246 | * First send the unload request to the host. | |
247 | */ | |
75ff3a8a | 248 | vmbus_initiate_unload(false); |
2db84eff | 249 | |
09a19628 VK |
250 | if (vmbus_connection.work_queue) { |
251 | drain_workqueue(vmbus_connection.work_queue); | |
da9fcb72 | 252 | destroy_workqueue(vmbus_connection.work_queue); |
09a19628 | 253 | } |
3e7ee490 | 254 | |
da9fcb72 | 255 | if (vmbus_connection.int_page) { |
df3493e0 | 256 | free_pages((unsigned long)vmbus_connection.int_page, 0); |
da9fcb72 | 257 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
258 | } |
259 | ||
a100d88d RK |
260 | free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0); |
261 | free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); | |
8681db44 GKH |
262 | vmbus_connection.monitor_pages[0] = NULL; |
263 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 HJ |
264 | } |
265 | ||
3a28fa35 S |
266 | /* |
267 | * Map the given relid to the corresponding channel based on the | |
268 | * per-cpu list of channels that have been affinitized to this CPU. | |
269 | * This will be used in the channel callback path as we can do this | |
270 | * mapping in a lock-free fashion. | |
271 | */ | |
272 | static struct vmbus_channel *pcpu_relid2channel(u32 relid) | |
273 | { | |
274 | struct vmbus_channel *channel; | |
275 | struct vmbus_channel *found_channel = NULL; | |
276 | int cpu = smp_processor_id(); | |
277 | struct list_head *pcpu_head = &hv_context.percpu_list[cpu]; | |
278 | ||
279 | list_for_each_entry(channel, pcpu_head, percpu_list) { | |
280 | if (channel->offermsg.child_relid == relid) { | |
281 | found_channel = channel; | |
282 | break; | |
283 | } | |
284 | } | |
285 | ||
286 | return found_channel; | |
287 | } | |
3e7ee490 | 288 | |
3e189519 | 289 | /* |
c6977677 HZ |
290 | * relid2channel - Get the channel object given its |
291 | * child relative id (ie channel id) | |
fd8b85ea | 292 | */ |
d43e2fe7 | 293 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 294 | { |
aded7165 | 295 | struct vmbus_channel *channel; |
15b2f647 | 296 | struct vmbus_channel *found_channel = NULL; |
e68d2971 S |
297 | struct list_head *cur, *tmp; |
298 | struct vmbus_channel *cur_sc; | |
3e7ee490 | 299 | |
85d9aa70 DC |
300 | BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); |
301 | ||
da9fcb72 | 302 | list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |
15b2f647 HZ |
303 | if (channel->offermsg.child_relid == relid) { |
304 | found_channel = channel; | |
3e7ee490 | 305 | break; |
e68d2971 S |
306 | } else if (!list_empty(&channel->sc_list)) { |
307 | /* | |
308 | * Deal with sub-channels. | |
309 | */ | |
310 | list_for_each_safe(cur, tmp, &channel->sc_list) { | |
311 | cur_sc = list_entry(cur, struct vmbus_channel, | |
312 | sc_list); | |
313 | if (cur_sc->offermsg.child_relid == relid) { | |
314 | found_channel = cur_sc; | |
315 | break; | |
316 | } | |
317 | } | |
3e7ee490 HJ |
318 | } |
319 | } | |
3e7ee490 | 320 | |
15b2f647 | 321 | return found_channel; |
3e7ee490 HJ |
322 | } |
323 | ||
3e189519 | 324 | /* |
c6977677 | 325 | * process_chn_event - Process a channel event notification |
fd8b85ea | 326 | */ |
35436487 | 327 | static void process_chn_event(u32 relid) |
3e7ee490 | 328 | { |
aded7165 | 329 | struct vmbus_channel *channel; |
f878f3d5 S |
330 | void *arg; |
331 | bool read_state; | |
332 | u32 bytes_to_read; | |
3e7ee490 | 333 | |
454f18a9 BP |
334 | /* |
335 | * Find the channel based on this relid and invokes the | |
336 | * channel callback to process the event | |
337 | */ | |
3a28fa35 | 338 | channel = pcpu_relid2channel(relid); |
3e7ee490 | 339 | |
37f492ce | 340 | if (!channel) |
24326039 | 341 | return; |
24326039 S |
342 | |
343 | /* | |
344 | * A channel once created is persistent even when there | |
345 | * is no driver handling the device. An unloading driver | |
d3ba720d S |
346 | * sets the onchannel_callback to NULL on the same CPU |
347 | * as where this interrupt is handled (in an interrupt context). | |
348 | * Thus, checking and invoking the driver specific callback takes | |
349 | * care of orderly unloading of the driver. | |
24326039 S |
350 | */ |
351 | ||
f878f3d5 S |
352 | if (channel->onchannel_callback != NULL) { |
353 | arg = channel->channel_callback_context; | |
354 | read_state = channel->batched_reading; | |
355 | /* | |
356 | * This callback reads the messages sent by the host. | |
357 | * We can optimize host to guest signaling by ensuring: | |
358 | * 1. While reading the channel, we disable interrupts from | |
359 | * host. | |
360 | * 2. Ensure that we process all posted messages from the host | |
361 | * before returning from this callback. | |
362 | * 3. Once we return, enable signaling from the host. Once this | |
363 | * state is set we check to see if additional packets are | |
364 | * available to read. In this case we repeat the process. | |
365 | */ | |
366 | ||
367 | do { | |
affb1aff S |
368 | if (read_state) |
369 | hv_begin_read(&channel->inbound); | |
f878f3d5 | 370 | channel->onchannel_callback(arg); |
affb1aff S |
371 | if (read_state) |
372 | bytes_to_read = hv_end_read(&channel->inbound); | |
373 | else | |
374 | bytes_to_read = 0; | |
f878f3d5 | 375 | } while (read_state && (bytes_to_read != 0)); |
f878f3d5 | 376 | } |
3e7ee490 HJ |
377 | } |
378 | ||
3e189519 | 379 | /* |
c6977677 | 380 | * vmbus_on_event - Handler for events |
fd8b85ea | 381 | */ |
6de3d6aa | 382 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 383 | { |
35436487 | 384 | u32 dword; |
6552ecd7 | 385 | u32 maxdword; |
3e7ee490 | 386 | int bit; |
35436487 | 387 | u32 relid; |
6552ecd7 S |
388 | u32 *recv_int_page = NULL; |
389 | void *page_addr; | |
390 | int cpu = smp_processor_id(); | |
391 | union hv_synic_event_flags *event; | |
392 | ||
6c4e5f9c | 393 | if (vmbus_proto_version < VERSION_WIN8) { |
6552ecd7 S |
394 | maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5; |
395 | recv_int_page = vmbus_connection.recv_int_page; | |
396 | } else { | |
397 | /* | |
398 | * When the host is win8 and beyond, the event page | |
399 | * can be directly checked to get the id of the channel | |
400 | * that has the interrupt pending. | |
401 | */ | |
402 | maxdword = HV_EVENT_FLAGS_DWORD_COUNT; | |
403 | page_addr = hv_context.synic_event_page[cpu]; | |
404 | event = (union hv_synic_event_flags *)page_addr + | |
405 | VMBUS_MESSAGE_SINT; | |
406 | recv_int_page = event->flags32; | |
407 | } | |
408 | ||
409 | ||
3e7ee490 | 410 | |
454f18a9 | 411 | /* Check events */ |
242b45aa OH |
412 | if (!recv_int_page) |
413 | return; | |
414 | for (dword = 0; dword < maxdword; dword++) { | |
415 | if (!recv_int_page[dword]) | |
416 | continue; | |
417 | for (bit = 0; bit < 32; bit++) { | |
d9add43b S |
418 | if (sync_test_and_clear_bit(bit, |
419 | (unsigned long *)&recv_int_page[dword])) { | |
242b45aa OH |
420 | relid = (dword << 5) + bit; |
421 | ||
d9add43b | 422 | if (relid == 0) |
6d81d330 S |
423 | /* |
424 | * Special case - vmbus | |
425 | * channel protocol msg | |
426 | */ | |
242b45aa | 427 | continue; |
d9add43b | 428 | |
35436487 | 429 | process_chn_event(relid); |
3e7ee490 | 430 | } |
242b45aa | 431 | } |
3e7ee490 | 432 | } |
3e7ee490 HJ |
433 | } |
434 | ||
3e189519 | 435 | /* |
c6977677 | 436 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 437 | */ |
c6977677 | 438 | int vmbus_post_msg(void *buffer, size_t buflen) |
3e7ee490 | 439 | { |
15b2f647 | 440 | union hv_connection_id conn_id; |
5289d3d1 S |
441 | int ret = 0; |
442 | int retries = 0; | |
8de0d7e9 | 443 | u32 usec = 1; |
3e7ee490 | 444 | |
15b2f647 HZ |
445 | conn_id.asu32 = 0; |
446 | conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID; | |
5289d3d1 S |
447 | |
448 | /* | |
449 | * hv_post_message() can have transient failures because of | |
450 | * insufficient resources. Retry the operation a couple of | |
451 | * times before giving up. | |
452 | */ | |
e1c0d82d | 453 | while (retries < 20) { |
fdeebcc6 S |
454 | ret = hv_post_message(conn_id, 1, buffer, buflen); |
455 | ||
456 | switch (ret) { | |
89f9f679 DC |
457 | case HV_STATUS_INVALID_CONNECTION_ID: |
458 | /* | |
459 | * We could get this if we send messages too | |
460 | * frequently. | |
461 | */ | |
462 | ret = -EAGAIN; | |
463 | break; | |
464 | case HV_STATUS_INSUFFICIENT_MEMORY: | |
fdeebcc6 S |
465 | case HV_STATUS_INSUFFICIENT_BUFFERS: |
466 | ret = -ENOMEM; | |
fdeebcc6 S |
467 | break; |
468 | case HV_STATUS_SUCCESS: | |
5289d3d1 | 469 | return ret; |
fdeebcc6 S |
470 | default: |
471 | pr_err("hv_post_msg() failed; error code:%d\n", ret); | |
472 | return -EINVAL; | |
473 | } | |
474 | ||
5289d3d1 | 475 | retries++; |
8de0d7e9 S |
476 | udelay(usec); |
477 | if (usec < 2048) | |
478 | usec *= 2; | |
5289d3d1 S |
479 | } |
480 | return ret; | |
3e7ee490 HJ |
481 | } |
482 | ||
3e189519 | 483 | /* |
c6977677 | 484 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 485 | */ |
1b807e10 | 486 | void vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 487 | { |
21c3bef5 | 488 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 489 | |
3be77774 S |
490 | if (!channel->is_dedicated_interrupt) { |
491 | /* Each u32 represents 32 channels */ | |
492 | sync_set_bit(child_relid & 31, | |
493 | (unsigned long *)vmbus_connection.send_int_page + | |
494 | (child_relid >> 5)); | |
495 | } | |
496 | ||
1b807e10 | 497 | hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL); |
3e7ee490 | 498 | } |
5cc47247 | 499 | EXPORT_SYMBOL_GPL(vmbus_set_event); |