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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]); | |
565a8b69 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. | |
b01eac71 AN |
91 | * For post win8 hosts, we support receiving channel messagges on |
92 | * all the CPUs. This is needed for kexec to work correctly where | |
93 | * the CPU attempting to connect may not be CPU 0. | |
565a8b69 | 94 | */ |
b01eac71 AN |
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 | } | |
610071c3 S |
101 | |
102 | /* | |
103 | * Add to list before we send the request since we may | |
104 | * receive the response before returning from this routine | |
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 | /* Wait for the connection response */ | |
269f9794 | 123 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
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 | /* Check if successful */ | |
130 | if (msginfo->response.version_response.version_supported) { | |
131 | vmbus_connection.conn_state = CONNECTED; | |
132 | } else { | |
610071c3 S |
133 | return -ECONNREFUSED; |
134 | } | |
135 | ||
136 | return ret; | |
137 | } | |
138 | ||
3e189519 | 139 | /* |
c6977677 | 140 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 141 | */ |
c6977677 | 142 | int vmbus_connect(void) |
3e7ee490 | 143 | { |
fd8b85ea | 144 | int ret = 0; |
15b2f647 | 145 | struct vmbus_channel_msginfo *msginfo = NULL; |
610071c3 | 146 | __u32 version; |
3e7ee490 | 147 | |
454f18a9 | 148 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
149 | vmbus_connection.conn_state = CONNECTING; |
150 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
151 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 152 | ret = -ENOMEM; |
b0043863 | 153 | goto cleanup; |
de65a384 | 154 | } |
3e7ee490 | 155 | |
da9fcb72 | 156 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 157 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 158 | |
da9fcb72 | 159 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
6bb5209b | 160 | mutex_init(&vmbus_connection.channel_mutex); |
3e7ee490 | 161 | |
454f18a9 BP |
162 | /* |
163 | * Setup the vmbus event connection for channel interrupt | |
164 | * abstraction stuff | |
165 | */ | |
df3493e0 S |
166 | vmbus_connection.int_page = |
167 | (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); | |
da9fcb72 | 168 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 169 | ret = -ENOMEM; |
b0043863 | 170 | goto cleanup; |
3e7ee490 HJ |
171 | } |
172 | ||
da9fcb72 HZ |
173 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
174 | vmbus_connection.send_int_page = | |
175 | (void *)((unsigned long)vmbus_connection.int_page + | |
fd8b85ea | 176 | (PAGE_SIZE >> 1)); |
3e7ee490 | 177 | |
fd8b85ea GKH |
178 | /* |
179 | * Setup the monitor notification facility. The 1st page for | |
180 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 181 | */ |
8681db44 GKH |
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)) { | |
3a7546d9 | 186 | ret = -ENOMEM; |
b0043863 | 187 | goto cleanup; |
3e7ee490 HJ |
188 | } |
189 | ||
15b2f647 | 190 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
191 | sizeof(struct vmbus_channel_initiate_contact), |
192 | GFP_KERNEL); | |
15b2f647 | 193 | if (msginfo == NULL) { |
8cad0af9 | 194 | ret = -ENOMEM; |
b0043863 | 195 | goto cleanup; |
3e7ee490 HJ |
196 | } |
197 | ||
454f18a9 | 198 | /* |
610071c3 S |
199 | * Negotiate a compatible VMBUS version number with the |
200 | * host. We start with the highest number we can support | |
201 | * and work our way down until we negotiate a compatible | |
202 | * version. | |
454f18a9 | 203 | */ |
3e7ee490 | 204 | |
2a5c43a8 | 205 | version = VERSION_CURRENT; |
3e7ee490 | 206 | |
610071c3 S |
207 | do { |
208 | ret = vmbus_negotiate_version(msginfo, version); | |
8bbf9f44 | 209 | if (ret == -ETIMEDOUT) |
666b9adc S |
210 | goto cleanup; |
211 | ||
212 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 213 | break; |
3e7ee490 | 214 | |
610071c3 S |
215 | version = vmbus_get_next_version(version); |
216 | } while (version != VERSION_INVAL); | |
3e7ee490 | 217 | |
610071c3 | 218 | if (version == VERSION_INVAL) |
b0043863 | 219 | goto cleanup; |
3e7ee490 | 220 | |
37f7278b | 221 | vmbus_proto_version = version; |
3bacaf0c S |
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 | ||
15b2f647 | 228 | kfree(msginfo); |
3e7ee490 HJ |
229 | return 0; |
230 | ||
b0043863 | 231 | cleanup: |
3bacaf0c | 232 | pr_err("Unable to connect to host\n"); |
09a19628 | 233 | |
da9fcb72 | 234 | vmbus_connection.conn_state = DISCONNECTED; |
09a19628 VK |
235 | vmbus_disconnect(); |
236 | ||
237 | kfree(msginfo); | |
238 | ||
239 | return ret; | |
240 | } | |
3e7ee490 | 241 | |
09a19628 VK |
242 | void vmbus_disconnect(void) |
243 | { | |
2db84eff S |
244 | /* |
245 | * First send the unload request to the host. | |
246 | */ | |
0e9f0780 | 247 | vmbus_initiate_unload(false); |
2db84eff | 248 | |
09a19628 VK |
249 | if (vmbus_connection.work_queue) { |
250 | drain_workqueue(vmbus_connection.work_queue); | |
da9fcb72 | 251 | destroy_workqueue(vmbus_connection.work_queue); |
09a19628 | 252 | } |
3e7ee490 | 253 | |
da9fcb72 | 254 | if (vmbus_connection.int_page) { |
df3493e0 | 255 | free_pages((unsigned long)vmbus_connection.int_page, 0); |
da9fcb72 | 256 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
257 | } |
258 | ||
a100d88d RK |
259 | free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0); |
260 | free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); | |
8681db44 GKH |
261 | vmbus_connection.monitor_pages[0] = NULL; |
262 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 HJ |
263 | } |
264 | ||
3a28fa35 S |
265 | /* |
266 | * Map the given relid to the corresponding channel based on the | |
267 | * per-cpu list of channels that have been affinitized to this CPU. | |
268 | * This will be used in the channel callback path as we can do this | |
269 | * mapping in a lock-free fashion. | |
270 | */ | |
271 | static 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 | } | |
3e7ee490 | 287 | |
3e189519 | 288 | /* |
c6977677 HZ |
289 | * relid2channel - Get the channel object given its |
290 | * child relative id (ie channel id) | |
fd8b85ea | 291 | */ |
d43e2fe7 | 292 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 293 | { |
aded7165 | 294 | struct vmbus_channel *channel; |
15b2f647 | 295 | struct vmbus_channel *found_channel = NULL; |
e68d2971 S |
296 | struct list_head *cur, *tmp; |
297 | struct vmbus_channel *cur_sc; | |
3e7ee490 | 298 | |
3173614d DC |
299 | BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); |
300 | ||
da9fcb72 | 301 | list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |
15b2f647 HZ |
302 | if (channel->offermsg.child_relid == relid) { |
303 | found_channel = channel; | |
3e7ee490 | 304 | break; |
e68d2971 S |
305 | } else if (!list_empty(&channel->sc_list)) { |
306 | /* | |
307 | * Deal with sub-channels. | |
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 | } | |
3e7ee490 HJ |
317 | } |
318 | } | |
3e7ee490 | 319 | |
15b2f647 | 320 | return found_channel; |
3e7ee490 HJ |
321 | } |
322 | ||
3e189519 | 323 | /* |
c6977677 | 324 | * process_chn_event - Process a channel event notification |
fd8b85ea | 325 | */ |
35436487 | 326 | static void process_chn_event(u32 relid) |
3e7ee490 | 327 | { |
aded7165 | 328 | struct vmbus_channel *channel; |
f878f3d5 S |
329 | void *arg; |
330 | bool read_state; | |
331 | u32 bytes_to_read; | |
3e7ee490 | 332 | |
454f18a9 BP |
333 | /* |
334 | * Find the channel based on this relid and invokes the | |
335 | * channel callback to process the event | |
336 | */ | |
3a28fa35 | 337 | channel = pcpu_relid2channel(relid); |
3e7ee490 | 338 | |
37f492ce | 339 | if (!channel) |
24326039 | 340 | return; |
24326039 S |
341 | |
342 | /* | |
343 | * A channel once created is persistent even when there | |
344 | * is no driver handling the device. An unloading driver | |
d3ba720d S |
345 | * sets the onchannel_callback to NULL on the same CPU |
346 | * as where this interrupt is handled (in an interrupt context). | |
347 | * Thus, checking and invoking the driver specific callback takes | |
348 | * care of orderly unloading of the driver. | |
24326039 S |
349 | */ |
350 | ||
f878f3d5 S |
351 | if (channel->onchannel_callback != NULL) { |
352 | arg = channel->channel_callback_context; | |
353 | read_state = channel->batched_reading; | |
354 | /* | |
355 | * This callback reads the messages sent by the host. | |
356 | * We can optimize host to guest signaling by ensuring: | |
357 | * 1. While reading the channel, we disable interrupts from | |
358 | * host. | |
359 | * 2. Ensure that we process all posted messages from the host | |
360 | * before returning from this callback. | |
361 | * 3. Once we return, enable signaling from the host. Once this | |
362 | * state is set we check to see if additional packets are | |
363 | * available to read. In this case we repeat the process. | |
364 | */ | |
365 | ||
366 | do { | |
affb1aff S |
367 | if (read_state) |
368 | hv_begin_read(&channel->inbound); | |
f878f3d5 | 369 | channel->onchannel_callback(arg); |
affb1aff S |
370 | if (read_state) |
371 | bytes_to_read = hv_end_read(&channel->inbound); | |
372 | else | |
373 | bytes_to_read = 0; | |
f878f3d5 | 374 | } while (read_state && (bytes_to_read != 0)); |
f878f3d5 | 375 | } |
3e7ee490 HJ |
376 | } |
377 | ||
3e189519 | 378 | /* |
c6977677 | 379 | * vmbus_on_event - Handler for events |
fd8b85ea | 380 | */ |
6de3d6aa | 381 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 382 | { |
35436487 | 383 | u32 dword; |
6552ecd7 | 384 | u32 maxdword; |
3e7ee490 | 385 | int bit; |
35436487 | 386 | u32 relid; |
6552ecd7 S |
387 | u32 *recv_int_page = NULL; |
388 | void *page_addr; | |
389 | int cpu = smp_processor_id(); | |
390 | union hv_synic_event_flags *event; | |
391 | ||
6c4e5f9c | 392 | if (vmbus_proto_version < VERSION_WIN8) { |
6552ecd7 S |
393 | maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5; |
394 | recv_int_page = vmbus_connection.recv_int_page; | |
395 | } else { | |
396 | /* | |
397 | * When the host is win8 and beyond, the event page | |
398 | * can be directly checked to get the id of the channel | |
399 | * that has the interrupt pending. | |
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 | ||
3e7ee490 | 409 | |
454f18a9 | 410 | /* Check events */ |
242b45aa OH |
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++) { | |
d9add43b S |
417 | if (sync_test_and_clear_bit(bit, |
418 | (unsigned long *)&recv_int_page[dword])) { | |
242b45aa OH |
419 | relid = (dword << 5) + bit; |
420 | ||
d9add43b | 421 | if (relid == 0) |
6d81d330 S |
422 | /* |
423 | * Special case - vmbus | |
424 | * channel protocol msg | |
425 | */ | |
242b45aa | 426 | continue; |
d9add43b | 427 | |
35436487 | 428 | process_chn_event(relid); |
3e7ee490 | 429 | } |
242b45aa | 430 | } |
3e7ee490 | 431 | } |
3e7ee490 HJ |
432 | } |
433 | ||
3e189519 | 434 | /* |
c6977677 | 435 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 436 | */ |
c6977677 | 437 | int vmbus_post_msg(void *buffer, size_t buflen) |
3e7ee490 | 438 | { |
15b2f647 | 439 | union hv_connection_id conn_id; |
5289d3d1 S |
440 | int ret = 0; |
441 | int retries = 0; | |
e1c0d82d | 442 | u32 msec = 1; |
3e7ee490 | 443 | |
15b2f647 HZ |
444 | conn_id.asu32 = 0; |
445 | conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID; | |
5289d3d1 S |
446 | |
447 | /* | |
448 | * hv_post_message() can have transient failures because of | |
449 | * insufficient resources. Retry the operation a couple of | |
450 | * times before giving up. | |
451 | */ | |
e1c0d82d | 452 | while (retries < 20) { |
fdeebcc6 S |
453 | ret = hv_post_message(conn_id, 1, buffer, buflen); |
454 | ||
455 | switch (ret) { | |
89f9f679 DC |
456 | case HV_STATUS_INVALID_CONNECTION_ID: |
457 | /* | |
458 | * We could get this if we send messages too | |
459 | * frequently. | |
460 | */ | |
461 | ret = -EAGAIN; | |
462 | break; | |
463 | case HV_STATUS_INSUFFICIENT_MEMORY: | |
fdeebcc6 S |
464 | case HV_STATUS_INSUFFICIENT_BUFFERS: |
465 | ret = -ENOMEM; | |
fdeebcc6 S |
466 | break; |
467 | case HV_STATUS_SUCCESS: | |
5289d3d1 | 468 | return ret; |
fdeebcc6 S |
469 | default: |
470 | pr_err("hv_post_msg() failed; error code:%d\n", ret); | |
471 | return -EINVAL; | |
472 | } | |
473 | ||
5289d3d1 | 474 | retries++; |
e1c0d82d HZ |
475 | msleep(msec); |
476 | if (msec < 2048) | |
477 | msec *= 2; | |
5289d3d1 S |
478 | } |
479 | return ret; | |
3e7ee490 HJ |
480 | } |
481 | ||
3e189519 | 482 | /* |
c6977677 | 483 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 484 | */ |
aa7d50af | 485 | int vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 486 | { |
21c3bef5 | 487 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 488 | |
3be77774 S |
489 | if (!channel->is_dedicated_interrupt) { |
490 | /* Each u32 represents 32 channels */ | |
491 | sync_set_bit(child_relid & 31, | |
492 | (unsigned long *)vmbus_connection.send_int_page + | |
493 | (child_relid >> 5)); | |
494 | } | |
495 | ||
aa7d50af | 496 | return hv_signal_event(channel->sig_event); |
3e7ee490 | 497 | } |