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> |
fc53662f VK |
34 | #include <asm/mshyperv.h> |
35 | ||
0f2a6619 | 36 | #include "hyperv_vmbus.h" |
3e7ee490 | 37 | |
3e7ee490 | 38 | |
da9fcb72 HZ |
39 | struct vmbus_connection vmbus_connection = { |
40 | .conn_state = DISCONNECTED, | |
41 | .next_gpadl_handle = ATOMIC_INIT(0xE1E10), | |
3e7ee490 | 42 | }; |
95096f2f | 43 | EXPORT_SYMBOL_GPL(vmbus_connection); |
3e7ee490 | 44 | |
37f7278b S |
45 | /* |
46 | * Negotiated protocol version with the host. | |
47 | */ | |
48 | __u32 vmbus_proto_version; | |
49 | EXPORT_SYMBOL_GPL(vmbus_proto_version); | |
50 | ||
610071c3 S |
51 | static __u32 vmbus_get_next_version(__u32 current_version) |
52 | { | |
53 | switch (current_version) { | |
54 | case (VERSION_WIN7): | |
55 | return VERSION_WS2008; | |
56 | ||
57 | case (VERSION_WIN8): | |
58 | return VERSION_WIN7; | |
59 | ||
03367ef5 S |
60 | case (VERSION_WIN8_1): |
61 | return VERSION_WIN8; | |
62 | ||
6c4e5f9c KM |
63 | case (VERSION_WIN10): |
64 | return VERSION_WIN8_1; | |
65 | ||
ae20b254 DC |
66 | case (VERSION_WIN10_V5): |
67 | return VERSION_WIN10; | |
68 | ||
610071c3 S |
69 | case (VERSION_WS2008): |
70 | default: | |
71 | return VERSION_INVAL; | |
72 | } | |
73 | } | |
74 | ||
75 | static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, | |
76 | __u32 version) | |
77 | { | |
78 | int ret = 0; | |
41e270f6 | 79 | unsigned int cur_cpu; |
610071c3 S |
80 | struct vmbus_channel_initiate_contact *msg; |
81 | unsigned long flags; | |
610071c3 S |
82 | |
83 | init_completion(&msginfo->waitevent); | |
84 | ||
85 | msg = (struct vmbus_channel_initiate_contact *)msginfo->msg; | |
86 | ||
ae20b254 | 87 | memset(msg, 0, sizeof(*msg)); |
610071c3 S |
88 | msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; |
89 | msg->vmbus_version_requested = version; | |
ae20b254 DC |
90 | |
91 | /* | |
92 | * VMBus protocol 5.0 (VERSION_WIN10_V5) requires that we must use | |
93 | * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message, | |
94 | * and for subsequent messages, we must use the Message Connection ID | |
95 | * field in the host-returned Version Response Message. And, with | |
96 | * VERSION_WIN10_V5, we don't use msg->interrupt_page, but we tell | |
97 | * the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for | |
98 | * compatibility. | |
99 | * | |
100 | * On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1). | |
101 | */ | |
102 | if (version >= VERSION_WIN10_V5) { | |
103 | msg->msg_sint = VMBUS_MESSAGE_SINT; | |
104 | vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID_4; | |
105 | } else { | |
106 | msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); | |
107 | vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID; | |
108 | } | |
109 | ||
8681db44 GKH |
110 | msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]); |
111 | msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]); | |
b282e4c0 S |
112 | /* |
113 | * We want all channel messages to be delivered on CPU 0. | |
114 | * This has been the behavior pre-win8. This is not | |
115 | * perf issue and having all channel messages delivered on CPU 0 | |
116 | * would be ok. | |
72686447 AN |
117 | * For post win8 hosts, we support receiving channel messagges on |
118 | * all the CPUs. This is needed for kexec to work correctly where | |
119 | * the CPU attempting to connect may not be CPU 0. | |
b282e4c0 | 120 | */ |
54a66265 | 121 | if (version >= VERSION_WIN8_1) { |
41e270f6 DC |
122 | cur_cpu = get_cpu(); |
123 | msg->target_vcpu = hv_cpu_number_to_vp_number(cur_cpu); | |
124 | vmbus_connection.connect_cpu = cur_cpu; | |
125 | put_cpu(); | |
54a66265 | 126 | } else { |
72686447 | 127 | msg->target_vcpu = 0; |
54a66265 S |
128 | vmbus_connection.connect_cpu = 0; |
129 | } | |
610071c3 S |
130 | |
131 | /* | |
132 | * Add to list before we send the request since we may | |
133 | * receive the response before returning from this routine | |
134 | */ | |
135 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
136 | list_add_tail(&msginfo->msglistentry, | |
137 | &vmbus_connection.chn_msg_list); | |
138 | ||
139 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
140 | ||
141 | ret = vmbus_post_msg(msg, | |
c0bb0392 VK |
142 | sizeof(struct vmbus_channel_initiate_contact), |
143 | true); | |
034ebf55 VK |
144 | |
145 | trace_vmbus_negotiate_version(msg, ret); | |
146 | ||
610071c3 S |
147 | if (ret != 0) { |
148 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
149 | list_del(&msginfo->msglistentry); | |
150 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, | |
151 | flags); | |
152 | return ret; | |
153 | } | |
154 | ||
155 | /* Wait for the connection response */ | |
269f9794 | 156 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
157 | |
158 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
159 | list_del(&msginfo->msglistentry); | |
160 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
161 | ||
162 | /* Check if successful */ | |
163 | if (msginfo->response.version_response.version_supported) { | |
164 | vmbus_connection.conn_state = CONNECTED; | |
ae20b254 DC |
165 | |
166 | if (version >= VERSION_WIN10_V5) | |
167 | vmbus_connection.msg_conn_id = | |
168 | msginfo->response.version_response.msg_conn_id; | |
610071c3 | 169 | } else { |
610071c3 S |
170 | return -ECONNREFUSED; |
171 | } | |
172 | ||
173 | return ret; | |
174 | } | |
175 | ||
3e189519 | 176 | /* |
c6977677 | 177 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 178 | */ |
c6977677 | 179 | int vmbus_connect(void) |
3e7ee490 | 180 | { |
fd8b85ea | 181 | int ret = 0; |
15b2f647 | 182 | struct vmbus_channel_msginfo *msginfo = NULL; |
610071c3 | 183 | __u32 version; |
3e7ee490 | 184 | |
454f18a9 | 185 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
186 | vmbus_connection.conn_state = CONNECTING; |
187 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
188 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 189 | ret = -ENOMEM; |
b0043863 | 190 | goto cleanup; |
de65a384 | 191 | } |
3e7ee490 | 192 | |
37c2578c DC |
193 | vmbus_connection.handle_primary_chan_wq = |
194 | create_workqueue("hv_pri_chan"); | |
195 | if (!vmbus_connection.handle_primary_chan_wq) { | |
196 | ret = -ENOMEM; | |
197 | goto cleanup; | |
198 | } | |
199 | ||
200 | vmbus_connection.handle_sub_chan_wq = | |
201 | create_workqueue("hv_sub_chan"); | |
202 | if (!vmbus_connection.handle_sub_chan_wq) { | |
203 | ret = -ENOMEM; | |
204 | goto cleanup; | |
205 | } | |
206 | ||
da9fcb72 | 207 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 208 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 209 | |
da9fcb72 | 210 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
d6f591e3 | 211 | mutex_init(&vmbus_connection.channel_mutex); |
3e7ee490 | 212 | |
454f18a9 BP |
213 | /* |
214 | * Setup the vmbus event connection for channel interrupt | |
215 | * abstraction stuff | |
216 | */ | |
df3493e0 S |
217 | vmbus_connection.int_page = |
218 | (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); | |
da9fcb72 | 219 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 220 | ret = -ENOMEM; |
b0043863 | 221 | goto cleanup; |
3e7ee490 HJ |
222 | } |
223 | ||
da9fcb72 HZ |
224 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
225 | vmbus_connection.send_int_page = | |
226 | (void *)((unsigned long)vmbus_connection.int_page + | |
fd8b85ea | 227 | (PAGE_SIZE >> 1)); |
3e7ee490 | 228 | |
fd8b85ea GKH |
229 | /* |
230 | * Setup the monitor notification facility. The 1st page for | |
231 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 232 | */ |
8681db44 GKH |
233 | vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); |
234 | vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); | |
235 | if ((vmbus_connection.monitor_pages[0] == NULL) || | |
236 | (vmbus_connection.monitor_pages[1] == NULL)) { | |
3a7546d9 | 237 | ret = -ENOMEM; |
b0043863 | 238 | goto cleanup; |
3e7ee490 HJ |
239 | } |
240 | ||
15b2f647 | 241 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
242 | sizeof(struct vmbus_channel_initiate_contact), |
243 | GFP_KERNEL); | |
15b2f647 | 244 | if (msginfo == NULL) { |
8cad0af9 | 245 | ret = -ENOMEM; |
b0043863 | 246 | goto cleanup; |
3e7ee490 HJ |
247 | } |
248 | ||
454f18a9 | 249 | /* |
610071c3 S |
250 | * Negotiate a compatible VMBUS version number with the |
251 | * host. We start with the highest number we can support | |
252 | * and work our way down until we negotiate a compatible | |
253 | * version. | |
454f18a9 | 254 | */ |
3e7ee490 | 255 | |
2a5c43a8 | 256 | version = VERSION_CURRENT; |
3e7ee490 | 257 | |
610071c3 S |
258 | do { |
259 | ret = vmbus_negotiate_version(msginfo, version); | |
8bbf9f44 | 260 | if (ret == -ETIMEDOUT) |
666b9adc S |
261 | goto cleanup; |
262 | ||
263 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 264 | break; |
3e7ee490 | 265 | |
610071c3 S |
266 | version = vmbus_get_next_version(version); |
267 | } while (version != VERSION_INVAL); | |
3e7ee490 | 268 | |
610071c3 | 269 | if (version == VERSION_INVAL) |
b0043863 | 270 | goto cleanup; |
3e7ee490 | 271 | |
37f7278b | 272 | vmbus_proto_version = version; |
8de8af7e S |
273 | pr_info("Vmbus version:%d.%d\n", |
274 | version >> 16, version & 0xFFFF); | |
3bacaf0c | 275 | |
15b2f647 | 276 | kfree(msginfo); |
3e7ee490 HJ |
277 | return 0; |
278 | ||
b0043863 | 279 | cleanup: |
3bacaf0c | 280 | pr_err("Unable to connect to host\n"); |
09a19628 | 281 | |
da9fcb72 | 282 | vmbus_connection.conn_state = DISCONNECTED; |
09a19628 VK |
283 | vmbus_disconnect(); |
284 | ||
285 | kfree(msginfo); | |
286 | ||
287 | return ret; | |
288 | } | |
3e7ee490 | 289 | |
09a19628 VK |
290 | void vmbus_disconnect(void) |
291 | { | |
2db84eff S |
292 | /* |
293 | * First send the unload request to the host. | |
294 | */ | |
75ff3a8a | 295 | vmbus_initiate_unload(false); |
2db84eff | 296 | |
37c2578c DC |
297 | if (vmbus_connection.handle_sub_chan_wq) |
298 | destroy_workqueue(vmbus_connection.handle_sub_chan_wq); | |
299 | ||
300 | if (vmbus_connection.handle_primary_chan_wq) | |
301 | destroy_workqueue(vmbus_connection.handle_primary_chan_wq); | |
302 | ||
303 | if (vmbus_connection.work_queue) | |
da9fcb72 | 304 | destroy_workqueue(vmbus_connection.work_queue); |
3e7ee490 | 305 | |
da9fcb72 | 306 | if (vmbus_connection.int_page) { |
df3493e0 | 307 | free_pages((unsigned long)vmbus_connection.int_page, 0); |
da9fcb72 | 308 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
309 | } |
310 | ||
a100d88d RK |
311 | free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0); |
312 | free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); | |
8681db44 GKH |
313 | vmbus_connection.monitor_pages[0] = NULL; |
314 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 HJ |
315 | } |
316 | ||
3e189519 | 317 | /* |
c6977677 HZ |
318 | * relid2channel - Get the channel object given its |
319 | * child relative id (ie channel id) | |
fd8b85ea | 320 | */ |
d43e2fe7 | 321 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 322 | { |
aded7165 | 323 | struct vmbus_channel *channel; |
15b2f647 | 324 | struct vmbus_channel *found_channel = NULL; |
e68d2971 S |
325 | struct list_head *cur, *tmp; |
326 | struct vmbus_channel *cur_sc; | |
3e7ee490 | 327 | |
85d9aa70 DC |
328 | BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); |
329 | ||
da9fcb72 | 330 | list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |
15b2f647 HZ |
331 | if (channel->offermsg.child_relid == relid) { |
332 | found_channel = channel; | |
3e7ee490 | 333 | break; |
e68d2971 S |
334 | } else if (!list_empty(&channel->sc_list)) { |
335 | /* | |
336 | * Deal with sub-channels. | |
337 | */ | |
338 | list_for_each_safe(cur, tmp, &channel->sc_list) { | |
339 | cur_sc = list_entry(cur, struct vmbus_channel, | |
340 | sc_list); | |
341 | if (cur_sc->offermsg.child_relid == relid) { | |
342 | found_channel = cur_sc; | |
343 | break; | |
344 | } | |
345 | } | |
3e7ee490 HJ |
346 | } |
347 | } | |
3e7ee490 | 348 | |
15b2f647 | 349 | return found_channel; |
3e7ee490 HJ |
350 | } |
351 | ||
3e189519 | 352 | /* |
631e63a9 | 353 | * vmbus_on_event - Process a channel event notification |
ada6eb11 SH |
354 | * |
355 | * For batched channels (default) optimize host to guest signaling | |
356 | * by ensuring: | |
357 | * 1. While reading the channel, we disable interrupts from host. | |
358 | * 2. Ensure that we process all posted messages from the host | |
359 | * before returning from this callback. | |
360 | * 3. Once we return, enable signaling from the host. Once this | |
361 | * state is set we check to see if additional packets are | |
362 | * available to read. In this case we repeat the process. | |
363 | * If this tasklet has been running for a long time | |
364 | * then reschedule ourselves. | |
fd8b85ea | 365 | */ |
631e63a9 | 366 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 367 | { |
631e63a9 | 368 | struct vmbus_channel *channel = (void *) data; |
ada6eb11 | 369 | unsigned long time_limit = jiffies + 2; |
3e7ee490 | 370 | |
991f8f1c VK |
371 | trace_vmbus_on_event(channel); |
372 | ||
ada6eb11 SH |
373 | do { |
374 | void (*callback_fn)(void *); | |
375 | ||
376 | /* A channel once created is persistent even when | |
377 | * there is no driver handling the device. An | |
378 | * unloading driver sets the onchannel_callback to NULL. | |
f878f3d5 | 379 | */ |
ada6eb11 SH |
380 | callback_fn = READ_ONCE(channel->onchannel_callback); |
381 | if (unlikely(callback_fn == NULL)) | |
382 | return; | |
f878f3d5 | 383 | |
ada6eb11 SH |
384 | (*callback_fn)(channel->channel_callback_context); |
385 | ||
386 | if (channel->callback_mode != HV_CALL_BATCHED) | |
387 | return; | |
388 | ||
389 | if (likely(hv_end_read(&channel->inbound) == 0)) | |
390 | return; | |
391 | ||
392 | hv_begin_read(&channel->inbound); | |
393 | } while (likely(time_before(jiffies, time_limit))); | |
394 | ||
395 | /* The time limit (2 jiffies) has been reached */ | |
396 | tasklet_schedule(&channel->callback_event); | |
3e7ee490 HJ |
397 | } |
398 | ||
3e189519 | 399 | /* |
c6977677 | 400 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 401 | */ |
c0bb0392 | 402 | int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep) |
3e7ee490 | 403 | { |
ae20b254 | 404 | struct vmbus_channel_message_header *hdr; |
15b2f647 | 405 | union hv_connection_id conn_id; |
5289d3d1 S |
406 | int ret = 0; |
407 | int retries = 0; | |
8de0d7e9 | 408 | u32 usec = 1; |
3e7ee490 | 409 | |
15b2f647 | 410 | conn_id.asu32 = 0; |
ae20b254 | 411 | conn_id.u.id = vmbus_connection.msg_conn_id; |
5289d3d1 S |
412 | |
413 | /* | |
414 | * hv_post_message() can have transient failures because of | |
415 | * insufficient resources. Retry the operation a couple of | |
416 | * times before giving up. | |
417 | */ | |
c0bb0392 | 418 | while (retries < 100) { |
fdeebcc6 S |
419 | ret = hv_post_message(conn_id, 1, buffer, buflen); |
420 | ||
421 | switch (ret) { | |
89f9f679 | 422 | case HV_STATUS_INVALID_CONNECTION_ID: |
ae20b254 DC |
423 | /* |
424 | * See vmbus_negotiate_version(): VMBus protocol 5.0 | |
425 | * requires that we must use | |
426 | * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate | |
427 | * Contact message, but on old hosts that only | |
428 | * support VMBus protocol 4.0 or lower, here we get | |
429 | * HV_STATUS_INVALID_CONNECTION_ID and we should | |
430 | * return an error immediately without retrying. | |
431 | */ | |
89760937 | 432 | hdr = buffer; |
ae20b254 DC |
433 | if (hdr->msgtype == CHANNELMSG_INITIATE_CONTACT) |
434 | return -EINVAL; | |
89f9f679 DC |
435 | /* |
436 | * We could get this if we send messages too | |
437 | * frequently. | |
438 | */ | |
439 | ret = -EAGAIN; | |
440 | break; | |
441 | case HV_STATUS_INSUFFICIENT_MEMORY: | |
fdeebcc6 | 442 | case HV_STATUS_INSUFFICIENT_BUFFERS: |
48f4ccdf | 443 | ret = -ENOBUFS; |
fdeebcc6 S |
444 | break; |
445 | case HV_STATUS_SUCCESS: | |
5289d3d1 | 446 | return ret; |
fdeebcc6 S |
447 | default: |
448 | pr_err("hv_post_msg() failed; error code:%d\n", ret); | |
449 | return -EINVAL; | |
450 | } | |
451 | ||
5289d3d1 | 452 | retries++; |
c0bb0392 VK |
453 | if (can_sleep && usec > 1000) |
454 | msleep(usec / 1000); | |
455 | else if (usec < MAX_UDELAY_MS * 1000) | |
456 | udelay(usec); | |
457 | else | |
458 | mdelay(usec / 1000); | |
459 | ||
e917a5e2 | 460 | if (retries < 22) |
8de0d7e9 | 461 | usec *= 2; |
5289d3d1 S |
462 | } |
463 | return ret; | |
3e7ee490 HJ |
464 | } |
465 | ||
3e189519 | 466 | /* |
c6977677 | 467 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 468 | */ |
1b807e10 | 469 | void vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 470 | { |
21c3bef5 | 471 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 472 | |
5c1bec61 SH |
473 | if (!channel->is_dedicated_interrupt) |
474 | vmbus_send_interrupt(child_relid); | |
3be77774 | 475 | |
6981fbf3 SH |
476 | ++channel->sig_events; |
477 | ||
05784171 | 478 | hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event); |
3e7ee490 | 479 | } |
5cc47247 | 480 | EXPORT_SYMBOL_GPL(vmbus_set_event); |