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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 | ||
610071c3 S |
61 | case (VERSION_WS2008): |
62 | default: | |
63 | return VERSION_INVAL; | |
64 | } | |
65 | } | |
66 | ||
67 | static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, | |
68 | __u32 version) | |
69 | { | |
70 | int ret = 0; | |
71 | struct vmbus_channel_initiate_contact *msg; | |
72 | unsigned long flags; | |
610071c3 S |
73 | |
74 | init_completion(&msginfo->waitevent); | |
75 | ||
76 | msg = (struct vmbus_channel_initiate_contact *)msginfo->msg; | |
77 | ||
78 | msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; | |
79 | msg->vmbus_version_requested = version; | |
80 | msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); | |
8681db44 GKH |
81 | msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]); |
82 | msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]); | |
03367ef5 | 83 | if (version == VERSION_WIN8_1) |
e28bab48 | 84 | msg->target_vcpu = hv_context.vp_index[smp_processor_id()]; |
610071c3 S |
85 | |
86 | /* | |
87 | * Add to list before we send the request since we may | |
88 | * receive the response before returning from this routine | |
89 | */ | |
90 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
91 | list_add_tail(&msginfo->msglistentry, | |
92 | &vmbus_connection.chn_msg_list); | |
93 | ||
94 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
95 | ||
96 | ret = vmbus_post_msg(msg, | |
97 | sizeof(struct vmbus_channel_initiate_contact)); | |
98 | if (ret != 0) { | |
99 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
100 | list_del(&msginfo->msglistentry); | |
101 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, | |
102 | flags); | |
103 | return ret; | |
104 | } | |
105 | ||
106 | /* Wait for the connection response */ | |
269f9794 | 107 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
108 | |
109 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
110 | list_del(&msginfo->msglistentry); | |
111 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
112 | ||
113 | /* Check if successful */ | |
114 | if (msginfo->response.version_response.version_supported) { | |
115 | vmbus_connection.conn_state = CONNECTED; | |
116 | } else { | |
610071c3 S |
117 | return -ECONNREFUSED; |
118 | } | |
119 | ||
120 | return ret; | |
121 | } | |
122 | ||
3e189519 | 123 | /* |
c6977677 | 124 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 125 | */ |
c6977677 | 126 | int vmbus_connect(void) |
3e7ee490 | 127 | { |
fd8b85ea | 128 | int ret = 0; |
15b2f647 | 129 | struct vmbus_channel_msginfo *msginfo = NULL; |
610071c3 | 130 | __u32 version; |
3e7ee490 | 131 | |
454f18a9 | 132 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
133 | vmbus_connection.conn_state = CONNECTING; |
134 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
135 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 136 | ret = -ENOMEM; |
b0043863 | 137 | goto cleanup; |
de65a384 | 138 | } |
3e7ee490 | 139 | |
da9fcb72 | 140 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 141 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 142 | |
da9fcb72 | 143 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
15b2f647 | 144 | spin_lock_init(&vmbus_connection.channel_lock); |
3e7ee490 | 145 | |
454f18a9 BP |
146 | /* |
147 | * Setup the vmbus event connection for channel interrupt | |
148 | * abstraction stuff | |
149 | */ | |
df3493e0 S |
150 | vmbus_connection.int_page = |
151 | (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); | |
da9fcb72 | 152 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 153 | ret = -ENOMEM; |
b0043863 | 154 | goto cleanup; |
3e7ee490 HJ |
155 | } |
156 | ||
da9fcb72 HZ |
157 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
158 | vmbus_connection.send_int_page = | |
159 | (void *)((unsigned long)vmbus_connection.int_page + | |
fd8b85ea | 160 | (PAGE_SIZE >> 1)); |
3e7ee490 | 161 | |
fd8b85ea GKH |
162 | /* |
163 | * Setup the monitor notification facility. The 1st page for | |
164 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 165 | */ |
8681db44 GKH |
166 | vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); |
167 | vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); | |
168 | if ((vmbus_connection.monitor_pages[0] == NULL) || | |
169 | (vmbus_connection.monitor_pages[1] == NULL)) { | |
3a7546d9 | 170 | ret = -ENOMEM; |
b0043863 | 171 | goto cleanup; |
3e7ee490 HJ |
172 | } |
173 | ||
15b2f647 | 174 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
175 | sizeof(struct vmbus_channel_initiate_contact), |
176 | GFP_KERNEL); | |
15b2f647 | 177 | if (msginfo == NULL) { |
8cad0af9 | 178 | ret = -ENOMEM; |
b0043863 | 179 | goto cleanup; |
3e7ee490 HJ |
180 | } |
181 | ||
454f18a9 | 182 | /* |
610071c3 S |
183 | * Negotiate a compatible VMBUS version number with the |
184 | * host. We start with the highest number we can support | |
185 | * and work our way down until we negotiate a compatible | |
186 | * version. | |
454f18a9 | 187 | */ |
3e7ee490 | 188 | |
2a5c43a8 | 189 | version = VERSION_CURRENT; |
3e7ee490 | 190 | |
610071c3 S |
191 | do { |
192 | ret = vmbus_negotiate_version(msginfo, version); | |
8bbf9f44 | 193 | if (ret == -ETIMEDOUT) |
666b9adc S |
194 | goto cleanup; |
195 | ||
196 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 197 | break; |
3e7ee490 | 198 | |
610071c3 S |
199 | version = vmbus_get_next_version(version); |
200 | } while (version != VERSION_INVAL); | |
3e7ee490 | 201 | |
610071c3 | 202 | if (version == VERSION_INVAL) |
b0043863 | 203 | goto cleanup; |
3e7ee490 | 204 | |
37f7278b | 205 | vmbus_proto_version = version; |
3bacaf0c S |
206 | pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n", |
207 | host_info_eax, host_info_ebx >> 16, | |
208 | host_info_ebx & 0xFFFF, host_info_ecx, | |
209 | host_info_edx >> 24, host_info_edx & 0xFFFFFF, | |
210 | version >> 16, version & 0xFFFF); | |
211 | ||
15b2f647 | 212 | kfree(msginfo); |
3e7ee490 HJ |
213 | return 0; |
214 | ||
b0043863 | 215 | cleanup: |
3bacaf0c | 216 | pr_err("Unable to connect to host\n"); |
da9fcb72 | 217 | vmbus_connection.conn_state = DISCONNECTED; |
3e7ee490 | 218 | |
da9fcb72 HZ |
219 | if (vmbus_connection.work_queue) |
220 | destroy_workqueue(vmbus_connection.work_queue); | |
3e7ee490 | 221 | |
da9fcb72 | 222 | if (vmbus_connection.int_page) { |
df3493e0 | 223 | free_pages((unsigned long)vmbus_connection.int_page, 0); |
da9fcb72 | 224 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
225 | } |
226 | ||
a100d88d RK |
227 | free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0); |
228 | free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); | |
8681db44 GKH |
229 | vmbus_connection.monitor_pages[0] = NULL; |
230 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 | 231 | |
dd9b15dc | 232 | kfree(msginfo); |
3e7ee490 | 233 | |
3e7ee490 HJ |
234 | return ret; |
235 | } | |
236 | ||
3a28fa35 S |
237 | /* |
238 | * Map the given relid to the corresponding channel based on the | |
239 | * per-cpu list of channels that have been affinitized to this CPU. | |
240 | * This will be used in the channel callback path as we can do this | |
241 | * mapping in a lock-free fashion. | |
242 | */ | |
243 | static struct vmbus_channel *pcpu_relid2channel(u32 relid) | |
244 | { | |
245 | struct vmbus_channel *channel; | |
246 | struct vmbus_channel *found_channel = NULL; | |
247 | int cpu = smp_processor_id(); | |
248 | struct list_head *pcpu_head = &hv_context.percpu_list[cpu]; | |
249 | ||
250 | list_for_each_entry(channel, pcpu_head, percpu_list) { | |
251 | if (channel->offermsg.child_relid == relid) { | |
252 | found_channel = channel; | |
253 | break; | |
254 | } | |
255 | } | |
256 | ||
257 | return found_channel; | |
258 | } | |
3e7ee490 | 259 | |
3e189519 | 260 | /* |
c6977677 HZ |
261 | * relid2channel - Get the channel object given its |
262 | * child relative id (ie channel id) | |
fd8b85ea | 263 | */ |
c6977677 | 264 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 265 | { |
aded7165 | 266 | struct vmbus_channel *channel; |
15b2f647 | 267 | struct vmbus_channel *found_channel = NULL; |
0f5e44ca | 268 | unsigned long flags; |
e68d2971 S |
269 | struct list_head *cur, *tmp; |
270 | struct vmbus_channel *cur_sc; | |
3e7ee490 | 271 | |
15b2f647 | 272 | spin_lock_irqsave(&vmbus_connection.channel_lock, flags); |
da9fcb72 | 273 | list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |
15b2f647 HZ |
274 | if (channel->offermsg.child_relid == relid) { |
275 | found_channel = channel; | |
3e7ee490 | 276 | break; |
e68d2971 S |
277 | } else if (!list_empty(&channel->sc_list)) { |
278 | /* | |
279 | * Deal with sub-channels. | |
280 | */ | |
281 | list_for_each_safe(cur, tmp, &channel->sc_list) { | |
282 | cur_sc = list_entry(cur, struct vmbus_channel, | |
283 | sc_list); | |
284 | if (cur_sc->offermsg.child_relid == relid) { | |
285 | found_channel = cur_sc; | |
286 | break; | |
287 | } | |
288 | } | |
3e7ee490 HJ |
289 | } |
290 | } | |
15b2f647 | 291 | spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); |
3e7ee490 | 292 | |
15b2f647 | 293 | return found_channel; |
3e7ee490 HJ |
294 | } |
295 | ||
3e189519 | 296 | /* |
c6977677 | 297 | * process_chn_event - Process a channel event notification |
fd8b85ea | 298 | */ |
35436487 | 299 | static void process_chn_event(u32 relid) |
3e7ee490 | 300 | { |
aded7165 | 301 | struct vmbus_channel *channel; |
f878f3d5 S |
302 | void *arg; |
303 | bool read_state; | |
304 | u32 bytes_to_read; | |
3e7ee490 | 305 | |
454f18a9 BP |
306 | /* |
307 | * Find the channel based on this relid and invokes the | |
308 | * channel callback to process the event | |
309 | */ | |
3a28fa35 | 310 | channel = pcpu_relid2channel(relid); |
3e7ee490 | 311 | |
24326039 S |
312 | if (!channel) { |
313 | pr_err("channel not found for relid - %u\n", relid); | |
314 | return; | |
315 | } | |
316 | ||
317 | /* | |
318 | * A channel once created is persistent even when there | |
319 | * is no driver handling the device. An unloading driver | |
d3ba720d S |
320 | * sets the onchannel_callback to NULL on the same CPU |
321 | * as where this interrupt is handled (in an interrupt context). | |
322 | * Thus, checking and invoking the driver specific callback takes | |
323 | * care of orderly unloading of the driver. | |
24326039 S |
324 | */ |
325 | ||
f878f3d5 S |
326 | if (channel->onchannel_callback != NULL) { |
327 | arg = channel->channel_callback_context; | |
328 | read_state = channel->batched_reading; | |
329 | /* | |
330 | * This callback reads the messages sent by the host. | |
331 | * We can optimize host to guest signaling by ensuring: | |
332 | * 1. While reading the channel, we disable interrupts from | |
333 | * host. | |
334 | * 2. Ensure that we process all posted messages from the host | |
335 | * before returning from this callback. | |
336 | * 3. Once we return, enable signaling from the host. Once this | |
337 | * state is set we check to see if additional packets are | |
338 | * available to read. In this case we repeat the process. | |
339 | */ | |
340 | ||
341 | do { | |
affb1aff S |
342 | if (read_state) |
343 | hv_begin_read(&channel->inbound); | |
f878f3d5 | 344 | channel->onchannel_callback(arg); |
affb1aff S |
345 | if (read_state) |
346 | bytes_to_read = hv_end_read(&channel->inbound); | |
347 | else | |
348 | bytes_to_read = 0; | |
f878f3d5 S |
349 | } while (read_state && (bytes_to_read != 0)); |
350 | } else { | |
24326039 | 351 | pr_err("no channel callback for relid - %u\n", relid); |
f878f3d5 | 352 | } |
d9add43b | 353 | |
3e7ee490 HJ |
354 | } |
355 | ||
3e189519 | 356 | /* |
c6977677 | 357 | * vmbus_on_event - Handler for events |
fd8b85ea | 358 | */ |
6de3d6aa | 359 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 360 | { |
35436487 | 361 | u32 dword; |
6552ecd7 | 362 | u32 maxdword; |
3e7ee490 | 363 | int bit; |
35436487 | 364 | u32 relid; |
6552ecd7 S |
365 | u32 *recv_int_page = NULL; |
366 | void *page_addr; | |
367 | int cpu = smp_processor_id(); | |
368 | union hv_synic_event_flags *event; | |
369 | ||
370 | if ((vmbus_proto_version == VERSION_WS2008) || | |
371 | (vmbus_proto_version == VERSION_WIN7)) { | |
372 | maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5; | |
373 | recv_int_page = vmbus_connection.recv_int_page; | |
374 | } else { | |
375 | /* | |
376 | * When the host is win8 and beyond, the event page | |
377 | * can be directly checked to get the id of the channel | |
378 | * that has the interrupt pending. | |
379 | */ | |
380 | maxdword = HV_EVENT_FLAGS_DWORD_COUNT; | |
381 | page_addr = hv_context.synic_event_page[cpu]; | |
382 | event = (union hv_synic_event_flags *)page_addr + | |
383 | VMBUS_MESSAGE_SINT; | |
384 | recv_int_page = event->flags32; | |
385 | } | |
386 | ||
387 | ||
3e7ee490 | 388 | |
454f18a9 | 389 | /* Check events */ |
242b45aa OH |
390 | if (!recv_int_page) |
391 | return; | |
392 | for (dword = 0; dword < maxdword; dword++) { | |
393 | if (!recv_int_page[dword]) | |
394 | continue; | |
395 | for (bit = 0; bit < 32; bit++) { | |
d9add43b S |
396 | if (sync_test_and_clear_bit(bit, |
397 | (unsigned long *)&recv_int_page[dword])) { | |
242b45aa OH |
398 | relid = (dword << 5) + bit; |
399 | ||
d9add43b | 400 | if (relid == 0) |
6d81d330 S |
401 | /* |
402 | * Special case - vmbus | |
403 | * channel protocol msg | |
404 | */ | |
242b45aa | 405 | continue; |
d9add43b | 406 | |
35436487 | 407 | process_chn_event(relid); |
3e7ee490 | 408 | } |
242b45aa | 409 | } |
3e7ee490 | 410 | } |
3e7ee490 HJ |
411 | } |
412 | ||
3e189519 | 413 | /* |
c6977677 | 414 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 415 | */ |
c6977677 | 416 | int vmbus_post_msg(void *buffer, size_t buflen) |
3e7ee490 | 417 | { |
15b2f647 | 418 | union hv_connection_id conn_id; |
5289d3d1 S |
419 | int ret = 0; |
420 | int retries = 0; | |
3e7ee490 | 421 | |
15b2f647 HZ |
422 | conn_id.asu32 = 0; |
423 | conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID; | |
5289d3d1 S |
424 | |
425 | /* | |
426 | * hv_post_message() can have transient failures because of | |
427 | * insufficient resources. Retry the operation a couple of | |
428 | * times before giving up. | |
429 | */ | |
430 | while (retries < 3) { | |
431 | ret = hv_post_message(conn_id, 1, buffer, buflen); | |
432 | if (ret != HV_STATUS_INSUFFICIENT_BUFFERS) | |
433 | return ret; | |
434 | retries++; | |
435 | msleep(100); | |
436 | } | |
437 | return ret; | |
3e7ee490 HJ |
438 | } |
439 | ||
3e189519 | 440 | /* |
c6977677 | 441 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 442 | */ |
21c3bef5 | 443 | int vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 444 | { |
21c3bef5 | 445 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 446 | |
3be77774 S |
447 | if (!channel->is_dedicated_interrupt) { |
448 | /* Each u32 represents 32 channels */ | |
449 | sync_set_bit(child_relid & 31, | |
450 | (unsigned long *)vmbus_connection.send_int_page + | |
451 | (child_relid >> 5)); | |
452 | } | |
453 | ||
454 | return hv_signal_event(channel->sig_event); | |
3e7ee490 | 455 | } |