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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> |
fc53662f VK |
35 | #include <asm/mshyperv.h> |
36 | ||
0f2a6619 | 37 | #include "hyperv_vmbus.h" |
3e7ee490 | 38 | |
3e7ee490 | 39 | |
da9fcb72 HZ |
40 | struct vmbus_connection vmbus_connection = { |
41 | .conn_state = DISCONNECTED, | |
42 | .next_gpadl_handle = ATOMIC_INIT(0xE1E10), | |
3e7ee490 | 43 | }; |
95096f2f | 44 | EXPORT_SYMBOL_GPL(vmbus_connection); |
3e7ee490 | 45 | |
37f7278b S |
46 | /* |
47 | * Negotiated protocol version with the host. | |
48 | */ | |
49 | __u32 vmbus_proto_version; | |
50 | EXPORT_SYMBOL_GPL(vmbus_proto_version); | |
51 | ||
610071c3 S |
52 | static __u32 vmbus_get_next_version(__u32 current_version) |
53 | { | |
54 | switch (current_version) { | |
55 | case (VERSION_WIN7): | |
56 | return VERSION_WS2008; | |
57 | ||
58 | case (VERSION_WIN8): | |
59 | return VERSION_WIN7; | |
60 | ||
03367ef5 S |
61 | case (VERSION_WIN8_1): |
62 | return VERSION_WIN8; | |
63 | ||
6c4e5f9c KM |
64 | case (VERSION_WIN10): |
65 | return VERSION_WIN8_1; | |
66 | ||
610071c3 S |
67 | case (VERSION_WS2008): |
68 | default: | |
69 | return VERSION_INVAL; | |
70 | } | |
71 | } | |
72 | ||
73 | static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, | |
74 | __u32 version) | |
75 | { | |
76 | int ret = 0; | |
77 | struct vmbus_channel_initiate_contact *msg; | |
78 | unsigned long flags; | |
610071c3 S |
79 | |
80 | init_completion(&msginfo->waitevent); | |
81 | ||
82 | msg = (struct vmbus_channel_initiate_contact *)msginfo->msg; | |
83 | ||
84 | msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; | |
85 | msg->vmbus_version_requested = version; | |
86 | msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); | |
8681db44 GKH |
87 | msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]); |
88 | msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]); | |
b282e4c0 S |
89 | /* |
90 | * We want all channel messages to be delivered on CPU 0. | |
91 | * This has been the behavior pre-win8. This is not | |
92 | * perf issue and having all channel messages delivered on CPU 0 | |
93 | * would be ok. | |
72686447 AN |
94 | * For post win8 hosts, we support receiving channel messagges on |
95 | * all the CPUs. This is needed for kexec to work correctly where | |
96 | * the CPU attempting to connect may not be CPU 0. | |
b282e4c0 | 97 | */ |
54a66265 | 98 | if (version >= VERSION_WIN8_1) { |
37cdd991 | 99 | msg->target_vcpu = hv_context.vp_index[smp_processor_id()]; |
54a66265 S |
100 | vmbus_connection.connect_cpu = smp_processor_id(); |
101 | } else { | |
72686447 | 102 | msg->target_vcpu = 0; |
54a66265 S |
103 | vmbus_connection.connect_cpu = 0; |
104 | } | |
610071c3 S |
105 | |
106 | /* | |
107 | * Add to list before we send the request since we may | |
108 | * receive the response before returning from this routine | |
109 | */ | |
110 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
111 | list_add_tail(&msginfo->msglistentry, | |
112 | &vmbus_connection.chn_msg_list); | |
113 | ||
114 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
115 | ||
116 | ret = vmbus_post_msg(msg, | |
c0bb0392 VK |
117 | sizeof(struct vmbus_channel_initiate_contact), |
118 | true); | |
610071c3 S |
119 | if (ret != 0) { |
120 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
121 | list_del(&msginfo->msglistentry); | |
122 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, | |
123 | flags); | |
124 | return ret; | |
125 | } | |
126 | ||
127 | /* Wait for the connection response */ | |
269f9794 | 128 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
129 | |
130 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
131 | list_del(&msginfo->msglistentry); | |
132 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
133 | ||
134 | /* Check if successful */ | |
135 | if (msginfo->response.version_response.version_supported) { | |
136 | vmbus_connection.conn_state = CONNECTED; | |
137 | } else { | |
610071c3 S |
138 | return -ECONNREFUSED; |
139 | } | |
140 | ||
141 | return ret; | |
142 | } | |
143 | ||
3e189519 | 144 | /* |
c6977677 | 145 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 146 | */ |
c6977677 | 147 | int vmbus_connect(void) |
3e7ee490 | 148 | { |
fd8b85ea | 149 | int ret = 0; |
15b2f647 | 150 | struct vmbus_channel_msginfo *msginfo = NULL; |
610071c3 | 151 | __u32 version; |
3e7ee490 | 152 | |
454f18a9 | 153 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
154 | vmbus_connection.conn_state = CONNECTING; |
155 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
156 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 157 | ret = -ENOMEM; |
b0043863 | 158 | goto cleanup; |
de65a384 | 159 | } |
3e7ee490 | 160 | |
da9fcb72 | 161 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 162 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 163 | |
da9fcb72 | 164 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
d6f591e3 | 165 | mutex_init(&vmbus_connection.channel_mutex); |
3e7ee490 | 166 | |
454f18a9 BP |
167 | /* |
168 | * Setup the vmbus event connection for channel interrupt | |
169 | * abstraction stuff | |
170 | */ | |
df3493e0 S |
171 | vmbus_connection.int_page = |
172 | (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); | |
da9fcb72 | 173 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 174 | ret = -ENOMEM; |
b0043863 | 175 | goto cleanup; |
3e7ee490 HJ |
176 | } |
177 | ||
da9fcb72 HZ |
178 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
179 | vmbus_connection.send_int_page = | |
180 | (void *)((unsigned long)vmbus_connection.int_page + | |
fd8b85ea | 181 | (PAGE_SIZE >> 1)); |
3e7ee490 | 182 | |
fd8b85ea GKH |
183 | /* |
184 | * Setup the monitor notification facility. The 1st page for | |
185 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 186 | */ |
8681db44 GKH |
187 | vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); |
188 | vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); | |
189 | if ((vmbus_connection.monitor_pages[0] == NULL) || | |
190 | (vmbus_connection.monitor_pages[1] == NULL)) { | |
3a7546d9 | 191 | ret = -ENOMEM; |
b0043863 | 192 | goto cleanup; |
3e7ee490 HJ |
193 | } |
194 | ||
15b2f647 | 195 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
196 | sizeof(struct vmbus_channel_initiate_contact), |
197 | GFP_KERNEL); | |
15b2f647 | 198 | if (msginfo == NULL) { |
8cad0af9 | 199 | ret = -ENOMEM; |
b0043863 | 200 | goto cleanup; |
3e7ee490 HJ |
201 | } |
202 | ||
454f18a9 | 203 | /* |
610071c3 S |
204 | * Negotiate a compatible VMBUS version number with the |
205 | * host. We start with the highest number we can support | |
206 | * and work our way down until we negotiate a compatible | |
207 | * version. | |
454f18a9 | 208 | */ |
3e7ee490 | 209 | |
2a5c43a8 | 210 | version = VERSION_CURRENT; |
3e7ee490 | 211 | |
610071c3 S |
212 | do { |
213 | ret = vmbus_negotiate_version(msginfo, version); | |
8bbf9f44 | 214 | if (ret == -ETIMEDOUT) |
666b9adc S |
215 | goto cleanup; |
216 | ||
217 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 218 | break; |
3e7ee490 | 219 | |
610071c3 S |
220 | version = vmbus_get_next_version(version); |
221 | } while (version != VERSION_INVAL); | |
3e7ee490 | 222 | |
610071c3 | 223 | if (version == VERSION_INVAL) |
b0043863 | 224 | goto cleanup; |
3e7ee490 | 225 | |
37f7278b | 226 | vmbus_proto_version = version; |
8de8af7e S |
227 | pr_info("Vmbus version:%d.%d\n", |
228 | version >> 16, version & 0xFFFF); | |
3bacaf0c | 229 | |
15b2f647 | 230 | kfree(msginfo); |
3e7ee490 HJ |
231 | return 0; |
232 | ||
b0043863 | 233 | cleanup: |
3bacaf0c | 234 | pr_err("Unable to connect to host\n"); |
09a19628 | 235 | |
da9fcb72 | 236 | vmbus_connection.conn_state = DISCONNECTED; |
09a19628 VK |
237 | vmbus_disconnect(); |
238 | ||
239 | kfree(msginfo); | |
240 | ||
241 | return ret; | |
242 | } | |
3e7ee490 | 243 | |
09a19628 VK |
244 | void vmbus_disconnect(void) |
245 | { | |
2db84eff S |
246 | /* |
247 | * First send the unload request to the host. | |
248 | */ | |
75ff3a8a | 249 | vmbus_initiate_unload(false); |
2db84eff | 250 | |
09a19628 VK |
251 | if (vmbus_connection.work_queue) { |
252 | drain_workqueue(vmbus_connection.work_queue); | |
da9fcb72 | 253 | destroy_workqueue(vmbus_connection.work_queue); |
09a19628 | 254 | } |
3e7ee490 | 255 | |
da9fcb72 | 256 | if (vmbus_connection.int_page) { |
df3493e0 | 257 | free_pages((unsigned long)vmbus_connection.int_page, 0); |
da9fcb72 | 258 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
259 | } |
260 | ||
a100d88d RK |
261 | free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0); |
262 | free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); | |
8681db44 GKH |
263 | vmbus_connection.monitor_pages[0] = NULL; |
264 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 HJ |
265 | } |
266 | ||
3e189519 | 267 | /* |
c6977677 HZ |
268 | * relid2channel - Get the channel object given its |
269 | * child relative id (ie channel id) | |
fd8b85ea | 270 | */ |
d43e2fe7 | 271 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 272 | { |
aded7165 | 273 | struct vmbus_channel *channel; |
15b2f647 | 274 | struct vmbus_channel *found_channel = NULL; |
e68d2971 S |
275 | struct list_head *cur, *tmp; |
276 | struct vmbus_channel *cur_sc; | |
3e7ee490 | 277 | |
85d9aa70 DC |
278 | BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); |
279 | ||
da9fcb72 | 280 | list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { |
15b2f647 HZ |
281 | if (channel->offermsg.child_relid == relid) { |
282 | found_channel = channel; | |
3e7ee490 | 283 | break; |
e68d2971 S |
284 | } else if (!list_empty(&channel->sc_list)) { |
285 | /* | |
286 | * Deal with sub-channels. | |
287 | */ | |
288 | list_for_each_safe(cur, tmp, &channel->sc_list) { | |
289 | cur_sc = list_entry(cur, struct vmbus_channel, | |
290 | sc_list); | |
291 | if (cur_sc->offermsg.child_relid == relid) { | |
292 | found_channel = cur_sc; | |
293 | break; | |
294 | } | |
295 | } | |
3e7ee490 HJ |
296 | } |
297 | } | |
3e7ee490 | 298 | |
15b2f647 | 299 | return found_channel; |
3e7ee490 HJ |
300 | } |
301 | ||
3e189519 | 302 | /* |
631e63a9 | 303 | * vmbus_on_event - Process a channel event notification |
ada6eb11 SH |
304 | * |
305 | * For batched channels (default) optimize host to guest signaling | |
306 | * by ensuring: | |
307 | * 1. While reading the channel, we disable interrupts from host. | |
308 | * 2. Ensure that we process all posted messages from the host | |
309 | * before returning from this callback. | |
310 | * 3. Once we return, enable signaling from the host. Once this | |
311 | * state is set we check to see if additional packets are | |
312 | * available to read. In this case we repeat the process. | |
313 | * If this tasklet has been running for a long time | |
314 | * then reschedule ourselves. | |
fd8b85ea | 315 | */ |
631e63a9 | 316 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 317 | { |
631e63a9 | 318 | struct vmbus_channel *channel = (void *) data; |
ada6eb11 | 319 | unsigned long time_limit = jiffies + 2; |
3e7ee490 | 320 | |
ada6eb11 SH |
321 | do { |
322 | void (*callback_fn)(void *); | |
323 | ||
324 | /* A channel once created is persistent even when | |
325 | * there is no driver handling the device. An | |
326 | * unloading driver sets the onchannel_callback to NULL. | |
f878f3d5 | 327 | */ |
ada6eb11 SH |
328 | callback_fn = READ_ONCE(channel->onchannel_callback); |
329 | if (unlikely(callback_fn == NULL)) | |
330 | return; | |
f878f3d5 | 331 | |
ada6eb11 SH |
332 | (*callback_fn)(channel->channel_callback_context); |
333 | ||
334 | if (channel->callback_mode != HV_CALL_BATCHED) | |
335 | return; | |
336 | ||
337 | if (likely(hv_end_read(&channel->inbound) == 0)) | |
338 | return; | |
339 | ||
340 | hv_begin_read(&channel->inbound); | |
341 | } while (likely(time_before(jiffies, time_limit))); | |
342 | ||
343 | /* The time limit (2 jiffies) has been reached */ | |
344 | tasklet_schedule(&channel->callback_event); | |
3e7ee490 HJ |
345 | } |
346 | ||
3e189519 | 347 | /* |
c6977677 | 348 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 349 | */ |
c0bb0392 | 350 | int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep) |
3e7ee490 | 351 | { |
15b2f647 | 352 | union hv_connection_id conn_id; |
5289d3d1 S |
353 | int ret = 0; |
354 | int retries = 0; | |
8de0d7e9 | 355 | u32 usec = 1; |
3e7ee490 | 356 | |
15b2f647 HZ |
357 | conn_id.asu32 = 0; |
358 | conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID; | |
5289d3d1 S |
359 | |
360 | /* | |
361 | * hv_post_message() can have transient failures because of | |
362 | * insufficient resources. Retry the operation a couple of | |
363 | * times before giving up. | |
364 | */ | |
c0bb0392 | 365 | while (retries < 100) { |
fdeebcc6 S |
366 | ret = hv_post_message(conn_id, 1, buffer, buflen); |
367 | ||
368 | switch (ret) { | |
89f9f679 DC |
369 | case HV_STATUS_INVALID_CONNECTION_ID: |
370 | /* | |
371 | * We could get this if we send messages too | |
372 | * frequently. | |
373 | */ | |
374 | ret = -EAGAIN; | |
375 | break; | |
376 | case HV_STATUS_INSUFFICIENT_MEMORY: | |
fdeebcc6 | 377 | case HV_STATUS_INSUFFICIENT_BUFFERS: |
48f4ccdf | 378 | ret = -ENOBUFS; |
fdeebcc6 S |
379 | break; |
380 | case HV_STATUS_SUCCESS: | |
5289d3d1 | 381 | return ret; |
fdeebcc6 S |
382 | default: |
383 | pr_err("hv_post_msg() failed; error code:%d\n", ret); | |
384 | return -EINVAL; | |
385 | } | |
386 | ||
5289d3d1 | 387 | retries++; |
c0bb0392 VK |
388 | if (can_sleep && usec > 1000) |
389 | msleep(usec / 1000); | |
390 | else if (usec < MAX_UDELAY_MS * 1000) | |
391 | udelay(usec); | |
392 | else | |
393 | mdelay(usec / 1000); | |
394 | ||
e917a5e2 | 395 | if (retries < 22) |
8de0d7e9 | 396 | usec *= 2; |
5289d3d1 S |
397 | } |
398 | return ret; | |
3e7ee490 HJ |
399 | } |
400 | ||
3e189519 | 401 | /* |
c6977677 | 402 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 403 | */ |
1b807e10 | 404 | void vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 405 | { |
21c3bef5 | 406 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 407 | |
5c1bec61 SH |
408 | if (!channel->is_dedicated_interrupt) |
409 | vmbus_send_interrupt(child_relid); | |
3be77774 | 410 | |
05784171 | 411 | hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event); |
3e7ee490 | 412 | } |
5cc47247 | 413 | EXPORT_SYMBOL_GPL(vmbus_set_event); |