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3b20eb23 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3e7ee490 HJ |
2 | /* |
3 | * | |
4 | * Copyright (c) 2009, Microsoft Corporation. | |
5 | * | |
3e7ee490 HJ |
6 | * Authors: |
7 | * Haiyang Zhang <haiyangz@microsoft.com> | |
8 | * Hank Janssen <hjanssen@microsoft.com> | |
3e7ee490 | 9 | */ |
0a46618d HJ |
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
11 | ||
a0086dc5 | 12 | #include <linux/kernel.h> |
0c3b7b2f S |
13 | #include <linux/sched.h> |
14 | #include <linux/wait.h> | |
5289d3d1 | 15 | #include <linux/delay.h> |
a0086dc5 | 16 | #include <linux/mm.h> |
931cccc9 | 17 | #include <linux/module.h> |
5a0e3ad6 | 18 | #include <linux/slab.h> |
a0086dc5 | 19 | #include <linux/vmalloc.h> |
46a97191 | 20 | #include <linux/hyperv.h> |
37f7278b | 21 | #include <linux/export.h> |
fc53662f VK |
22 | #include <asm/mshyperv.h> |
23 | ||
0f2a6619 | 24 | #include "hyperv_vmbus.h" |
3e7ee490 | 25 | |
3e7ee490 | 26 | |
da9fcb72 HZ |
27 | struct vmbus_connection vmbus_connection = { |
28 | .conn_state = DISCONNECTED, | |
29 | .next_gpadl_handle = ATOMIC_INIT(0xE1E10), | |
b307b389 DC |
30 | |
31 | .ready_for_suspend_event= COMPLETION_INITIALIZER( | |
32 | vmbus_connection.ready_for_suspend_event), | |
d8bd2d44 DC |
33 | .ready_for_resume_event = COMPLETION_INITIALIZER( |
34 | vmbus_connection.ready_for_resume_event), | |
3e7ee490 | 35 | }; |
95096f2f | 36 | EXPORT_SYMBOL_GPL(vmbus_connection); |
3e7ee490 | 37 | |
37f7278b S |
38 | /* |
39 | * Negotiated protocol version with the host. | |
40 | */ | |
41 | __u32 vmbus_proto_version; | |
42 | EXPORT_SYMBOL_GPL(vmbus_proto_version); | |
43 | ||
bedc61a9 AP |
44 | /* |
45 | * Table of VMBus versions listed from newest to oldest. | |
46 | */ | |
47 | static __u32 vmbus_versions[] = { | |
2d4f49b3 AP |
48 | VERSION_WIN10_V5_2, |
49 | VERSION_WIN10_V5_1, | |
bedc61a9 | 50 | VERSION_WIN10_V5, |
2d4f49b3 | 51 | VERSION_WIN10_V4_1, |
bedc61a9 AP |
52 | VERSION_WIN10, |
53 | VERSION_WIN8_1, | |
54 | VERSION_WIN8, | |
55 | VERSION_WIN7, | |
56 | VERSION_WS2008 | |
57 | }; | |
610071c3 | 58 | |
931cccc9 AP |
59 | /* |
60 | * Maximal VMBus protocol version guests can negotiate. Useful to cap the | |
61 | * VMBus version for testing and debugging purpose. | |
62 | */ | |
63 | static uint max_version = VERSION_WIN10_V5_2; | |
64 | ||
65 | module_param(max_version, uint, S_IRUGO); | |
66 | MODULE_PARM_DESC(max_version, | |
67 | "Maximal VMBus protocol version which can be negotiated"); | |
68 | ||
f53335e3 | 69 | int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version) |
610071c3 S |
70 | { |
71 | int ret = 0; | |
72 | struct vmbus_channel_initiate_contact *msg; | |
73 | unsigned long flags; | |
610071c3 S |
74 | |
75 | init_completion(&msginfo->waitevent); | |
76 | ||
77 | msg = (struct vmbus_channel_initiate_contact *)msginfo->msg; | |
78 | ||
ae20b254 | 79 | memset(msg, 0, sizeof(*msg)); |
610071c3 S |
80 | msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; |
81 | msg->vmbus_version_requested = version; | |
ae20b254 DC |
82 | |
83 | /* | |
2d4f49b3 AP |
84 | * VMBus protocol 5.0 (VERSION_WIN10_V5) and higher require that we must |
85 | * use VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message, | |
ae20b254 DC |
86 | * and for subsequent messages, we must use the Message Connection ID |
87 | * field in the host-returned Version Response Message. And, with | |
2d4f49b3 AP |
88 | * VERSION_WIN10_V5 and higher, we don't use msg->interrupt_page, but we |
89 | * tell the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for | |
ae20b254 DC |
90 | * compatibility. |
91 | * | |
92 | * On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1). | |
93 | */ | |
94 | if (version >= VERSION_WIN10_V5) { | |
95 | msg->msg_sint = VMBUS_MESSAGE_SINT; | |
96 | vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID_4; | |
97 | } else { | |
98 | msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); | |
99 | vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID; | |
100 | } | |
101 | ||
8681db44 GKH |
102 | msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]); |
103 | msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]); | |
8a857c55 | 104 | msg->target_vcpu = hv_cpu_number_to_vp_number(VMBUS_CONNECT_CPU); |
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); | |
034ebf55 VK |
119 | |
120 | trace_vmbus_negotiate_version(msg, ret); | |
121 | ||
610071c3 S |
122 | if (ret != 0) { |
123 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
124 | list_del(&msginfo->msglistentry); | |
125 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, | |
126 | flags); | |
127 | return ret; | |
128 | } | |
129 | ||
130 | /* Wait for the connection response */ | |
269f9794 | 131 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
132 | |
133 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
134 | list_del(&msginfo->msglistentry); | |
135 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
136 | ||
137 | /* Check if successful */ | |
138 | if (msginfo->response.version_response.version_supported) { | |
139 | vmbus_connection.conn_state = CONNECTED; | |
ae20b254 DC |
140 | |
141 | if (version >= VERSION_WIN10_V5) | |
142 | vmbus_connection.msg_conn_id = | |
143 | msginfo->response.version_response.msg_conn_id; | |
610071c3 | 144 | } else { |
610071c3 S |
145 | return -ECONNREFUSED; |
146 | } | |
147 | ||
148 | return ret; | |
149 | } | |
150 | ||
3e189519 | 151 | /* |
c6977677 | 152 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 153 | */ |
c6977677 | 154 | int vmbus_connect(void) |
3e7ee490 | 155 | { |
15b2f647 | 156 | struct vmbus_channel_msginfo *msginfo = NULL; |
bedc61a9 | 157 | int i, ret = 0; |
610071c3 | 158 | __u32 version; |
3e7ee490 | 159 | |
454f18a9 | 160 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
161 | vmbus_connection.conn_state = CONNECTING; |
162 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
163 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 164 | ret = -ENOMEM; |
b0043863 | 165 | goto cleanup; |
de65a384 | 166 | } |
3e7ee490 | 167 | |
37c2578c DC |
168 | vmbus_connection.handle_primary_chan_wq = |
169 | create_workqueue("hv_pri_chan"); | |
170 | if (!vmbus_connection.handle_primary_chan_wq) { | |
171 | ret = -ENOMEM; | |
172 | goto cleanup; | |
173 | } | |
174 | ||
175 | vmbus_connection.handle_sub_chan_wq = | |
176 | create_workqueue("hv_sub_chan"); | |
177 | if (!vmbus_connection.handle_sub_chan_wq) { | |
178 | ret = -ENOMEM; | |
179 | goto cleanup; | |
180 | } | |
181 | ||
da9fcb72 | 182 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 183 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 184 | |
da9fcb72 | 185 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
d6f591e3 | 186 | mutex_init(&vmbus_connection.channel_mutex); |
3e7ee490 | 187 | |
454f18a9 BP |
188 | /* |
189 | * Setup the vmbus event connection for channel interrupt | |
190 | * abstraction stuff | |
191 | */ | |
df3493e0 | 192 | vmbus_connection.int_page = |
53edce00 | 193 | (void *)hv_alloc_hyperv_zeroed_page(); |
da9fcb72 | 194 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 195 | ret = -ENOMEM; |
b0043863 | 196 | goto cleanup; |
3e7ee490 HJ |
197 | } |
198 | ||
da9fcb72 HZ |
199 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
200 | vmbus_connection.send_int_page = | |
201 | (void *)((unsigned long)vmbus_connection.int_page + | |
53edce00 | 202 | (HV_HYP_PAGE_SIZE >> 1)); |
3e7ee490 | 203 | |
fd8b85ea GKH |
204 | /* |
205 | * Setup the monitor notification facility. The 1st page for | |
206 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 207 | */ |
53edce00 HP |
208 | vmbus_connection.monitor_pages[0] = (void *)hv_alloc_hyperv_zeroed_page(); |
209 | vmbus_connection.monitor_pages[1] = (void *)hv_alloc_hyperv_zeroed_page(); | |
8681db44 GKH |
210 | if ((vmbus_connection.monitor_pages[0] == NULL) || |
211 | (vmbus_connection.monitor_pages[1] == NULL)) { | |
3a7546d9 | 212 | ret = -ENOMEM; |
b0043863 | 213 | goto cleanup; |
3e7ee490 HJ |
214 | } |
215 | ||
15b2f647 | 216 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
217 | sizeof(struct vmbus_channel_initiate_contact), |
218 | GFP_KERNEL); | |
15b2f647 | 219 | if (msginfo == NULL) { |
8cad0af9 | 220 | ret = -ENOMEM; |
b0043863 | 221 | goto cleanup; |
3e7ee490 HJ |
222 | } |
223 | ||
454f18a9 | 224 | /* |
610071c3 S |
225 | * Negotiate a compatible VMBUS version number with the |
226 | * host. We start with the highest number we can support | |
227 | * and work our way down until we negotiate a compatible | |
228 | * version. | |
454f18a9 | 229 | */ |
3e7ee490 | 230 | |
bedc61a9 AP |
231 | for (i = 0; ; i++) { |
232 | if (i == ARRAY_SIZE(vmbus_versions)) | |
233 | goto cleanup; | |
234 | ||
235 | version = vmbus_versions[i]; | |
931cccc9 AP |
236 | if (version > max_version) |
237 | continue; | |
3e7ee490 | 238 | |
610071c3 | 239 | ret = vmbus_negotiate_version(msginfo, version); |
8bbf9f44 | 240 | if (ret == -ETIMEDOUT) |
666b9adc S |
241 | goto cleanup; |
242 | ||
243 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 244 | break; |
bedc61a9 | 245 | } |
3e7ee490 | 246 | |
37f7278b | 247 | vmbus_proto_version = version; |
8de8af7e S |
248 | pr_info("Vmbus version:%d.%d\n", |
249 | version >> 16, version & 0xFFFF); | |
3bacaf0c | 250 | |
8b6a877c APM |
251 | vmbus_connection.channels = kcalloc(MAX_CHANNEL_RELIDS, |
252 | sizeof(struct vmbus_channel *), | |
253 | GFP_KERNEL); | |
254 | if (vmbus_connection.channels == NULL) { | |
255 | ret = -ENOMEM; | |
256 | goto cleanup; | |
257 | } | |
258 | ||
15b2f647 | 259 | kfree(msginfo); |
3e7ee490 HJ |
260 | return 0; |
261 | ||
b0043863 | 262 | cleanup: |
3bacaf0c | 263 | pr_err("Unable to connect to host\n"); |
09a19628 | 264 | |
da9fcb72 | 265 | vmbus_connection.conn_state = DISCONNECTED; |
09a19628 VK |
266 | vmbus_disconnect(); |
267 | ||
268 | kfree(msginfo); | |
269 | ||
270 | return ret; | |
271 | } | |
3e7ee490 | 272 | |
09a19628 VK |
273 | void vmbus_disconnect(void) |
274 | { | |
2db84eff S |
275 | /* |
276 | * First send the unload request to the host. | |
277 | */ | |
75ff3a8a | 278 | vmbus_initiate_unload(false); |
2db84eff | 279 | |
37c2578c DC |
280 | if (vmbus_connection.handle_sub_chan_wq) |
281 | destroy_workqueue(vmbus_connection.handle_sub_chan_wq); | |
282 | ||
283 | if (vmbus_connection.handle_primary_chan_wq) | |
284 | destroy_workqueue(vmbus_connection.handle_primary_chan_wq); | |
285 | ||
286 | if (vmbus_connection.work_queue) | |
da9fcb72 | 287 | destroy_workqueue(vmbus_connection.work_queue); |
3e7ee490 | 288 | |
da9fcb72 | 289 | if (vmbus_connection.int_page) { |
53edce00 | 290 | hv_free_hyperv_page((unsigned long)vmbus_connection.int_page); |
da9fcb72 | 291 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
292 | } |
293 | ||
53edce00 HP |
294 | hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[0]); |
295 | hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[1]); | |
8681db44 GKH |
296 | vmbus_connection.monitor_pages[0] = NULL; |
297 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 HJ |
298 | } |
299 | ||
3e189519 | 300 | /* |
c6977677 HZ |
301 | * relid2channel - Get the channel object given its |
302 | * child relative id (ie channel id) | |
fd8b85ea | 303 | */ |
d43e2fe7 | 304 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 305 | { |
8b6a877c APM |
306 | if (WARN_ON(relid >= MAX_CHANNEL_RELIDS)) |
307 | return NULL; | |
308 | return READ_ONCE(vmbus_connection.channels[relid]); | |
3e7ee490 HJ |
309 | } |
310 | ||
3e189519 | 311 | /* |
631e63a9 | 312 | * vmbus_on_event - Process a channel event notification |
ada6eb11 SH |
313 | * |
314 | * For batched channels (default) optimize host to guest signaling | |
315 | * by ensuring: | |
316 | * 1. While reading the channel, we disable interrupts from host. | |
317 | * 2. Ensure that we process all posted messages from the host | |
318 | * before returning from this callback. | |
319 | * 3. Once we return, enable signaling from the host. Once this | |
320 | * state is set we check to see if additional packets are | |
321 | * available to read. In this case we repeat the process. | |
322 | * If this tasklet has been running for a long time | |
323 | * then reschedule ourselves. | |
fd8b85ea | 324 | */ |
631e63a9 | 325 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 326 | { |
631e63a9 | 327 | struct vmbus_channel *channel = (void *) data; |
ada6eb11 | 328 | unsigned long time_limit = jiffies + 2; |
3e7ee490 | 329 | |
991f8f1c VK |
330 | trace_vmbus_on_event(channel); |
331 | ||
af9ca6f9 | 332 | hv_debug_delay_test(channel, INTERRUPT_DELAY); |
ada6eb11 SH |
333 | do { |
334 | void (*callback_fn)(void *); | |
335 | ||
336 | /* A channel once created is persistent even when | |
337 | * there is no driver handling the device. An | |
338 | * unloading driver sets the onchannel_callback to NULL. | |
f878f3d5 | 339 | */ |
ada6eb11 SH |
340 | callback_fn = READ_ONCE(channel->onchannel_callback); |
341 | if (unlikely(callback_fn == NULL)) | |
342 | return; | |
f878f3d5 | 343 | |
ada6eb11 SH |
344 | (*callback_fn)(channel->channel_callback_context); |
345 | ||
346 | if (channel->callback_mode != HV_CALL_BATCHED) | |
347 | return; | |
348 | ||
349 | if (likely(hv_end_read(&channel->inbound) == 0)) | |
350 | return; | |
351 | ||
352 | hv_begin_read(&channel->inbound); | |
353 | } while (likely(time_before(jiffies, time_limit))); | |
354 | ||
355 | /* The time limit (2 jiffies) has been reached */ | |
356 | tasklet_schedule(&channel->callback_event); | |
3e7ee490 HJ |
357 | } |
358 | ||
3e189519 | 359 | /* |
c6977677 | 360 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 361 | */ |
c0bb0392 | 362 | int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep) |
3e7ee490 | 363 | { |
ae20b254 | 364 | struct vmbus_channel_message_header *hdr; |
15b2f647 | 365 | union hv_connection_id conn_id; |
5289d3d1 S |
366 | int ret = 0; |
367 | int retries = 0; | |
8de0d7e9 | 368 | u32 usec = 1; |
3e7ee490 | 369 | |
15b2f647 | 370 | conn_id.asu32 = 0; |
ae20b254 | 371 | conn_id.u.id = vmbus_connection.msg_conn_id; |
5289d3d1 S |
372 | |
373 | /* | |
374 | * hv_post_message() can have transient failures because of | |
375 | * insufficient resources. Retry the operation a couple of | |
376 | * times before giving up. | |
377 | */ | |
c0bb0392 | 378 | while (retries < 100) { |
fdeebcc6 S |
379 | ret = hv_post_message(conn_id, 1, buffer, buflen); |
380 | ||
381 | switch (ret) { | |
89f9f679 | 382 | case HV_STATUS_INVALID_CONNECTION_ID: |
ae20b254 DC |
383 | /* |
384 | * See vmbus_negotiate_version(): VMBus protocol 5.0 | |
2d4f49b3 | 385 | * and higher require that we must use |
ae20b254 DC |
386 | * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate |
387 | * Contact message, but on old hosts that only | |
388 | * support VMBus protocol 4.0 or lower, here we get | |
389 | * HV_STATUS_INVALID_CONNECTION_ID and we should | |
390 | * return an error immediately without retrying. | |
391 | */ | |
89760937 | 392 | hdr = buffer; |
ae20b254 DC |
393 | if (hdr->msgtype == CHANNELMSG_INITIATE_CONTACT) |
394 | return -EINVAL; | |
89f9f679 DC |
395 | /* |
396 | * We could get this if we send messages too | |
397 | * frequently. | |
398 | */ | |
399 | ret = -EAGAIN; | |
400 | break; | |
401 | case HV_STATUS_INSUFFICIENT_MEMORY: | |
fdeebcc6 | 402 | case HV_STATUS_INSUFFICIENT_BUFFERS: |
48f4ccdf | 403 | ret = -ENOBUFS; |
fdeebcc6 S |
404 | break; |
405 | case HV_STATUS_SUCCESS: | |
5289d3d1 | 406 | return ret; |
fdeebcc6 S |
407 | default: |
408 | pr_err("hv_post_msg() failed; error code:%d\n", ret); | |
409 | return -EINVAL; | |
410 | } | |
411 | ||
5289d3d1 | 412 | retries++; |
c0bb0392 VK |
413 | if (can_sleep && usec > 1000) |
414 | msleep(usec / 1000); | |
415 | else if (usec < MAX_UDELAY_MS * 1000) | |
416 | udelay(usec); | |
417 | else | |
418 | mdelay(usec / 1000); | |
419 | ||
e917a5e2 | 420 | if (retries < 22) |
8de0d7e9 | 421 | usec *= 2; |
5289d3d1 S |
422 | } |
423 | return ret; | |
3e7ee490 HJ |
424 | } |
425 | ||
3e189519 | 426 | /* |
c6977677 | 427 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 428 | */ |
1b807e10 | 429 | void vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 430 | { |
21c3bef5 | 431 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 432 | |
5c1bec61 SH |
433 | if (!channel->is_dedicated_interrupt) |
434 | vmbus_send_interrupt(child_relid); | |
3be77774 | 435 | |
6981fbf3 SH |
436 | ++channel->sig_events; |
437 | ||
05784171 | 438 | hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event); |
3e7ee490 | 439 | } |
5cc47247 | 440 | EXPORT_SYMBOL_GPL(vmbus_set_event); |