Commit | Line | Data |
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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> |
f2f136c0 TL |
22 | #include <linux/io.h> |
23 | #include <linux/set_memory.h> | |
fc53662f VK |
24 | #include <asm/mshyperv.h> |
25 | ||
0f2a6619 | 26 | #include "hyperv_vmbus.h" |
3e7ee490 | 27 | |
3e7ee490 | 28 | |
da9fcb72 HZ |
29 | struct vmbus_connection vmbus_connection = { |
30 | .conn_state = DISCONNECTED, | |
8c2d5e06 APM |
31 | .unload_event = COMPLETION_INITIALIZER( |
32 | vmbus_connection.unload_event), | |
da9fcb72 | 33 | .next_gpadl_handle = ATOMIC_INIT(0xE1E10), |
b307b389 | 34 | |
f850a4ca | 35 | .ready_for_suspend_event = COMPLETION_INITIALIZER( |
b307b389 | 36 | vmbus_connection.ready_for_suspend_event), |
d8bd2d44 DC |
37 | .ready_for_resume_event = COMPLETION_INITIALIZER( |
38 | vmbus_connection.ready_for_resume_event), | |
3e7ee490 | 39 | }; |
95096f2f | 40 | EXPORT_SYMBOL_GPL(vmbus_connection); |
3e7ee490 | 41 | |
37f7278b S |
42 | /* |
43 | * Negotiated protocol version with the host. | |
44 | */ | |
45 | __u32 vmbus_proto_version; | |
46 | EXPORT_SYMBOL_GPL(vmbus_proto_version); | |
47 | ||
bedc61a9 AP |
48 | /* |
49 | * Table of VMBus versions listed from newest to oldest. | |
a6b94c6b MK |
50 | * VERSION_WIN7 and VERSION_WS2008 are no longer supported in |
51 | * Linux guests and are not listed. | |
bedc61a9 AP |
52 | */ |
53 | static __u32 vmbus_versions[] = { | |
1df53d21 | 54 | VERSION_WIN10_V5_3, |
2d4f49b3 AP |
55 | VERSION_WIN10_V5_2, |
56 | VERSION_WIN10_V5_1, | |
bedc61a9 | 57 | VERSION_WIN10_V5, |
2d4f49b3 | 58 | VERSION_WIN10_V4_1, |
bedc61a9 AP |
59 | VERSION_WIN10, |
60 | VERSION_WIN8_1, | |
a6b94c6b | 61 | VERSION_WIN8 |
bedc61a9 | 62 | }; |
610071c3 | 63 | |
931cccc9 AP |
64 | /* |
65 | * Maximal VMBus protocol version guests can negotiate. Useful to cap the | |
66 | * VMBus version for testing and debugging purpose. | |
67 | */ | |
1df53d21 | 68 | static uint max_version = VERSION_WIN10_V5_3; |
931cccc9 AP |
69 | |
70 | module_param(max_version, uint, S_IRUGO); | |
71 | MODULE_PARM_DESC(max_version, | |
72 | "Maximal VMBus protocol version which can be negotiated"); | |
73 | ||
f53335e3 | 74 | int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version) |
610071c3 S |
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 | ||
ae20b254 | 84 | memset(msg, 0, sizeof(*msg)); |
610071c3 S |
85 | msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; |
86 | msg->vmbus_version_requested = version; | |
ae20b254 DC |
87 | |
88 | /* | |
2d4f49b3 AP |
89 | * VMBus protocol 5.0 (VERSION_WIN10_V5) and higher require that we must |
90 | * use VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message, | |
ae20b254 DC |
91 | * and for subsequent messages, we must use the Message Connection ID |
92 | * field in the host-returned Version Response Message. And, with | |
2d4f49b3 AP |
93 | * VERSION_WIN10_V5 and higher, we don't use msg->interrupt_page, but we |
94 | * tell the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for | |
ae20b254 DC |
95 | * compatibility. |
96 | * | |
97 | * On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1). | |
98 | */ | |
99 | if (version >= VERSION_WIN10_V5) { | |
100 | msg->msg_sint = VMBUS_MESSAGE_SINT; | |
101 | vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID_4; | |
102 | } else { | |
103 | msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); | |
104 | vmbus_connection.msg_conn_id = VMBUS_MESSAGE_CONNECTION_ID; | |
105 | } | |
106 | ||
f2f136c0 TL |
107 | msg->monitor_page1 = vmbus_connection.monitor_pages_pa[0]; |
108 | msg->monitor_page2 = vmbus_connection.monitor_pages_pa[1]; | |
109 | ||
8a857c55 | 110 | msg->target_vcpu = hv_cpu_number_to_vp_number(VMBUS_CONNECT_CPU); |
610071c3 S |
111 | |
112 | /* | |
113 | * Add to list before we send the request since we may | |
114 | * receive the response before returning from this routine | |
115 | */ | |
116 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
117 | list_add_tail(&msginfo->msglistentry, | |
118 | &vmbus_connection.chn_msg_list); | |
119 | ||
120 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
121 | ||
122 | ret = vmbus_post_msg(msg, | |
c0bb0392 VK |
123 | sizeof(struct vmbus_channel_initiate_contact), |
124 | true); | |
034ebf55 VK |
125 | |
126 | trace_vmbus_negotiate_version(msg, ret); | |
127 | ||
610071c3 S |
128 | if (ret != 0) { |
129 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
130 | list_del(&msginfo->msglistentry); | |
131 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, | |
132 | flags); | |
133 | return ret; | |
134 | } | |
135 | ||
136 | /* Wait for the connection response */ | |
269f9794 | 137 | wait_for_completion(&msginfo->waitevent); |
610071c3 S |
138 | |
139 | spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); | |
140 | list_del(&msginfo->msglistentry); | |
141 | spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); | |
142 | ||
143 | /* Check if successful */ | |
144 | if (msginfo->response.version_response.version_supported) { | |
145 | vmbus_connection.conn_state = CONNECTED; | |
ae20b254 DC |
146 | |
147 | if (version >= VERSION_WIN10_V5) | |
148 | vmbus_connection.msg_conn_id = | |
149 | msginfo->response.version_response.msg_conn_id; | |
610071c3 | 150 | } else { |
610071c3 S |
151 | return -ECONNREFUSED; |
152 | } | |
153 | ||
154 | return ret; | |
155 | } | |
156 | ||
3e189519 | 157 | /* |
c6977677 | 158 | * vmbus_connect - Sends a connect request on the partition service connection |
fd8b85ea | 159 | */ |
c6977677 | 160 | int vmbus_connect(void) |
3e7ee490 | 161 | { |
15b2f647 | 162 | struct vmbus_channel_msginfo *msginfo = NULL; |
bedc61a9 | 163 | int i, ret = 0; |
610071c3 | 164 | __u32 version; |
3e7ee490 | 165 | |
454f18a9 | 166 | /* Initialize the vmbus connection */ |
da9fcb72 HZ |
167 | vmbus_connection.conn_state = CONNECTING; |
168 | vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); | |
169 | if (!vmbus_connection.work_queue) { | |
3a7546d9 | 170 | ret = -ENOMEM; |
b0043863 | 171 | goto cleanup; |
de65a384 | 172 | } |
3e7ee490 | 173 | |
52be9355 SG |
174 | vmbus_connection.rescind_work_queue = |
175 | create_workqueue("hv_vmbus_rescind"); | |
176 | if (!vmbus_connection.rescind_work_queue) { | |
177 | ret = -ENOMEM; | |
178 | goto cleanup; | |
179 | } | |
180 | vmbus_connection.ignore_any_offer_msg = false; | |
181 | ||
37c2578c DC |
182 | vmbus_connection.handle_primary_chan_wq = |
183 | create_workqueue("hv_pri_chan"); | |
184 | if (!vmbus_connection.handle_primary_chan_wq) { | |
185 | ret = -ENOMEM; | |
186 | goto cleanup; | |
187 | } | |
188 | ||
189 | vmbus_connection.handle_sub_chan_wq = | |
190 | create_workqueue("hv_sub_chan"); | |
191 | if (!vmbus_connection.handle_sub_chan_wq) { | |
192 | ret = -ENOMEM; | |
193 | goto cleanup; | |
194 | } | |
195 | ||
da9fcb72 | 196 | INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); |
15b2f647 | 197 | spin_lock_init(&vmbus_connection.channelmsg_lock); |
3e7ee490 | 198 | |
da9fcb72 | 199 | INIT_LIST_HEAD(&vmbus_connection.chn_list); |
d6f591e3 | 200 | mutex_init(&vmbus_connection.channel_mutex); |
3e7ee490 | 201 | |
454f18a9 BP |
202 | /* |
203 | * Setup the vmbus event connection for channel interrupt | |
204 | * abstraction stuff | |
205 | */ | |
df3493e0 | 206 | vmbus_connection.int_page = |
53edce00 | 207 | (void *)hv_alloc_hyperv_zeroed_page(); |
da9fcb72 | 208 | if (vmbus_connection.int_page == NULL) { |
3a7546d9 | 209 | ret = -ENOMEM; |
b0043863 | 210 | goto cleanup; |
3e7ee490 HJ |
211 | } |
212 | ||
da9fcb72 HZ |
213 | vmbus_connection.recv_int_page = vmbus_connection.int_page; |
214 | vmbus_connection.send_int_page = | |
215 | (void *)((unsigned long)vmbus_connection.int_page + | |
53edce00 | 216 | (HV_HYP_PAGE_SIZE >> 1)); |
3e7ee490 | 217 | |
fd8b85ea GKH |
218 | /* |
219 | * Setup the monitor notification facility. The 1st page for | |
220 | * parent->child and the 2nd page for child->parent | |
454f18a9 | 221 | */ |
53edce00 HP |
222 | vmbus_connection.monitor_pages[0] = (void *)hv_alloc_hyperv_zeroed_page(); |
223 | vmbus_connection.monitor_pages[1] = (void *)hv_alloc_hyperv_zeroed_page(); | |
8681db44 GKH |
224 | if ((vmbus_connection.monitor_pages[0] == NULL) || |
225 | (vmbus_connection.monitor_pages[1] == NULL)) { | |
3a7546d9 | 226 | ret = -ENOMEM; |
b0043863 | 227 | goto cleanup; |
3e7ee490 HJ |
228 | } |
229 | ||
f2f136c0 TL |
230 | vmbus_connection.monitor_pages_original[0] |
231 | = vmbus_connection.monitor_pages[0]; | |
232 | vmbus_connection.monitor_pages_original[1] | |
233 | = vmbus_connection.monitor_pages[1]; | |
234 | vmbus_connection.monitor_pages_pa[0] | |
235 | = virt_to_phys(vmbus_connection.monitor_pages[0]); | |
236 | vmbus_connection.monitor_pages_pa[1] | |
237 | = virt_to_phys(vmbus_connection.monitor_pages[1]); | |
238 | ||
239 | if (hv_is_isolation_supported()) { | |
240 | ret = set_memory_decrypted((unsigned long) | |
241 | vmbus_connection.monitor_pages[0], | |
242 | 1); | |
243 | ret |= set_memory_decrypted((unsigned long) | |
244 | vmbus_connection.monitor_pages[1], | |
245 | 1); | |
246 | if (ret) | |
247 | goto cleanup; | |
248 | ||
249 | /* | |
250 | * Isolation VM with AMD SNP needs to access monitor page via | |
251 | * address space above shared gpa boundary. | |
252 | */ | |
253 | if (hv_isolation_type_snp()) { | |
254 | vmbus_connection.monitor_pages_pa[0] += | |
255 | ms_hyperv.shared_gpa_boundary; | |
256 | vmbus_connection.monitor_pages_pa[1] += | |
257 | ms_hyperv.shared_gpa_boundary; | |
258 | ||
259 | vmbus_connection.monitor_pages[0] | |
260 | = memremap(vmbus_connection.monitor_pages_pa[0], | |
261 | HV_HYP_PAGE_SIZE, | |
262 | MEMREMAP_WB); | |
263 | if (!vmbus_connection.monitor_pages[0]) { | |
264 | ret = -ENOMEM; | |
265 | goto cleanup; | |
266 | } | |
267 | ||
268 | vmbus_connection.monitor_pages[1] | |
269 | = memremap(vmbus_connection.monitor_pages_pa[1], | |
270 | HV_HYP_PAGE_SIZE, | |
271 | MEMREMAP_WB); | |
272 | if (!vmbus_connection.monitor_pages[1]) { | |
273 | ret = -ENOMEM; | |
274 | goto cleanup; | |
275 | } | |
276 | } | |
277 | ||
278 | /* | |
279 | * Set memory host visibility hvcall smears memory | |
280 | * and so zero monitor pages here. | |
281 | */ | |
282 | memset(vmbus_connection.monitor_pages[0], 0x00, | |
283 | HV_HYP_PAGE_SIZE); | |
284 | memset(vmbus_connection.monitor_pages[1], 0x00, | |
285 | HV_HYP_PAGE_SIZE); | |
286 | ||
287 | } | |
288 | ||
15b2f647 | 289 | msginfo = kzalloc(sizeof(*msginfo) + |
fd8b85ea GKH |
290 | sizeof(struct vmbus_channel_initiate_contact), |
291 | GFP_KERNEL); | |
15b2f647 | 292 | if (msginfo == NULL) { |
8cad0af9 | 293 | ret = -ENOMEM; |
b0043863 | 294 | goto cleanup; |
3e7ee490 HJ |
295 | } |
296 | ||
454f18a9 | 297 | /* |
610071c3 S |
298 | * Negotiate a compatible VMBUS version number with the |
299 | * host. We start with the highest number we can support | |
300 | * and work our way down until we negotiate a compatible | |
301 | * version. | |
454f18a9 | 302 | */ |
3e7ee490 | 303 | |
bedc61a9 | 304 | for (i = 0; ; i++) { |
9de6655c JC |
305 | if (i == ARRAY_SIZE(vmbus_versions)) { |
306 | ret = -EDOM; | |
bedc61a9 | 307 | goto cleanup; |
9de6655c | 308 | } |
bedc61a9 AP |
309 | |
310 | version = vmbus_versions[i]; | |
931cccc9 AP |
311 | if (version > max_version) |
312 | continue; | |
3e7ee490 | 313 | |
610071c3 | 314 | ret = vmbus_negotiate_version(msginfo, version); |
8bbf9f44 | 315 | if (ret == -ETIMEDOUT) |
666b9adc S |
316 | goto cleanup; |
317 | ||
318 | if (vmbus_connection.conn_state == CONNECTED) | |
610071c3 | 319 | break; |
bedc61a9 | 320 | } |
3e7ee490 | 321 | |
7ef4b2f0 APM |
322 | if (hv_is_isolation_supported() && version < VERSION_WIN10_V5_2) { |
323 | pr_err("Invalid VMBus version %d.%d (expected >= %d.%d) from the host supporting isolation\n", | |
324 | version >> 16, version & 0xFFFF, VERSION_WIN10_V5_2 >> 16, VERSION_WIN10_V5_2 & 0xFFFF); | |
325 | ret = -EINVAL; | |
326 | goto cleanup; | |
327 | } | |
328 | ||
37f7278b | 329 | vmbus_proto_version = version; |
8de8af7e S |
330 | pr_info("Vmbus version:%d.%d\n", |
331 | version >> 16, version & 0xFFFF); | |
3bacaf0c | 332 | |
8b6a877c APM |
333 | vmbus_connection.channels = kcalloc(MAX_CHANNEL_RELIDS, |
334 | sizeof(struct vmbus_channel *), | |
335 | GFP_KERNEL); | |
336 | if (vmbus_connection.channels == NULL) { | |
337 | ret = -ENOMEM; | |
338 | goto cleanup; | |
339 | } | |
340 | ||
15b2f647 | 341 | kfree(msginfo); |
3e7ee490 HJ |
342 | return 0; |
343 | ||
b0043863 | 344 | cleanup: |
3bacaf0c | 345 | pr_err("Unable to connect to host\n"); |
09a19628 | 346 | |
da9fcb72 | 347 | vmbus_connection.conn_state = DISCONNECTED; |
09a19628 VK |
348 | vmbus_disconnect(); |
349 | ||
350 | kfree(msginfo); | |
351 | ||
352 | return ret; | |
353 | } | |
3e7ee490 | 354 | |
09a19628 VK |
355 | void vmbus_disconnect(void) |
356 | { | |
2db84eff S |
357 | /* |
358 | * First send the unload request to the host. | |
359 | */ | |
75ff3a8a | 360 | vmbus_initiate_unload(false); |
2db84eff | 361 | |
37c2578c DC |
362 | if (vmbus_connection.handle_sub_chan_wq) |
363 | destroy_workqueue(vmbus_connection.handle_sub_chan_wq); | |
364 | ||
365 | if (vmbus_connection.handle_primary_chan_wq) | |
366 | destroy_workqueue(vmbus_connection.handle_primary_chan_wq); | |
367 | ||
52be9355 SG |
368 | if (vmbus_connection.rescind_work_queue) |
369 | destroy_workqueue(vmbus_connection.rescind_work_queue); | |
370 | ||
37c2578c | 371 | if (vmbus_connection.work_queue) |
da9fcb72 | 372 | destroy_workqueue(vmbus_connection.work_queue); |
3e7ee490 | 373 | |
da9fcb72 | 374 | if (vmbus_connection.int_page) { |
53edce00 | 375 | hv_free_hyperv_page((unsigned long)vmbus_connection.int_page); |
da9fcb72 | 376 | vmbus_connection.int_page = NULL; |
3e7ee490 HJ |
377 | } |
378 | ||
f2f136c0 TL |
379 | if (hv_is_isolation_supported()) { |
380 | /* | |
381 | * memunmap() checks input address is ioremap address or not | |
382 | * inside. It doesn't unmap any thing in the non-SNP CVM and | |
383 | * so not check CVM type here. | |
384 | */ | |
385 | memunmap(vmbus_connection.monitor_pages[0]); | |
386 | memunmap(vmbus_connection.monitor_pages[1]); | |
387 | ||
388 | set_memory_encrypted((unsigned long) | |
389 | vmbus_connection.monitor_pages_original[0], | |
390 | 1); | |
391 | set_memory_encrypted((unsigned long) | |
392 | vmbus_connection.monitor_pages_original[1], | |
393 | 1); | |
394 | } | |
395 | ||
396 | hv_free_hyperv_page((unsigned long) | |
397 | vmbus_connection.monitor_pages_original[0]); | |
398 | hv_free_hyperv_page((unsigned long) | |
399 | vmbus_connection.monitor_pages_original[1]); | |
400 | vmbus_connection.monitor_pages_original[0] = | |
401 | vmbus_connection.monitor_pages[0] = NULL; | |
402 | vmbus_connection.monitor_pages_original[1] = | |
403 | vmbus_connection.monitor_pages[1] = NULL; | |
3e7ee490 HJ |
404 | } |
405 | ||
3e189519 | 406 | /* |
c6977677 HZ |
407 | * relid2channel - Get the channel object given its |
408 | * child relative id (ie channel id) | |
fd8b85ea | 409 | */ |
d43e2fe7 | 410 | struct vmbus_channel *relid2channel(u32 relid) |
3e7ee490 | 411 | { |
1eb65c86 MG |
412 | if (vmbus_connection.channels == NULL) { |
413 | pr_warn_once("relid2channel: relid=%d: No channels mapped!\n", relid); | |
414 | return NULL; | |
415 | } | |
8b6a877c APM |
416 | if (WARN_ON(relid >= MAX_CHANNEL_RELIDS)) |
417 | return NULL; | |
418 | return READ_ONCE(vmbus_connection.channels[relid]); | |
3e7ee490 HJ |
419 | } |
420 | ||
3e189519 | 421 | /* |
631e63a9 | 422 | * vmbus_on_event - Process a channel event notification |
ada6eb11 SH |
423 | * |
424 | * For batched channels (default) optimize host to guest signaling | |
425 | * by ensuring: | |
426 | * 1. While reading the channel, we disable interrupts from host. | |
427 | * 2. Ensure that we process all posted messages from the host | |
428 | * before returning from this callback. | |
429 | * 3. Once we return, enable signaling from the host. Once this | |
430 | * state is set we check to see if additional packets are | |
431 | * available to read. In this case we repeat the process. | |
432 | * If this tasklet has been running for a long time | |
433 | * then reschedule ourselves. | |
fd8b85ea | 434 | */ |
631e63a9 | 435 | void vmbus_on_event(unsigned long data) |
3e7ee490 | 436 | { |
631e63a9 | 437 | struct vmbus_channel *channel = (void *) data; |
78c65f0f | 438 | void (*callback_fn)(void *context); |
3e7ee490 | 439 | |
991f8f1c VK |
440 | trace_vmbus_on_event(channel); |
441 | ||
af9ca6f9 | 442 | hv_debug_delay_test(channel, INTERRUPT_DELAY); |
ada6eb11 | 443 | |
78c65f0f SS |
444 | /* A channel once created is persistent even when |
445 | * there is no driver handling the device. An | |
446 | * unloading driver sets the onchannel_callback to NULL. | |
447 | */ | |
448 | callback_fn = READ_ONCE(channel->onchannel_callback); | |
449 | if (unlikely(!callback_fn)) | |
450 | return; | |
ada6eb11 | 451 | |
78c65f0f | 452 | (*callback_fn)(channel->channel_callback_context); |
ada6eb11 | 453 | |
78c65f0f SS |
454 | if (channel->callback_mode != HV_CALL_BATCHED) |
455 | return; | |
ada6eb11 | 456 | |
78c65f0f SS |
457 | if (likely(hv_end_read(&channel->inbound) == 0)) |
458 | return; | |
ada6eb11 | 459 | |
78c65f0f | 460 | hv_begin_read(&channel->inbound); |
ada6eb11 | 461 | tasklet_schedule(&channel->callback_event); |
3e7ee490 HJ |
462 | } |
463 | ||
3e189519 | 464 | /* |
c6977677 | 465 | * vmbus_post_msg - Send a msg on the vmbus's message connection |
fd8b85ea | 466 | */ |
c0bb0392 | 467 | int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep) |
3e7ee490 | 468 | { |
ae20b254 | 469 | struct vmbus_channel_message_header *hdr; |
15b2f647 | 470 | union hv_connection_id conn_id; |
5289d3d1 S |
471 | int ret = 0; |
472 | int retries = 0; | |
8de0d7e9 | 473 | u32 usec = 1; |
3e7ee490 | 474 | |
15b2f647 | 475 | conn_id.asu32 = 0; |
ae20b254 | 476 | conn_id.u.id = vmbus_connection.msg_conn_id; |
5289d3d1 S |
477 | |
478 | /* | |
479 | * hv_post_message() can have transient failures because of | |
480 | * insufficient resources. Retry the operation a couple of | |
481 | * times before giving up. | |
482 | */ | |
c0bb0392 | 483 | while (retries < 100) { |
fdeebcc6 S |
484 | ret = hv_post_message(conn_id, 1, buffer, buflen); |
485 | ||
486 | switch (ret) { | |
89f9f679 | 487 | case HV_STATUS_INVALID_CONNECTION_ID: |
ae20b254 DC |
488 | /* |
489 | * See vmbus_negotiate_version(): VMBus protocol 5.0 | |
2d4f49b3 | 490 | * and higher require that we must use |
ae20b254 DC |
491 | * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate |
492 | * Contact message, but on old hosts that only | |
493 | * support VMBus protocol 4.0 or lower, here we get | |
494 | * HV_STATUS_INVALID_CONNECTION_ID and we should | |
495 | * return an error immediately without retrying. | |
496 | */ | |
89760937 | 497 | hdr = buffer; |
ae20b254 DC |
498 | if (hdr->msgtype == CHANNELMSG_INITIATE_CONTACT) |
499 | return -EINVAL; | |
89f9f679 DC |
500 | /* |
501 | * We could get this if we send messages too | |
502 | * frequently. | |
503 | */ | |
504 | ret = -EAGAIN; | |
505 | break; | |
506 | case HV_STATUS_INSUFFICIENT_MEMORY: | |
fdeebcc6 | 507 | case HV_STATUS_INSUFFICIENT_BUFFERS: |
48f4ccdf | 508 | ret = -ENOBUFS; |
fdeebcc6 S |
509 | break; |
510 | case HV_STATUS_SUCCESS: | |
5289d3d1 | 511 | return ret; |
fdeebcc6 S |
512 | default: |
513 | pr_err("hv_post_msg() failed; error code:%d\n", ret); | |
514 | return -EINVAL; | |
515 | } | |
516 | ||
5289d3d1 | 517 | retries++; |
c0bb0392 VK |
518 | if (can_sleep && usec > 1000) |
519 | msleep(usec / 1000); | |
520 | else if (usec < MAX_UDELAY_MS * 1000) | |
521 | udelay(usec); | |
522 | else | |
523 | mdelay(usec / 1000); | |
524 | ||
e917a5e2 | 525 | if (retries < 22) |
8de0d7e9 | 526 | usec *= 2; |
5289d3d1 S |
527 | } |
528 | return ret; | |
3e7ee490 HJ |
529 | } |
530 | ||
3e189519 | 531 | /* |
c6977677 | 532 | * vmbus_set_event - Send an event notification to the parent |
fd8b85ea | 533 | */ |
1b807e10 | 534 | void vmbus_set_event(struct vmbus_channel *channel) |
3e7ee490 | 535 | { |
21c3bef5 | 536 | u32 child_relid = channel->offermsg.child_relid; |
7c369f40 | 537 | |
5c1bec61 SH |
538 | if (!channel->is_dedicated_interrupt) |
539 | vmbus_send_interrupt(child_relid); | |
3be77774 | 540 | |
6981fbf3 SH |
541 | ++channel->sig_events; |
542 | ||
20c89a55 TL |
543 | if (hv_isolation_type_snp()) |
544 | hv_ghcb_hypercall(HVCALL_SIGNAL_EVENT, &channel->sig_event, | |
545 | NULL, sizeof(channel->sig_event)); | |
546 | else | |
547 | hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event); | |
3e7ee490 | 548 | } |
5cc47247 | 549 | EXPORT_SYMBOL_GPL(vmbus_set_event); |