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9aa8b50b S |
1 | /* |
2 | * Copyright (c) 2012, Microsoft Corporation. | |
3 | * | |
4 | * Author: | |
5 | * K. Y. Srinivasan <kys@microsoft.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License version 2 as published | |
9 | * by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
14 | * NON INFRINGEMENT. See the GNU General Public License for more | |
15 | * details. | |
16 | * | |
17 | */ | |
18 | ||
19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
20 | ||
21 | #include <linux/kernel.h> | |
22 | #include <linux/mman.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/kthread.h> | |
28 | #include <linux/completion.h> | |
29 | #include <linux/memory_hotplug.h> | |
30 | #include <linux/memory.h> | |
31 | #include <linux/notifier.h> | |
9aa8b50b S |
32 | #include <linux/percpu_counter.h> |
33 | ||
34 | #include <linux/hyperv.h> | |
35 | ||
36 | /* | |
37 | * We begin with definitions supporting the Dynamic Memory protocol | |
38 | * with the host. | |
39 | * | |
40 | * Begin protocol definitions. | |
41 | */ | |
42 | ||
43 | ||
44 | ||
45 | /* | |
46 | * Protocol versions. The low word is the minor version, the high word the major | |
47 | * version. | |
48 | * | |
49 | * History: | |
50 | * Initial version 1.0 | |
51 | * Changed to 0.1 on 2009/03/25 | |
52 | * Changes to 0.2 on 2009/05/14 | |
53 | * Changes to 0.3 on 2009/12/03 | |
54 | * Changed to 1.0 on 2011/04/05 | |
55 | */ | |
56 | ||
57 | #define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor))) | |
58 | #define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16) | |
59 | #define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff) | |
60 | ||
61 | enum { | |
62 | DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3), | |
63 | DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0), | |
64 | ||
65 | DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1, | |
66 | DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2, | |
67 | ||
68 | DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN8 | |
69 | }; | |
70 | ||
71 | ||
72 | ||
73 | /* | |
74 | * Message Types | |
75 | */ | |
76 | ||
77 | enum dm_message_type { | |
78 | /* | |
79 | * Version 0.3 | |
80 | */ | |
81 | DM_ERROR = 0, | |
82 | DM_VERSION_REQUEST = 1, | |
83 | DM_VERSION_RESPONSE = 2, | |
84 | DM_CAPABILITIES_REPORT = 3, | |
85 | DM_CAPABILITIES_RESPONSE = 4, | |
86 | DM_STATUS_REPORT = 5, | |
87 | DM_BALLOON_REQUEST = 6, | |
88 | DM_BALLOON_RESPONSE = 7, | |
89 | DM_UNBALLOON_REQUEST = 8, | |
90 | DM_UNBALLOON_RESPONSE = 9, | |
91 | DM_MEM_HOT_ADD_REQUEST = 10, | |
92 | DM_MEM_HOT_ADD_RESPONSE = 11, | |
93 | DM_VERSION_03_MAX = 11, | |
94 | /* | |
95 | * Version 1.0. | |
96 | */ | |
97 | DM_INFO_MESSAGE = 12, | |
98 | DM_VERSION_1_MAX = 12 | |
99 | }; | |
100 | ||
101 | ||
102 | /* | |
103 | * Structures defining the dynamic memory management | |
104 | * protocol. | |
105 | */ | |
106 | ||
107 | union dm_version { | |
108 | struct { | |
109 | __u16 minor_version; | |
110 | __u16 major_version; | |
111 | }; | |
112 | __u32 version; | |
113 | } __packed; | |
114 | ||
115 | ||
116 | union dm_caps { | |
117 | struct { | |
118 | __u64 balloon:1; | |
119 | __u64 hot_add:1; | |
120 | __u64 reservedz:62; | |
121 | } cap_bits; | |
122 | __u64 caps; | |
123 | } __packed; | |
124 | ||
125 | union dm_mem_page_range { | |
126 | struct { | |
127 | /* | |
128 | * The PFN number of the first page in the range. | |
129 | * 40 bits is the architectural limit of a PFN | |
130 | * number for AMD64. | |
131 | */ | |
132 | __u64 start_page:40; | |
133 | /* | |
134 | * The number of pages in the range. | |
135 | */ | |
136 | __u64 page_cnt:24; | |
137 | } finfo; | |
138 | __u64 page_range; | |
139 | } __packed; | |
140 | ||
141 | ||
142 | ||
143 | /* | |
144 | * The header for all dynamic memory messages: | |
145 | * | |
146 | * type: Type of the message. | |
147 | * size: Size of the message in bytes; including the header. | |
148 | * trans_id: The guest is responsible for manufacturing this ID. | |
149 | */ | |
150 | ||
151 | struct dm_header { | |
152 | __u16 type; | |
153 | __u16 size; | |
154 | __u32 trans_id; | |
155 | } __packed; | |
156 | ||
157 | /* | |
158 | * A generic message format for dynamic memory. | |
159 | * Specific message formats are defined later in the file. | |
160 | */ | |
161 | ||
162 | struct dm_message { | |
163 | struct dm_header hdr; | |
164 | __u8 data[]; /* enclosed message */ | |
165 | } __packed; | |
166 | ||
167 | ||
168 | /* | |
169 | * Specific message types supporting the dynamic memory protocol. | |
170 | */ | |
171 | ||
172 | /* | |
173 | * Version negotiation message. Sent from the guest to the host. | |
174 | * The guest is free to try different versions until the host | |
175 | * accepts the version. | |
176 | * | |
177 | * dm_version: The protocol version requested. | |
178 | * is_last_attempt: If TRUE, this is the last version guest will request. | |
179 | * reservedz: Reserved field, set to zero. | |
180 | */ | |
181 | ||
182 | struct dm_version_request { | |
183 | struct dm_header hdr; | |
184 | union dm_version version; | |
185 | __u32 is_last_attempt:1; | |
186 | __u32 reservedz:31; | |
187 | } __packed; | |
188 | ||
189 | /* | |
190 | * Version response message; Host to Guest and indicates | |
191 | * if the host has accepted the version sent by the guest. | |
192 | * | |
193 | * is_accepted: If TRUE, host has accepted the version and the guest | |
194 | * should proceed to the next stage of the protocol. FALSE indicates that | |
195 | * guest should re-try with a different version. | |
196 | * | |
197 | * reservedz: Reserved field, set to zero. | |
198 | */ | |
199 | ||
200 | struct dm_version_response { | |
201 | struct dm_header hdr; | |
202 | __u64 is_accepted:1; | |
203 | __u64 reservedz:63; | |
204 | } __packed; | |
205 | ||
206 | /* | |
207 | * Message reporting capabilities. This is sent from the guest to the | |
208 | * host. | |
209 | */ | |
210 | ||
211 | struct dm_capabilities { | |
212 | struct dm_header hdr; | |
213 | union dm_caps caps; | |
214 | __u64 min_page_cnt; | |
215 | __u64 max_page_number; | |
216 | } __packed; | |
217 | ||
218 | /* | |
219 | * Response to the capabilities message. This is sent from the host to the | |
220 | * guest. This message notifies if the host has accepted the guest's | |
221 | * capabilities. If the host has not accepted, the guest must shutdown | |
222 | * the service. | |
223 | * | |
224 | * is_accepted: Indicates if the host has accepted guest's capabilities. | |
225 | * reservedz: Must be 0. | |
226 | */ | |
227 | ||
228 | struct dm_capabilities_resp_msg { | |
229 | struct dm_header hdr; | |
230 | __u64 is_accepted:1; | |
231 | __u64 reservedz:63; | |
232 | } __packed; | |
233 | ||
234 | /* | |
235 | * This message is used to report memory pressure from the guest. | |
236 | * This message is not part of any transaction and there is no | |
237 | * response to this message. | |
238 | * | |
239 | * num_avail: Available memory in pages. | |
240 | * num_committed: Committed memory in pages. | |
241 | * page_file_size: The accumulated size of all page files | |
242 | * in the system in pages. | |
243 | * zero_free: The nunber of zero and free pages. | |
244 | * page_file_writes: The writes to the page file in pages. | |
245 | * io_diff: An indicator of file cache efficiency or page file activity, | |
246 | * calculated as File Cache Page Fault Count - Page Read Count. | |
247 | * This value is in pages. | |
248 | * | |
249 | * Some of these metrics are Windows specific and fortunately | |
250 | * the algorithm on the host side that computes the guest memory | |
251 | * pressure only uses num_committed value. | |
252 | */ | |
253 | ||
254 | struct dm_status { | |
255 | struct dm_header hdr; | |
256 | __u64 num_avail; | |
257 | __u64 num_committed; | |
258 | __u64 page_file_size; | |
259 | __u64 zero_free; | |
260 | __u32 page_file_writes; | |
261 | __u32 io_diff; | |
262 | } __packed; | |
263 | ||
264 | ||
265 | /* | |
266 | * Message to ask the guest to allocate memory - balloon up message. | |
267 | * This message is sent from the host to the guest. The guest may not be | |
268 | * able to allocate as much memory as requested. | |
269 | * | |
270 | * num_pages: number of pages to allocate. | |
271 | */ | |
272 | ||
273 | struct dm_balloon { | |
274 | struct dm_header hdr; | |
275 | __u32 num_pages; | |
276 | __u32 reservedz; | |
277 | } __packed; | |
278 | ||
279 | ||
280 | /* | |
281 | * Balloon response message; this message is sent from the guest | |
282 | * to the host in response to the balloon message. | |
283 | * | |
284 | * reservedz: Reserved; must be set to zero. | |
285 | * more_pages: If FALSE, this is the last message of the transaction. | |
286 | * if TRUE there will atleast one more message from the guest. | |
287 | * | |
288 | * range_count: The number of ranges in the range array. | |
289 | * | |
290 | * range_array: An array of page ranges returned to the host. | |
291 | * | |
292 | */ | |
293 | ||
294 | struct dm_balloon_response { | |
295 | struct dm_header hdr; | |
296 | __u32 reservedz; | |
297 | __u32 more_pages:1; | |
298 | __u32 range_count:31; | |
299 | union dm_mem_page_range range_array[]; | |
300 | } __packed; | |
301 | ||
302 | /* | |
303 | * Un-balloon message; this message is sent from the host | |
304 | * to the guest to give guest more memory. | |
305 | * | |
306 | * more_pages: If FALSE, this is the last message of the transaction. | |
307 | * if TRUE there will atleast one more message from the guest. | |
308 | * | |
309 | * reservedz: Reserved; must be set to zero. | |
310 | * | |
311 | * range_count: The number of ranges in the range array. | |
312 | * | |
313 | * range_array: An array of page ranges returned to the host. | |
314 | * | |
315 | */ | |
316 | ||
317 | struct dm_unballoon_request { | |
318 | struct dm_header hdr; | |
319 | __u32 more_pages:1; | |
320 | __u32 reservedz:31; | |
321 | __u32 range_count; | |
322 | union dm_mem_page_range range_array[]; | |
323 | } __packed; | |
324 | ||
325 | /* | |
326 | * Un-balloon response message; this message is sent from the guest | |
327 | * to the host in response to an unballoon request. | |
328 | * | |
329 | */ | |
330 | ||
331 | struct dm_unballoon_response { | |
332 | struct dm_header hdr; | |
333 | } __packed; | |
334 | ||
335 | ||
336 | /* | |
337 | * Hot add request message. Message sent from the host to the guest. | |
338 | * | |
339 | * mem_range: Memory range to hot add. | |
340 | * | |
341 | * On Linux we currently don't support this since we cannot hot add | |
342 | * arbitrary granularity of memory. | |
343 | */ | |
344 | ||
345 | struct dm_hot_add { | |
346 | struct dm_header hdr; | |
347 | union dm_mem_page_range range; | |
348 | } __packed; | |
349 | ||
350 | /* | |
351 | * Hot add response message. | |
352 | * This message is sent by the guest to report the status of a hot add request. | |
353 | * If page_count is less than the requested page count, then the host should | |
354 | * assume all further hot add requests will fail, since this indicates that | |
355 | * the guest has hit an upper physical memory barrier. | |
356 | * | |
357 | * Hot adds may also fail due to low resources; in this case, the guest must | |
358 | * not complete this message until the hot add can succeed, and the host must | |
359 | * not send a new hot add request until the response is sent. | |
360 | * If VSC fails to hot add memory DYNMEM_NUMBER_OF_UNSUCCESSFUL_HOTADD_ATTEMPTS | |
361 | * times it fails the request. | |
362 | * | |
363 | * | |
364 | * page_count: number of pages that were successfully hot added. | |
365 | * | |
366 | * result: result of the operation 1: success, 0: failure. | |
367 | * | |
368 | */ | |
369 | ||
370 | struct dm_hot_add_response { | |
371 | struct dm_header hdr; | |
372 | __u32 page_count; | |
373 | __u32 result; | |
374 | } __packed; | |
375 | ||
376 | /* | |
377 | * Types of information sent from host to the guest. | |
378 | */ | |
379 | ||
380 | enum dm_info_type { | |
381 | INFO_TYPE_MAX_PAGE_CNT = 0, | |
382 | MAX_INFO_TYPE | |
383 | }; | |
384 | ||
385 | ||
386 | /* | |
387 | * Header for the information message. | |
388 | */ | |
389 | ||
390 | struct dm_info_header { | |
391 | enum dm_info_type type; | |
392 | __u32 data_size; | |
393 | } __packed; | |
394 | ||
395 | /* | |
396 | * This message is sent from the host to the guest to pass | |
397 | * some relevant information (win8 addition). | |
398 | * | |
399 | * reserved: no used. | |
400 | * info_size: size of the information blob. | |
401 | * info: information blob. | |
402 | */ | |
403 | ||
404 | struct dm_info_msg { | |
6427a0d7 | 405 | struct dm_header hdr; |
9aa8b50b S |
406 | __u32 reserved; |
407 | __u32 info_size; | |
408 | __u8 info[]; | |
409 | }; | |
410 | ||
411 | /* | |
412 | * End protocol definitions. | |
413 | */ | |
414 | ||
415 | static bool hot_add; | |
416 | static bool do_hot_add; | |
e500d158 S |
417 | /* |
418 | * Delay reporting memory pressure by | |
419 | * the specified number of seconds. | |
420 | */ | |
421 | static uint pressure_report_delay = 30; | |
9aa8b50b S |
422 | |
423 | module_param(hot_add, bool, (S_IRUGO | S_IWUSR)); | |
424 | MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add"); | |
425 | ||
e500d158 S |
426 | module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR)); |
427 | MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure"); | |
9aa8b50b S |
428 | static atomic_t trans_id = ATOMIC_INIT(0); |
429 | ||
430 | static int dm_ring_size = (5 * PAGE_SIZE); | |
431 | ||
432 | /* | |
433 | * Driver specific state. | |
434 | */ | |
435 | ||
436 | enum hv_dm_state { | |
437 | DM_INITIALIZING = 0, | |
438 | DM_INITIALIZED, | |
439 | DM_BALLOON_UP, | |
440 | DM_BALLOON_DOWN, | |
441 | DM_HOT_ADD, | |
442 | DM_INIT_ERROR | |
443 | }; | |
444 | ||
445 | ||
446 | static __u8 recv_buffer[PAGE_SIZE]; | |
447 | static __u8 *send_buffer; | |
448 | #define PAGES_IN_2M 512 | |
449 | ||
450 | struct hv_dynmem_device { | |
451 | struct hv_device *dev; | |
452 | enum hv_dm_state state; | |
453 | struct completion host_event; | |
454 | struct completion config_event; | |
455 | ||
456 | /* | |
457 | * Number of pages we have currently ballooned out. | |
458 | */ | |
459 | unsigned int num_pages_ballooned; | |
460 | ||
461 | /* | |
462 | * This thread handles both balloon/hot-add | |
463 | * requests from the host as well as notifying | |
464 | * the host with regards to memory pressure in | |
465 | * the guest. | |
466 | */ | |
467 | struct task_struct *thread; | |
468 | ||
469 | /* | |
470 | * We start with the highest version we can support | |
471 | * and downgrade based on the host; we save here the | |
472 | * next version to try. | |
473 | */ | |
474 | __u32 next_version; | |
475 | }; | |
476 | ||
477 | static struct hv_dynmem_device dm_device; | |
478 | ||
479 | static void hot_add_req(struct hv_dynmem_device *dm, struct dm_hot_add *msg) | |
480 | { | |
481 | ||
482 | struct dm_hot_add_response resp; | |
483 | ||
484 | if (do_hot_add) { | |
485 | ||
486 | pr_info("Memory hot add not supported\n"); | |
487 | ||
488 | /* | |
489 | * Currently we do not support hot add. | |
490 | * Just fail the request. | |
491 | */ | |
492 | } | |
493 | ||
494 | memset(&resp, 0, sizeof(struct dm_hot_add_response)); | |
495 | resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE; | |
496 | resp.hdr.size = sizeof(struct dm_hot_add_response); | |
497 | resp.hdr.trans_id = atomic_inc_return(&trans_id); | |
498 | ||
499 | resp.page_count = 0; | |
500 | resp.result = 0; | |
501 | ||
502 | dm->state = DM_INITIALIZED; | |
503 | vmbus_sendpacket(dm->dev->channel, &resp, | |
504 | sizeof(struct dm_hot_add_response), | |
505 | (unsigned long)NULL, | |
506 | VM_PKT_DATA_INBAND, 0); | |
507 | ||
508 | } | |
509 | ||
510 | static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg) | |
511 | { | |
6427a0d7 S |
512 | struct dm_info_header *info_hdr; |
513 | ||
514 | info_hdr = (struct dm_info_header *)msg->info; | |
515 | ||
516 | switch (info_hdr->type) { | |
9aa8b50b S |
517 | case INFO_TYPE_MAX_PAGE_CNT: |
518 | pr_info("Received INFO_TYPE_MAX_PAGE_CNT\n"); | |
6427a0d7 | 519 | pr_info("Data Size is %d\n", info_hdr->data_size); |
9aa8b50b S |
520 | break; |
521 | default: | |
6427a0d7 | 522 | pr_info("Received Unknown type: %d\n", info_hdr->type); |
9aa8b50b S |
523 | } |
524 | } | |
525 | ||
1c7db96f S |
526 | unsigned long compute_balloon_floor(void) |
527 | { | |
528 | unsigned long min_pages; | |
529 | #define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT)) | |
530 | /* Simple continuous piecewiese linear function: | |
531 | * max MiB -> min MiB gradient | |
532 | * 0 0 | |
533 | * 16 16 | |
534 | * 32 24 | |
535 | * 128 72 (1/2) | |
536 | * 512 168 (1/4) | |
537 | * 2048 360 (1/8) | |
538 | * 8192 552 (1/32) | |
539 | * 32768 1320 | |
540 | * 131072 4392 | |
541 | */ | |
542 | if (totalram_pages < MB2PAGES(128)) | |
543 | min_pages = MB2PAGES(8) + (totalram_pages >> 1); | |
544 | else if (totalram_pages < MB2PAGES(512)) | |
545 | min_pages = MB2PAGES(40) + (totalram_pages >> 2); | |
546 | else if (totalram_pages < MB2PAGES(2048)) | |
547 | min_pages = MB2PAGES(104) + (totalram_pages >> 3); | |
548 | else | |
549 | min_pages = MB2PAGES(296) + (totalram_pages >> 5); | |
550 | #undef MB2PAGES | |
551 | return min_pages; | |
552 | } | |
553 | ||
9aa8b50b S |
554 | /* |
555 | * Post our status as it relates memory pressure to the | |
556 | * host. Host expects the guests to post this status | |
557 | * periodically at 1 second intervals. | |
558 | * | |
559 | * The metrics specified in this protocol are very Windows | |
560 | * specific and so we cook up numbers here to convey our memory | |
561 | * pressure. | |
562 | */ | |
563 | ||
564 | static void post_status(struct hv_dynmem_device *dm) | |
565 | { | |
566 | struct dm_status status; | |
0731572b | 567 | struct sysinfo val; |
9aa8b50b | 568 | |
e500d158 S |
569 | if (pressure_report_delay > 0) { |
570 | --pressure_report_delay; | |
571 | return; | |
572 | } | |
0731572b | 573 | si_meminfo(&val); |
9aa8b50b S |
574 | memset(&status, 0, sizeof(struct dm_status)); |
575 | status.hdr.type = DM_STATUS_REPORT; | |
576 | status.hdr.size = sizeof(struct dm_status); | |
577 | status.hdr.trans_id = atomic_inc_return(&trans_id); | |
578 | ||
0731572b S |
579 | /* |
580 | * The host expects the guest to report free memory. | |
581 | * Further, the host expects the pressure information to | |
582 | * include the ballooned out pages. | |
1c7db96f S |
583 | * For a given amount of memory that we are managing, we |
584 | * need to compute a floor below which we should not balloon. | |
585 | * Compute this and add it to the pressure report. | |
0731572b S |
586 | */ |
587 | status.num_avail = val.freeram; | |
1c7db96f S |
588 | status.num_committed = vm_memory_committed() + |
589 | dm->num_pages_ballooned + | |
590 | compute_balloon_floor(); | |
9aa8b50b S |
591 | |
592 | vmbus_sendpacket(dm->dev->channel, &status, | |
593 | sizeof(struct dm_status), | |
594 | (unsigned long)NULL, | |
595 | VM_PKT_DATA_INBAND, 0); | |
596 | ||
597 | } | |
598 | ||
989623c7 | 599 | static void free_balloon_pages(struct hv_dynmem_device *dm, |
9aa8b50b S |
600 | union dm_mem_page_range *range_array) |
601 | { | |
602 | int num_pages = range_array->finfo.page_cnt; | |
603 | __u64 start_frame = range_array->finfo.start_page; | |
604 | struct page *pg; | |
605 | int i; | |
606 | ||
607 | for (i = 0; i < num_pages; i++) { | |
608 | pg = pfn_to_page(i + start_frame); | |
609 | __free_page(pg); | |
610 | dm->num_pages_ballooned--; | |
611 | } | |
612 | } | |
613 | ||
614 | ||
615 | ||
616 | static int alloc_balloon_pages(struct hv_dynmem_device *dm, int num_pages, | |
617 | struct dm_balloon_response *bl_resp, int alloc_unit, | |
618 | bool *alloc_error) | |
619 | { | |
620 | int i = 0; | |
621 | struct page *pg; | |
622 | ||
623 | if (num_pages < alloc_unit) | |
624 | return 0; | |
625 | ||
626 | for (i = 0; (i * alloc_unit) < num_pages; i++) { | |
627 | if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) > | |
628 | PAGE_SIZE) | |
629 | return i * alloc_unit; | |
630 | ||
631 | /* | |
632 | * We execute this code in a thread context. Furthermore, | |
633 | * we don't want the kernel to try too hard. | |
634 | */ | |
635 | pg = alloc_pages(GFP_HIGHUSER | __GFP_NORETRY | | |
636 | __GFP_NOMEMALLOC | __GFP_NOWARN, | |
637 | get_order(alloc_unit << PAGE_SHIFT)); | |
638 | ||
639 | if (!pg) { | |
640 | *alloc_error = true; | |
641 | return i * alloc_unit; | |
642 | } | |
643 | ||
644 | ||
645 | dm->num_pages_ballooned += alloc_unit; | |
646 | ||
647 | bl_resp->range_count++; | |
648 | bl_resp->range_array[i].finfo.start_page = | |
649 | page_to_pfn(pg); | |
650 | bl_resp->range_array[i].finfo.page_cnt = alloc_unit; | |
651 | bl_resp->hdr.size += sizeof(union dm_mem_page_range); | |
652 | ||
653 | } | |
654 | ||
655 | return num_pages; | |
656 | } | |
657 | ||
658 | ||
659 | ||
660 | static void balloon_up(struct hv_dynmem_device *dm, struct dm_balloon *req) | |
661 | { | |
662 | int num_pages = req->num_pages; | |
663 | int num_ballooned = 0; | |
664 | struct dm_balloon_response *bl_resp; | |
665 | int alloc_unit; | |
666 | int ret; | |
667 | bool alloc_error = false; | |
668 | bool done = false; | |
669 | int i; | |
670 | ||
671 | ||
672 | /* | |
673 | * Currently, we only support 4k allocations. | |
674 | */ | |
675 | alloc_unit = 1; | |
676 | ||
677 | while (!done) { | |
678 | bl_resp = (struct dm_balloon_response *)send_buffer; | |
679 | memset(send_buffer, 0, PAGE_SIZE); | |
680 | bl_resp->hdr.type = DM_BALLOON_RESPONSE; | |
681 | bl_resp->hdr.trans_id = atomic_inc_return(&trans_id); | |
682 | bl_resp->hdr.size = sizeof(struct dm_balloon_response); | |
683 | bl_resp->more_pages = 1; | |
684 | ||
685 | ||
686 | num_pages -= num_ballooned; | |
687 | num_ballooned = alloc_balloon_pages(dm, num_pages, | |
688 | bl_resp, alloc_unit, | |
689 | &alloc_error); | |
690 | ||
691 | if ((alloc_error) || (num_ballooned == num_pages)) { | |
692 | bl_resp->more_pages = 0; | |
693 | done = true; | |
694 | dm->state = DM_INITIALIZED; | |
695 | } | |
696 | ||
697 | /* | |
698 | * We are pushing a lot of data through the channel; | |
699 | * deal with transient failures caused because of the | |
700 | * lack of space in the ring buffer. | |
701 | */ | |
702 | ||
703 | do { | |
704 | ret = vmbus_sendpacket(dm_device.dev->channel, | |
705 | bl_resp, | |
706 | bl_resp->hdr.size, | |
707 | (unsigned long)NULL, | |
708 | VM_PKT_DATA_INBAND, 0); | |
709 | ||
710 | if (ret == -EAGAIN) | |
711 | msleep(20); | |
712 | ||
713 | } while (ret == -EAGAIN); | |
714 | ||
715 | if (ret) { | |
716 | /* | |
717 | * Free up the memory we allocatted. | |
718 | */ | |
719 | pr_info("Balloon response failed\n"); | |
720 | ||
721 | for (i = 0; i < bl_resp->range_count; i++) | |
722 | free_balloon_pages(dm, | |
723 | &bl_resp->range_array[i]); | |
724 | ||
725 | done = true; | |
726 | } | |
727 | } | |
728 | ||
729 | } | |
730 | ||
731 | static void balloon_down(struct hv_dynmem_device *dm, | |
732 | struct dm_unballoon_request *req) | |
733 | { | |
734 | union dm_mem_page_range *range_array = req->range_array; | |
735 | int range_count = req->range_count; | |
736 | struct dm_unballoon_response resp; | |
737 | int i; | |
738 | ||
739 | for (i = 0; i < range_count; i++) | |
740 | free_balloon_pages(dm, &range_array[i]); | |
741 | ||
742 | if (req->more_pages == 1) | |
743 | return; | |
744 | ||
745 | memset(&resp, 0, sizeof(struct dm_unballoon_response)); | |
746 | resp.hdr.type = DM_UNBALLOON_RESPONSE; | |
747 | resp.hdr.trans_id = atomic_inc_return(&trans_id); | |
748 | resp.hdr.size = sizeof(struct dm_unballoon_response); | |
749 | ||
750 | vmbus_sendpacket(dm_device.dev->channel, &resp, | |
751 | sizeof(struct dm_unballoon_response), | |
752 | (unsigned long)NULL, | |
753 | VM_PKT_DATA_INBAND, 0); | |
754 | ||
755 | dm->state = DM_INITIALIZED; | |
756 | } | |
757 | ||
758 | static void balloon_onchannelcallback(void *context); | |
759 | ||
760 | static int dm_thread_func(void *dm_dev) | |
761 | { | |
762 | struct hv_dynmem_device *dm = dm_dev; | |
763 | int t; | |
764 | unsigned long scan_start; | |
765 | ||
766 | while (!kthread_should_stop()) { | |
767 | t = wait_for_completion_timeout(&dm_device.config_event, 1*HZ); | |
768 | /* | |
769 | * The host expects us to post information on the memory | |
770 | * pressure every second. | |
771 | */ | |
772 | ||
773 | if (t == 0) | |
774 | post_status(dm); | |
775 | ||
776 | scan_start = jiffies; | |
777 | switch (dm->state) { | |
778 | case DM_BALLOON_UP: | |
779 | balloon_up(dm, (struct dm_balloon *)recv_buffer); | |
780 | break; | |
781 | ||
782 | case DM_HOT_ADD: | |
783 | hot_add_req(dm, (struct dm_hot_add *)recv_buffer); | |
784 | break; | |
785 | default: | |
786 | break; | |
787 | } | |
788 | ||
789 | if (!time_in_range(jiffies, scan_start, scan_start + HZ)) | |
790 | post_status(dm); | |
791 | ||
792 | } | |
793 | ||
794 | return 0; | |
795 | } | |
796 | ||
797 | ||
798 | static void version_resp(struct hv_dynmem_device *dm, | |
799 | struct dm_version_response *vresp) | |
800 | { | |
801 | struct dm_version_request version_req; | |
802 | int ret; | |
803 | ||
804 | if (vresp->is_accepted) { | |
805 | /* | |
806 | * We are done; wakeup the | |
807 | * context waiting for version | |
808 | * negotiation. | |
809 | */ | |
810 | complete(&dm->host_event); | |
811 | return; | |
812 | } | |
813 | /* | |
814 | * If there are more versions to try, continue | |
815 | * with negotiations; if not | |
816 | * shutdown the service since we are not able | |
817 | * to negotiate a suitable version number | |
818 | * with the host. | |
819 | */ | |
820 | if (dm->next_version == 0) | |
821 | goto version_error; | |
822 | ||
823 | dm->next_version = 0; | |
824 | memset(&version_req, 0, sizeof(struct dm_version_request)); | |
825 | version_req.hdr.type = DM_VERSION_REQUEST; | |
826 | version_req.hdr.size = sizeof(struct dm_version_request); | |
827 | version_req.hdr.trans_id = atomic_inc_return(&trans_id); | |
828 | version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN7; | |
829 | version_req.is_last_attempt = 1; | |
830 | ||
831 | ret = vmbus_sendpacket(dm->dev->channel, &version_req, | |
832 | sizeof(struct dm_version_request), | |
833 | (unsigned long)NULL, | |
834 | VM_PKT_DATA_INBAND, 0); | |
835 | ||
836 | if (ret) | |
837 | goto version_error; | |
838 | ||
839 | return; | |
840 | ||
841 | version_error: | |
842 | dm->state = DM_INIT_ERROR; | |
843 | complete(&dm->host_event); | |
844 | } | |
845 | ||
846 | static void cap_resp(struct hv_dynmem_device *dm, | |
847 | struct dm_capabilities_resp_msg *cap_resp) | |
848 | { | |
849 | if (!cap_resp->is_accepted) { | |
850 | pr_info("Capabilities not accepted by host\n"); | |
851 | dm->state = DM_INIT_ERROR; | |
852 | } | |
853 | complete(&dm->host_event); | |
854 | } | |
855 | ||
856 | static void balloon_onchannelcallback(void *context) | |
857 | { | |
858 | struct hv_device *dev = context; | |
859 | u32 recvlen; | |
860 | u64 requestid; | |
861 | struct dm_message *dm_msg; | |
862 | struct dm_header *dm_hdr; | |
863 | struct hv_dynmem_device *dm = hv_get_drvdata(dev); | |
864 | ||
865 | memset(recv_buffer, 0, sizeof(recv_buffer)); | |
866 | vmbus_recvpacket(dev->channel, recv_buffer, | |
867 | PAGE_SIZE, &recvlen, &requestid); | |
868 | ||
869 | if (recvlen > 0) { | |
870 | dm_msg = (struct dm_message *)recv_buffer; | |
871 | dm_hdr = &dm_msg->hdr; | |
872 | ||
873 | switch (dm_hdr->type) { | |
874 | case DM_VERSION_RESPONSE: | |
875 | version_resp(dm, | |
876 | (struct dm_version_response *)dm_msg); | |
877 | break; | |
878 | ||
879 | case DM_CAPABILITIES_RESPONSE: | |
880 | cap_resp(dm, | |
881 | (struct dm_capabilities_resp_msg *)dm_msg); | |
882 | break; | |
883 | ||
884 | case DM_BALLOON_REQUEST: | |
885 | dm->state = DM_BALLOON_UP; | |
886 | complete(&dm->config_event); | |
887 | break; | |
888 | ||
889 | case DM_UNBALLOON_REQUEST: | |
890 | dm->state = DM_BALLOON_DOWN; | |
891 | balloon_down(dm, | |
892 | (struct dm_unballoon_request *)recv_buffer); | |
893 | break; | |
894 | ||
895 | case DM_MEM_HOT_ADD_REQUEST: | |
896 | dm->state = DM_HOT_ADD; | |
897 | complete(&dm->config_event); | |
898 | break; | |
899 | ||
900 | case DM_INFO_MESSAGE: | |
901 | process_info(dm, (struct dm_info_msg *)dm_msg); | |
902 | break; | |
903 | ||
904 | default: | |
905 | pr_err("Unhandled message: type: %d\n", dm_hdr->type); | |
906 | ||
907 | } | |
908 | } | |
909 | ||
910 | } | |
911 | ||
912 | static int balloon_probe(struct hv_device *dev, | |
913 | const struct hv_vmbus_device_id *dev_id) | |
914 | { | |
915 | int ret, t; | |
916 | struct dm_version_request version_req; | |
917 | struct dm_capabilities cap_msg; | |
918 | ||
919 | do_hot_add = hot_add; | |
920 | ||
921 | /* | |
922 | * First allocate a send buffer. | |
923 | */ | |
924 | ||
925 | send_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
926 | if (!send_buffer) | |
927 | return -ENOMEM; | |
928 | ||
929 | ret = vmbus_open(dev->channel, dm_ring_size, dm_ring_size, NULL, 0, | |
930 | balloon_onchannelcallback, dev); | |
931 | ||
932 | if (ret) | |
33080c1c | 933 | goto probe_error0; |
9aa8b50b S |
934 | |
935 | dm_device.dev = dev; | |
936 | dm_device.state = DM_INITIALIZING; | |
937 | dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN7; | |
938 | init_completion(&dm_device.host_event); | |
939 | init_completion(&dm_device.config_event); | |
940 | ||
941 | dm_device.thread = | |
942 | kthread_run(dm_thread_func, &dm_device, "hv_balloon"); | |
943 | if (IS_ERR(dm_device.thread)) { | |
944 | ret = PTR_ERR(dm_device.thread); | |
33080c1c | 945 | goto probe_error1; |
9aa8b50b S |
946 | } |
947 | ||
948 | hv_set_drvdata(dev, &dm_device); | |
949 | /* | |
950 | * Initiate the hand shake with the host and negotiate | |
951 | * a version that the host can support. We start with the | |
952 | * highest version number and go down if the host cannot | |
953 | * support it. | |
954 | */ | |
955 | memset(&version_req, 0, sizeof(struct dm_version_request)); | |
956 | version_req.hdr.type = DM_VERSION_REQUEST; | |
957 | version_req.hdr.size = sizeof(struct dm_version_request); | |
958 | version_req.hdr.trans_id = atomic_inc_return(&trans_id); | |
959 | version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN8; | |
960 | version_req.is_last_attempt = 0; | |
961 | ||
962 | ret = vmbus_sendpacket(dev->channel, &version_req, | |
963 | sizeof(struct dm_version_request), | |
964 | (unsigned long)NULL, | |
965 | VM_PKT_DATA_INBAND, | |
966 | VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); | |
967 | if (ret) | |
33080c1c | 968 | goto probe_error2; |
9aa8b50b S |
969 | |
970 | t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ); | |
971 | if (t == 0) { | |
972 | ret = -ETIMEDOUT; | |
33080c1c | 973 | goto probe_error2; |
9aa8b50b S |
974 | } |
975 | ||
976 | /* | |
977 | * If we could not negotiate a compatible version with the host | |
978 | * fail the probe function. | |
979 | */ | |
980 | if (dm_device.state == DM_INIT_ERROR) { | |
981 | ret = -ETIMEDOUT; | |
33080c1c | 982 | goto probe_error2; |
9aa8b50b S |
983 | } |
984 | /* | |
985 | * Now submit our capabilities to the host. | |
986 | */ | |
987 | memset(&cap_msg, 0, sizeof(struct dm_capabilities)); | |
988 | cap_msg.hdr.type = DM_CAPABILITIES_REPORT; | |
989 | cap_msg.hdr.size = sizeof(struct dm_capabilities); | |
990 | cap_msg.hdr.trans_id = atomic_inc_return(&trans_id); | |
991 | ||
992 | cap_msg.caps.cap_bits.balloon = 1; | |
993 | /* | |
994 | * While we currently don't support hot-add, | |
995 | * we still advertise this capability since the | |
996 | * host requires that guests partcipating in the | |
997 | * dynamic memory protocol support hot add. | |
998 | */ | |
999 | cap_msg.caps.cap_bits.hot_add = 1; | |
1000 | ||
1001 | /* | |
1002 | * Currently the host does not use these | |
1003 | * values and we set them to what is done in the | |
1004 | * Windows driver. | |
1005 | */ | |
1006 | cap_msg.min_page_cnt = 0; | |
1007 | cap_msg.max_page_number = -1; | |
1008 | ||
1009 | ret = vmbus_sendpacket(dev->channel, &cap_msg, | |
1010 | sizeof(struct dm_capabilities), | |
1011 | (unsigned long)NULL, | |
1012 | VM_PKT_DATA_INBAND, | |
1013 | VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); | |
1014 | if (ret) | |
33080c1c | 1015 | goto probe_error2; |
9aa8b50b S |
1016 | |
1017 | t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ); | |
1018 | if (t == 0) { | |
1019 | ret = -ETIMEDOUT; | |
33080c1c | 1020 | goto probe_error2; |
9aa8b50b S |
1021 | } |
1022 | ||
1023 | /* | |
1024 | * If the host does not like our capabilities, | |
1025 | * fail the probe function. | |
1026 | */ | |
1027 | if (dm_device.state == DM_INIT_ERROR) { | |
1028 | ret = -ETIMEDOUT; | |
33080c1c | 1029 | goto probe_error2; |
9aa8b50b S |
1030 | } |
1031 | ||
1032 | dm_device.state = DM_INITIALIZED; | |
1033 | ||
1034 | return 0; | |
1035 | ||
33080c1c | 1036 | probe_error2: |
9aa8b50b S |
1037 | kthread_stop(dm_device.thread); |
1038 | ||
33080c1c | 1039 | probe_error1: |
9aa8b50b | 1040 | vmbus_close(dev->channel); |
33080c1c S |
1041 | probe_error0: |
1042 | kfree(send_buffer); | |
9aa8b50b S |
1043 | return ret; |
1044 | } | |
1045 | ||
1046 | static int balloon_remove(struct hv_device *dev) | |
1047 | { | |
1048 | struct hv_dynmem_device *dm = hv_get_drvdata(dev); | |
1049 | ||
1050 | if (dm->num_pages_ballooned != 0) | |
1051 | pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned); | |
1052 | ||
1053 | vmbus_close(dev->channel); | |
1054 | kthread_stop(dm->thread); | |
33080c1c | 1055 | kfree(send_buffer); |
9aa8b50b S |
1056 | |
1057 | return 0; | |
1058 | } | |
1059 | ||
1060 | static const struct hv_vmbus_device_id id_table[] = { | |
1061 | /* Dynamic Memory Class ID */ | |
1062 | /* 525074DC-8985-46e2-8057-A307DC18A502 */ | |
d13984e5 | 1063 | { HV_DM_GUID, }, |
9aa8b50b S |
1064 | { }, |
1065 | }; | |
1066 | ||
1067 | MODULE_DEVICE_TABLE(vmbus, id_table); | |
1068 | ||
1069 | static struct hv_driver balloon_drv = { | |
1070 | .name = "hv_balloon", | |
1071 | .id_table = id_table, | |
1072 | .probe = balloon_probe, | |
1073 | .remove = balloon_remove, | |
1074 | }; | |
1075 | ||
1076 | static int __init init_balloon_drv(void) | |
1077 | { | |
1078 | ||
1079 | return vmbus_driver_register(&balloon_drv); | |
1080 | } | |
1081 | ||
1082 | static void exit_balloon_drv(void) | |
1083 | { | |
1084 | ||
1085 | vmbus_driver_unregister(&balloon_drv); | |
1086 | } | |
1087 | ||
1088 | module_init(init_balloon_drv); | |
1089 | module_exit(exit_balloon_drv); | |
1090 | ||
1091 | MODULE_DESCRIPTION("Hyper-V Balloon"); | |
1092 | MODULE_VERSION(HV_DRV_VERSION); | |
1093 | MODULE_LICENSE("GPL"); |