Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 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/jiffies.h> |
| 23 | #include <linux/mman.h> |
| 24 | #include <linux/delay.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/module.h> |
| 27 | #include <linux/slab.h> |
| 28 | #include <linux/kthread.h> |
| 29 | #include <linux/completion.h> |
| 30 | #include <linux/memory_hotplug.h> |
| 31 | #include <linux/memory.h> |
| 32 | #include <linux/notifier.h> |
| 33 | #include <linux/percpu_counter.h> |
| 34 | |
| 35 | #include <linux/hyperv.h> |
| 36 | |
| 37 | /* |
| 38 | * We begin with definitions supporting the Dynamic Memory protocol |
| 39 | * with the host. |
| 40 | * |
| 41 | * Begin protocol definitions. |
| 42 | */ |
| 43 | |
| 44 | |
| 45 | |
| 46 | /* |
| 47 | * Protocol versions. The low word is the minor version, the high word the major |
| 48 | * version. |
| 49 | * |
| 50 | * History: |
| 51 | * Initial version 1.0 |
| 52 | * Changed to 0.1 on 2009/03/25 |
| 53 | * Changes to 0.2 on 2009/05/14 |
| 54 | * Changes to 0.3 on 2009/12/03 |
| 55 | * Changed to 1.0 on 2011/04/05 |
| 56 | */ |
| 57 | |
| 58 | #define DYNMEM_MAKE_VERSION(Major, Minor) ((__u32)(((Major) << 16) | (Minor))) |
| 59 | #define DYNMEM_MAJOR_VERSION(Version) ((__u32)(Version) >> 16) |
| 60 | #define DYNMEM_MINOR_VERSION(Version) ((__u32)(Version) & 0xff) |
| 61 | |
| 62 | enum { |
| 63 | DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3), |
| 64 | DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0), |
| 65 | DYNMEM_PROTOCOL_VERSION_3 = DYNMEM_MAKE_VERSION(2, 0), |
| 66 | |
| 67 | DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1, |
| 68 | DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2, |
| 69 | DYNMEM_PROTOCOL_VERSION_WIN10 = DYNMEM_PROTOCOL_VERSION_3, |
| 70 | |
| 71 | DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN10 |
| 72 | }; |
| 73 | |
| 74 | |
| 75 | |
| 76 | /* |
| 77 | * Message Types |
| 78 | */ |
| 79 | |
| 80 | enum dm_message_type { |
| 81 | /* |
| 82 | * Version 0.3 |
| 83 | */ |
| 84 | DM_ERROR = 0, |
| 85 | DM_VERSION_REQUEST = 1, |
| 86 | DM_VERSION_RESPONSE = 2, |
| 87 | DM_CAPABILITIES_REPORT = 3, |
| 88 | DM_CAPABILITIES_RESPONSE = 4, |
| 89 | DM_STATUS_REPORT = 5, |
| 90 | DM_BALLOON_REQUEST = 6, |
| 91 | DM_BALLOON_RESPONSE = 7, |
| 92 | DM_UNBALLOON_REQUEST = 8, |
| 93 | DM_UNBALLOON_RESPONSE = 9, |
| 94 | DM_MEM_HOT_ADD_REQUEST = 10, |
| 95 | DM_MEM_HOT_ADD_RESPONSE = 11, |
| 96 | DM_VERSION_03_MAX = 11, |
| 97 | /* |
| 98 | * Version 1.0. |
| 99 | */ |
| 100 | DM_INFO_MESSAGE = 12, |
| 101 | DM_VERSION_1_MAX = 12 |
| 102 | }; |
| 103 | |
| 104 | |
| 105 | /* |
| 106 | * Structures defining the dynamic memory management |
| 107 | * protocol. |
| 108 | */ |
| 109 | |
| 110 | union dm_version { |
| 111 | struct { |
| 112 | __u16 minor_version; |
| 113 | __u16 major_version; |
| 114 | }; |
| 115 | __u32 version; |
| 116 | } __packed; |
| 117 | |
| 118 | |
| 119 | union dm_caps { |
| 120 | struct { |
| 121 | __u64 balloon:1; |
| 122 | __u64 hot_add:1; |
| 123 | /* |
| 124 | * To support guests that may have alignment |
| 125 | * limitations on hot-add, the guest can specify |
| 126 | * its alignment requirements; a value of n |
| 127 | * represents an alignment of 2^n in mega bytes. |
| 128 | */ |
| 129 | __u64 hot_add_alignment:4; |
| 130 | __u64 reservedz:58; |
| 131 | } cap_bits; |
| 132 | __u64 caps; |
| 133 | } __packed; |
| 134 | |
| 135 | union dm_mem_page_range { |
| 136 | struct { |
| 137 | /* |
| 138 | * The PFN number of the first page in the range. |
| 139 | * 40 bits is the architectural limit of a PFN |
| 140 | * number for AMD64. |
| 141 | */ |
| 142 | __u64 start_page:40; |
| 143 | /* |
| 144 | * The number of pages in the range. |
| 145 | */ |
| 146 | __u64 page_cnt:24; |
| 147 | } finfo; |
| 148 | __u64 page_range; |
| 149 | } __packed; |
| 150 | |
| 151 | |
| 152 | |
| 153 | /* |
| 154 | * The header for all dynamic memory messages: |
| 155 | * |
| 156 | * type: Type of the message. |
| 157 | * size: Size of the message in bytes; including the header. |
| 158 | * trans_id: The guest is responsible for manufacturing this ID. |
| 159 | */ |
| 160 | |
| 161 | struct dm_header { |
| 162 | __u16 type; |
| 163 | __u16 size; |
| 164 | __u32 trans_id; |
| 165 | } __packed; |
| 166 | |
| 167 | /* |
| 168 | * A generic message format for dynamic memory. |
| 169 | * Specific message formats are defined later in the file. |
| 170 | */ |
| 171 | |
| 172 | struct dm_message { |
| 173 | struct dm_header hdr; |
| 174 | __u8 data[]; /* enclosed message */ |
| 175 | } __packed; |
| 176 | |
| 177 | |
| 178 | /* |
| 179 | * Specific message types supporting the dynamic memory protocol. |
| 180 | */ |
| 181 | |
| 182 | /* |
| 183 | * Version negotiation message. Sent from the guest to the host. |
| 184 | * The guest is free to try different versions until the host |
| 185 | * accepts the version. |
| 186 | * |
| 187 | * dm_version: The protocol version requested. |
| 188 | * is_last_attempt: If TRUE, this is the last version guest will request. |
| 189 | * reservedz: Reserved field, set to zero. |
| 190 | */ |
| 191 | |
| 192 | struct dm_version_request { |
| 193 | struct dm_header hdr; |
| 194 | union dm_version version; |
| 195 | __u32 is_last_attempt:1; |
| 196 | __u32 reservedz:31; |
| 197 | } __packed; |
| 198 | |
| 199 | /* |
| 200 | * Version response message; Host to Guest and indicates |
| 201 | * if the host has accepted the version sent by the guest. |
| 202 | * |
| 203 | * is_accepted: If TRUE, host has accepted the version and the guest |
| 204 | * should proceed to the next stage of the protocol. FALSE indicates that |
| 205 | * guest should re-try with a different version. |
| 206 | * |
| 207 | * reservedz: Reserved field, set to zero. |
| 208 | */ |
| 209 | |
| 210 | struct dm_version_response { |
| 211 | struct dm_header hdr; |
| 212 | __u64 is_accepted:1; |
| 213 | __u64 reservedz:63; |
| 214 | } __packed; |
| 215 | |
| 216 | /* |
| 217 | * Message reporting capabilities. This is sent from the guest to the |
| 218 | * host. |
| 219 | */ |
| 220 | |
| 221 | struct dm_capabilities { |
| 222 | struct dm_header hdr; |
| 223 | union dm_caps caps; |
| 224 | __u64 min_page_cnt; |
| 225 | __u64 max_page_number; |
| 226 | } __packed; |
| 227 | |
| 228 | /* |
| 229 | * Response to the capabilities message. This is sent from the host to the |
| 230 | * guest. This message notifies if the host has accepted the guest's |
| 231 | * capabilities. If the host has not accepted, the guest must shutdown |
| 232 | * the service. |
| 233 | * |
| 234 | * is_accepted: Indicates if the host has accepted guest's capabilities. |
| 235 | * reservedz: Must be 0. |
| 236 | */ |
| 237 | |
| 238 | struct dm_capabilities_resp_msg { |
| 239 | struct dm_header hdr; |
| 240 | __u64 is_accepted:1; |
| 241 | __u64 reservedz:63; |
| 242 | } __packed; |
| 243 | |
| 244 | /* |
| 245 | * This message is used to report memory pressure from the guest. |
| 246 | * This message is not part of any transaction and there is no |
| 247 | * response to this message. |
| 248 | * |
| 249 | * num_avail: Available memory in pages. |
| 250 | * num_committed: Committed memory in pages. |
| 251 | * page_file_size: The accumulated size of all page files |
| 252 | * in the system in pages. |
| 253 | * zero_free: The nunber of zero and free pages. |
| 254 | * page_file_writes: The writes to the page file in pages. |
| 255 | * io_diff: An indicator of file cache efficiency or page file activity, |
| 256 | * calculated as File Cache Page Fault Count - Page Read Count. |
| 257 | * This value is in pages. |
| 258 | * |
| 259 | * Some of these metrics are Windows specific and fortunately |
| 260 | * the algorithm on the host side that computes the guest memory |
| 261 | * pressure only uses num_committed value. |
| 262 | */ |
| 263 | |
| 264 | struct dm_status { |
| 265 | struct dm_header hdr; |
| 266 | __u64 num_avail; |
| 267 | __u64 num_committed; |
| 268 | __u64 page_file_size; |
| 269 | __u64 zero_free; |
| 270 | __u32 page_file_writes; |
| 271 | __u32 io_diff; |
| 272 | } __packed; |
| 273 | |
| 274 | |
| 275 | /* |
| 276 | * Message to ask the guest to allocate memory - balloon up message. |
| 277 | * This message is sent from the host to the guest. The guest may not be |
| 278 | * able to allocate as much memory as requested. |
| 279 | * |
| 280 | * num_pages: number of pages to allocate. |
| 281 | */ |
| 282 | |
| 283 | struct dm_balloon { |
| 284 | struct dm_header hdr; |
| 285 | __u32 num_pages; |
| 286 | __u32 reservedz; |
| 287 | } __packed; |
| 288 | |
| 289 | |
| 290 | /* |
| 291 | * Balloon response message; this message is sent from the guest |
| 292 | * to the host in response to the balloon message. |
| 293 | * |
| 294 | * reservedz: Reserved; must be set to zero. |
| 295 | * more_pages: If FALSE, this is the last message of the transaction. |
| 296 | * if TRUE there will atleast one more message from the guest. |
| 297 | * |
| 298 | * range_count: The number of ranges in the range array. |
| 299 | * |
| 300 | * range_array: An array of page ranges returned to the host. |
| 301 | * |
| 302 | */ |
| 303 | |
| 304 | struct dm_balloon_response { |
| 305 | struct dm_header hdr; |
| 306 | __u32 reservedz; |
| 307 | __u32 more_pages:1; |
| 308 | __u32 range_count:31; |
| 309 | union dm_mem_page_range range_array[]; |
| 310 | } __packed; |
| 311 | |
| 312 | /* |
| 313 | * Un-balloon message; this message is sent from the host |
| 314 | * to the guest to give guest more memory. |
| 315 | * |
| 316 | * more_pages: If FALSE, this is the last message of the transaction. |
| 317 | * if TRUE there will atleast one more message from the guest. |
| 318 | * |
| 319 | * reservedz: Reserved; must be set to zero. |
| 320 | * |
| 321 | * range_count: The number of ranges in the range array. |
| 322 | * |
| 323 | * range_array: An array of page ranges returned to the host. |
| 324 | * |
| 325 | */ |
| 326 | |
| 327 | struct dm_unballoon_request { |
| 328 | struct dm_header hdr; |
| 329 | __u32 more_pages:1; |
| 330 | __u32 reservedz:31; |
| 331 | __u32 range_count; |
| 332 | union dm_mem_page_range range_array[]; |
| 333 | } __packed; |
| 334 | |
| 335 | /* |
| 336 | * Un-balloon response message; this message is sent from the guest |
| 337 | * to the host in response to an unballoon request. |
| 338 | * |
| 339 | */ |
| 340 | |
| 341 | struct dm_unballoon_response { |
| 342 | struct dm_header hdr; |
| 343 | } __packed; |
| 344 | |
| 345 | |
| 346 | /* |
| 347 | * Hot add request message. Message sent from the host to the guest. |
| 348 | * |
| 349 | * mem_range: Memory range to hot add. |
| 350 | * |
| 351 | * On Linux we currently don't support this since we cannot hot add |
| 352 | * arbitrary granularity of memory. |
| 353 | */ |
| 354 | |
| 355 | struct dm_hot_add { |
| 356 | struct dm_header hdr; |
| 357 | union dm_mem_page_range range; |
| 358 | } __packed; |
| 359 | |
| 360 | /* |
| 361 | * Hot add response message. |
| 362 | * This message is sent by the guest to report the status of a hot add request. |
| 363 | * If page_count is less than the requested page count, then the host should |
| 364 | * assume all further hot add requests will fail, since this indicates that |
| 365 | * the guest has hit an upper physical memory barrier. |
| 366 | * |
| 367 | * Hot adds may also fail due to low resources; in this case, the guest must |
| 368 | * not complete this message until the hot add can succeed, and the host must |
| 369 | * not send a new hot add request until the response is sent. |
| 370 | * If VSC fails to hot add memory DYNMEM_NUMBER_OF_UNSUCCESSFUL_HOTADD_ATTEMPTS |
| 371 | * times it fails the request. |
| 372 | * |
| 373 | * |
| 374 | * page_count: number of pages that were successfully hot added. |
| 375 | * |
| 376 | * result: result of the operation 1: success, 0: failure. |
| 377 | * |
| 378 | */ |
| 379 | |
| 380 | struct dm_hot_add_response { |
| 381 | struct dm_header hdr; |
| 382 | __u32 page_count; |
| 383 | __u32 result; |
| 384 | } __packed; |
| 385 | |
| 386 | /* |
| 387 | * Types of information sent from host to the guest. |
| 388 | */ |
| 389 | |
| 390 | enum dm_info_type { |
| 391 | INFO_TYPE_MAX_PAGE_CNT = 0, |
| 392 | MAX_INFO_TYPE |
| 393 | }; |
| 394 | |
| 395 | |
| 396 | /* |
| 397 | * Header for the information message. |
| 398 | */ |
| 399 | |
| 400 | struct dm_info_header { |
| 401 | enum dm_info_type type; |
| 402 | __u32 data_size; |
| 403 | } __packed; |
| 404 | |
| 405 | /* |
| 406 | * This message is sent from the host to the guest to pass |
| 407 | * some relevant information (win8 addition). |
| 408 | * |
| 409 | * reserved: no used. |
| 410 | * info_size: size of the information blob. |
| 411 | * info: information blob. |
| 412 | */ |
| 413 | |
| 414 | struct dm_info_msg { |
| 415 | struct dm_header hdr; |
| 416 | __u32 reserved; |
| 417 | __u32 info_size; |
| 418 | __u8 info[]; |
| 419 | }; |
| 420 | |
| 421 | /* |
| 422 | * End protocol definitions. |
| 423 | */ |
| 424 | |
| 425 | /* |
| 426 | * State to manage hot adding memory into the guest. |
| 427 | * The range start_pfn : end_pfn specifies the range |
| 428 | * that the host has asked us to hot add. The range |
| 429 | * start_pfn : ha_end_pfn specifies the range that we have |
| 430 | * currently hot added. We hot add in multiples of 128M |
| 431 | * chunks; it is possible that we may not be able to bring |
| 432 | * online all the pages in the region. The range |
| 433 | * covered_start_pfn:covered_end_pfn defines the pages that can |
| 434 | * be brough online. |
| 435 | */ |
| 436 | |
| 437 | struct hv_hotadd_state { |
| 438 | struct list_head list; |
| 439 | unsigned long start_pfn; |
| 440 | unsigned long covered_start_pfn; |
| 441 | unsigned long covered_end_pfn; |
| 442 | unsigned long ha_end_pfn; |
| 443 | unsigned long end_pfn; |
| 444 | /* |
| 445 | * A list of gaps. |
| 446 | */ |
| 447 | struct list_head gap_list; |
| 448 | }; |
| 449 | |
| 450 | struct hv_hotadd_gap { |
| 451 | struct list_head list; |
| 452 | unsigned long start_pfn; |
| 453 | unsigned long end_pfn; |
| 454 | }; |
| 455 | |
| 456 | struct balloon_state { |
| 457 | __u32 num_pages; |
| 458 | struct work_struct wrk; |
| 459 | }; |
| 460 | |
| 461 | struct hot_add_wrk { |
| 462 | union dm_mem_page_range ha_page_range; |
| 463 | union dm_mem_page_range ha_region_range; |
| 464 | struct work_struct wrk; |
| 465 | }; |
| 466 | |
| 467 | static bool hot_add = true; |
| 468 | static bool do_hot_add; |
| 469 | /* |
| 470 | * Delay reporting memory pressure by |
| 471 | * the specified number of seconds. |
| 472 | */ |
| 473 | static uint pressure_report_delay = 45; |
| 474 | |
| 475 | /* |
| 476 | * The last time we posted a pressure report to host. |
| 477 | */ |
| 478 | static unsigned long last_post_time; |
| 479 | |
| 480 | module_param(hot_add, bool, (S_IRUGO | S_IWUSR)); |
| 481 | MODULE_PARM_DESC(hot_add, "If set attempt memory hot_add"); |
| 482 | |
| 483 | module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR)); |
| 484 | MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure"); |
| 485 | static atomic_t trans_id = ATOMIC_INIT(0); |
| 486 | |
| 487 | static int dm_ring_size = (5 * PAGE_SIZE); |
| 488 | |
| 489 | /* |
| 490 | * Driver specific state. |
| 491 | */ |
| 492 | |
| 493 | enum hv_dm_state { |
| 494 | DM_INITIALIZING = 0, |
| 495 | DM_INITIALIZED, |
| 496 | DM_BALLOON_UP, |
| 497 | DM_BALLOON_DOWN, |
| 498 | DM_HOT_ADD, |
| 499 | DM_INIT_ERROR |
| 500 | }; |
| 501 | |
| 502 | |
| 503 | static __u8 recv_buffer[PAGE_SIZE]; |
| 504 | static __u8 *send_buffer; |
| 505 | #define PAGES_IN_2M 512 |
| 506 | #define HA_CHUNK (32 * 1024) |
| 507 | |
| 508 | struct hv_dynmem_device { |
| 509 | struct hv_device *dev; |
| 510 | enum hv_dm_state state; |
| 511 | struct completion host_event; |
| 512 | struct completion config_event; |
| 513 | |
| 514 | /* |
| 515 | * Number of pages we have currently ballooned out. |
| 516 | */ |
| 517 | unsigned int num_pages_ballooned; |
| 518 | unsigned int num_pages_onlined; |
| 519 | unsigned int num_pages_added; |
| 520 | |
| 521 | /* |
| 522 | * State to manage the ballooning (up) operation. |
| 523 | */ |
| 524 | struct balloon_state balloon_wrk; |
| 525 | |
| 526 | /* |
| 527 | * State to execute the "hot-add" operation. |
| 528 | */ |
| 529 | struct hot_add_wrk ha_wrk; |
| 530 | |
| 531 | /* |
| 532 | * This state tracks if the host has specified a hot-add |
| 533 | * region. |
| 534 | */ |
| 535 | bool host_specified_ha_region; |
| 536 | |
| 537 | /* |
| 538 | * State to synchronize hot-add. |
| 539 | */ |
| 540 | struct completion ol_waitevent; |
| 541 | bool ha_waiting; |
| 542 | /* |
| 543 | * This thread handles hot-add |
| 544 | * requests from the host as well as notifying |
| 545 | * the host with regards to memory pressure in |
| 546 | * the guest. |
| 547 | */ |
| 548 | struct task_struct *thread; |
| 549 | |
| 550 | struct mutex ha_region_mutex; |
| 551 | |
| 552 | /* |
| 553 | * A list of hot-add regions. |
| 554 | */ |
| 555 | struct list_head ha_region_list; |
| 556 | |
| 557 | /* |
| 558 | * We start with the highest version we can support |
| 559 | * and downgrade based on the host; we save here the |
| 560 | * next version to try. |
| 561 | */ |
| 562 | __u32 next_version; |
| 563 | }; |
| 564 | |
| 565 | static struct hv_dynmem_device dm_device; |
| 566 | |
| 567 | static void post_status(struct hv_dynmem_device *dm); |
| 568 | |
| 569 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 570 | static int hv_memory_notifier(struct notifier_block *nb, unsigned long val, |
| 571 | void *v) |
| 572 | { |
| 573 | struct memory_notify *mem = (struct memory_notify *)v; |
| 574 | |
| 575 | switch (val) { |
| 576 | case MEM_GOING_ONLINE: |
| 577 | mutex_lock(&dm_device.ha_region_mutex); |
| 578 | break; |
| 579 | |
| 580 | case MEM_ONLINE: |
| 581 | dm_device.num_pages_onlined += mem->nr_pages; |
| 582 | case MEM_CANCEL_ONLINE: |
| 583 | if (val == MEM_ONLINE || |
| 584 | mutex_is_locked(&dm_device.ha_region_mutex)) |
| 585 | mutex_unlock(&dm_device.ha_region_mutex); |
| 586 | if (dm_device.ha_waiting) { |
| 587 | dm_device.ha_waiting = false; |
| 588 | complete(&dm_device.ol_waitevent); |
| 589 | } |
| 590 | break; |
| 591 | |
| 592 | case MEM_OFFLINE: |
| 593 | mutex_lock(&dm_device.ha_region_mutex); |
| 594 | dm_device.num_pages_onlined -= mem->nr_pages; |
| 595 | mutex_unlock(&dm_device.ha_region_mutex); |
| 596 | break; |
| 597 | case MEM_GOING_OFFLINE: |
| 598 | case MEM_CANCEL_OFFLINE: |
| 599 | break; |
| 600 | } |
| 601 | return NOTIFY_OK; |
| 602 | } |
| 603 | |
| 604 | static struct notifier_block hv_memory_nb = { |
| 605 | .notifier_call = hv_memory_notifier, |
| 606 | .priority = 0 |
| 607 | }; |
| 608 | |
| 609 | /* Check if the particular page is backed and can be onlined and online it. */ |
| 610 | static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg) |
| 611 | { |
| 612 | unsigned long cur_start_pgp; |
| 613 | unsigned long cur_end_pgp; |
| 614 | struct hv_hotadd_gap *gap; |
| 615 | |
| 616 | cur_start_pgp = (unsigned long)pfn_to_page(has->covered_start_pfn); |
| 617 | cur_end_pgp = (unsigned long)pfn_to_page(has->covered_end_pfn); |
| 618 | |
| 619 | /* The page is not backed. */ |
| 620 | if (((unsigned long)pg < cur_start_pgp) || |
| 621 | ((unsigned long)pg >= cur_end_pgp)) |
| 622 | return; |
| 623 | |
| 624 | /* Check for gaps. */ |
| 625 | list_for_each_entry(gap, &has->gap_list, list) { |
| 626 | cur_start_pgp = (unsigned long) |
| 627 | pfn_to_page(gap->start_pfn); |
| 628 | cur_end_pgp = (unsigned long) |
| 629 | pfn_to_page(gap->end_pfn); |
| 630 | if (((unsigned long)pg >= cur_start_pgp) && |
| 631 | ((unsigned long)pg < cur_end_pgp)) { |
| 632 | return; |
| 633 | } |
| 634 | } |
| 635 | |
| 636 | /* This frame is currently backed; online the page. */ |
| 637 | __online_page_set_limits(pg); |
| 638 | __online_page_increment_counters(pg); |
| 639 | __online_page_free(pg); |
| 640 | } |
| 641 | |
| 642 | static void hv_bring_pgs_online(struct hv_hotadd_state *has, |
| 643 | unsigned long start_pfn, unsigned long size) |
| 644 | { |
| 645 | int i; |
| 646 | |
| 647 | for (i = 0; i < size; i++) |
| 648 | hv_page_online_one(has, pfn_to_page(start_pfn + i)); |
| 649 | } |
| 650 | |
| 651 | static void hv_mem_hot_add(unsigned long start, unsigned long size, |
| 652 | unsigned long pfn_count, |
| 653 | struct hv_hotadd_state *has) |
| 654 | { |
| 655 | int ret = 0; |
| 656 | int i, nid; |
| 657 | unsigned long start_pfn; |
| 658 | unsigned long processed_pfn; |
| 659 | unsigned long total_pfn = pfn_count; |
| 660 | |
| 661 | for (i = 0; i < (size/HA_CHUNK); i++) { |
| 662 | start_pfn = start + (i * HA_CHUNK); |
| 663 | has->ha_end_pfn += HA_CHUNK; |
| 664 | |
| 665 | if (total_pfn > HA_CHUNK) { |
| 666 | processed_pfn = HA_CHUNK; |
| 667 | total_pfn -= HA_CHUNK; |
| 668 | } else { |
| 669 | processed_pfn = total_pfn; |
| 670 | total_pfn = 0; |
| 671 | } |
| 672 | |
| 673 | has->covered_end_pfn += processed_pfn; |
| 674 | |
| 675 | init_completion(&dm_device.ol_waitevent); |
| 676 | dm_device.ha_waiting = true; |
| 677 | |
| 678 | mutex_unlock(&dm_device.ha_region_mutex); |
| 679 | nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn)); |
| 680 | ret = add_memory(nid, PFN_PHYS((start_pfn)), |
| 681 | (HA_CHUNK << PAGE_SHIFT)); |
| 682 | |
| 683 | if (ret) { |
| 684 | pr_info("hot_add memory failed error is %d\n", ret); |
| 685 | if (ret == -EEXIST) { |
| 686 | /* |
| 687 | * This error indicates that the error |
| 688 | * is not a transient failure. This is the |
| 689 | * case where the guest's physical address map |
| 690 | * precludes hot adding memory. Stop all further |
| 691 | * memory hot-add. |
| 692 | */ |
| 693 | do_hot_add = false; |
| 694 | } |
| 695 | has->ha_end_pfn -= HA_CHUNK; |
| 696 | has->covered_end_pfn -= processed_pfn; |
| 697 | mutex_lock(&dm_device.ha_region_mutex); |
| 698 | break; |
| 699 | } |
| 700 | |
| 701 | /* |
| 702 | * Wait for the memory block to be onlined. |
| 703 | * Since the hot add has succeeded, it is ok to |
| 704 | * proceed even if the pages in the hot added region |
| 705 | * have not been "onlined" within the allowed time. |
| 706 | */ |
| 707 | wait_for_completion_timeout(&dm_device.ol_waitevent, 5*HZ); |
| 708 | mutex_lock(&dm_device.ha_region_mutex); |
| 709 | post_status(&dm_device); |
| 710 | } |
| 711 | |
| 712 | return; |
| 713 | } |
| 714 | |
| 715 | static void hv_online_page(struct page *pg) |
| 716 | { |
| 717 | struct list_head *cur; |
| 718 | struct hv_hotadd_state *has; |
| 719 | unsigned long cur_start_pgp; |
| 720 | unsigned long cur_end_pgp; |
| 721 | |
| 722 | list_for_each(cur, &dm_device.ha_region_list) { |
| 723 | has = list_entry(cur, struct hv_hotadd_state, list); |
| 724 | cur_start_pgp = (unsigned long) |
| 725 | pfn_to_page(has->start_pfn); |
| 726 | cur_end_pgp = (unsigned long)pfn_to_page(has->end_pfn); |
| 727 | |
| 728 | /* The page belongs to a different HAS. */ |
| 729 | if (((unsigned long)pg < cur_start_pgp) || |
| 730 | ((unsigned long)pg >= cur_end_pgp)) |
| 731 | continue; |
| 732 | |
| 733 | hv_page_online_one(has, pg); |
| 734 | break; |
| 735 | } |
| 736 | } |
| 737 | |
| 738 | static int pfn_covered(unsigned long start_pfn, unsigned long pfn_cnt) |
| 739 | { |
| 740 | struct list_head *cur; |
| 741 | struct hv_hotadd_state *has; |
| 742 | struct hv_hotadd_gap *gap; |
| 743 | unsigned long residual, new_inc; |
| 744 | |
| 745 | if (list_empty(&dm_device.ha_region_list)) |
| 746 | return false; |
| 747 | |
| 748 | list_for_each(cur, &dm_device.ha_region_list) { |
| 749 | has = list_entry(cur, struct hv_hotadd_state, list); |
| 750 | |
| 751 | /* |
| 752 | * If the pfn range we are dealing with is not in the current |
| 753 | * "hot add block", move on. |
| 754 | */ |
| 755 | if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn) |
| 756 | continue; |
| 757 | |
| 758 | /* |
| 759 | * If the current start pfn is not where the covered_end |
| 760 | * is, create a gap and update covered_end_pfn. |
| 761 | */ |
| 762 | if (has->covered_end_pfn != start_pfn) { |
| 763 | gap = kzalloc(sizeof(struct hv_hotadd_gap), GFP_ATOMIC); |
| 764 | if (!gap) |
| 765 | return -ENOMEM; |
| 766 | |
| 767 | INIT_LIST_HEAD(&gap->list); |
| 768 | gap->start_pfn = has->covered_end_pfn; |
| 769 | gap->end_pfn = start_pfn; |
| 770 | list_add_tail(&gap->list, &has->gap_list); |
| 771 | |
| 772 | has->covered_end_pfn = start_pfn; |
| 773 | } |
| 774 | |
| 775 | /* |
| 776 | * If the current hot add-request extends beyond |
| 777 | * our current limit; extend it. |
| 778 | */ |
| 779 | if ((start_pfn + pfn_cnt) > has->end_pfn) { |
| 780 | residual = (start_pfn + pfn_cnt - has->end_pfn); |
| 781 | /* |
| 782 | * Extend the region by multiples of HA_CHUNK. |
| 783 | */ |
| 784 | new_inc = (residual / HA_CHUNK) * HA_CHUNK; |
| 785 | if (residual % HA_CHUNK) |
| 786 | new_inc += HA_CHUNK; |
| 787 | |
| 788 | has->end_pfn += new_inc; |
| 789 | } |
| 790 | |
| 791 | return 1; |
| 792 | } |
| 793 | |
| 794 | return 0; |
| 795 | } |
| 796 | |
| 797 | static unsigned long handle_pg_range(unsigned long pg_start, |
| 798 | unsigned long pg_count) |
| 799 | { |
| 800 | unsigned long start_pfn = pg_start; |
| 801 | unsigned long pfn_cnt = pg_count; |
| 802 | unsigned long size; |
| 803 | struct list_head *cur; |
| 804 | struct hv_hotadd_state *has; |
| 805 | unsigned long pgs_ol = 0; |
| 806 | unsigned long old_covered_state; |
| 807 | |
| 808 | if (list_empty(&dm_device.ha_region_list)) |
| 809 | return 0; |
| 810 | |
| 811 | list_for_each(cur, &dm_device.ha_region_list) { |
| 812 | has = list_entry(cur, struct hv_hotadd_state, list); |
| 813 | |
| 814 | /* |
| 815 | * If the pfn range we are dealing with is not in the current |
| 816 | * "hot add block", move on. |
| 817 | */ |
| 818 | if (start_pfn < has->start_pfn || start_pfn >= has->end_pfn) |
| 819 | continue; |
| 820 | |
| 821 | old_covered_state = has->covered_end_pfn; |
| 822 | |
| 823 | if (start_pfn < has->ha_end_pfn) { |
| 824 | /* |
| 825 | * This is the case where we are backing pages |
| 826 | * in an already hot added region. Bring |
| 827 | * these pages online first. |
| 828 | */ |
| 829 | pgs_ol = has->ha_end_pfn - start_pfn; |
| 830 | if (pgs_ol > pfn_cnt) |
| 831 | pgs_ol = pfn_cnt; |
| 832 | |
| 833 | has->covered_end_pfn += pgs_ol; |
| 834 | pfn_cnt -= pgs_ol; |
| 835 | /* |
| 836 | * Check if the corresponding memory block is already |
| 837 | * online by checking its last previously backed page. |
| 838 | * In case it is we need to bring rest (which was not |
| 839 | * backed previously) online too. |
| 840 | */ |
| 841 | if (start_pfn > has->start_pfn && |
| 842 | !PageReserved(pfn_to_page(start_pfn - 1))) |
| 843 | hv_bring_pgs_online(has, start_pfn, pgs_ol); |
| 844 | |
| 845 | } |
| 846 | |
| 847 | if ((has->ha_end_pfn < has->end_pfn) && (pfn_cnt > 0)) { |
| 848 | /* |
| 849 | * We have some residual hot add range |
| 850 | * that needs to be hot added; hot add |
| 851 | * it now. Hot add a multiple of |
| 852 | * of HA_CHUNK that fully covers the pages |
| 853 | * we have. |
| 854 | */ |
| 855 | size = (has->end_pfn - has->ha_end_pfn); |
| 856 | if (pfn_cnt <= size) { |
| 857 | size = ((pfn_cnt / HA_CHUNK) * HA_CHUNK); |
| 858 | if (pfn_cnt % HA_CHUNK) |
| 859 | size += HA_CHUNK; |
| 860 | } else { |
| 861 | pfn_cnt = size; |
| 862 | } |
| 863 | hv_mem_hot_add(has->ha_end_pfn, size, pfn_cnt, has); |
| 864 | } |
| 865 | /* |
| 866 | * If we managed to online any pages that were given to us, |
| 867 | * we declare success. |
| 868 | */ |
| 869 | return has->covered_end_pfn - old_covered_state; |
| 870 | |
| 871 | } |
| 872 | |
| 873 | return 0; |
| 874 | } |
| 875 | |
| 876 | static unsigned long process_hot_add(unsigned long pg_start, |
| 877 | unsigned long pfn_cnt, |
| 878 | unsigned long rg_start, |
| 879 | unsigned long rg_size) |
| 880 | { |
| 881 | struct hv_hotadd_state *ha_region = NULL; |
| 882 | int covered; |
| 883 | |
| 884 | if (pfn_cnt == 0) |
| 885 | return 0; |
| 886 | |
| 887 | if (!dm_device.host_specified_ha_region) { |
| 888 | covered = pfn_covered(pg_start, pfn_cnt); |
| 889 | if (covered < 0) |
| 890 | return 0; |
| 891 | |
| 892 | if (covered) |
| 893 | goto do_pg_range; |
| 894 | } |
| 895 | |
| 896 | /* |
| 897 | * If the host has specified a hot-add range; deal with it first. |
| 898 | */ |
| 899 | |
| 900 | if (rg_size != 0) { |
| 901 | ha_region = kzalloc(sizeof(struct hv_hotadd_state), GFP_KERNEL); |
| 902 | if (!ha_region) |
| 903 | return 0; |
| 904 | |
| 905 | INIT_LIST_HEAD(&ha_region->list); |
| 906 | INIT_LIST_HEAD(&ha_region->gap_list); |
| 907 | |
| 908 | list_add_tail(&ha_region->list, &dm_device.ha_region_list); |
| 909 | ha_region->start_pfn = rg_start; |
| 910 | ha_region->ha_end_pfn = rg_start; |
| 911 | ha_region->covered_start_pfn = pg_start; |
| 912 | ha_region->covered_end_pfn = pg_start; |
| 913 | ha_region->end_pfn = rg_start + rg_size; |
| 914 | } |
| 915 | |
| 916 | do_pg_range: |
| 917 | /* |
| 918 | * Process the page range specified; bringing them |
| 919 | * online if possible. |
| 920 | */ |
| 921 | return handle_pg_range(pg_start, pfn_cnt); |
| 922 | } |
| 923 | |
| 924 | #endif |
| 925 | |
| 926 | static void hot_add_req(struct work_struct *dummy) |
| 927 | { |
| 928 | struct dm_hot_add_response resp; |
| 929 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 930 | unsigned long pg_start, pfn_cnt; |
| 931 | unsigned long rg_start, rg_sz; |
| 932 | #endif |
| 933 | struct hv_dynmem_device *dm = &dm_device; |
| 934 | |
| 935 | memset(&resp, 0, sizeof(struct dm_hot_add_response)); |
| 936 | resp.hdr.type = DM_MEM_HOT_ADD_RESPONSE; |
| 937 | resp.hdr.size = sizeof(struct dm_hot_add_response); |
| 938 | |
| 939 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 940 | mutex_lock(&dm_device.ha_region_mutex); |
| 941 | pg_start = dm->ha_wrk.ha_page_range.finfo.start_page; |
| 942 | pfn_cnt = dm->ha_wrk.ha_page_range.finfo.page_cnt; |
| 943 | |
| 944 | rg_start = dm->ha_wrk.ha_region_range.finfo.start_page; |
| 945 | rg_sz = dm->ha_wrk.ha_region_range.finfo.page_cnt; |
| 946 | |
| 947 | if ((rg_start == 0) && (!dm->host_specified_ha_region)) { |
| 948 | unsigned long region_size; |
| 949 | unsigned long region_start; |
| 950 | |
| 951 | /* |
| 952 | * The host has not specified the hot-add region. |
| 953 | * Based on the hot-add page range being specified, |
| 954 | * compute a hot-add region that can cover the pages |
| 955 | * that need to be hot-added while ensuring the alignment |
| 956 | * and size requirements of Linux as it relates to hot-add. |
| 957 | */ |
| 958 | region_start = pg_start; |
| 959 | region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK; |
| 960 | if (pfn_cnt % HA_CHUNK) |
| 961 | region_size += HA_CHUNK; |
| 962 | |
| 963 | region_start = (pg_start / HA_CHUNK) * HA_CHUNK; |
| 964 | |
| 965 | rg_start = region_start; |
| 966 | rg_sz = region_size; |
| 967 | } |
| 968 | |
| 969 | if (do_hot_add) |
| 970 | resp.page_count = process_hot_add(pg_start, pfn_cnt, |
| 971 | rg_start, rg_sz); |
| 972 | |
| 973 | dm->num_pages_added += resp.page_count; |
| 974 | mutex_unlock(&dm_device.ha_region_mutex); |
| 975 | #endif |
| 976 | /* |
| 977 | * The result field of the response structure has the |
| 978 | * following semantics: |
| 979 | * |
| 980 | * 1. If all or some pages hot-added: Guest should return success. |
| 981 | * |
| 982 | * 2. If no pages could be hot-added: |
| 983 | * |
| 984 | * If the guest returns success, then the host |
| 985 | * will not attempt any further hot-add operations. This |
| 986 | * signifies a permanent failure. |
| 987 | * |
| 988 | * If the guest returns failure, then this failure will be |
| 989 | * treated as a transient failure and the host may retry the |
| 990 | * hot-add operation after some delay. |
| 991 | */ |
| 992 | if (resp.page_count > 0) |
| 993 | resp.result = 1; |
| 994 | else if (!do_hot_add) |
| 995 | resp.result = 1; |
| 996 | else |
| 997 | resp.result = 0; |
| 998 | |
| 999 | if (!do_hot_add || (resp.page_count == 0)) |
| 1000 | pr_info("Memory hot add failed\n"); |
| 1001 | |
| 1002 | dm->state = DM_INITIALIZED; |
| 1003 | resp.hdr.trans_id = atomic_inc_return(&trans_id); |
| 1004 | vmbus_sendpacket(dm->dev->channel, &resp, |
| 1005 | sizeof(struct dm_hot_add_response), |
| 1006 | (unsigned long)NULL, |
| 1007 | VM_PKT_DATA_INBAND, 0); |
| 1008 | } |
| 1009 | |
| 1010 | static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg) |
| 1011 | { |
| 1012 | struct dm_info_header *info_hdr; |
| 1013 | |
| 1014 | info_hdr = (struct dm_info_header *)msg->info; |
| 1015 | |
| 1016 | switch (info_hdr->type) { |
| 1017 | case INFO_TYPE_MAX_PAGE_CNT: |
| 1018 | pr_info("Received INFO_TYPE_MAX_PAGE_CNT\n"); |
| 1019 | pr_info("Data Size is %d\n", info_hdr->data_size); |
| 1020 | break; |
| 1021 | default: |
| 1022 | pr_info("Received Unknown type: %d\n", info_hdr->type); |
| 1023 | } |
| 1024 | } |
| 1025 | |
| 1026 | static unsigned long compute_balloon_floor(void) |
| 1027 | { |
| 1028 | unsigned long min_pages; |
| 1029 | #define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT)) |
| 1030 | /* Simple continuous piecewiese linear function: |
| 1031 | * max MiB -> min MiB gradient |
| 1032 | * 0 0 |
| 1033 | * 16 16 |
| 1034 | * 32 24 |
| 1035 | * 128 72 (1/2) |
| 1036 | * 512 168 (1/4) |
| 1037 | * 2048 360 (1/8) |
| 1038 | * 8192 744 (1/16) |
| 1039 | * 32768 1512 (1/32) |
| 1040 | */ |
| 1041 | if (totalram_pages < MB2PAGES(128)) |
| 1042 | min_pages = MB2PAGES(8) + (totalram_pages >> 1); |
| 1043 | else if (totalram_pages < MB2PAGES(512)) |
| 1044 | min_pages = MB2PAGES(40) + (totalram_pages >> 2); |
| 1045 | else if (totalram_pages < MB2PAGES(2048)) |
| 1046 | min_pages = MB2PAGES(104) + (totalram_pages >> 3); |
| 1047 | else if (totalram_pages < MB2PAGES(8192)) |
| 1048 | min_pages = MB2PAGES(232) + (totalram_pages >> 4); |
| 1049 | else |
| 1050 | min_pages = MB2PAGES(488) + (totalram_pages >> 5); |
| 1051 | #undef MB2PAGES |
| 1052 | return min_pages; |
| 1053 | } |
| 1054 | |
| 1055 | /* |
| 1056 | * Post our status as it relates memory pressure to the |
| 1057 | * host. Host expects the guests to post this status |
| 1058 | * periodically at 1 second intervals. |
| 1059 | * |
| 1060 | * The metrics specified in this protocol are very Windows |
| 1061 | * specific and so we cook up numbers here to convey our memory |
| 1062 | * pressure. |
| 1063 | */ |
| 1064 | |
| 1065 | static void post_status(struct hv_dynmem_device *dm) |
| 1066 | { |
| 1067 | struct dm_status status; |
| 1068 | struct sysinfo val; |
| 1069 | unsigned long now = jiffies; |
| 1070 | unsigned long last_post = last_post_time; |
| 1071 | |
| 1072 | if (pressure_report_delay > 0) { |
| 1073 | --pressure_report_delay; |
| 1074 | return; |
| 1075 | } |
| 1076 | |
| 1077 | if (!time_after(now, (last_post_time + HZ))) |
| 1078 | return; |
| 1079 | |
| 1080 | si_meminfo(&val); |
| 1081 | memset(&status, 0, sizeof(struct dm_status)); |
| 1082 | status.hdr.type = DM_STATUS_REPORT; |
| 1083 | status.hdr.size = sizeof(struct dm_status); |
| 1084 | status.hdr.trans_id = atomic_inc_return(&trans_id); |
| 1085 | |
| 1086 | /* |
| 1087 | * The host expects the guest to report free and committed memory. |
| 1088 | * Furthermore, the host expects the pressure information to include |
| 1089 | * the ballooned out pages. For a given amount of memory that we are |
| 1090 | * managing we need to compute a floor below which we should not |
| 1091 | * balloon. Compute this and add it to the pressure report. |
| 1092 | * We also need to report all offline pages (num_pages_added - |
| 1093 | * num_pages_onlined) as committed to the host, otherwise it can try |
| 1094 | * asking us to balloon them out. |
| 1095 | */ |
| 1096 | status.num_avail = val.freeram; |
| 1097 | status.num_committed = vm_memory_committed() + |
| 1098 | dm->num_pages_ballooned + |
| 1099 | (dm->num_pages_added > dm->num_pages_onlined ? |
| 1100 | dm->num_pages_added - dm->num_pages_onlined : 0) + |
| 1101 | compute_balloon_floor(); |
| 1102 | |
| 1103 | /* |
| 1104 | * If our transaction ID is no longer current, just don't |
| 1105 | * send the status. This can happen if we were interrupted |
| 1106 | * after we picked our transaction ID. |
| 1107 | */ |
| 1108 | if (status.hdr.trans_id != atomic_read(&trans_id)) |
| 1109 | return; |
| 1110 | |
| 1111 | /* |
| 1112 | * If the last post time that we sampled has changed, |
| 1113 | * we have raced, don't post the status. |
| 1114 | */ |
| 1115 | if (last_post != last_post_time) |
| 1116 | return; |
| 1117 | |
| 1118 | last_post_time = jiffies; |
| 1119 | vmbus_sendpacket(dm->dev->channel, &status, |
| 1120 | sizeof(struct dm_status), |
| 1121 | (unsigned long)NULL, |
| 1122 | VM_PKT_DATA_INBAND, 0); |
| 1123 | |
| 1124 | } |
| 1125 | |
| 1126 | static void free_balloon_pages(struct hv_dynmem_device *dm, |
| 1127 | union dm_mem_page_range *range_array) |
| 1128 | { |
| 1129 | int num_pages = range_array->finfo.page_cnt; |
| 1130 | __u64 start_frame = range_array->finfo.start_page; |
| 1131 | struct page *pg; |
| 1132 | int i; |
| 1133 | |
| 1134 | for (i = 0; i < num_pages; i++) { |
| 1135 | pg = pfn_to_page(i + start_frame); |
| 1136 | __free_page(pg); |
| 1137 | dm->num_pages_ballooned--; |
| 1138 | } |
| 1139 | } |
| 1140 | |
| 1141 | |
| 1142 | |
| 1143 | static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm, |
| 1144 | unsigned int num_pages, |
| 1145 | struct dm_balloon_response *bl_resp, |
| 1146 | int alloc_unit) |
| 1147 | { |
| 1148 | unsigned int i = 0; |
| 1149 | struct page *pg; |
| 1150 | |
| 1151 | if (num_pages < alloc_unit) |
| 1152 | return 0; |
| 1153 | |
| 1154 | for (i = 0; (i * alloc_unit) < num_pages; i++) { |
| 1155 | if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) > |
| 1156 | PAGE_SIZE) |
| 1157 | return i * alloc_unit; |
| 1158 | |
| 1159 | /* |
| 1160 | * We execute this code in a thread context. Furthermore, |
| 1161 | * we don't want the kernel to try too hard. |
| 1162 | */ |
| 1163 | pg = alloc_pages(GFP_HIGHUSER | __GFP_NORETRY | |
| 1164 | __GFP_NOMEMALLOC | __GFP_NOWARN, |
| 1165 | get_order(alloc_unit << PAGE_SHIFT)); |
| 1166 | |
| 1167 | if (!pg) |
| 1168 | return i * alloc_unit; |
| 1169 | |
| 1170 | dm->num_pages_ballooned += alloc_unit; |
| 1171 | |
| 1172 | /* |
| 1173 | * If we allocatted 2M pages; split them so we |
| 1174 | * can free them in any order we get. |
| 1175 | */ |
| 1176 | |
| 1177 | if (alloc_unit != 1) |
| 1178 | split_page(pg, get_order(alloc_unit << PAGE_SHIFT)); |
| 1179 | |
| 1180 | bl_resp->range_count++; |
| 1181 | bl_resp->range_array[i].finfo.start_page = |
| 1182 | page_to_pfn(pg); |
| 1183 | bl_resp->range_array[i].finfo.page_cnt = alloc_unit; |
| 1184 | bl_resp->hdr.size += sizeof(union dm_mem_page_range); |
| 1185 | |
| 1186 | } |
| 1187 | |
| 1188 | return num_pages; |
| 1189 | } |
| 1190 | |
| 1191 | |
| 1192 | |
| 1193 | static void balloon_up(struct work_struct *dummy) |
| 1194 | { |
| 1195 | unsigned int num_pages = dm_device.balloon_wrk.num_pages; |
| 1196 | unsigned int num_ballooned = 0; |
| 1197 | struct dm_balloon_response *bl_resp; |
| 1198 | int alloc_unit; |
| 1199 | int ret; |
| 1200 | bool done = false; |
| 1201 | int i; |
| 1202 | struct sysinfo val; |
| 1203 | unsigned long floor; |
| 1204 | |
| 1205 | /* The host balloons pages in 2M granularity. */ |
| 1206 | WARN_ON_ONCE(num_pages % PAGES_IN_2M != 0); |
| 1207 | |
| 1208 | /* |
| 1209 | * We will attempt 2M allocations. However, if we fail to |
| 1210 | * allocate 2M chunks, we will go back to 4k allocations. |
| 1211 | */ |
| 1212 | alloc_unit = 512; |
| 1213 | |
| 1214 | si_meminfo(&val); |
| 1215 | floor = compute_balloon_floor(); |
| 1216 | |
| 1217 | /* Refuse to balloon below the floor, keep the 2M granularity. */ |
| 1218 | if (val.freeram < num_pages || val.freeram - num_pages < floor) { |
| 1219 | num_pages = val.freeram > floor ? (val.freeram - floor) : 0; |
| 1220 | num_pages -= num_pages % PAGES_IN_2M; |
| 1221 | } |
| 1222 | |
| 1223 | while (!done) { |
| 1224 | bl_resp = (struct dm_balloon_response *)send_buffer; |
| 1225 | memset(send_buffer, 0, PAGE_SIZE); |
| 1226 | bl_resp->hdr.type = DM_BALLOON_RESPONSE; |
| 1227 | bl_resp->hdr.size = sizeof(struct dm_balloon_response); |
| 1228 | bl_resp->more_pages = 1; |
| 1229 | |
| 1230 | |
| 1231 | num_pages -= num_ballooned; |
| 1232 | num_ballooned = alloc_balloon_pages(&dm_device, num_pages, |
| 1233 | bl_resp, alloc_unit); |
| 1234 | |
| 1235 | if (alloc_unit != 1 && num_ballooned == 0) { |
| 1236 | alloc_unit = 1; |
| 1237 | continue; |
| 1238 | } |
| 1239 | |
| 1240 | if (num_ballooned == 0 || num_ballooned == num_pages) { |
| 1241 | bl_resp->more_pages = 0; |
| 1242 | done = true; |
| 1243 | dm_device.state = DM_INITIALIZED; |
| 1244 | } |
| 1245 | |
| 1246 | /* |
| 1247 | * We are pushing a lot of data through the channel; |
| 1248 | * deal with transient failures caused because of the |
| 1249 | * lack of space in the ring buffer. |
| 1250 | */ |
| 1251 | |
| 1252 | do { |
| 1253 | bl_resp->hdr.trans_id = atomic_inc_return(&trans_id); |
| 1254 | ret = vmbus_sendpacket(dm_device.dev->channel, |
| 1255 | bl_resp, |
| 1256 | bl_resp->hdr.size, |
| 1257 | (unsigned long)NULL, |
| 1258 | VM_PKT_DATA_INBAND, 0); |
| 1259 | |
| 1260 | if (ret == -EAGAIN) |
| 1261 | msleep(20); |
| 1262 | post_status(&dm_device); |
| 1263 | } while (ret == -EAGAIN); |
| 1264 | |
| 1265 | if (ret) { |
| 1266 | /* |
| 1267 | * Free up the memory we allocatted. |
| 1268 | */ |
| 1269 | pr_info("Balloon response failed\n"); |
| 1270 | |
| 1271 | for (i = 0; i < bl_resp->range_count; i++) |
| 1272 | free_balloon_pages(&dm_device, |
| 1273 | &bl_resp->range_array[i]); |
| 1274 | |
| 1275 | done = true; |
| 1276 | } |
| 1277 | } |
| 1278 | |
| 1279 | } |
| 1280 | |
| 1281 | static void balloon_down(struct hv_dynmem_device *dm, |
| 1282 | struct dm_unballoon_request *req) |
| 1283 | { |
| 1284 | union dm_mem_page_range *range_array = req->range_array; |
| 1285 | int range_count = req->range_count; |
| 1286 | struct dm_unballoon_response resp; |
| 1287 | int i; |
| 1288 | |
| 1289 | for (i = 0; i < range_count; i++) { |
| 1290 | free_balloon_pages(dm, &range_array[i]); |
| 1291 | complete(&dm_device.config_event); |
| 1292 | } |
| 1293 | |
| 1294 | if (req->more_pages == 1) |
| 1295 | return; |
| 1296 | |
| 1297 | memset(&resp, 0, sizeof(struct dm_unballoon_response)); |
| 1298 | resp.hdr.type = DM_UNBALLOON_RESPONSE; |
| 1299 | resp.hdr.trans_id = atomic_inc_return(&trans_id); |
| 1300 | resp.hdr.size = sizeof(struct dm_unballoon_response); |
| 1301 | |
| 1302 | vmbus_sendpacket(dm_device.dev->channel, &resp, |
| 1303 | sizeof(struct dm_unballoon_response), |
| 1304 | (unsigned long)NULL, |
| 1305 | VM_PKT_DATA_INBAND, 0); |
| 1306 | |
| 1307 | dm->state = DM_INITIALIZED; |
| 1308 | } |
| 1309 | |
| 1310 | static void balloon_onchannelcallback(void *context); |
| 1311 | |
| 1312 | static int dm_thread_func(void *dm_dev) |
| 1313 | { |
| 1314 | struct hv_dynmem_device *dm = dm_dev; |
| 1315 | |
| 1316 | while (!kthread_should_stop()) { |
| 1317 | wait_for_completion_interruptible_timeout( |
| 1318 | &dm_device.config_event, 1*HZ); |
| 1319 | /* |
| 1320 | * The host expects us to post information on the memory |
| 1321 | * pressure every second. |
| 1322 | */ |
| 1323 | reinit_completion(&dm_device.config_event); |
| 1324 | post_status(dm); |
| 1325 | } |
| 1326 | |
| 1327 | return 0; |
| 1328 | } |
| 1329 | |
| 1330 | |
| 1331 | static void version_resp(struct hv_dynmem_device *dm, |
| 1332 | struct dm_version_response *vresp) |
| 1333 | { |
| 1334 | struct dm_version_request version_req; |
| 1335 | int ret; |
| 1336 | |
| 1337 | if (vresp->is_accepted) { |
| 1338 | /* |
| 1339 | * We are done; wakeup the |
| 1340 | * context waiting for version |
| 1341 | * negotiation. |
| 1342 | */ |
| 1343 | complete(&dm->host_event); |
| 1344 | return; |
| 1345 | } |
| 1346 | /* |
| 1347 | * If there are more versions to try, continue |
| 1348 | * with negotiations; if not |
| 1349 | * shutdown the service since we are not able |
| 1350 | * to negotiate a suitable version number |
| 1351 | * with the host. |
| 1352 | */ |
| 1353 | if (dm->next_version == 0) |
| 1354 | goto version_error; |
| 1355 | |
| 1356 | memset(&version_req, 0, sizeof(struct dm_version_request)); |
| 1357 | version_req.hdr.type = DM_VERSION_REQUEST; |
| 1358 | version_req.hdr.size = sizeof(struct dm_version_request); |
| 1359 | version_req.hdr.trans_id = atomic_inc_return(&trans_id); |
| 1360 | version_req.version.version = dm->next_version; |
| 1361 | |
| 1362 | /* |
| 1363 | * Set the next version to try in case current version fails. |
| 1364 | * Win7 protocol ought to be the last one to try. |
| 1365 | */ |
| 1366 | switch (version_req.version.version) { |
| 1367 | case DYNMEM_PROTOCOL_VERSION_WIN8: |
| 1368 | dm->next_version = DYNMEM_PROTOCOL_VERSION_WIN7; |
| 1369 | version_req.is_last_attempt = 0; |
| 1370 | break; |
| 1371 | default: |
| 1372 | dm->next_version = 0; |
| 1373 | version_req.is_last_attempt = 1; |
| 1374 | } |
| 1375 | |
| 1376 | ret = vmbus_sendpacket(dm->dev->channel, &version_req, |
| 1377 | sizeof(struct dm_version_request), |
| 1378 | (unsigned long)NULL, |
| 1379 | VM_PKT_DATA_INBAND, 0); |
| 1380 | |
| 1381 | if (ret) |
| 1382 | goto version_error; |
| 1383 | |
| 1384 | return; |
| 1385 | |
| 1386 | version_error: |
| 1387 | dm->state = DM_INIT_ERROR; |
| 1388 | complete(&dm->host_event); |
| 1389 | } |
| 1390 | |
| 1391 | static void cap_resp(struct hv_dynmem_device *dm, |
| 1392 | struct dm_capabilities_resp_msg *cap_resp) |
| 1393 | { |
| 1394 | if (!cap_resp->is_accepted) { |
| 1395 | pr_info("Capabilities not accepted by host\n"); |
| 1396 | dm->state = DM_INIT_ERROR; |
| 1397 | } |
| 1398 | complete(&dm->host_event); |
| 1399 | } |
| 1400 | |
| 1401 | static void balloon_onchannelcallback(void *context) |
| 1402 | { |
| 1403 | struct hv_device *dev = context; |
| 1404 | u32 recvlen; |
| 1405 | u64 requestid; |
| 1406 | struct dm_message *dm_msg; |
| 1407 | struct dm_header *dm_hdr; |
| 1408 | struct hv_dynmem_device *dm = hv_get_drvdata(dev); |
| 1409 | struct dm_balloon *bal_msg; |
| 1410 | struct dm_hot_add *ha_msg; |
| 1411 | union dm_mem_page_range *ha_pg_range; |
| 1412 | union dm_mem_page_range *ha_region; |
| 1413 | |
| 1414 | memset(recv_buffer, 0, sizeof(recv_buffer)); |
| 1415 | vmbus_recvpacket(dev->channel, recv_buffer, |
| 1416 | PAGE_SIZE, &recvlen, &requestid); |
| 1417 | |
| 1418 | if (recvlen > 0) { |
| 1419 | dm_msg = (struct dm_message *)recv_buffer; |
| 1420 | dm_hdr = &dm_msg->hdr; |
| 1421 | |
| 1422 | switch (dm_hdr->type) { |
| 1423 | case DM_VERSION_RESPONSE: |
| 1424 | version_resp(dm, |
| 1425 | (struct dm_version_response *)dm_msg); |
| 1426 | break; |
| 1427 | |
| 1428 | case DM_CAPABILITIES_RESPONSE: |
| 1429 | cap_resp(dm, |
| 1430 | (struct dm_capabilities_resp_msg *)dm_msg); |
| 1431 | break; |
| 1432 | |
| 1433 | case DM_BALLOON_REQUEST: |
| 1434 | if (dm->state == DM_BALLOON_UP) |
| 1435 | pr_warn("Currently ballooning\n"); |
| 1436 | bal_msg = (struct dm_balloon *)recv_buffer; |
| 1437 | dm->state = DM_BALLOON_UP; |
| 1438 | dm_device.balloon_wrk.num_pages = bal_msg->num_pages; |
| 1439 | schedule_work(&dm_device.balloon_wrk.wrk); |
| 1440 | break; |
| 1441 | |
| 1442 | case DM_UNBALLOON_REQUEST: |
| 1443 | dm->state = DM_BALLOON_DOWN; |
| 1444 | balloon_down(dm, |
| 1445 | (struct dm_unballoon_request *)recv_buffer); |
| 1446 | break; |
| 1447 | |
| 1448 | case DM_MEM_HOT_ADD_REQUEST: |
| 1449 | if (dm->state == DM_HOT_ADD) |
| 1450 | pr_warn("Currently hot-adding\n"); |
| 1451 | dm->state = DM_HOT_ADD; |
| 1452 | ha_msg = (struct dm_hot_add *)recv_buffer; |
| 1453 | if (ha_msg->hdr.size == sizeof(struct dm_hot_add)) { |
| 1454 | /* |
| 1455 | * This is a normal hot-add request specifying |
| 1456 | * hot-add memory. |
| 1457 | */ |
| 1458 | ha_pg_range = &ha_msg->range; |
| 1459 | dm->ha_wrk.ha_page_range = *ha_pg_range; |
| 1460 | dm->ha_wrk.ha_region_range.page_range = 0; |
| 1461 | } else { |
| 1462 | /* |
| 1463 | * Host is specifying that we first hot-add |
| 1464 | * a region and then partially populate this |
| 1465 | * region. |
| 1466 | */ |
| 1467 | dm->host_specified_ha_region = true; |
| 1468 | ha_pg_range = &ha_msg->range; |
| 1469 | ha_region = &ha_pg_range[1]; |
| 1470 | dm->ha_wrk.ha_page_range = *ha_pg_range; |
| 1471 | dm->ha_wrk.ha_region_range = *ha_region; |
| 1472 | } |
| 1473 | schedule_work(&dm_device.ha_wrk.wrk); |
| 1474 | break; |
| 1475 | |
| 1476 | case DM_INFO_MESSAGE: |
| 1477 | process_info(dm, (struct dm_info_msg *)dm_msg); |
| 1478 | break; |
| 1479 | |
| 1480 | default: |
| 1481 | pr_err("Unhandled message: type: %d\n", dm_hdr->type); |
| 1482 | |
| 1483 | } |
| 1484 | } |
| 1485 | |
| 1486 | } |
| 1487 | |
| 1488 | static int balloon_probe(struct hv_device *dev, |
| 1489 | const struct hv_vmbus_device_id *dev_id) |
| 1490 | { |
| 1491 | int ret; |
| 1492 | unsigned long t; |
| 1493 | struct dm_version_request version_req; |
| 1494 | struct dm_capabilities cap_msg; |
| 1495 | |
| 1496 | do_hot_add = hot_add; |
| 1497 | |
| 1498 | /* |
| 1499 | * First allocate a send buffer. |
| 1500 | */ |
| 1501 | |
| 1502 | send_buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
| 1503 | if (!send_buffer) |
| 1504 | return -ENOMEM; |
| 1505 | |
| 1506 | ret = vmbus_open(dev->channel, dm_ring_size, dm_ring_size, NULL, 0, |
| 1507 | balloon_onchannelcallback, dev); |
| 1508 | |
| 1509 | if (ret) |
| 1510 | goto probe_error0; |
| 1511 | |
| 1512 | dm_device.dev = dev; |
| 1513 | dm_device.state = DM_INITIALIZING; |
| 1514 | dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN8; |
| 1515 | init_completion(&dm_device.host_event); |
| 1516 | init_completion(&dm_device.config_event); |
| 1517 | INIT_LIST_HEAD(&dm_device.ha_region_list); |
| 1518 | mutex_init(&dm_device.ha_region_mutex); |
| 1519 | INIT_WORK(&dm_device.balloon_wrk.wrk, balloon_up); |
| 1520 | INIT_WORK(&dm_device.ha_wrk.wrk, hot_add_req); |
| 1521 | dm_device.host_specified_ha_region = false; |
| 1522 | |
| 1523 | dm_device.thread = |
| 1524 | kthread_run(dm_thread_func, &dm_device, "hv_balloon"); |
| 1525 | if (IS_ERR(dm_device.thread)) { |
| 1526 | ret = PTR_ERR(dm_device.thread); |
| 1527 | goto probe_error1; |
| 1528 | } |
| 1529 | |
| 1530 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 1531 | set_online_page_callback(&hv_online_page); |
| 1532 | register_memory_notifier(&hv_memory_nb); |
| 1533 | #endif |
| 1534 | |
| 1535 | hv_set_drvdata(dev, &dm_device); |
| 1536 | /* |
| 1537 | * Initiate the hand shake with the host and negotiate |
| 1538 | * a version that the host can support. We start with the |
| 1539 | * highest version number and go down if the host cannot |
| 1540 | * support it. |
| 1541 | */ |
| 1542 | memset(&version_req, 0, sizeof(struct dm_version_request)); |
| 1543 | version_req.hdr.type = DM_VERSION_REQUEST; |
| 1544 | version_req.hdr.size = sizeof(struct dm_version_request); |
| 1545 | version_req.hdr.trans_id = atomic_inc_return(&trans_id); |
| 1546 | version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN10; |
| 1547 | version_req.is_last_attempt = 0; |
| 1548 | |
| 1549 | ret = vmbus_sendpacket(dev->channel, &version_req, |
| 1550 | sizeof(struct dm_version_request), |
| 1551 | (unsigned long)NULL, |
| 1552 | VM_PKT_DATA_INBAND, 0); |
| 1553 | if (ret) |
| 1554 | goto probe_error2; |
| 1555 | |
| 1556 | t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ); |
| 1557 | if (t == 0) { |
| 1558 | ret = -ETIMEDOUT; |
| 1559 | goto probe_error2; |
| 1560 | } |
| 1561 | |
| 1562 | /* |
| 1563 | * If we could not negotiate a compatible version with the host |
| 1564 | * fail the probe function. |
| 1565 | */ |
| 1566 | if (dm_device.state == DM_INIT_ERROR) { |
| 1567 | ret = -ETIMEDOUT; |
| 1568 | goto probe_error2; |
| 1569 | } |
| 1570 | /* |
| 1571 | * Now submit our capabilities to the host. |
| 1572 | */ |
| 1573 | memset(&cap_msg, 0, sizeof(struct dm_capabilities)); |
| 1574 | cap_msg.hdr.type = DM_CAPABILITIES_REPORT; |
| 1575 | cap_msg.hdr.size = sizeof(struct dm_capabilities); |
| 1576 | cap_msg.hdr.trans_id = atomic_inc_return(&trans_id); |
| 1577 | |
| 1578 | cap_msg.caps.cap_bits.balloon = 1; |
| 1579 | cap_msg.caps.cap_bits.hot_add = 1; |
| 1580 | |
| 1581 | /* |
| 1582 | * Specify our alignment requirements as it relates |
| 1583 | * memory hot-add. Specify 128MB alignment. |
| 1584 | */ |
| 1585 | cap_msg.caps.cap_bits.hot_add_alignment = 7; |
| 1586 | |
| 1587 | /* |
| 1588 | * Currently the host does not use these |
| 1589 | * values and we set them to what is done in the |
| 1590 | * Windows driver. |
| 1591 | */ |
| 1592 | cap_msg.min_page_cnt = 0; |
| 1593 | cap_msg.max_page_number = -1; |
| 1594 | |
| 1595 | ret = vmbus_sendpacket(dev->channel, &cap_msg, |
| 1596 | sizeof(struct dm_capabilities), |
| 1597 | (unsigned long)NULL, |
| 1598 | VM_PKT_DATA_INBAND, 0); |
| 1599 | if (ret) |
| 1600 | goto probe_error2; |
| 1601 | |
| 1602 | t = wait_for_completion_timeout(&dm_device.host_event, 5*HZ); |
| 1603 | if (t == 0) { |
| 1604 | ret = -ETIMEDOUT; |
| 1605 | goto probe_error2; |
| 1606 | } |
| 1607 | |
| 1608 | /* |
| 1609 | * If the host does not like our capabilities, |
| 1610 | * fail the probe function. |
| 1611 | */ |
| 1612 | if (dm_device.state == DM_INIT_ERROR) { |
| 1613 | ret = -ETIMEDOUT; |
| 1614 | goto probe_error2; |
| 1615 | } |
| 1616 | |
| 1617 | dm_device.state = DM_INITIALIZED; |
| 1618 | |
| 1619 | return 0; |
| 1620 | |
| 1621 | probe_error2: |
| 1622 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 1623 | restore_online_page_callback(&hv_online_page); |
| 1624 | #endif |
| 1625 | kthread_stop(dm_device.thread); |
| 1626 | |
| 1627 | probe_error1: |
| 1628 | vmbus_close(dev->channel); |
| 1629 | probe_error0: |
| 1630 | kfree(send_buffer); |
| 1631 | return ret; |
| 1632 | } |
| 1633 | |
| 1634 | static int balloon_remove(struct hv_device *dev) |
| 1635 | { |
| 1636 | struct hv_dynmem_device *dm = hv_get_drvdata(dev); |
| 1637 | struct list_head *cur, *tmp; |
| 1638 | struct hv_hotadd_state *has; |
| 1639 | struct hv_hotadd_gap *gap, *tmp_gap; |
| 1640 | |
| 1641 | if (dm->num_pages_ballooned != 0) |
| 1642 | pr_warn("Ballooned pages: %d\n", dm->num_pages_ballooned); |
| 1643 | |
| 1644 | cancel_work_sync(&dm->balloon_wrk.wrk); |
| 1645 | cancel_work_sync(&dm->ha_wrk.wrk); |
| 1646 | |
| 1647 | vmbus_close(dev->channel); |
| 1648 | kthread_stop(dm->thread); |
| 1649 | kfree(send_buffer); |
| 1650 | #ifdef CONFIG_MEMORY_HOTPLUG |
| 1651 | restore_online_page_callback(&hv_online_page); |
| 1652 | unregister_memory_notifier(&hv_memory_nb); |
| 1653 | #endif |
| 1654 | list_for_each_safe(cur, tmp, &dm->ha_region_list) { |
| 1655 | has = list_entry(cur, struct hv_hotadd_state, list); |
| 1656 | list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) { |
| 1657 | list_del(&gap->list); |
| 1658 | kfree(gap); |
| 1659 | } |
| 1660 | list_del(&has->list); |
| 1661 | kfree(has); |
| 1662 | } |
| 1663 | |
| 1664 | return 0; |
| 1665 | } |
| 1666 | |
| 1667 | static const struct hv_vmbus_device_id id_table[] = { |
| 1668 | /* Dynamic Memory Class ID */ |
| 1669 | /* 525074DC-8985-46e2-8057-A307DC18A502 */ |
| 1670 | { HV_DM_GUID, }, |
| 1671 | { }, |
| 1672 | }; |
| 1673 | |
| 1674 | MODULE_DEVICE_TABLE(vmbus, id_table); |
| 1675 | |
| 1676 | static struct hv_driver balloon_drv = { |
| 1677 | .name = "hv_balloon", |
| 1678 | .id_table = id_table, |
| 1679 | .probe = balloon_probe, |
| 1680 | .remove = balloon_remove, |
| 1681 | }; |
| 1682 | |
| 1683 | static int __init init_balloon_drv(void) |
| 1684 | { |
| 1685 | |
| 1686 | return vmbus_driver_register(&balloon_drv); |
| 1687 | } |
| 1688 | |
| 1689 | module_init(init_balloon_drv); |
| 1690 | |
| 1691 | MODULE_DESCRIPTION("Hyper-V Balloon"); |
| 1692 | MODULE_LICENSE("GPL"); |