include/exec/ram_addr.h

   1 /*
   2  * Declarations for cpu physical memory functions
   3  *
   4  * Copyright 2011 Red Hat, Inc. and/or its affiliates
   5  *
   6  * Authors:
   7  *  Avi Kivity <avi@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or
  10  * later.  See the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 /*
  15  * This header is for use by exec.c and memory.c ONLY.  Do not include it.
  16  * The functions declared here will be removed soon.
  17  */
  18
  19 #ifndef RAM_ADDR_H
  20 #define RAM_ADDR_H
  21
  22 #ifndef CONFIG_USER_ONLY
  23 #include "cpu.h"
  24 #include "sysemu/xen.h"
  25 #include "sysemu/tcg.h"
  26 #include "exec/ramlist.h"
  27 #include "exec/ramblock.h"
  28
  29 extern uint64_t total_dirty_pages;
  30
  31 /**
  32  * clear_bmap_size: calculate clear bitmap size
  33  *
  34  * @pages: number of guest pages
  35  * @shift: guest page number shift
  36  *
  37  * Returns: number of bits for the clear bitmap
  38  */
  39 static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
  40 {
  41     return DIV_ROUND_UP(pages, 1UL << shift);
  42 }
  43
  44 /**
  45  * clear_bmap_set: set clear bitmap for the page range.  Must be with
  46  * bitmap_mutex held.
  47  *
  48  * @rb: the ramblock to operate on
  49  * @start: the start page number
  50  * @size: number of pages to set in the bitmap
  51  *
  52  * Returns: None
  53  */
  54 static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
  55                                   uint64_t npages)
  56 {
  57     uint8_t shift = rb->clear_bmap_shift;
  58
  59     bitmap_set(rb->clear_bmap, start >> shift, clear_bmap_size(npages, shift));
  60 }
  61
  62 /**
  63  * clear_bmap_test_and_clear: test clear bitmap for the page, clear if set.
  64  * Must be with bitmap_mutex held.
  65  *
  66  * @rb: the ramblock to operate on
  67  * @page: the page number to check
  68  *
  69  * Returns: true if the bit was set, false otherwise
  70  */
  71 static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
  72 {
  73     uint8_t shift = rb->clear_bmap_shift;
  74
  75     return bitmap_test_and_clear(rb->clear_bmap, page >> shift, 1);
  76 }
  77
  78 static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
  79 {
  80     return (b && b->host && offset < b->used_length) ? true : false;
  81 }
  82
  83 static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
  84 {
  85     assert(offset_in_ramblock(block, offset));
  86     return (char *)block->host + offset;
  87 }
  88
  89 static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
  90                                                             RAMBlock *rb)
  91 {
  92     uint64_t host_addr_offset =
  93             (uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
  94     return host_addr_offset >> TARGET_PAGE_BITS;
  95 }
  96
  97 bool ramblock_is_pmem(RAMBlock *rb);
  98
  99 long qemu_minrampagesize(void);
 100 long qemu_maxrampagesize(void);
 101
 102 /**
 103  * qemu_ram_alloc_from_file,
 104  * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified backing
 105  *                          file or device
 106  *
 107  * Parameters:
 108  *  @size: the size in bytes of the ram block
 109  *  @mr: the memory region where the ram block is
 110  *  @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM,
 111  *              RAM_NORESERVE.
 112  *  @mem_path or @fd: specify the backing file or device
 113  *  @offset: Offset into target file
 114  *  @readonly: true to open @path for reading, false for read/write.
 115  *  @errp: pointer to Error*, to store an error if it happens
 116  *
 117  * Return:
 118  *  On success, return a pointer to the ram block.
 119  *  On failure, return NULL.
 120  */
 121 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
 122                                    uint32_t ram_flags, const char *mem_path,
 123                                    off_t offset, bool readonly, Error **errp);
 124 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
 125                                  uint32_t ram_flags, int fd, off_t offset,
 126                                  bool readonly, Error **errp);
 127
 128 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
 129                                   MemoryRegion *mr, Error **errp);
 130 RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr,
 131                          Error **errp);
 132 RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
 133                                     void (*resized)(const char*,
 134                                                     uint64_t length,
 135                                                     void *host),
 136                                     MemoryRegion *mr, Error **errp);
 137 void qemu_ram_free(RAMBlock *block);
 138
 139 int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
 140
 141 void qemu_ram_msync(RAMBlock *block, ram_addr_t start, ram_addr_t length);
 142
 143 /* Clear whole block of mem */
 144 static inline void qemu_ram_block_writeback(RAMBlock *block)
 145 {
 146     qemu_ram_msync(block, 0, block->used_length);
 147 }
 148
 149 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
 150 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
 151
 152 static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
 153                                                  ram_addr_t length,
 154                                                  unsigned client)
 155 {
 156     DirtyMemoryBlocks *blocks;
 157     unsigned long end, page;
 158     unsigned long idx, offset, base;
 159     bool dirty = false;
 160
 161     assert(client < DIRTY_MEMORY_NUM);
 162
 163     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
 164     page = start >> TARGET_PAGE_BITS;
 165
 166     WITH_RCU_READ_LOCK_GUARD() {
 167         blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
 168
 169         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
 170         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
 171         base = page - offset;
 172         while (page < end) {
 173             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
 174             unsigned long num = next - base;
 175             unsigned long found = find_next_bit(blocks->blocks[idx],
 176                                                 num, offset);
 177             if (found < num) {
 178                 dirty = true;
 179                 break;
 180             }
 181
 182             page = next;
 183             idx++;
 184             offset = 0;
 185             base += DIRTY_MEMORY_BLOCK_SIZE;
 186         }
 187     }
 188
 189     return dirty;
 190 }
 191
 192 static inline bool cpu_physical_memory_all_dirty(ram_addr_t start,
 193                                                  ram_addr_t length,
 194                                                  unsigned client)
 195 {
 196     DirtyMemoryBlocks *blocks;
 197     unsigned long end, page;
 198     unsigned long idx, offset, base;
 199     bool dirty = true;
 200
 201     assert(client < DIRTY_MEMORY_NUM);
 202
 203     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
 204     page = start >> TARGET_PAGE_BITS;
 205
 206     RCU_READ_LOCK_GUARD();
 207
 208     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
 209
 210     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
 211     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
 212     base = page - offset;
 213     while (page < end) {
 214         unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
 215         unsigned long num = next - base;
 216         unsigned long found = find_next_zero_bit(blocks->blocks[idx], num, offset);
 217         if (found < num) {
 218             dirty = false;
 219             break;
 220         }
 221
 222         page = next;
 223         idx++;
 224         offset = 0;
 225         base += DIRTY_MEMORY_BLOCK_SIZE;
 226     }
 227
 228     return dirty;
 229 }
 230
 231 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
 232                                                       unsigned client)
 233 {
 234     return cpu_physical_memory_get_dirty(addr, 1, client);
 235 }
 236
 237 static inline bool cpu_physical_memory_is_clean(ram_addr_t addr)
 238 {
 239     bool vga = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_VGA);
 240     bool code = cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_CODE);
 241     bool migration =
 242         cpu_physical_memory_get_dirty_flag(addr, DIRTY_MEMORY_MIGRATION);
 243     return !(vga && code && migration);
 244 }
 245
 246 static inline uint8_t cpu_physical_memory_range_includes_clean(ram_addr_t start,
 247                                                                ram_addr_t length,
 248                                                                uint8_t mask)
 249 {
 250     uint8_t ret = 0;
 251
 252     if (mask & (1 << DIRTY_MEMORY_VGA) &&
 253         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_VGA)) {
 254         ret |= (1 << DIRTY_MEMORY_VGA);
 255     }
 256     if (mask & (1 << DIRTY_MEMORY_CODE) &&
 257         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_CODE)) {
 258         ret |= (1 << DIRTY_MEMORY_CODE);
 259     }
 260     if (mask & (1 << DIRTY_MEMORY_MIGRATION) &&
 261         !cpu_physical_memory_all_dirty(start, length, DIRTY_MEMORY_MIGRATION)) {
 262         ret |= (1 << DIRTY_MEMORY_MIGRATION);
 263     }
 264     return ret;
 265 }
 266
 267 static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
 268                                                       unsigned client)
 269 {
 270     unsigned long page, idx, offset;
 271     DirtyMemoryBlocks *blocks;
 272
 273     assert(client < DIRTY_MEMORY_NUM);
 274
 275     page = addr >> TARGET_PAGE_BITS;
 276     idx = page / DIRTY_MEMORY_BLOCK_SIZE;
 277     offset = page % DIRTY_MEMORY_BLOCK_SIZE;
 278
 279     RCU_READ_LOCK_GUARD();
 280
 281     blocks = qatomic_rcu_read(&ram_list.dirty_memory[client]);
 282
 283     set_bit_atomic(offset, blocks->blocks[idx]);
 284 }
 285
 286 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
 287                                                        ram_addr_t length,
 288                                                        uint8_t mask)
 289 {
 290     DirtyMemoryBlocks *blocks[DIRTY_MEMORY_NUM];
 291     unsigned long end, page;
 292     unsigned long idx, offset, base;
 293     int i;
 294
 295     if (!mask && !xen_enabled()) {
 296         return;
 297     }
 298
 299     end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
 300     page = start >> TARGET_PAGE_BITS;
 301
 302     WITH_RCU_READ_LOCK_GUARD() {
 303         for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
 304             blocks[i] = qatomic_rcu_read(&ram_list.dirty_memory[i]);
 305         }
 306
 307         idx = page / DIRTY_MEMORY_BLOCK_SIZE;
 308         offset = page % DIRTY_MEMORY_BLOCK_SIZE;
 309         base = page - offset;
 310         while (page < end) {
 311             unsigned long next = MIN(end, base + DIRTY_MEMORY_BLOCK_SIZE);
 312
 313             if (likely(mask & (1 << DIRTY_MEMORY_MIGRATION))) {
 314                 bitmap_set_atomic(blocks[DIRTY_MEMORY_MIGRATION]->blocks[idx],
 315                                   offset, next - page);
 316             }
 317             if (unlikely(mask & (1 << DIRTY_MEMORY_VGA))) {
 318                 bitmap_set_atomic(blocks[DIRTY_MEMORY_VGA]->blocks[idx],
 319                                   offset, next - page);
 320             }
 321             if (unlikely(mask & (1 << DIRTY_MEMORY_CODE))) {
 322                 bitmap_set_atomic(blocks[DIRTY_MEMORY_CODE]->blocks[idx],
 323                                   offset, next - page);
 324             }
 325
 326             page = next;
 327             idx++;
 328             offset = 0;
 329             base += DIRTY_MEMORY_BLOCK_SIZE;
 330         }
 331     }
 332
 333     xen_hvm_modified_memory(start, length);
 334 }
 335
 336 #if !defined(_WIN32)
 337
 338 /*
 339  * Contrary to cpu_physical_memory_sync_dirty_bitmap() this function returns
 340  * the number of dirty pages in @bitmap passed as argument. On the other hand,
 341  * cpu_physical_memory_sync_dirty_bitmap() returns newly dirtied pages that
 342  * weren't set in the global migration bitmap.
 343  */
 344 static inline
 345 uint64_t cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
 346                                                 ram_addr_t start,
 347                                                 ram_addr_t pages)
 348 {
 349     unsigned long i, j;
 350     unsigned long page_number, c, nbits;
 351     hwaddr addr;
 352     ram_addr_t ram_addr;
 353     uint64_t num_dirty = 0;
 354     unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
 355     unsigned long hpratio = qemu_real_host_page_size() / TARGET_PAGE_SIZE;
 356     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
 357
 358     /* start address is aligned at the start of a word? */
 359     if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
 360         (hpratio == 1)) {
 361         unsigned long **blocks[DIRTY_MEMORY_NUM];
 362         unsigned long idx;
 363         unsigned long offset;
 364         long k;
 365         long nr = BITS_TO_LONGS(pages);
 366
 367         idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
 368         offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
 369                           DIRTY_MEMORY_BLOCK_SIZE);
 370
 371         WITH_RCU_READ_LOCK_GUARD() {
 372             for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
 373                 blocks[i] =
 374                     qatomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
 375             }
 376
 377             for (k = 0; k < nr; k++) {
 378                 if (bitmap[k]) {
 379                     unsigned long temp = leul_to_cpu(bitmap[k]);
 380
 381                     nbits = ctpopl(temp);
 382                     qatomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
 383
 384                     if (global_dirty_tracking) {
 385                         qatomic_or(
 386                                 &blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
 387                                 temp);
 388                         if (unlikely(
 389                             global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
 390                             total_dirty_pages += nbits;
 391                         }
 392                     }
 393
 394                     num_dirty += nbits;
 395
 396                     if (tcg_enabled()) {
 397                         qatomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
 398                                    temp);
 399                     }
 400                 }
 401
 402                 if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
 403                     offset = 0;
 404                     idx++;
 405                 }
 406             }
 407         }
 408
 409         xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
 410     } else {
 411         uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
 412
 413         if (!global_dirty_tracking) {
 414             clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
 415         }
 416
 417         /*
 418          * bitmap-traveling is faster than memory-traveling (for addr...)
 419          * especially when most of the memory is not dirty.
 420          */
 421         for (i = 0; i < len; i++) {
 422             if (bitmap[i] != 0) {
 423                 c = leul_to_cpu(bitmap[i]);
 424                 nbits = ctpopl(c);
 425                 if (unlikely(global_dirty_tracking & GLOBAL_DIRTY_DIRTY_RATE)) {
 426                     total_dirty_pages += nbits;
 427                 }
 428                 num_dirty += nbits;
 429                 do {
 430                     j = ctzl(c);
 431                     c &= ~(1ul << j);
 432                     page_number = (i * HOST_LONG_BITS + j) * hpratio;
 433                     addr = page_number * TARGET_PAGE_SIZE;
 434                     ram_addr = start + addr;
 435                     cpu_physical_memory_set_dirty_range(ram_addr,
 436                                        TARGET_PAGE_SIZE * hpratio, clients);
 437                 } while (c != 0);
 438             }
 439         }
 440     }
 441
 442     return num_dirty;
 443 }
 444 #endif /* not _WIN32 */
 445
 446 bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
 447                                               ram_addr_t length,
 448                                               unsigned client);
 449
 450 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
 451     (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
 452
 453 bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
 454                                             ram_addr_t start,
 455                                             ram_addr_t length);
 456
 457 static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
 458                                                          ram_addr_t length)
 459 {
 460     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
 461     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
 462     cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
 463 }
 464
 465
 466 /* Called with RCU critical section */
 467 static inline
 468 uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
 469                                                ram_addr_t start,
 470                                                ram_addr_t length)
 471 {
 472     ram_addr_t addr;
 473     unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
 474     uint64_t num_dirty = 0;
 475     unsigned long *dest = rb->bmap;
 476
 477     /* start address and length is aligned at the start of a word? */
 478     if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
 479          (start + rb->offset) &&
 480         !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
 481         int k;
 482         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
 483         unsigned long * const *src;
 484         unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
 485         unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
 486                                         DIRTY_MEMORY_BLOCK_SIZE);
 487         unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
 488
 489         src = qatomic_rcu_read(
 490                 &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
 491
 492         for (k = page; k < page + nr; k++) {
 493             if (src[idx][offset]) {
 494                 unsigned long bits = qatomic_xchg(&src[idx][offset], 0);
 495                 unsigned long new_dirty;
 496                 new_dirty = ~dest[k];
 497                 dest[k] |= bits;
 498                 new_dirty &= bits;
 499                 num_dirty += ctpopl(new_dirty);
 500             }
 501
 502             if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
 503                 offset = 0;
 504                 idx++;
 505             }
 506         }
 507
 508         if (rb->clear_bmap) {
 509             /*
 510              * Postpone the dirty bitmap clear to the point before we
 511              * really send the pages, also we will split the clear
 512              * dirty procedure into smaller chunks.
 513              */
 514             clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
 515                            length >> TARGET_PAGE_BITS);
 516         } else {
 517             /* Slow path - still do that in a huge chunk */
 518             memory_region_clear_dirty_bitmap(rb->mr, start, length);
 519         }
 520     } else {
 521         ram_addr_t offset = rb->offset;
 522
 523         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
 524             if (cpu_physical_memory_test_and_clear_dirty(
 525                         start + addr + offset,
 526                         TARGET_PAGE_SIZE,
 527                         DIRTY_MEMORY_MIGRATION)) {
 528                 long k = (start + addr) >> TARGET_PAGE_BITS;
 529                 if (!test_and_set_bit(k, dest)) {
 530                     num_dirty++;
 531                 }
 532             }
 533         }
 534     }
 535
 536     return num_dirty;
 537 }
 538 #endif
 539 #endif