LXR qemu/include/exec/ram

   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 "hw/xen/xen.h"
  25#include "sysemu/tcg.h"
  26#include "exec/ramlist.h"
  27#include "exec/ramblock.h"
  28
  29/**
  30 * clear_bmap_size: calculate clear bitmap size
  31 *
  32 * @pages: number of guest pages
  33 * @shift: guest page number shift
  34 *
  35 * Returns: number of bits for the clear bitmap
  36 */
  37static inline long clear_bmap_size(uint64_t pages, uint8_t shift)
  38{
  39    return DIV_ROUND_UP(pages, 1UL << shift);
  40}
  41
  42/**
  43 * clear_bmap_set: set clear bitmap for the page range
  44 *
  45 * @rb: the ramblock to operate on
  46 * @start: the start page number
  47 * @size: number of pages to set in the bitmap
  48 *
  49 * Returns: None
  50 */
  51static inline void clear_bmap_set(RAMBlock *rb, uint64_t start,
  52                                  uint64_t npages)
  53{
  54    uint8_t shift = rb->clear_bmap_shift;
  55
  56    bitmap_set_atomic(rb->clear_bmap, start >> shift,
  57                      clear_bmap_size(npages, shift));
  58}
  59
  60/**
  61 * clear_bmap_test_and_clear: test clear bitmap for the page, clear if set
  62 *
  63 * @rb: the ramblock to operate on
  64 * @page: the page number to check
  65 *
  66 * Returns: true if the bit was set, false otherwise
  67 */
  68static inline bool clear_bmap_test_and_clear(RAMBlock *rb, uint64_t page)
  69{
  70    uint8_t shift = rb->clear_bmap_shift;
  71
  72    return bitmap_test_and_clear_atomic(rb->clear_bmap, page >> shift, 1);
  73}
  74
  75static inline bool offset_in_ramblock(RAMBlock *b, ram_addr_t offset)
  76{
  77    return (b && b->host && offset < b->used_length) ? true : false;
  78}
  79
  80static inline void *ramblock_ptr(RAMBlock *block, ram_addr_t offset)
  81{
  82    assert(offset_in_ramblock(block, offset));
  83    return (char *)block->host + offset;
  84}
  85
  86static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
  87                                                            RAMBlock *rb)
  88{
  89    uint64_t host_addr_offset =
  90            (uint64_t)(uintptr_t)(host_addr - (void *)rb->host);
  91    return host_addr_offset >> TARGET_PAGE_BITS;
  92}
  93
  94bool ramblock_is_pmem(RAMBlock *rb);
  95
  96long qemu_minrampagesize(void);
  97long qemu_maxrampagesize(void);
  98
  99/**
 100 * qemu_ram_alloc_from_file,
 101 * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified backing
 102 *                          file or device
 103 *
 104 * Parameters:
 105 *  @size: the size in bytes of the ram block
 106 *  @mr: the memory region where the ram block is
 107 *  @ram_flags: specify the properties of the ram block, which can be one
 108 *              or bit-or of following values
 109 *              - RAM_SHARED: mmap the backing file or device with MAP_SHARED
 110 *              - RAM_PMEM: the backend @mem_path or @fd is persistent memory
 111 *              Other bits are ignored.
 112 *  @mem_path or @fd: specify the backing file or device
 113 *  @errp: pointer to Error*, to store an error if it happens
 114 *
 115 * Return:
 116 *  On success, return a pointer to the ram block.
 117 *  On failure, return NULL.
 118 */
 119RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
 120                                   uint32_t ram_flags, const char *mem_path,
 121                                   Error **errp);
 122RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
 123                                 uint32_t ram_flags, int fd,
 124                                 Error **errp);
 125
 126RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
 127                                  MemoryRegion *mr, Error **errp);
 128RAMBlock *qemu_ram_alloc(ram_addr_t size, bool share, MemoryRegion *mr,
 129                         Error **errp);
 130RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size,
 131                                    void (*resized)(const char*,
 132                                                    uint64_t length,
 133                                                    void *host),
 134                                    MemoryRegion *mr, Error **errp);
 135void qemu_ram_free(RAMBlock *block);
 136
 137int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
 138
 139void qemu_ram_writeback(RAMBlock *block, ram_addr_t start, ram_addr_t length);
 140
 141/* Clear whole block of mem */
 142static inline void qemu_ram_block_writeback(RAMBlock *block)
 143{
 144    qemu_ram_writeback(block, 0, block->used_length);
 145}
 146
 147#define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
 148#define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
 149
 150void tb_invalidate_phys_range(ram_addr_t start, ram_addr_t end);
 151
 152static 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 = atomic_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
 192static 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 = atomic_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
 231static 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
 237static 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
 246static 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
 267static 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 = atomic_rcu_read(&ram_list.dirty_memory[client]);
 282
 283    set_bit_atomic(offset, blocks->blocks[idx]);
 284}
 285
 286static 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] = atomic_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)
 337static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap,
 338                                                          ram_addr_t start,
 339                                                          ram_addr_t pages)
 340{
 341    unsigned long i, j;
 342    unsigned long page_number, c;
 343    hwaddr addr;
 344    ram_addr_t ram_addr;
 345    unsigned long len = (pages + HOST_LONG_BITS - 1) / HOST_LONG_BITS;
 346    unsigned long hpratio = qemu_real_host_page_size / TARGET_PAGE_SIZE;
 347    unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
 348
 349    /* start address is aligned at the start of a word? */
 350    if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
 351        (hpratio == 1)) {
 352        unsigned long **blocks[DIRTY_MEMORY_NUM];
 353        unsigned long idx;
 354        unsigned long offset;
 355        long k;
 356        long nr = BITS_TO_LONGS(pages);
 357
 358        idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
 359        offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
 360                          DIRTY_MEMORY_BLOCK_SIZE);
 361
 362        WITH_RCU_READ_LOCK_GUARD() {
 363            for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
 364                blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
 365            }
 366
 367            for (k = 0; k < nr; k++) {
 368                if (bitmap[k]) {
 369                    unsigned long temp = leul_to_cpu(bitmap[k]);
 370
 371                    atomic_or(&blocks[DIRTY_MEMORY_VGA][idx][offset], temp);
 372
 373                    if (global_dirty_log) {
 374                        atomic_or(&blocks[DIRTY_MEMORY_MIGRATION][idx][offset],
 375                                  temp);
 376                    }
 377
 378                    if (tcg_enabled()) {
 379                        atomic_or(&blocks[DIRTY_MEMORY_CODE][idx][offset],
 380                                  temp);
 381                    }
 382                }
 383
 384                if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
 385                    offset = 0;
 386                    idx++;
 387                }
 388            }
 389        }
 390
 391        xen_hvm_modified_memory(start, pages << TARGET_PAGE_BITS);
 392    } else {
 393        uint8_t clients = tcg_enabled() ? DIRTY_CLIENTS_ALL : DIRTY_CLIENTS_NOCODE;
 394
 395        if (!global_dirty_log) {
 396            clients &= ~(1 << DIRTY_MEMORY_MIGRATION);
 397        }
 398
 399        /*
 400         * bitmap-traveling is faster than memory-traveling (for addr...)
 401         * especially when most of the memory is not dirty.
 402         */
 403        for (i = 0; i < len; i++) {
 404            if (bitmap[i] != 0) {
 405                c = leul_to_cpu(bitmap[i]);
 406                do {
 407                    j = ctzl(c);
 408                    c &= ~(1ul << j);
 409                    page_number = (i * HOST_LONG_BITS + j) * hpratio;
 410                    addr = page_number * TARGET_PAGE_SIZE;
 411                    ram_addr = start + addr;
 412                    cpu_physical_memory_set_dirty_range(ram_addr,
 413                                       TARGET_PAGE_SIZE * hpratio, clients);
 414                } while (c != 0);
 415            }
 416        }
 417    }
 418}
 419#endif /* not _WIN32 */
 420
 421bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
 422                                              ram_addr_t length,
 423                                              unsigned client);
 424
 425DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
 426    (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client);
 427
 428bool cpu_physical_memory_snapshot_get_dirty(DirtyBitmapSnapshot *snap,
 429                                            ram_addr_t start,
 430                                            ram_addr_t length);
 431
 432static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start,
 433                                                         ram_addr_t length)
 434{
 435    cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION);
 436    cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA);
 437    cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE);
 438}
 439
 440
 441/* Called with RCU critical section */
 442static inline
 443uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
 444                                               ram_addr_t start,
 445                                               ram_addr_t length,
 446                                               uint64_t *real_dirty_pages)
 447{
 448    ram_addr_t addr;
 449    unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
 450    uint64_t num_dirty = 0;
 451    unsigned long *dest = rb->bmap;
 452
 453    /* start address and length is aligned at the start of a word? */
 454    if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
 455         (start + rb->offset) &&
 456        !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
 457        int k;
 458        int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
 459        unsigned long * const *src;
 460        unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
 461        unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
 462                                        DIRTY_MEMORY_BLOCK_SIZE);
 463        unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
 464
 465        src = atomic_rcu_read(
 466                &ram_list.dirty_memory[DIRTY_MEMORY_MIGRATION])->blocks;
 467
 468        for (k = page; k < page + nr; k++) {
 469            if (src[idx][offset]) {
 470                unsigned long bits = atomic_xchg(&src[idx][offset], 0);
 471                unsigned long new_dirty;
 472                *real_dirty_pages += ctpopl(bits);
 473                new_dirty = ~dest[k];
 474                dest[k] |= bits;
 475                new_dirty &= bits;
 476                num_dirty += ctpopl(new_dirty);
 477            }
 478
 479            if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
 480                offset = 0;
 481                idx++;
 482            }
 483        }
 484
 485        if (rb->clear_bmap) {
 486            /*
 487             * Postpone the dirty bitmap clear to the point before we
 488             * really send the pages, also we will split the clear
 489             * dirty procedure into smaller chunks.
 490             */
 491            clear_bmap_set(rb, start >> TARGET_PAGE_BITS,
 492                           length >> TARGET_PAGE_BITS);
 493        } else {
 494            /* Slow path - still do that in a huge chunk */
 495            memory_region_clear_dirty_bitmap(rb->mr, start, length);
 496        }
 497    } else {
 498        ram_addr_t offset = rb->offset;
 499
 500        for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
 501            if (cpu_physical_memory_test_and_clear_dirty(
 502                        start + addr + offset,
 503                        TARGET_PAGE_SIZE,
 504                        DIRTY_MEMORY_MIGRATION)) {
 505                *real_dirty_pages += 1;
 506                long k = (start + addr) >> TARGET_PAGE_BITS;
 507                if (!test_and_set_bit(k, dest)) {
 508                    num_dirty++;
 509                }
 510            }
 511        }
 512    }
 513
 514    return num_dirty;
 515}
 516#endif
 517#endif
 518