qemu/softmmu/memory_mapping.c
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   1/*
   2 * QEMU memory mapping
   3 *
   4 * Copyright Fujitsu, Corp. 2011, 2012
   5 *
   6 * Authors:
   7 *     Wen Congyang <wency@cn.fujitsu.com>
   8 *
   9 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10 * See the COPYING file in the top-level directory.
  11 *
  12 */
  13
  14#include "qemu/osdep.h"
  15#include "qapi/error.h"
  16
  17#include "sysemu/memory_mapping.h"
  18#include "exec/memory.h"
  19#include "exec/address-spaces.h"
  20
  21//#define DEBUG_GUEST_PHYS_REGION_ADD
  22
  23static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
  24                                                   MemoryMapping *mapping)
  25{
  26    MemoryMapping *p;
  27
  28    QTAILQ_FOREACH(p, &list->head, next) {
  29        if (p->phys_addr >= mapping->phys_addr) {
  30            QTAILQ_INSERT_BEFORE(p, mapping, next);
  31            return;
  32        }
  33    }
  34    QTAILQ_INSERT_TAIL(&list->head, mapping, next);
  35}
  36
  37static void create_new_memory_mapping(MemoryMappingList *list,
  38                                      hwaddr phys_addr,
  39                                      hwaddr virt_addr,
  40                                      ram_addr_t length)
  41{
  42    MemoryMapping *memory_mapping;
  43
  44    memory_mapping = g_malloc(sizeof(MemoryMapping));
  45    memory_mapping->phys_addr = phys_addr;
  46    memory_mapping->virt_addr = virt_addr;
  47    memory_mapping->length = length;
  48    list->last_mapping = memory_mapping;
  49    list->num++;
  50    memory_mapping_list_add_mapping_sorted(list, memory_mapping);
  51}
  52
  53static inline bool mapping_contiguous(MemoryMapping *map,
  54                                      hwaddr phys_addr,
  55                                      hwaddr virt_addr)
  56{
  57    return phys_addr == map->phys_addr + map->length &&
  58           virt_addr == map->virt_addr + map->length;
  59}
  60
  61/*
  62 * [map->phys_addr, map->phys_addr + map->length) and
  63 * [phys_addr, phys_addr + length) have intersection?
  64 */
  65static inline bool mapping_have_same_region(MemoryMapping *map,
  66                                            hwaddr phys_addr,
  67                                            ram_addr_t length)
  68{
  69    return !(phys_addr + length < map->phys_addr ||
  70             phys_addr >= map->phys_addr + map->length);
  71}
  72
  73/*
  74 * [map->phys_addr, map->phys_addr + map->length) and
  75 * [phys_addr, phys_addr + length) have intersection. The virtual address in the
  76 * intersection are the same?
  77 */
  78static inline bool mapping_conflict(MemoryMapping *map,
  79                                    hwaddr phys_addr,
  80                                    hwaddr virt_addr)
  81{
  82    return virt_addr - map->virt_addr != phys_addr - map->phys_addr;
  83}
  84
  85/*
  86 * [map->virt_addr, map->virt_addr + map->length) and
  87 * [virt_addr, virt_addr + length) have intersection. And the physical address
  88 * in the intersection are the same.
  89 */
  90static inline void mapping_merge(MemoryMapping *map,
  91                                 hwaddr virt_addr,
  92                                 ram_addr_t length)
  93{
  94    if (virt_addr < map->virt_addr) {
  95        map->length += map->virt_addr - virt_addr;
  96        map->virt_addr = virt_addr;
  97    }
  98
  99    if ((virt_addr + length) >
 100        (map->virt_addr + map->length)) {
 101        map->length = virt_addr + length - map->virt_addr;
 102    }
 103}
 104
 105void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
 106                                          hwaddr phys_addr,
 107                                          hwaddr virt_addr,
 108                                          ram_addr_t length)
 109{
 110    MemoryMapping *memory_mapping, *last_mapping;
 111
 112    if (QTAILQ_EMPTY(&list->head)) {
 113        create_new_memory_mapping(list, phys_addr, virt_addr, length);
 114        return;
 115    }
 116
 117    last_mapping = list->last_mapping;
 118    if (last_mapping) {
 119        if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {
 120            last_mapping->length += length;
 121            return;
 122        }
 123    }
 124
 125    QTAILQ_FOREACH(memory_mapping, &list->head, next) {
 126        if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {
 127            memory_mapping->length += length;
 128            list->last_mapping = memory_mapping;
 129            return;
 130        }
 131
 132        if (phys_addr + length < memory_mapping->phys_addr) {
 133            /* create a new region before memory_mapping */
 134            break;
 135        }
 136
 137        if (mapping_have_same_region(memory_mapping, phys_addr, length)) {
 138            if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {
 139                continue;
 140            }
 141
 142            /* merge this region into memory_mapping */
 143            mapping_merge(memory_mapping, virt_addr, length);
 144            list->last_mapping = memory_mapping;
 145            return;
 146        }
 147    }
 148
 149    /* this region can not be merged into any existed memory mapping. */
 150    create_new_memory_mapping(list, phys_addr, virt_addr, length);
 151}
 152
 153void memory_mapping_list_free(MemoryMappingList *list)
 154{
 155    MemoryMapping *p, *q;
 156
 157    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
 158        QTAILQ_REMOVE(&list->head, p, next);
 159        g_free(p);
 160    }
 161
 162    list->num = 0;
 163    list->last_mapping = NULL;
 164}
 165
 166void memory_mapping_list_init(MemoryMappingList *list)
 167{
 168    list->num = 0;
 169    list->last_mapping = NULL;
 170    QTAILQ_INIT(&list->head);
 171}
 172
 173void guest_phys_blocks_free(GuestPhysBlockList *list)
 174{
 175    GuestPhysBlock *p, *q;
 176
 177    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
 178        QTAILQ_REMOVE(&list->head, p, next);
 179        memory_region_unref(p->mr);
 180        g_free(p);
 181    }
 182    list->num = 0;
 183}
 184
 185void guest_phys_blocks_init(GuestPhysBlockList *list)
 186{
 187    list->num = 0;
 188    QTAILQ_INIT(&list->head);
 189}
 190
 191typedef struct GuestPhysListener {
 192    GuestPhysBlockList *list;
 193    MemoryListener listener;
 194} GuestPhysListener;
 195
 196static void guest_phys_block_add_section(GuestPhysListener *g,
 197                                         MemoryRegionSection *section)
 198{
 199    const hwaddr target_start = section->offset_within_address_space;
 200    const hwaddr target_end = target_start + int128_get64(section->size);
 201    uint8_t *host_addr = memory_region_get_ram_ptr(section->mr) +
 202                         section->offset_within_region;
 203    GuestPhysBlock *predecessor = NULL;
 204
 205    /* find continuity in guest physical address space */
 206    if (!QTAILQ_EMPTY(&g->list->head)) {
 207        hwaddr predecessor_size;
 208
 209        predecessor = QTAILQ_LAST(&g->list->head);
 210        predecessor_size = predecessor->target_end - predecessor->target_start;
 211
 212        /* the memory API guarantees monotonically increasing traversal */
 213        g_assert(predecessor->target_end <= target_start);
 214
 215        /* we want continuity in both guest-physical and host-virtual memory */
 216        if (predecessor->target_end < target_start ||
 217            predecessor->host_addr + predecessor_size != host_addr ||
 218            predecessor->mr != section->mr) {
 219            predecessor = NULL;
 220        }
 221    }
 222
 223    if (predecessor == NULL) {
 224        /* isolated mapping, allocate it and add it to the list */
 225        GuestPhysBlock *block = g_malloc0(sizeof *block);
 226
 227        block->target_start = target_start;
 228        block->target_end   = target_end;
 229        block->host_addr    = host_addr;
 230        block->mr           = section->mr;
 231        memory_region_ref(section->mr);
 232
 233        QTAILQ_INSERT_TAIL(&g->list->head, block, next);
 234        ++g->list->num;
 235    } else {
 236        /* expand predecessor until @target_end; predecessor's start doesn't
 237         * change
 238         */
 239        predecessor->target_end = target_end;
 240    }
 241
 242#ifdef DEBUG_GUEST_PHYS_REGION_ADD
 243    fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end="
 244            TARGET_FMT_plx ": %s (count: %u)\n", __func__, target_start,
 245            target_end, predecessor ? "joined" : "added", g->list->num);
 246#endif
 247}
 248
 249static int guest_phys_ram_populate_cb(MemoryRegionSection *section,
 250                                      void *opaque)
 251{
 252    GuestPhysListener *g = opaque;
 253
 254    guest_phys_block_add_section(g, section);
 255    return 0;
 256}
 257
 258static void guest_phys_blocks_region_add(MemoryListener *listener,
 259                                         MemoryRegionSection *section)
 260{
 261    GuestPhysListener *g = container_of(listener, GuestPhysListener, listener);
 262
 263    /* we only care about RAM */
 264    if (!memory_region_is_ram(section->mr) ||
 265        memory_region_is_ram_device(section->mr) ||
 266        memory_region_is_nonvolatile(section->mr)) {
 267        return;
 268    }
 269
 270    /* for special sparse regions, only add populated parts */
 271    if (memory_region_has_ram_discard_manager(section->mr)) {
 272        RamDiscardManager *rdm;
 273
 274        rdm = memory_region_get_ram_discard_manager(section->mr);
 275        ram_discard_manager_replay_populated(rdm, section,
 276                                             guest_phys_ram_populate_cb, g);
 277        return;
 278    }
 279
 280    guest_phys_block_add_section(g, section);
 281}
 282
 283void guest_phys_blocks_append(GuestPhysBlockList *list)
 284{
 285    GuestPhysListener g = { 0 };
 286
 287    g.list = list;
 288    g.listener.region_add = &guest_phys_blocks_region_add;
 289    memory_listener_register(&g.listener, &address_space_memory);
 290    memory_listener_unregister(&g.listener);
 291}
 292
 293static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
 294{
 295    CPUState *cpu;
 296
 297    CPU_FOREACH(cpu) {
 298        if (cpu_paging_enabled(cpu)) {
 299            return cpu;
 300        }
 301    }
 302
 303    return NULL;
 304}
 305
 306void qemu_get_guest_memory_mapping(MemoryMappingList *list,
 307                                   const GuestPhysBlockList *guest_phys_blocks,
 308                                   Error **errp)
 309{
 310    CPUState *cpu, *first_paging_enabled_cpu;
 311    GuestPhysBlock *block;
 312    ram_addr_t offset, length;
 313
 314    first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
 315    if (first_paging_enabled_cpu) {
 316        for (cpu = first_paging_enabled_cpu; cpu != NULL;
 317             cpu = CPU_NEXT(cpu)) {
 318            Error *err = NULL;
 319            cpu_get_memory_mapping(cpu, list, &err);
 320            if (err) {
 321                error_propagate(errp, err);
 322                return;
 323            }
 324        }
 325        return;
 326    }
 327
 328    /*
 329     * If the guest doesn't use paging, the virtual address is equal to physical
 330     * address.
 331     */
 332    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 333        offset = block->target_start;
 334        length = block->target_end - block->target_start;
 335        create_new_memory_mapping(list, offset, offset, length);
 336    }
 337}
 338
 339void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,
 340                                   const GuestPhysBlockList *guest_phys_blocks)
 341{
 342    GuestPhysBlock *block;
 343
 344    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 345        create_new_memory_mapping(list, block->target_start, 0,
 346                                  block->target_end - block->target_start);
 347    }
 348}
 349
 350void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
 351                           int64_t length)
 352{
 353    MemoryMapping *cur, *next;
 354
 355    QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {
 356        if (cur->phys_addr >= begin + length ||
 357            cur->phys_addr + cur->length <= begin) {
 358            QTAILQ_REMOVE(&list->head, cur, next);
 359            g_free(cur);
 360            list->num--;
 361            continue;
 362        }
 363
 364        if (cur->phys_addr < begin) {
 365            cur->length -= begin - cur->phys_addr;
 366            if (cur->virt_addr) {
 367                cur->virt_addr += begin - cur->phys_addr;
 368            }
 369            cur->phys_addr = begin;
 370        }
 371
 372        if (cur->phys_addr + cur->length > begin + length) {
 373            cur->length -= cur->phys_addr + cur->length - begin - length;
 374        }
 375    }
 376}
 377