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 "cpu.h"
  18#include "sysemu/memory_mapping.h"
  19#include "exec/memory.h"
  20#include "exec/address-spaces.h"
  21
  22//#define DEBUG_GUEST_PHYS_REGION_ADD
  23
  24static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
  25                                                   MemoryMapping *mapping)
  26{
  27    MemoryMapping *p;
  28
  29    QTAILQ_FOREACH(p, &list->head, next) {
  30        if (p->phys_addr >= mapping->phys_addr) {
  31            QTAILQ_INSERT_BEFORE(p, mapping, next);
  32            return;
  33        }
  34    }
  35    QTAILQ_INSERT_TAIL(&list->head, mapping, next);
  36}
  37
  38static void create_new_memory_mapping(MemoryMappingList *list,
  39                                      hwaddr phys_addr,
  40                                      hwaddr virt_addr,
  41                                      ram_addr_t length)
  42{
  43    MemoryMapping *memory_mapping;
  44
  45    memory_mapping = g_malloc(sizeof(MemoryMapping));
  46    memory_mapping->phys_addr = phys_addr;
  47    memory_mapping->virt_addr = virt_addr;
  48    memory_mapping->length = length;
  49    list->last_mapping = memory_mapping;
  50    list->num++;
  51    memory_mapping_list_add_mapping_sorted(list, memory_mapping);
  52}
  53
  54static inline bool mapping_contiguous(MemoryMapping *map,
  55                                      hwaddr phys_addr,
  56                                      hwaddr virt_addr)
  57{
  58    return phys_addr == map->phys_addr + map->length &&
  59           virt_addr == map->virt_addr + map->length;
  60}
  61
  62/*
  63 * [map->phys_addr, map->phys_addr + map->length) and
  64 * [phys_addr, phys_addr + length) have intersection?
  65 */
  66static inline bool mapping_have_same_region(MemoryMapping *map,
  67                                            hwaddr phys_addr,
  68                                            ram_addr_t length)
  69{
  70    return !(phys_addr + length < map->phys_addr ||
  71             phys_addr >= map->phys_addr + map->length);
  72}
  73
  74/*
  75 * [map->phys_addr, map->phys_addr + map->length) and
  76 * [phys_addr, phys_addr + length) have intersection. The virtual address in the
  77 * intersection are the same?
  78 */
  79static inline bool mapping_conflict(MemoryMapping *map,
  80                                    hwaddr phys_addr,
  81                                    hwaddr virt_addr)
  82{
  83    return virt_addr - map->virt_addr != phys_addr - map->phys_addr;
  84}
  85
  86/*
  87 * [map->virt_addr, map->virt_addr + map->length) and
  88 * [virt_addr, virt_addr + length) have intersection. And the physical address
  89 * in the intersection are the same.
  90 */
  91static inline void mapping_merge(MemoryMapping *map,
  92                                 hwaddr virt_addr,
  93                                 ram_addr_t length)
  94{
  95    if (virt_addr < map->virt_addr) {
  96        map->length += map->virt_addr - virt_addr;
  97        map->virt_addr = virt_addr;
  98    }
  99
 100    if ((virt_addr + length) >
 101        (map->virt_addr + map->length)) {
 102        map->length = virt_addr + length - map->virt_addr;
 103    }
 104}
 105
 106void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
 107                                          hwaddr phys_addr,
 108                                          hwaddr virt_addr,
 109                                          ram_addr_t length)
 110{
 111    MemoryMapping *memory_mapping, *last_mapping;
 112
 113    if (QTAILQ_EMPTY(&list->head)) {
 114        create_new_memory_mapping(list, phys_addr, virt_addr, length);
 115        return;
 116    }
 117
 118    last_mapping = list->last_mapping;
 119    if (last_mapping) {
 120        if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {
 121            last_mapping->length += length;
 122            return;
 123        }
 124    }
 125
 126    QTAILQ_FOREACH(memory_mapping, &list->head, next) {
 127        if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {
 128            memory_mapping->length += length;
 129            list->last_mapping = memory_mapping;
 130            return;
 131        }
 132
 133        if (phys_addr + length < memory_mapping->phys_addr) {
 134            /* create a new region before memory_mapping */
 135            break;
 136        }
 137
 138        if (mapping_have_same_region(memory_mapping, phys_addr, length)) {
 139            if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {
 140                continue;
 141            }
 142
 143            /* merge this region into memory_mapping */
 144            mapping_merge(memory_mapping, virt_addr, length);
 145            list->last_mapping = memory_mapping;
 146            return;
 147        }
 148    }
 149
 150    /* this region can not be merged into any existed memory mapping. */
 151    create_new_memory_mapping(list, phys_addr, virt_addr, length);
 152}
 153
 154void memory_mapping_list_free(MemoryMappingList *list)
 155{
 156    MemoryMapping *p, *q;
 157
 158    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
 159        QTAILQ_REMOVE(&list->head, p, next);
 160        g_free(p);
 161    }
 162
 163    list->num = 0;
 164    list->last_mapping = NULL;
 165}
 166
 167void memory_mapping_list_init(MemoryMappingList *list)
 168{
 169    list->num = 0;
 170    list->last_mapping = NULL;
 171    QTAILQ_INIT(&list->head);
 172}
 173
 174void guest_phys_blocks_free(GuestPhysBlockList *list)
 175{
 176    GuestPhysBlock *p, *q;
 177
 178    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
 179        QTAILQ_REMOVE(&list->head, p, next);
 180        memory_region_unref(p->mr);
 181        g_free(p);
 182    }
 183    list->num = 0;
 184}
 185
 186void guest_phys_blocks_init(GuestPhysBlockList *list)
 187{
 188    list->num = 0;
 189    QTAILQ_INIT(&list->head);
 190}
 191
 192typedef struct GuestPhysListener {
 193    GuestPhysBlockList *list;
 194    MemoryListener listener;
 195} GuestPhysListener;
 196
 197static void guest_phys_blocks_region_add(MemoryListener *listener,
 198                                         MemoryRegionSection *section)
 199{
 200    GuestPhysListener *g;
 201    uint64_t section_size;
 202    hwaddr target_start, target_end;
 203    uint8_t *host_addr;
 204    GuestPhysBlock *predecessor;
 205
 206    /* we only care about RAM */
 207    if (!memory_region_is_ram(section->mr) ||
 208        memory_region_is_ram_device(section->mr) ||
 209        memory_region_is_nonvolatile(section->mr)) {
 210        return;
 211    }
 212
 213    g            = container_of(listener, GuestPhysListener, listener);
 214    section_size = int128_get64(section->size);
 215    target_start = section->offset_within_address_space;
 216    target_end   = target_start + section_size;
 217    host_addr    = memory_region_get_ram_ptr(section->mr) +
 218                   section->offset_within_region;
 219    predecessor  = NULL;
 220
 221    /* find continuity in guest physical address space */
 222    if (!QTAILQ_EMPTY(&g->list->head)) {
 223        hwaddr predecessor_size;
 224
 225        predecessor = QTAILQ_LAST(&g->list->head);
 226        predecessor_size = predecessor->target_end - predecessor->target_start;
 227
 228        /* the memory API guarantees monotonically increasing traversal */
 229        g_assert(predecessor->target_end <= target_start);
 230
 231        /* we want continuity in both guest-physical and host-virtual memory */
 232        if (predecessor->target_end < target_start ||
 233            predecessor->host_addr + predecessor_size != host_addr) {
 234            predecessor = NULL;
 235        }
 236    }
 237
 238    if (predecessor == NULL) {
 239        /* isolated mapping, allocate it and add it to the list */
 240        GuestPhysBlock *block = g_malloc0(sizeof *block);
 241
 242        block->target_start = target_start;
 243        block->target_end   = target_end;
 244        block->host_addr    = host_addr;
 245        block->mr           = section->mr;
 246        memory_region_ref(section->mr);
 247
 248        QTAILQ_INSERT_TAIL(&g->list->head, block, next);
 249        ++g->list->num;
 250    } else {
 251        /* expand predecessor until @target_end; predecessor's start doesn't
 252         * change
 253         */
 254        predecessor->target_end = target_end;
 255    }
 256
 257#ifdef DEBUG_GUEST_PHYS_REGION_ADD
 258    fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end="
 259            TARGET_FMT_plx ": %s (count: %u)\n", __func__, target_start,
 260            target_end, predecessor ? "joined" : "added", g->list->num);
 261#endif
 262}
 263
 264void guest_phys_blocks_append(GuestPhysBlockList *list)
 265{
 266    GuestPhysListener g = { 0 };
 267
 268    g.list = list;
 269    g.listener.region_add = &guest_phys_blocks_region_add;
 270    memory_listener_register(&g.listener, &address_space_memory);
 271    memory_listener_unregister(&g.listener);
 272}
 273
 274static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
 275{
 276    CPUState *cpu;
 277
 278    CPU_FOREACH(cpu) {
 279        if (cpu_paging_enabled(cpu)) {
 280            return cpu;
 281        }
 282    }
 283
 284    return NULL;
 285}
 286
 287void qemu_get_guest_memory_mapping(MemoryMappingList *list,
 288                                   const GuestPhysBlockList *guest_phys_blocks,
 289                                   Error **errp)
 290{
 291    CPUState *cpu, *first_paging_enabled_cpu;
 292    GuestPhysBlock *block;
 293    ram_addr_t offset, length;
 294
 295    first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
 296    if (first_paging_enabled_cpu) {
 297        for (cpu = first_paging_enabled_cpu; cpu != NULL;
 298             cpu = CPU_NEXT(cpu)) {
 299            Error *err = NULL;
 300            cpu_get_memory_mapping(cpu, list, &err);
 301            if (err) {
 302                error_propagate(errp, err);
 303                return;
 304            }
 305        }
 306        return;
 307    }
 308
 309    /*
 310     * If the guest doesn't use paging, the virtual address is equal to physical
 311     * address.
 312     */
 313    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 314        offset = block->target_start;
 315        length = block->target_end - block->target_start;
 316        create_new_memory_mapping(list, offset, offset, length);
 317    }
 318}
 319
 320void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,
 321                                   const GuestPhysBlockList *guest_phys_blocks)
 322{
 323    GuestPhysBlock *block;
 324
 325    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 326        create_new_memory_mapping(list, block->target_start, 0,
 327                                  block->target_end - block->target_start);
 328    }
 329}
 330
 331void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
 332                           int64_t length)
 333{
 334    MemoryMapping *cur, *next;
 335
 336    QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {
 337        if (cur->phys_addr >= begin + length ||
 338            cur->phys_addr + cur->length <= begin) {
 339            QTAILQ_REMOVE(&list->head, cur, next);
 340            g_free(cur);
 341            list->num--;
 342            continue;
 343        }
 344
 345        if (cur->phys_addr < begin) {
 346            cur->length -= begin - cur->phys_addr;
 347            if (cur->virt_addr) {
 348                cur->virt_addr += begin - cur->phys_addr;
 349            }
 350            cur->phys_addr = begin;
 351        }
 352
 353        if (cur->phys_addr + cur->length > begin + length) {
 354            cur->length -= cur->phys_addr + cur->length - begin - length;
 355        }
 356    }
 357}
 358