qemu/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 <glib.h>
  15
  16#include "cpu.h"
  17#include "exec/cpu-all.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        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_blocks_region_add(MemoryListener *listener,
 197                                         MemoryRegionSection *section)
 198{
 199    GuestPhysListener *g;
 200    uint64_t section_size;
 201    hwaddr target_start, target_end;
 202    uint8_t *host_addr;
 203    GuestPhysBlock *predecessor;
 204
 205    /* we only care about RAM */
 206    if (!memory_region_is_ram(section->mr)) {
 207        return;
 208    }
 209
 210    g            = container_of(listener, GuestPhysListener, listener);
 211    section_size = int128_get64(section->size);
 212    target_start = section->offset_within_address_space;
 213    target_end   = target_start + section_size;
 214    host_addr    = memory_region_get_ram_ptr(section->mr) +
 215                   section->offset_within_region;
 216    predecessor  = NULL;
 217
 218    /* find continuity in guest physical address space */
 219    if (!QTAILQ_EMPTY(&g->list->head)) {
 220        hwaddr predecessor_size;
 221
 222        predecessor = QTAILQ_LAST(&g->list->head, GuestPhysBlockHead);
 223        predecessor_size = predecessor->target_end - predecessor->target_start;
 224
 225        /* the memory API guarantees monotonically increasing traversal */
 226        g_assert(predecessor->target_end <= target_start);
 227
 228        /* we want continuity in both guest-physical and host-virtual memory */
 229        if (predecessor->target_end < target_start ||
 230            predecessor->host_addr + predecessor_size != host_addr) {
 231            predecessor = NULL;
 232        }
 233    }
 234
 235    if (predecessor == NULL) {
 236        /* isolated mapping, allocate it and add it to the list */
 237        GuestPhysBlock *block = g_malloc0(sizeof *block);
 238
 239        block->target_start = target_start;
 240        block->target_end   = target_end;
 241        block->host_addr    = host_addr;
 242
 243        QTAILQ_INSERT_TAIL(&g->list->head, block, next);
 244        ++g->list->num;
 245    } else {
 246        /* expand predecessor until @target_end; predecessor's start doesn't
 247         * change
 248         */
 249        predecessor->target_end = target_end;
 250    }
 251
 252#ifdef DEBUG_GUEST_PHYS_REGION_ADD
 253    fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end="
 254            TARGET_FMT_plx ": %s (count: %u)\n", __FUNCTION__, target_start,
 255            target_end, predecessor ? "joined" : "added", g->list->num);
 256#endif
 257}
 258
 259void guest_phys_blocks_append(GuestPhysBlockList *list)
 260{
 261    GuestPhysListener g = { 0 };
 262
 263    g.list = list;
 264    g.listener.region_add = &guest_phys_blocks_region_add;
 265    memory_listener_register(&g.listener, &address_space_memory);
 266    memory_listener_unregister(&g.listener);
 267}
 268
 269static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
 270{
 271    CPUState *cpu;
 272
 273    CPU_FOREACH(cpu) {
 274        if (cpu_paging_enabled(cpu)) {
 275            return cpu;
 276        }
 277    }
 278
 279    return NULL;
 280}
 281
 282void qemu_get_guest_memory_mapping(MemoryMappingList *list,
 283                                   const GuestPhysBlockList *guest_phys_blocks,
 284                                   Error **errp)
 285{
 286    CPUState *cpu, *first_paging_enabled_cpu;
 287    GuestPhysBlock *block;
 288    ram_addr_t offset, length;
 289
 290    first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
 291    if (first_paging_enabled_cpu) {
 292        for (cpu = first_paging_enabled_cpu; cpu != NULL;
 293             cpu = CPU_NEXT(cpu)) {
 294            Error *err = NULL;
 295            cpu_get_memory_mapping(cpu, list, &err);
 296            if (err) {
 297                error_propagate(errp, err);
 298                return;
 299            }
 300        }
 301        return;
 302    }
 303
 304    /*
 305     * If the guest doesn't use paging, the virtual address is equal to physical
 306     * address.
 307     */
 308    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 309        offset = block->target_start;
 310        length = block->target_end - block->target_start;
 311        create_new_memory_mapping(list, offset, offset, length);
 312    }
 313}
 314
 315void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,
 316                                   const GuestPhysBlockList *guest_phys_blocks)
 317{
 318    GuestPhysBlock *block;
 319
 320    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 321        create_new_memory_mapping(list, block->target_start, 0,
 322                                  block->target_end - block->target_start);
 323    }
 324}
 325
 326void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
 327                           int64_t length)
 328{
 329    MemoryMapping *cur, *next;
 330
 331    QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {
 332        if (cur->phys_addr >= begin + length ||
 333            cur->phys_addr + cur->length <= begin) {
 334            QTAILQ_REMOVE(&list->head, cur, next);
 335            list->num--;
 336            continue;
 337        }
 338
 339        if (cur->phys_addr < begin) {
 340            cur->length -= begin - cur->phys_addr;
 341            if (cur->virt_addr) {
 342                cur->virt_addr += begin - cur->phys_addr;
 343            }
 344            cur->phys_addr = begin;
 345        }
 346
 347        if (cur->phys_addr + cur->length > begin + length) {
 348            cur->length -= cur->phys_addr + cur->length - begin - length;
 349        }
 350    }
 351}
 352