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 "qemu/osdep.h"
  15#include "qapi/error.h"
  16
  17#include "qemu-common.h"
  18#include "cpu.h"
  19#include "sysemu/memory_mapping.h"
  20#include "exec/memory.h"
  21#include "exec/address-spaces.h"
  22
  23//#define DEBUG_GUEST_PHYS_REGION_ADD
  24
  25static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
  26                                                   MemoryMapping *mapping)
  27{
  28    MemoryMapping *p;
  29
  30    QTAILQ_FOREACH(p, &list->head, next) {
  31        if (p->phys_addr >= mapping->phys_addr) {
  32            QTAILQ_INSERT_BEFORE(p, mapping, next);
  33            return;
  34        }
  35    }
  36    QTAILQ_INSERT_TAIL(&list->head, mapping, next);
  37}
  38
  39static void create_new_memory_mapping(MemoryMappingList *list,
  40                                      hwaddr phys_addr,
  41                                      hwaddr virt_addr,
  42                                      ram_addr_t length)
  43{
  44    MemoryMapping *memory_mapping;
  45
  46    memory_mapping = g_malloc(sizeof(MemoryMapping));
  47    memory_mapping->phys_addr = phys_addr;
  48    memory_mapping->virt_addr = virt_addr;
  49    memory_mapping->length = length;
  50    list->last_mapping = memory_mapping;
  51    list->num++;
  52    memory_mapping_list_add_mapping_sorted(list, memory_mapping);
  53}
  54
  55static inline bool mapping_contiguous(MemoryMapping *map,
  56                                      hwaddr phys_addr,
  57                                      hwaddr virt_addr)
  58{
  59    return phys_addr == map->phys_addr + map->length &&
  60           virt_addr == map->virt_addr + map->length;
  61}
  62
  63/*
  64 * [map->phys_addr, map->phys_addr + map->length) and
  65 * [phys_addr, phys_addr + length) have intersection?
  66 */
  67static inline bool mapping_have_same_region(MemoryMapping *map,
  68                                            hwaddr phys_addr,
  69                                            ram_addr_t length)
  70{
  71    return !(phys_addr + length < map->phys_addr ||
  72             phys_addr >= map->phys_addr + map->length);
  73}
  74
  75/*
  76 * [map->phys_addr, map->phys_addr + map->length) and
  77 * [phys_addr, phys_addr + length) have intersection. The virtual address in the
  78 * intersection are the same?
  79 */
  80static inline bool mapping_conflict(MemoryMapping *map,
  81                                    hwaddr phys_addr,
  82                                    hwaddr virt_addr)
  83{
  84    return virt_addr - map->virt_addr != phys_addr - map->phys_addr;
  85}
  86
  87/*
  88 * [map->virt_addr, map->virt_addr + map->length) and
  89 * [virt_addr, virt_addr + length) have intersection. And the physical address
  90 * in the intersection are the same.
  91 */
  92static inline void mapping_merge(MemoryMapping *map,
  93                                 hwaddr virt_addr,
  94                                 ram_addr_t length)
  95{
  96    if (virt_addr < map->virt_addr) {
  97        map->length += map->virt_addr - virt_addr;
  98        map->virt_addr = virt_addr;
  99    }
 100
 101    if ((virt_addr + length) >
 102        (map->virt_addr + map->length)) {
 103        map->length = virt_addr + length - map->virt_addr;
 104    }
 105}
 106
 107void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
 108                                          hwaddr phys_addr,
 109                                          hwaddr virt_addr,
 110                                          ram_addr_t length)
 111{
 112    MemoryMapping *memory_mapping, *last_mapping;
 113
 114    if (QTAILQ_EMPTY(&list->head)) {
 115        create_new_memory_mapping(list, phys_addr, virt_addr, length);
 116        return;
 117    }
 118
 119    last_mapping = list->last_mapping;
 120    if (last_mapping) {
 121        if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {
 122            last_mapping->length += length;
 123            return;
 124        }
 125    }
 126
 127    QTAILQ_FOREACH(memory_mapping, &list->head, next) {
 128        if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {
 129            memory_mapping->length += length;
 130            list->last_mapping = memory_mapping;
 131            return;
 132        }
 133
 134        if (phys_addr + length < memory_mapping->phys_addr) {
 135            /* create a new region before memory_mapping */
 136            break;
 137        }
 138
 139        if (mapping_have_same_region(memory_mapping, phys_addr, length)) {
 140            if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {
 141                continue;
 142            }
 143
 144            /* merge this region into memory_mapping */
 145            mapping_merge(memory_mapping, virt_addr, length);
 146            list->last_mapping = memory_mapping;
 147            return;
 148        }
 149    }
 150
 151    /* this region can not be merged into any existed memory mapping. */
 152    create_new_memory_mapping(list, phys_addr, virt_addr, length);
 153}
 154
 155void memory_mapping_list_free(MemoryMappingList *list)
 156{
 157    MemoryMapping *p, *q;
 158
 159    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
 160        QTAILQ_REMOVE(&list->head, p, next);
 161        g_free(p);
 162    }
 163
 164    list->num = 0;
 165    list->last_mapping = NULL;
 166}
 167
 168void memory_mapping_list_init(MemoryMappingList *list)
 169{
 170    list->num = 0;
 171    list->last_mapping = NULL;
 172    QTAILQ_INIT(&list->head);
 173}
 174
 175void guest_phys_blocks_free(GuestPhysBlockList *list)
 176{
 177    GuestPhysBlock *p, *q;
 178
 179    QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
 180        QTAILQ_REMOVE(&list->head, p, next);
 181        memory_region_unref(p->mr);
 182        g_free(p);
 183    }
 184    list->num = 0;
 185}
 186
 187void guest_phys_blocks_init(GuestPhysBlockList *list)
 188{
 189    list->num = 0;
 190    QTAILQ_INIT(&list->head);
 191}
 192
 193typedef struct GuestPhysListener {
 194    GuestPhysBlockList *list;
 195    MemoryListener listener;
 196} GuestPhysListener;
 197
 198static void guest_phys_blocks_region_add(MemoryListener *listener,
 199                                         MemoryRegionSection *section)
 200{
 201    GuestPhysListener *g;
 202    uint64_t section_size;
 203    hwaddr target_start, target_end;
 204    uint8_t *host_addr;
 205    GuestPhysBlock *predecessor;
 206
 207    /* we only care about RAM */
 208    if (!memory_region_is_ram(section->mr) ||
 209        memory_region_is_ram_device(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, GuestPhysBlockHead);
 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", __FUNCTION__, 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            list->num--;
 341            continue;
 342        }
 343
 344        if (cur->phys_addr < begin) {
 345            cur->length -= begin - cur->phys_addr;
 346            if (cur->virt_addr) {
 347                cur->virt_addr += begin - cur->phys_addr;
 348            }
 349            cur->phys_addr = begin;
 350        }
 351
 352        if (cur->phys_addr + cur->length > begin + length) {
 353            cur->length -= cur->phys_addr + cur->length - begin - length;
 354        }
 355    }
 356}
 357