softmmu/memory_mapping.c

   1 /*
   2  * QEMU memory mapping
   3  *
   4  * Copyright Fujitsu, Corp. 2011, 2012
   5  *
   6  * Authors:
   7  *     Wen Congyang <[email protected]>
   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
  23 static 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
  37 static 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
  53 static 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  */
  65 static 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  */
  78 static 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  */
  90 static 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
 105 void 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
 153 void 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
 166 void memory_mapping_list_init(MemoryMappingList *list)
 167 {
 168     list->num = 0;
 169     list->last_mapping = NULL;
 170     QTAILQ_INIT(&list->head);
 171 }
 172
 173 void 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
 185 void guest_phys_blocks_init(GuestPhysBlockList *list)
 186 {
 187     list->num = 0;
 188     QTAILQ_INIT(&list->head);
 189 }
 190
 191 typedef struct GuestPhysListener {
 192     GuestPhysBlockList *list;
 193     MemoryListener listener;
 194 } GuestPhysListener;
 195
 196 static 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
 249 static 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
 258 static 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
 283 void 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
 293 static 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
 306 void 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
 339 void 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
 350 void 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 }