memory_mapping.c

   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
  25 static 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
  39 static 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
  55 static 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  */
  67 static 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  */
  80 static 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  */
  92 static 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
 107 void 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
 155 void 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
 168 void memory_mapping_list_init(MemoryMappingList *list)
 169 {
 170     list->num = 0;
 171     list->last_mapping = NULL;
 172     QTAILQ_INIT(&list->head);
 173 }
 174
 175 void 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
 187 void guest_phys_blocks_init(GuestPhysBlockList *list)
 188 {
 189     list->num = 0;
 190     QTAILQ_INIT(&list->head);
 191 }
 192
 193 typedef struct GuestPhysListener {
 194     GuestPhysBlockList *list;
 195     MemoryListener listener;
 196 } GuestPhysListener;
 197
 198 static 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         memory_region_is_nonvolatile(section->mr)) {
 211         return;
 212     }
 213
 214     g            = container_of(listener, GuestPhysListener, listener);
 215     section_size = int128_get64(section->size);
 216     target_start = section->offset_within_address_space;
 217     target_end   = target_start + section_size;
 218     host_addr    = memory_region_get_ram_ptr(section->mr) +
 219                    section->offset_within_region;
 220     predecessor  = NULL;
 221
 222     /* find continuity in guest physical address space */
 223     if (!QTAILQ_EMPTY(&g->list->head)) {
 224         hwaddr predecessor_size;
 225
 226         predecessor = QTAILQ_LAST(&g->list->head, GuestPhysBlockHead);
 227         predecessor_size = predecessor->target_end - predecessor->target_start;
 228
 229         /* the memory API guarantees monotonically increasing traversal */
 230         g_assert(predecessor->target_end <= target_start);
 231
 232         /* we want continuity in both guest-physical and host-virtual memory */
 233         if (predecessor->target_end < target_start ||
 234             predecessor->host_addr + predecessor_size != host_addr) {
 235             predecessor = NULL;
 236         }
 237     }
 238
 239     if (predecessor == NULL) {
 240         /* isolated mapping, allocate it and add it to the list */
 241         GuestPhysBlock *block = g_malloc0(sizeof *block);
 242
 243         block->target_start = target_start;
 244         block->target_end   = target_end;
 245         block->host_addr    = host_addr;
 246         block->mr           = section->mr;
 247         memory_region_ref(section->mr);
 248
 249         QTAILQ_INSERT_TAIL(&g->list->head, block, next);
 250         ++g->list->num;
 251     } else {
 252         /* expand predecessor until @target_end; predecessor's start doesn't
 253          * change
 254          */
 255         predecessor->target_end = target_end;
 256     }
 257
 258 #ifdef DEBUG_GUEST_PHYS_REGION_ADD
 259     fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end="
 260             TARGET_FMT_plx ": %s (count: %u)\n", __func__, target_start,
 261             target_end, predecessor ? "joined" : "added", g->list->num);
 262 #endif
 263 }
 264
 265 void guest_phys_blocks_append(GuestPhysBlockList *list)
 266 {
 267     GuestPhysListener g = { 0 };
 268
 269     g.list = list;
 270     g.listener.region_add = &guest_phys_blocks_region_add;
 271     memory_listener_register(&g.listener, &address_space_memory);
 272     memory_listener_unregister(&g.listener);
 273 }
 274
 275 static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
 276 {
 277     CPUState *cpu;
 278
 279     CPU_FOREACH(cpu) {
 280         if (cpu_paging_enabled(cpu)) {
 281             return cpu;
 282         }
 283     }
 284
 285     return NULL;
 286 }
 287
 288 void qemu_get_guest_memory_mapping(MemoryMappingList *list,
 289                                    const GuestPhysBlockList *guest_phys_blocks,
 290                                    Error **errp)
 291 {
 292     CPUState *cpu, *first_paging_enabled_cpu;
 293     GuestPhysBlock *block;
 294     ram_addr_t offset, length;
 295
 296     first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
 297     if (first_paging_enabled_cpu) {
 298         for (cpu = first_paging_enabled_cpu; cpu != NULL;
 299              cpu = CPU_NEXT(cpu)) {
 300             Error *err = NULL;
 301             cpu_get_memory_mapping(cpu, list, &err);
 302             if (err) {
 303                 error_propagate(errp, err);
 304                 return;
 305             }
 306         }
 307         return;
 308     }
 309
 310     /*
 311      * If the guest doesn't use paging, the virtual address is equal to physical
 312      * address.
 313      */
 314     QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 315         offset = block->target_start;
 316         length = block->target_end - block->target_start;
 317         create_new_memory_mapping(list, offset, offset, length);
 318     }
 319 }
 320
 321 void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,
 322                                    const GuestPhysBlockList *guest_phys_blocks)
 323 {
 324     GuestPhysBlock *block;
 325
 326     QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
 327         create_new_memory_mapping(list, block->target_start, 0,
 328                                   block->target_end - block->target_start);
 329     }
 330 }
 331
 332 void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
 333                            int64_t length)
 334 {
 335     MemoryMapping *cur, *next;
 336
 337     QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {
 338         if (cur->phys_addr >= begin + length ||
 339             cur->phys_addr + cur->length <= begin) {
 340             QTAILQ_REMOVE(&list->head, cur, next);
 341             g_free(cur);
 342             list->num--;
 343             continue;
 344         }
 345
 346         if (cur->phys_addr < begin) {
 347             cur->length -= begin - cur->phys_addr;
 348             if (cur->virt_addr) {
 349                 cur->virt_addr += begin - cur->phys_addr;
 350             }
 351             cur->phys_addr = begin;
 352         }
 353
 354         if (cur->phys_addr + cur->length > begin + length) {
 355             cur->length -= cur->phys_addr + cur->length - begin - length;
 356         }
 357     }
 358 }