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