qemu

memory_mapping.c (11517B)

---

 /*
  * QEMU memory mapping
  *
  * Copyright Fujitsu, Corp. 2011, 2012
  *
  * Authors:
  *     Wen Congyang <wency@cn.fujitsu.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  *
  */
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 
 #include "sysemu/memory_mapping.h"
 #include "exec/memory.h"
 #include "exec/address-spaces.h"
 #include "hw/core/cpu.h"
 
 //#define DEBUG_GUEST_PHYS_REGION_ADD
 
 static void memory_mapping_list_add_mapping_sorted(MemoryMappingList *list,
                                                    MemoryMapping *mapping)
 {
     MemoryMapping *p;
 
     QTAILQ_FOREACH(p, &list->head, next) {
         if (p->phys_addr >= mapping->phys_addr) {
             QTAILQ_INSERT_BEFORE(p, mapping, next);
             return;
         }
     }
     QTAILQ_INSERT_TAIL(&list->head, mapping, next);
 }
 
 static void create_new_memory_mapping(MemoryMappingList *list,
                                       hwaddr phys_addr,
                                       hwaddr virt_addr,
                                       ram_addr_t length)
 {
     MemoryMapping *memory_mapping;
 
     memory_mapping = g_new(MemoryMapping, 1);
     memory_mapping->phys_addr = phys_addr;
     memory_mapping->virt_addr = virt_addr;
     memory_mapping->length = length;
     list->last_mapping = memory_mapping;
     list->num++;
     memory_mapping_list_add_mapping_sorted(list, memory_mapping);
 }
 
 static inline bool mapping_contiguous(MemoryMapping *map,
                                       hwaddr phys_addr,
                                       hwaddr virt_addr)
 {
     return phys_addr == map->phys_addr + map->length &&
            virt_addr == map->virt_addr + map->length;
 }
 
 /*
  * [map->phys_addr, map->phys_addr + map->length) and
  * [phys_addr, phys_addr + length) have intersection?
  */
 static inline bool mapping_have_same_region(MemoryMapping *map,
                                             hwaddr phys_addr,
                                             ram_addr_t length)
 {
     return !(phys_addr + length < map->phys_addr ||
              phys_addr >= map->phys_addr + map->length);
 }
 
 /*
  * [map->phys_addr, map->phys_addr + map->length) and
  * [phys_addr, phys_addr + length) have intersection. The virtual address in the
  * intersection are the same?
  */
 static inline bool mapping_conflict(MemoryMapping *map,
                                     hwaddr phys_addr,
                                     hwaddr virt_addr)
 {
     return virt_addr - map->virt_addr != phys_addr - map->phys_addr;
 }
 
 /*
  * [map->virt_addr, map->virt_addr + map->length) and
  * [virt_addr, virt_addr + length) have intersection. And the physical address
  * in the intersection are the same.
  */
 static inline void mapping_merge(MemoryMapping *map,
                                  hwaddr virt_addr,
                                  ram_addr_t length)
 {
     if (virt_addr < map->virt_addr) {
         map->length += map->virt_addr - virt_addr;
         map->virt_addr = virt_addr;
     }
 
     if ((virt_addr + length) >
         (map->virt_addr + map->length)) {
         map->length = virt_addr + length - map->virt_addr;
     }
 }
 
 void memory_mapping_list_add_merge_sorted(MemoryMappingList *list,
                                           hwaddr phys_addr,
                                           hwaddr virt_addr,
                                           ram_addr_t length)
 {
     MemoryMapping *memory_mapping, *last_mapping;
 
     if (QTAILQ_EMPTY(&list->head)) {
         create_new_memory_mapping(list, phys_addr, virt_addr, length);
         return;
     }
 
     last_mapping = list->last_mapping;
     if (last_mapping) {
         if (mapping_contiguous(last_mapping, phys_addr, virt_addr)) {
             last_mapping->length += length;
             return;
         }
     }
 
     QTAILQ_FOREACH(memory_mapping, &list->head, next) {
         if (mapping_contiguous(memory_mapping, phys_addr, virt_addr)) {
             memory_mapping->length += length;
             list->last_mapping = memory_mapping;
             return;
         }
 
         if (phys_addr + length < memory_mapping->phys_addr) {
             /* create a new region before memory_mapping */
             break;
         }
 
         if (mapping_have_same_region(memory_mapping, phys_addr, length)) {
             if (mapping_conflict(memory_mapping, phys_addr, virt_addr)) {
                 continue;
             }
 
             /* merge this region into memory_mapping */
             mapping_merge(memory_mapping, virt_addr, length);
             list->last_mapping = memory_mapping;
             return;
         }
     }
 
     /* this region can not be merged into any existed memory mapping. */
     create_new_memory_mapping(list, phys_addr, virt_addr, length);
 }
 
 void memory_mapping_list_free(MemoryMappingList *list)
 {
     MemoryMapping *p, *q;
 
     QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
         QTAILQ_REMOVE(&list->head, p, next);
         g_free(p);
     }
 
     list->num = 0;
     list->last_mapping = NULL;
 }
 
 void memory_mapping_list_init(MemoryMappingList *list)
 {
     list->num = 0;
     list->last_mapping = NULL;
     QTAILQ_INIT(&list->head);
 }
 
 void guest_phys_blocks_free(GuestPhysBlockList *list)
 {
     GuestPhysBlock *p, *q;
 
     QTAILQ_FOREACH_SAFE(p, &list->head, next, q) {
         QTAILQ_REMOVE(&list->head, p, next);
         memory_region_unref(p->mr);
         g_free(p);
     }
     list->num = 0;
 }
 
 void guest_phys_blocks_init(GuestPhysBlockList *list)
 {
     list->num = 0;
     QTAILQ_INIT(&list->head);
 }
 
 typedef struct GuestPhysListener {
     GuestPhysBlockList *list;
     MemoryListener listener;
 } GuestPhysListener;
 
 static void guest_phys_block_add_section(GuestPhysListener *g,
                                          MemoryRegionSection *section)
 {
     const hwaddr target_start = section->offset_within_address_space;
     const hwaddr target_end = target_start + int128_get64(section->size);
     uint8_t *host_addr = memory_region_get_ram_ptr(section->mr) +
                          section->offset_within_region;
     GuestPhysBlock *predecessor = NULL;
 
     /* find continuity in guest physical address space */
     if (!QTAILQ_EMPTY(&g->list->head)) {
         hwaddr predecessor_size;
 
         predecessor = QTAILQ_LAST(&g->list->head);
         predecessor_size = predecessor->target_end - predecessor->target_start;
 
         /* the memory API guarantees monotonically increasing traversal */
         g_assert(predecessor->target_end <= target_start);
 
         /* we want continuity in both guest-physical and host-virtual memory */
         if (predecessor->target_end < target_start ||
             predecessor->host_addr + predecessor_size != host_addr ||
             predecessor->mr != section->mr) {
             predecessor = NULL;
         }
     }
 
     if (predecessor == NULL) {
         /* isolated mapping, allocate it and add it to the list */
         GuestPhysBlock *block = g_malloc0(sizeof *block);
 
         block->target_start = target_start;
         block->target_end   = target_end;
         block->host_addr    = host_addr;
         block->mr           = section->mr;
         memory_region_ref(section->mr);
 
         QTAILQ_INSERT_TAIL(&g->list->head, block, next);
         ++g->list->num;
     } else {
         /* expand predecessor until @target_end; predecessor's start doesn't
          * change
          */
         predecessor->target_end = target_end;
     }
 
 #ifdef DEBUG_GUEST_PHYS_REGION_ADD
     fprintf(stderr, "%s: target_start=" TARGET_FMT_plx " target_end="
             TARGET_FMT_plx ": %s (count: %u)\n", __func__, target_start,
             target_end, predecessor ? "joined" : "added", g->list->num);
 #endif
 }
 
 static int guest_phys_ram_populate_cb(MemoryRegionSection *section,
                                       void *opaque)
 {
     GuestPhysListener *g = opaque;
 
     guest_phys_block_add_section(g, section);
     return 0;
 }
 
 static void guest_phys_blocks_region_add(MemoryListener *listener,
                                          MemoryRegionSection *section)
 {
     GuestPhysListener *g = container_of(listener, GuestPhysListener, listener);
 
     /* we only care about RAM */
     if (!memory_region_is_ram(section->mr) ||
         memory_region_is_ram_device(section->mr) ||
         memory_region_is_nonvolatile(section->mr)) {
         return;
     }
 
     /* for special sparse regions, only add populated parts */
     if (memory_region_has_ram_discard_manager(section->mr)) {
         RamDiscardManager *rdm;
 
         rdm = memory_region_get_ram_discard_manager(section->mr);
         ram_discard_manager_replay_populated(rdm, section,
                                              guest_phys_ram_populate_cb, g);
         return;
     }
 
     guest_phys_block_add_section(g, section);
 }
 
 void guest_phys_blocks_append(GuestPhysBlockList *list)
 {
     GuestPhysListener g = { 0 };
 
     g.list = list;
     g.listener.region_add = &guest_phys_blocks_region_add;
     memory_listener_register(&g.listener, &address_space_memory);
     memory_listener_unregister(&g.listener);
 }
 
 static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
 {
     CPUState *cpu;
 
     CPU_FOREACH(cpu) {
         if (cpu_paging_enabled(cpu)) {
             return cpu;
         }
     }
 
     return NULL;
 }
 
 void qemu_get_guest_memory_mapping(MemoryMappingList *list,
                                    const GuestPhysBlockList *guest_phys_blocks,
                                    Error **errp)
 {
     CPUState *cpu, *first_paging_enabled_cpu;
     GuestPhysBlock *block;
     ram_addr_t offset, length;
 
     first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
     if (first_paging_enabled_cpu) {
         for (cpu = first_paging_enabled_cpu; cpu != NULL;
              cpu = CPU_NEXT(cpu)) {
             Error *err = NULL;
             cpu_get_memory_mapping(cpu, list, &err);
             if (err) {
                 error_propagate(errp, err);
                 return;
             }
         }
         return;
     }
 
     /*
      * If the guest doesn't use paging, the virtual address is equal to physical
      * address.
      */
     QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
         offset = block->target_start;
         length = block->target_end - block->target_start;
         create_new_memory_mapping(list, offset, offset, length);
     }
 }
 
 void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,
                                    const GuestPhysBlockList *guest_phys_blocks)
 {
     GuestPhysBlock *block;
 
     QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
         create_new_memory_mapping(list, block->target_start, 0,
                                   block->target_end - block->target_start);
     }
 }
 
 void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
                            int64_t length)
 {
     MemoryMapping *cur, *next;
 
     QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {
         if (cur->phys_addr >= begin + length ||
             cur->phys_addr + cur->length <= begin) {
             QTAILQ_REMOVE(&list->head, cur, next);
             g_free(cur);
             list->num--;
             continue;
         }
 
         if (cur->phys_addr < begin) {
             cur->length -= begin - cur->phys_addr;
             if (cur->virt_addr) {
                 cur->virt_addr += begin - cur->phys_addr;
             }
             cur->phys_addr = begin;
         }
 
         if (cur->phys_addr + cur->length > begin + length) {
             cur->length -= cur->phys_addr + cur->length - begin - length;
         }
     }
 }