dump: rebase from host-private RAMBlock offsets to guest-physical addresses

RAMBlock.offset                   --> GuestPhysBlock.target_start
RAMBlock.offset + RAMBlock.length --> GuestPhysBlock.target_end
RAMBlock.length                   --> GuestPhysBlock.target_end -
                                      GuestPhysBlock.target_start

"GuestPhysBlock.host_addr" is only used when writing the dump contents.

This patch enables "crash" to work with the vmcore by rebasing the vmcore
from the left side of the following diagram to the right side:

host-private
offset
relative
to ram_addr   RAMBlock                  guest-visible paddrs
            0 +-------------------+.....+-------------------+ 0
              |         ^         |     |        ^          |
              |       640 KB      |     |      640 KB       |
              |         v         |     |        v          |
  0x0000a0000 +-------------------+.....+-------------------+ 0x0000a0000
              |         ^         |     |XXXXXXXXXXXXXXXXXXX|
              |       384 KB      |     |XXXXXXXXXXXXXXXXXXX|
              |         v         |     |XXXXXXXXXXXXXXXXXXX|
  0x000100000 +-------------------+.....+-------------------+ 0x000100000
              |         ^         |     |        ^          |
              |       3583 MB     |     |      3583 MB      |
              |         v         |     |        v          |
  0x0e0000000 +-------------------+.....+-------------------+ 0x0e0000000
              |         ^         |.    |XXXXXXXXXXXXXXXXXXX|
              | above_4g_mem_size | .   |XXXX PCI hole XXXXX|
              |         v         |  .  |XXXX          XXXXX|
     ram_size +-------------------+   . |XXXX  512 MB  XXXXX|
                                   .   .|XXXXXXXXXXXXXXXXXXX|
                                    .   +-------------------+ 0x100000000
                                     .  |         ^         |
                                      . | above_4g_mem_size |
                                       .|         v         |
                                        +-------------------+ ram_size
                                                              + 512 MB

Related RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=981582

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

1 files changed, 13 insertions, 9 deletions

diff --git a/memory_mapping.c b/memory_mapping.c
index 876f5aa..eeeeb44 100644
--- a/memory_mapping.c
+++ b/memory_mapping.c
@@ -279,10 +279,12 @@ static CPUState *find_paging_enabled_cpu(CPUState *start_cpu)
     return NULL;
 }
 
-void qemu_get_guest_memory_mapping(MemoryMappingList *list, Error **errp)
+void qemu_get_guest_memory_mapping(MemoryMappingList *list,
+                                   const GuestPhysBlockList *guest_phys_blocks,
+                                   Error **errp)
 {
     CPUState *cpu, *first_paging_enabled_cpu;
-    RAMBlock *block;
+    GuestPhysBlock *block;
     ram_addr_t offset, length;
 
     first_paging_enabled_cpu = find_paging_enabled_cpu(first_cpu);
@@ -302,19 +304,21 @@ void qemu_get_guest_memory_mapping(MemoryMappingList *list, Error **errp)
      * If the guest doesn't use paging, the virtual address is equal to physical
      * address.
      */
-    QTAILQ_FOREACH(block, &ram_list.blocks, next) {
-        offset = block->offset;
-        length = block->length;
+    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)
+void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list,
+                                   const GuestPhysBlockList *guest_phys_blocks)
 {
-    RAMBlock *block;
+    GuestPhysBlock *block;
 
-    QTAILQ_FOREACH(block, &ram_list.blocks, next) {
-        create_new_memory_mapping(list, block->offset, 0, block->length);
+    QTAILQ_FOREACH(block, &guest_phys_blocks->head, next) {
+        create_new_memory_mapping(list, block->target_start, 0,
+                                  block->target_end - block->target_start);
     }
 }