[PATCH v4 02/17] dump: Introduce GuestPhysBlock offset and length filter functions

[Janosch Frank]

The iteration over the memblocks is hard to understand so it's about
time to clean it up. Instead of manually grabbing the next memblock we
can use QTAILQ_FOREACH to iterate over all memblocks.

Additionally we move the calculation of the offset and length out by
using the dump_get_memblock_*() functions.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 dump/dump.c           | 37 +++++++++++++++++++++++++++++++++++++
 include/sysemu/dump.h |  5 +++++
 2 files changed, 42 insertions(+)

diff --git a/dump/dump.c b/dump/dump.c
index 0ed7cf9c7b..0fd7c76c1e 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -591,6 +591,43 @@ static void dump_begin(DumpState *s, Error **errp)
     write_elf_notes(s, errp);
 }
 
+int64_t dump_get_memblock_size(GuestPhysBlock *block, int64_t 
filter_area_start,
+                               int64_t filter_area_length)
+{
+    int64_t size, left, right;
+
+    /* No filter, return full size */
+    if (!filter_area_length) {
+        return block->target_end - block->target_start;
+    }
+
+    /* calculate the overlapped region. */
+    left = MAX(filter_area_start, block->target_start);
+    right = MIN(filter_area_start + filter_area_length, block->target_end);
+    size = right - left;
+    size = size > 0 ? size : 0;
+
+    return size;
+}
+
+int64_t dump_get_memblock_start(GuestPhysBlock *block, int64_t 
filter_area_start,
+                                int64_t filter_area_length)
+{
+    if (filter_area_length) {
+        /* return -1 if the block is not within filter area */
+        if (block->target_start >= filter_area_start + filter_area_length ||
+            block->target_end <= filter_area_start) {
+            return -1;
+        }
+
+        if (filter_area_start > block->target_start) {
+            return filter_area_start - block->target_start;
+        }
+    }
+
+    return 0;
+}
+
 static int get_next_block(DumpState *s, GuestPhysBlock *block)
 {
     while (1) {
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index ffc2ea1072..6ce3c24197 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -203,4 +203,9 @@ typedef struct DumpState {
 uint16_t cpu_to_dump16(DumpState *s, uint16_t val);
 uint32_t cpu_to_dump32(DumpState *s, uint32_t val);
 uint64_t cpu_to_dump64(DumpState *s, uint64_t val);
+
+int64_t dump_get_memblock_size(GuestPhysBlock *block, int64_t 
filter_area_start,
+                               int64_t filter_area_length);
+int64_t dump_get_memblock_start(GuestPhysBlock *block, int64_t 
filter_area_start,
+                                int64_t filter_area_length);
 #endif
-- 
2.34.1