[Qemu-devel] [PATCH v3 2/6] Introduce bit-based phys_ram_dirty for VGA, CODE, MIGRATION and MASTER.

[Yoshiaki Tamura]

Replaces byte-based phys_ram_dirty bitmap with four bit-based phys_ram_dirty
bitmap.  On allocation, it sets all bits in the bitmap.

Signed-off-by: Yoshiaki Tamura <tamura.yoshi...@lab.ntt.co.jp>
---
 exec.c        |   16 +++++++++++-----
 qemu-common.h |    3 +++
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/exec.c b/exec.c
index c74b0a4..b85cb26 100644
--- a/exec.c
+++ b/exec.c
@@ -110,7 +110,7 @@ uint8_t *code_gen_ptr;
 
 #if !defined(CONFIG_USER_ONLY)
 int phys_ram_fd;
-uint8_t *phys_ram_dirty;
+unsigned long *phys_ram_dirty[NUM_DIRTY_IDX];
 static int in_migration;
 
 typedef struct RAMBlock {
@@ -2825,10 +2825,16 @@ ram_addr_t qemu_ram_alloc(ram_addr_t size)
     new_block->next = ram_blocks;
     ram_blocks = new_block;
 
-    phys_ram_dirty = qemu_realloc(phys_ram_dirty,
-        (last_ram_offset + size) >> TARGET_PAGE_BITS);
-    memset(phys_ram_dirty + (last_ram_offset >> TARGET_PAGE_BITS),
-           0xff, size >> TARGET_PAGE_BITS);
+    if (BITMAP_SIZE(last_ram_offset + size) != BITMAP_SIZE(last_ram_offset)) {
+        int i;
+        for (i = MASTER_DIRTY_IDX; i < NUM_DIRTY_IDX; i++) {
+            phys_ram_dirty[i] 
+                = qemu_realloc(phys_ram_dirty[i],
+                               BITMAP_SIZE(last_ram_offset + size));
+            memset((uint8_t *)phys_ram_dirty[i] +
+                   BITMAP_SIZE(last_ram_offset), 0xff, BITMAP_SIZE(size));
+        }
+    }
 
     last_ram_offset += size;
 
diff --git a/qemu-common.h b/qemu-common.h
index 4ba0cda..efe5b1f 100644
--- a/qemu-common.h
+++ b/qemu-common.h
@@ -285,6 +285,9 @@ static inline uint8_t from_bcd(uint8_t val)
     return ((val >> 4) * 10) + (val & 0x0f);
 }
 
+#define ALIGN(x, y)  (((x)+(y)-1) & ~((y)-1))
+#define BITMAP_SIZE(m) (ALIGN(((m)>>TARGET_PAGE_BITS), HOST_LONG_BITS) / 8)
+
 #include "module.h"
 
 #endif /* dyngen-exec.h hack */
-- 
1.7.0.31.g1df487