[Qemu-devel] [PATCH 19/39] memory: split dirty bitmap into three

[Juan Quintela]

After all the previous patches, spliting the bitmap gets direct.

ToDo: Why can't i include "exec/memory.h" into cpu-all.h?  This is the
      reason that I have duplicated DIRTY_MEMORY_NUM.

ToDo2: current bitmaps have one int as index, this limit us to 8TB RAM
       guest, Should we move to longs?

Signed-off-by: Juan Quintela <quint...@redhat.com>
---
 exec.c                         |  9 ++++++---
 include/exec/cpu-all.h         |  4 +++-
 include/exec/memory-internal.h | 11 ++++-------
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/exec.c b/exec.c
index 38b5c1c..98700d3 100644
--- a/exec.c
+++ b/exec.c
@@ -1166,9 +1166,12 @@ ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void 
*host,
     new_ram_size = last_ram_offset() >> TARGET_PAGE_BITS;

     if (new_ram_size > old_ram_size) {
-        ram_list.phys_dirty = g_realloc(ram_list.phys_dirty, new_ram_size);
-        memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
-           0, size >> TARGET_PAGE_BITS);
+        int i;
+        for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
+            ram_list.dirty_memory[i] =
+                bitmap_zero_extend(ram_list.dirty_memory[i],
+                                   old_ram_size, new_ram_size);
+       }
     }
     cpu_physical_memory_set_dirty_range(new_block->offset, size);

diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h
index b6998f0..019dc20 100644
--- a/include/exec/cpu-all.h
+++ b/include/exec/cpu-all.h
@@ -456,10 +456,12 @@ typedef struct RAMBlock {
     int fd;
 } RAMBlock;

+#define DIRTY_MEMORY_NUM       3
+
 typedef struct RAMList {
     QemuMutex mutex;
     /* Protected by the iothread lock.  */
-    uint8_t *phys_dirty;
+    unsigned long *dirty_memory[DIRTY_MEMORY_NUM];
     RAMBlock *mru_block;
     /* Protected by the ramlist lock.  */
     QTAILQ_HEAD(, RAMBlock) blocks;
diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h
index 3f885a6..71f198e 100644
--- a/include/exec/memory-internal.h
+++ b/include/exec/memory-internal.h
@@ -44,7 +44,7 @@ static inline bool 
cpu_physical_memory_get_dirty_flag(ram_addr_t addr,
                                                       unsigned client)
 {
     assert(client < DIRTY_MEMORY_NUM);
-    return ram_list.phys_dirty[addr >> TARGET_PAGE_BITS] & (1 << client);
+    return test_bit(addr >> TARGET_PAGE_BITS, ram_list.dirty_memory[client]);
 }

 /* read dirty bit (return 0 or 1) */
@@ -75,7 +75,8 @@ static inline void 
cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
                                                       unsigned client)
 {
     assert(client < DIRTY_MEMORY_NUM);
-    ram_list.phys_dirty[addr >> TARGET_PAGE_BITS] |= (1 << client);
+
+    set_bit(addr >> TARGET_PAGE_BITS, ram_list.dirty_memory[client]);
 }

 static inline void cpu_physical_memory_set_dirty(ram_addr_t addr)
@@ -88,11 +89,7 @@ static inline void cpu_physical_memory_set_dirty(ram_addr_t 
addr)
 static inline void cpu_physical_memory_clear_dirty_flag(ram_addr_t addr,
                                                        unsigned client)
 {
-    int mask = ~(1 << client);
-
-    assert(client < DIRTY_MEMORY_NUM);
-
-    ram_list.phys_dirty[addr >> TARGET_PAGE_BITS] &= mask;
+    clear_bit(addr >> TARGET_PAGE_BITS, ram_list.dirty_memory[client]);
 }

 static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
-- 
1.8.3.1