Patchwork [v4,3/4] Use cpu_physical_memory_set_dirty_range() to update phys_ram_dirty.

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Submitter Yoshiaki Tamura
Date April 20, 2010, 3:40 a.m.
Message ID <1271734843-24231-4-git-send-email-tamura.yoshiaki@lab.ntt.co.jp>
Download mbox | patch
Permalink /patch/50511/
State New
Headers show

Comments

Yoshiaki Tamura - April 20, 2010, 3:40 a.m.
Modifies kvm_physical_sync_dirty_bitmap to use
cpu_physical_memory_set_dirty_range() to update the row of the bit-based
phys_ram_dirty bitmap at once.

Signed-off-by: OHMURA Kei <ohmura.kei@lab.ntt.co.jp>
Signed-off-by: Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>
---
 bswap.h   |    2 ++
 kvm-all.c |   33 +++++++++++++++------------------
 2 files changed, 17 insertions(+), 18 deletions(-)

Patch

diff --git a/bswap.h b/bswap.h
index aace9b7..956f3fa 100644
--- a/bswap.h
+++ b/bswap.h
@@ -205,8 +205,10 @@  static inline void cpu_to_be32wu(uint32_t *p, uint32_t v)
 
 #ifdef HOST_WORDS_BIGENDIAN
 #define cpu_to_32wu cpu_to_be32wu
+#define leul_to_cpu(v) le ## HOST_LONG_BITS ## _to_cpu(v)
 #else
 #define cpu_to_32wu cpu_to_le32wu
+#define leul_to_cpu(v) (v)
 #endif
 
 #undef le_bswap
diff --git a/kvm-all.c b/kvm-all.c
index 7aa5e57..db762ff 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -282,11 +282,6 @@  static int kvm_set_migration_log(int enable)
     return 0;
 }
 
-static int test_le_bit(unsigned long nr, unsigned char *addr)
-{
-    return (addr[nr >> 3] >> (nr & 7)) & 1;
-}
-
 /**
  * kvm_physical_sync_dirty_bitmap - Grab dirty bitmap from kernel space
  * This function updates qemu's dirty bitmap using cpu_physical_memory_set_dirty().
@@ -299,9 +294,9 @@  static int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
 					  target_phys_addr_t end_addr)
 {
     KVMState *s = kvm_state;
-    unsigned long size, allocated_size = 0;
-    target_phys_addr_t phys_addr;
-    ram_addr_t addr;
+    unsigned long size, page_number, addr, addr1, *bitmap,
+        allocated_size = 0;
+    unsigned int i, len;
     KVMDirtyLog d;
     KVMSlot *mem;
     int ret = 0;
@@ -313,7 +308,8 @@  static int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
             break;
         }
 
-        size = ((mem->memory_size >> TARGET_PAGE_BITS) + 7) / 8;
+        size = ((mem->memory_size >> TARGET_PAGE_BITS) + HOST_LONG_BITS - 1) /
+            HOST_LONG_BITS * HOST_LONG_SIZE;
         if (!d.dirty_bitmap) {
             d.dirty_bitmap = qemu_malloc(size);
         } else if (size > allocated_size) {
@@ -330,17 +326,18 @@  static int kvm_physical_sync_dirty_bitmap(target_phys_addr_t start_addr,
             break;
         }
 
-        for (phys_addr = mem->start_addr, addr = mem->phys_offset;
-             phys_addr < mem->start_addr + mem->memory_size;
-             phys_addr += TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) {
-            unsigned char *bitmap = (unsigned char *)d.dirty_bitmap;
-            unsigned nr = (phys_addr - mem->start_addr) >> TARGET_PAGE_BITS;
-
-            if (test_le_bit(nr, bitmap)) {
-                cpu_physical_memory_set_dirty(addr);
+        bitmap = (unsigned long *)d.dirty_bitmap;
+        len = size / HOST_LONG_SIZE;
+        for (i = 0; i < len; i++) {
+            if (bitmap[i] != 0) {
+                page_number = i * HOST_LONG_BITS;
+                addr1 = page_number * TARGET_PAGE_SIZE;
+                addr = mem->phys_offset + addr1;
+                cpu_physical_memory_set_dirty_range(addr, 
+                    leul_to_cpu(bitmap[i]));
             }
         }
-        start_addr = phys_addr;
+        start_addr = mem->start_addr + mem->memory_size;
     }
     qemu_free(d.dirty_bitmap);