[Qemu-devel] [PATCH 1/3] memory: drop find_ram_block()

[Gonglei]

On the one hand, we have already qemu_get_ram_block() whose function
is similar. On the other hand, we can directly use mr->ram_block but
searching RAMblock by ram_addr which is a kind of waste.

Signed-off-by: Gonglei <address@hidden>
---
 exec.c                    | 37 +++++++++----------------------------
 include/exec/cpu-common.h |  4 ++--
 include/exec/ram_addr.h   |  2 +-
 memory.c                  |  2 +-
 migration/ram.c           |  2 +-
 migration/savevm.c        |  4 ++--
 6 files changed, 16 insertions(+), 35 deletions(-)

diff --git a/exec.c b/exec.c
index c4f9036..101f0f4 100644
--- a/exec.c
+++ b/exec.c
@@ -1407,34 +1407,19 @@ static void qemu_ram_setup_dump(void *addr, ram_addr_t 
size)
     }
 }
 
-/* Called within an RCU critical section, or while the ramlist lock
- * is held.
- */
-static RAMBlock *find_ram_block(ram_addr_t addr)
-{
-    RAMBlock *block;
-
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
-        if (block->offset == addr) {
-            return block;
-        }
-    }
-
-    return NULL;
-}
-
 const char *qemu_ram_get_idstr(RAMBlock *rb)
 {
     return rb->idstr;
 }
 
 /* Called with iothread lock held.  */
-void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
+void qemu_ram_set_idstr(RAMBlock *block, const char *name, DeviceState *dev)
 {
-    RAMBlock *new_block, *block;
+    RAMBlock *new_block = block;
+    RAMBlock *old_block;
 
     rcu_read_lock();
-    new_block = find_ram_block(addr);
+
     assert(new_block);
     assert(!new_block->idstr[0]);
 
@@ -1447,8 +1432,9 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char 
*name, DeviceState *dev)
     }
     pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
 
-    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
-        if (block != new_block && !strcmp(block->idstr, new_block->idstr)) {
+    QLIST_FOREACH_RCU(old_block, &ram_list.blocks, next) {
+        if (old_block != new_block &&
+            !strcmp(old_block->idstr, new_block->idstr)) {
             fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
                     new_block->idstr);
             abort();
@@ -1458,17 +1444,14 @@ void qemu_ram_set_idstr(ram_addr_t addr, const char 
*name, DeviceState *dev)
 }
 
 /* Called with iothread lock held.  */
-void qemu_ram_unset_idstr(ram_addr_t addr)
+void qemu_ram_unset_idstr(RAMBlock *block)
 {
-    RAMBlock *block;
-
     /* FIXME: arch_init.c assumes that this is not called throughout
      * migration.  Ignore the problem since hot-unplug during migration
      * does not work anyway.
      */
 
     rcu_read_lock();
-    block = find_ram_block(addr);
     if (block) {
         memset(block->idstr, 0, sizeof(block->idstr));
     }
@@ -1492,10 +1475,8 @@ static int memory_try_enable_merging(void *addr, size_t 
len)
  * resize callback to update device state and/or add assertions to detect
  * misuse, if necessary.
  */
-int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp)
+int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp)
 {
-    RAMBlock *block = find_ram_block(base);
-
     assert(block);
 
     newsize = HOST_PAGE_ALIGN(newsize);
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 9e839e5..187df3b 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -65,8 +65,8 @@ MemoryRegion *qemu_ram_addr_from_host(void *ptr, ram_addr_t 
*ram_addr);
 RAMBlock *qemu_ram_block_by_name(const char *name);
 RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
                                    ram_addr_t *ram_addr, ram_addr_t *offset);
-void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev);
-void qemu_ram_unset_idstr(ram_addr_t addr);
+void qemu_ram_set_idstr(RAMBlock *block, const char *name, DeviceState *dev);
+void qemu_ram_unset_idstr(RAMBlock *block);
 const char *qemu_ram_get_idstr(RAMBlock *rb);
 
 void cpu_physical_memory_rw(hwaddr addr, uint8_t *buf,
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 5adf7a4..5b6e1b8 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -110,7 +110,7 @@ void qemu_set_ram_fd(ram_addr_t addr, int fd);
 void *qemu_get_ram_block_host_ptr(ram_addr_t addr);
 void qemu_ram_free(RAMBlock *block);
 
-int qemu_ram_resize(ram_addr_t base, ram_addr_t newsize, Error **errp);
+int qemu_ram_resize(RAMBlock *block, ram_addr_t newsize, Error **errp);
 
 #define DIRTY_CLIENTS_ALL     ((1 << DIRTY_MEMORY_NUM) - 1)
 #define DIRTY_CLIENTS_NOCODE  (DIRTY_CLIENTS_ALL & ~(1 << DIRTY_MEMORY_CODE))
diff --git a/memory.c b/memory.c
index f76f85d..239e6da 100644
--- a/memory.c
+++ b/memory.c
@@ -1671,7 +1671,7 @@ void memory_region_ram_resize(MemoryRegion *mr, 
ram_addr_t newsize, Error **errp
 {
     assert(mr->ram_block);
 
-    qemu_ram_resize(memory_region_get_ram_addr(mr), newsize, errp);
+    qemu_ram_resize(mr->ram_block, newsize, errp);
 }
 
 static void memory_region_update_coalesced_range_as(MemoryRegion *mr, 
AddressSpace *as)
diff --git a/migration/ram.c b/migration/ram.c
index 3f05738..28b5dd8 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2476,7 +2476,7 @@ static int ram_load(QEMUFile *f, void *opaque, int 
version_id)
                     if (length != block->used_length) {
                         Error *local_err = NULL;
 
-                        ret = qemu_ram_resize(block->offset, length,
+                        ret = qemu_ram_resize(block, length,
                                               &local_err);
                         if (local_err) {
                             error_report_err(local_err);
diff --git a/migration/savevm.c b/migration/savevm.c
index 16ba443..3a2e843 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2228,13 +2228,13 @@ void hmp_info_snapshots(Monitor *mon, const QDict 
*qdict)
 
 void vmstate_register_ram(MemoryRegion *mr, DeviceState *dev)
 {
-    qemu_ram_set_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK,
+    qemu_ram_set_idstr(mr->ram_block,
                        memory_region_name(mr), dev);
 }
 
 void vmstate_unregister_ram(MemoryRegion *mr, DeviceState *dev)
 {
-    qemu_ram_unset_idstr(memory_region_get_ram_addr(mr) & TARGET_PAGE_MASK);
+    qemu_ram_unset_idstr(mr->ram_block);
 }
 
 void vmstate_register_ram_global(MemoryRegion *mr)
-- 
1.7.12.4