[v3,05/35] protect the ramlist with a separate mutex

diff --git a/arch_init.c b/arch_init.c
index eb36a6a..a312434 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -553,7 +553,6 @@  static void ram_migration_cancel(void *opaque)
     migration_end();
 }
 
-
 static void reset_ram_globals(void)
 {
     last_block = NULL;
@@ -573,6 +572,7 @@  static int ram_save_setup(QEMUFile *f, void *opaque)
     bitmap_set(migration_bitmap, 1, ram_pages);
     migration_dirty_pages = ram_pages;
 
+    qemu_mutex_lock_ramlist();
     bytes_transferred = 0;
     reset_ram_globals();
 
@@ -600,6 +600,7 @@  static int ram_save_setup(QEMUFile *f, void *opaque)
         qemu_put_be64(f, block->length);
     }
 
+    qemu_mutex_unlock_ramlist();
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
 
     return 0;
@@ -614,6 +615,8 @@  static int ram_save_iterate(QEMUFile *f, void *opaque)
     uint64_t expected_downtime;
     MigrationState *s = migrate_get_current();
 
+    qemu_mutex_lock_ramlist();
+
     if (ram_list.version != last_version) {
         reset_ram_globals();
     }
@@ -662,6 +665,7 @@  static int ram_save_iterate(QEMUFile *f, void *opaque)
         bwidth = 0.000001;
     }
 
+    qemu_mutex_unlock_ramlist();
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
 
     expected_downtime = ram_save_remaining() * TARGET_PAGE_SIZE / bwidth;
@@ -682,6 +686,8 @@  static int ram_save_complete(QEMUFile *f, void *opaque)
 {
     migration_bitmap_sync();
 
+    qemu_mutex_lock_ramlist();
+
     /* try transferring iterative blocks of memory */
 
     /* flush all remaining blocks regardless of rate limiting */
@@ -697,6 +703,7 @@  static int ram_save_complete(QEMUFile *f, void *opaque)
     }
     memory_global_dirty_log_stop();
 
+    qemu_mutex_unlock_ramlist();
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
 
     g_free(migration_bitmap);
diff --git a/cpu-all.h b/cpu-all.h
index 84aea8b..b5fefc8 100644
--- a/cpu-all.h
+++ b/cpu-all.h
@@ -22,6 +22,7 @@ 
 #include "qemu-common.h"
 #include "qemu-tls.h"
 #include "cpu-common.h"
+#include "qemu-thread.h"
 
 /* some important defines:
  *
@@ -490,7 +491,9 @@  typedef struct RAMBlock {
     ram_addr_t offset;
     ram_addr_t length;
     uint32_t flags;
+    /* Protected by the iothread lock.  */
     QLIST_ENTRY(RAMBlock) next_mru;
+    /* Protected by the ramlist lock.  */
     QLIST_ENTRY(RAMBlock) next;
     char idstr[256];
 #if defined(__linux__) && !defined(TARGET_S390X)
@@ -499,9 +502,12 @@  typedef struct RAMBlock {
 } RAMBlock;
 
 typedef struct RAMList {
+    QemuMutex mutex;
+    /* Protected by the iothread lock.  */
     uint8_t *phys_dirty;
     uint32_t version;
     QLIST_HEAD(, RAMBlock) blocks_mru;
+    /* Protected by the ramlist lock.  */
     QLIST_HEAD(, RAMBlock) blocks;
 } RAMList;
 extern RAMList ram_list;
@@ -521,6 +527,8 @@  extern int mem_prealloc;
 
 void dump_exec_info(FILE *f, fprintf_function cpu_fprintf);
 ram_addr_t last_ram_offset(void);
+void qemu_mutex_lock_ramlist(void);
+void qemu_mutex_unlock_ramlist(void);
 #endif /* !CONFIG_USER_ONLY */
 
 int cpu_memory_rw_debug(CPUArchState *env, target_ulong addr,
diff --git a/exec.c b/exec.c
index f5a8aca..1414654 100644
--- a/exec.c
+++ b/exec.c
@@ -645,6 +645,7 @@  bool tcg_enabled(void)
 void cpu_exec_init_all(void)
 {
 #if !defined(CONFIG_USER_ONLY)
+    qemu_mutex_init(&ram_list.mutex);
     memory_map_init();
     io_mem_init();
 #endif
@@ -2324,6 +2325,16 @@  void qemu_flush_coalesced_mmio_buffer(void)
         kvm_flush_coalesced_mmio_buffer();
 }
 
+void qemu_mutex_lock_ramlist(void)
+{
+    qemu_mutex_lock(&ram_list.mutex);
+}
+
+void qemu_mutex_unlock_ramlist(void)
+{
+    qemu_mutex_unlock(&ram_list.mutex);
+}
+
 #if defined(__linux__) && !defined(TARGET_S390X)
 
 #include <sys/vfs.h>
@@ -2505,6 +2516,7 @@  void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
     }
     pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
 
+    qemu_mutex_lock_ramlist();
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (block != new_block && !strcmp(block->idstr, new_block->idstr)) {
             fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
@@ -2512,6 +2524,7 @@  void qemu_ram_set_idstr(ram_addr_t addr, const char *name, DeviceState *dev)
             abort();
         }
     }
+    qemu_mutex_unlock_ramlist();
 }
 
 static int memory_try_enable_merging(void *addr, size_t len)
@@ -2535,6 +2548,7 @@  ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
     size = TARGET_PAGE_ALIGN(size);
     new_block = g_malloc0(sizeof(*new_block));
 
+    qemu_mutex_lock_ramlist();
     new_block->mr = mr;
     new_block->offset = find_ram_offset(size);
     if (host) {
@@ -2570,6 +2584,7 @@  ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
     QLIST_INSERT_HEAD(&ram_list.blocks_mru, new_block, next_mru);
 
     ram_list.version++;
+    qemu_mutex_unlock_ramlist();
 
     ram_list.phys_dirty = g_realloc(ram_list.phys_dirty,
                                        last_ram_offset() >> TARGET_PAGE_BITS);
@@ -2595,21 +2610,24 @@  void qemu_ram_free_from_ptr(ram_addr_t addr)
 {
     RAMBlock *block;
 
+    qemu_mutex_lock_ramlist();
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (addr == block->offset) {
             QLIST_REMOVE(block, next);
             QLIST_REMOVE(block, next_mru);
             ram_list.version++;
             g_free(block);
-            return;
+            break;
         }
     }
+    qemu_mutex_unlock_ramlist();
 }
 
 void qemu_ram_free(ram_addr_t addr)
 {
     RAMBlock *block;
 
+    qemu_mutex_lock_ramlist();
     QLIST_FOREACH(block, &ram_list.blocks, next) {
         if (addr == block->offset) {
             QLIST_REMOVE(block, next);
@@ -2640,9 +2658,10 @@  void qemu_ram_free(ram_addr_t addr)
 #endif
             }
             g_free(block);
-            return;
+            break;
         }
     }
+    qemu_mutex_unlock_ramlist();
 
 }