[v10,2/7] system/physmem: Propagate AddressSpace to MapClient helpers

diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 8bc397e251..815342d043 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -147,8 +147,6 @@  void *cpu_physical_memory_map(hwaddr addr,
                               bool is_write);
 void cpu_physical_memory_unmap(void *buffer, hwaddr len,
                                bool is_write, hwaddr access_len);
-void cpu_register_map_client(QEMUBH *bh);
-void cpu_unregister_map_client(QEMUBH *bh);
 
 bool cpu_physical_memory_is_io(hwaddr phys_addr);
 
diff --git a/include/exec/memory.h b/include/exec/memory.h
index dadb5cd65a..e1e0c5a3de 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -2946,8 +2946,8 @@  bool address_space_access_valid(AddressSpace *as, hwaddr addr, hwaddr len,
  * May return %NULL and set *@plen to zero(0), if resources needed to perform
  * the mapping are exhausted.
  * Use only for reads OR writes - not for read-modify-write operations.
- * Use cpu_register_map_client() to know when retrying the map operation is
- * likely to succeed.
+ * Use address_space_register_map_client() to know when retrying the map
+ * operation is likely to succeed.
  *
  * @as: #AddressSpace to be accessed
  * @addr: address within that address space
@@ -2972,6 +2972,28 @@  void *address_space_map(AddressSpace *as, hwaddr addr,
 void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
                          bool is_write, hwaddr access_len);
 
+/*
+ * address_space_register_map_client: Register a callback to invoke when
+ * resources for address_space_map() are available again.
+ *
+ * address_space_map may fail when there are not enough resources available,
+ * such as when bounce buffer memory would exceed the limit. The callback can
+ * be used to retry the address_space_map operation. Note that the callback
+ * gets automatically removed after firing.
+ *
+ * @as: #AddressSpace to be accessed
+ * @bh: callback to invoke when address_space_map() retry is appropriate
+ */
+void address_space_register_map_client(AddressSpace *as, QEMUBH *bh);
+
+/*
+ * address_space_unregister_map_client: Unregister a callback that has
+ * previously been registered and not fired yet.
+ *
+ * @as: #AddressSpace to be accessed
+ * @bh: callback to unregister
+ */
+void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh);
 
 /* Internal functions, part of the implementation of address_space_read.  */
 MemTxResult address_space_read_full(AddressSpace *as, hwaddr addr,
diff --git a/system/dma-helpers.c b/system/dma-helpers.c
index 9b221cf94e..74013308f5 100644
--- a/system/dma-helpers.c
+++ b/system/dma-helpers.c
@@ -169,7 +169,7 @@  static void dma_blk_cb(void *opaque, int ret)
     if (dbs->iov.size == 0) {
         trace_dma_map_wait(dbs);
         dbs->bh = aio_bh_new(ctx, reschedule_dma, dbs);
-        cpu_register_map_client(dbs->bh);
+        address_space_register_map_client(dbs->sg->as, dbs->bh);
         return;
     }
 
@@ -197,7 +197,7 @@  static void dma_aio_cancel(BlockAIOCB *acb)
     }
 
     if (dbs->bh) {
-        cpu_unregister_map_client(dbs->bh);
+        address_space_unregister_map_client(dbs->sg->as, dbs->bh);
         qemu_bh_delete(dbs->bh);
         dbs->bh = NULL;
     }
diff --git a/system/physmem.c b/system/physmem.c
index 5486014cf2..27e754ff57 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3065,24 +3065,24 @@  QemuMutex map_client_list_lock;
 static QLIST_HEAD(, MapClient) map_client_list
     = QLIST_HEAD_INITIALIZER(map_client_list);
 
-static void cpu_unregister_map_client_do(MapClient *client)
+static void address_space_unregister_map_client_do(MapClient *client)
 {
     QLIST_REMOVE(client, link);
     g_free(client);
 }
 
-static void cpu_notify_map_clients_locked(void)
+static void address_space_notify_map_clients_locked(AddressSpace *as)
 {
     MapClient *client;
 
     while (!QLIST_EMPTY(&map_client_list)) {
         client = QLIST_FIRST(&map_client_list);
         qemu_bh_schedule(client->bh);
-        cpu_unregister_map_client_do(client);
+        address_space_unregister_map_client_do(client);
     }
 }
 
-void cpu_register_map_client(QEMUBH *bh)
+void address_space_register_map_client(AddressSpace *as, QEMUBH *bh)
 {
     MapClient *client = g_malloc(sizeof(*client));
 
@@ -3092,7 +3092,7 @@  void cpu_register_map_client(QEMUBH *bh)
     /* Write map_client_list before reading in_use.  */
     smp_mb();
     if (!qatomic_read(&bounce.in_use)) {
-        cpu_notify_map_clients_locked();
+        address_space_notify_map_clients_locked(as);
     }
 }
 
@@ -3112,23 +3112,23 @@  void cpu_exec_init_all(void)
     qemu_mutex_init(&map_client_list_lock);
 }
 
-void cpu_unregister_map_client(QEMUBH *bh)
+void address_space_unregister_map_client(AddressSpace *as, QEMUBH *bh)
 {
     MapClient *client;
 
     QEMU_LOCK_GUARD(&map_client_list_lock);
     QLIST_FOREACH(client, &map_client_list, link) {
         if (client->bh == bh) {
-            cpu_unregister_map_client_do(client);
+            address_space_unregister_map_client_do(client);
             break;
         }
     }
 }
 
-static void cpu_notify_map_clients(void)
+static void address_space_notify_map_clients(AddressSpace *as)
 {
     QEMU_LOCK_GUARD(&map_client_list_lock);
-    cpu_notify_map_clients_locked();
+    address_space_notify_map_clients_locked(as);
 }
 
 static bool flatview_access_valid(FlatView *fv, hwaddr addr, hwaddr len,
@@ -3195,8 +3195,8 @@  flatview_extend_translation(FlatView *fv, hwaddr addr,
  * May map a subset of the requested range, given by and returned in *plen.
  * May return NULL if resources needed to perform the mapping are exhausted.
  * Use only for reads OR writes - not for read-modify-write operations.
- * Use cpu_register_map_client() to know when retrying the map operation is
- * likely to succeed.
+ * Use address_space_register_map_client() to know when retrying the map
+ * operation is likely to succeed.
  */
 void *address_space_map(AddressSpace *as,
                         hwaddr addr,
@@ -3279,7 +3279,7 @@  void address_space_unmap(AddressSpace *as, void *buffer, hwaddr len,
     memory_region_unref(bounce.mr);
     /* Clear in_use before reading map_client_list.  */
     qatomic_set_mb(&bounce.in_use, false);
-    cpu_notify_map_clients();
+    address_space_notify_map_clients(as);
 }
 
 void *cpu_physical_memory_map(hwaddr addr,