Add map client retry notification (Avi Kivity)
The target memory mapping API may fail if the bounce buffer resources
are exhausted. Add a notification mechanism to allow clients to retry
the mapping operation when resources become available again.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6395 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/exec.c b/exec.c
index 6dd88fc..56e5e48 100644
--- a/exec.c
+++ b/exec.c
@@ -3053,10 +3053,49 @@
static BounceBuffer bounce;
+typedef struct MapClient {
+ void *opaque;
+ void (*callback)(void *opaque);
+ LIST_ENTRY(MapClient) link;
+} MapClient;
+
+static LIST_HEAD(map_client_list, MapClient) map_client_list
+ = LIST_HEAD_INITIALIZER(map_client_list);
+
+void *cpu_register_map_client(void *opaque, void (*callback)(void *opaque))
+{
+ MapClient *client = qemu_malloc(sizeof(*client));
+
+ client->opaque = opaque;
+ client->callback = callback;
+ LIST_INSERT_HEAD(&map_client_list, client, link);
+ return client;
+}
+
+void cpu_unregister_map_client(void *_client)
+{
+ MapClient *client = (MapClient *)_client;
+
+ LIST_REMOVE(client, link);
+}
+
+static void cpu_notify_map_clients(void)
+{
+ MapClient *client;
+
+ while (!LIST_EMPTY(&map_client_list)) {
+ client = LIST_FIRST(&map_client_list);
+ client->callback(client->opaque);
+ LIST_REMOVE(client, link);
+ }
+}
+
/* Map a physical memory region into a host virtual address.
* 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.
*/
void *cpu_physical_memory_map(target_phys_addr_t addr,
target_phys_addr_t *plen,
@@ -3146,6 +3185,7 @@
}
qemu_free(bounce.buffer);
bounce.buffer = NULL;
+ cpu_notify_map_clients();
}
/* warning: addr must be aligned */