fw_cfg: interface to trigger callback on read

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 32 insertions, 5 deletions

diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index d0820e507b..f5dc3ea845 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -42,6 +42,7 @@ typedef struct FWCfgEntry {
     uint8_t *data;
     void *callback_opaque;
     FWCfgCallback callback;
+    FWCfgReadCallback read_callback;
 } FWCfgEntry;
 
 struct FWCfgState {
@@ -249,8 +250,12 @@ static uint8_t fw_cfg_read(FWCfgState *s)
 
     if (s->cur_entry == FW_CFG_INVALID || !e->data || s->cur_offset >= e->len)
         ret = 0;
-    else
+    else {
+        if (e->read_callback) {
+            e->read_callback(e->callback_opaque, s->cur_offset);
+        }
         ret = e->data[s->cur_offset++];
+    }
 
     trace_fw_cfg_read(s, ret);
     return ret;
@@ -381,7 +386,10 @@ static const VMStateDescription vmstate_fw_cfg = {
     }
 };
 
-void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)
+static void fw_cfg_add_bytes_read_callback(FWCfgState *s, uint16_t key,
+                                           FWCfgReadCallback callback,
+                                           void *callback_opaque,
+                                           void *data, size_t len)
 {
     int arch = !!(key & FW_CFG_ARCH_LOCAL);
 
@@ -391,6 +399,13 @@ void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)
 
     s->entries[arch][key].data = data;
     s->entries[arch][key].len = (uint32_t)len;
+    s->entries[arch][key].read_callback = callback;
+    s->entries[arch][key].callback_opaque = callback_opaque;
+}
+
+void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len)
+{
+    fw_cfg_add_bytes_read_callback(s, key, NULL, NULL, data, len);
 }
 
 void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value)
@@ -444,8 +459,9 @@ void fw_cfg_add_callback(FWCfgState *s, uint16_t key, FWCfgCallback callback,
     s->entries[arch][key].callback = callback;
 }
 
-void fw_cfg_add_file(FWCfgState *s,  const char *filename,
-                     void *data, size_t len)
+void fw_cfg_add_file_callback(FWCfgState *s,  const char *filename,
+                              FWCfgReadCallback callback, void *callback_opaque,
+                              void *data, size_t len)
 {
     int i, index;
     size_t dsize;
@@ -459,7 +475,8 @@ void fw_cfg_add_file(FWCfgState *s,  const char *filename,
     index = be32_to_cpu(s->files->count);
     assert(index < FW_CFG_FILE_SLOTS);
 
-    fw_cfg_add_bytes(s, FW_CFG_FILE_FIRST + index, data, len);
+    fw_cfg_add_bytes_read_callback(s, FW_CFG_FILE_FIRST + index,
+                                   callback, callback_opaque, data, len);
 
     pstrcpy(s->files->f[index].name, sizeof(s->files->f[index].name),
             filename);
@@ -477,6 +494,12 @@ void fw_cfg_add_file(FWCfgState *s,  const char *filename,
     s->files->count = cpu_to_be32(index+1);
 }
 
+void fw_cfg_add_file(FWCfgState *s,  const char *filename,
+                     void *data, size_t len)
+{
+    fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len);
+}
+
 static void fw_cfg_machine_ready(struct Notifier *n, void *data)
 {
     size_t len;
diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h
index f60dd676c8..2ab0fc2950 100644
--- a/include/hw/nvram/fw_cfg.h
+++ b/include/hw/nvram/fw_cfg.h
@@ -60,6 +60,7 @@ typedef struct FWCfgFiles {
 } FWCfgFiles;
 
 typedef void (*FWCfgCallback)(void *opaque, uint8_t *data);
+typedef void (*FWCfgReadCallback)(void *opaque, uint32_t offset);
 
 void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len);
 void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value);
@@ -70,6 +71,9 @@ void fw_cfg_add_callback(FWCfgState *s, uint16_t key, FWCfgCallback callback,
                          void *callback_opaque, void *data, size_t len);
 void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data,
                      size_t len);
+void fw_cfg_add_file_callback(FWCfgState *s, const char *filename,
+                              FWCfgReadCallback callback, void *callback_opaque,
+                              void *data, size_t len);
 FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port,
                         hwaddr crl_addr, hwaddr data_addr);