fw_cfg: add write callback

Reintroduce the write callback that was removed when write support was
removed in commit 023e3148567ac898c7258138f8e86c3c2bb40d07.

Contrary to the previous callback implementation, the write_cb
callback is called whenever a write happened, so handlers must be
ready to handle partial write as necessary.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/hw/core/loader.c b/hw/core/loader.c
index 4593061445..91669d65aa 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -1023,7 +1023,7 @@ MemoryRegion *rom_add_blob(const char *name, const void *blob, size_t len,
         }
 
         fw_cfg_add_file_callback(fw_cfg, fw_file_name,
-                                 fw_callback, callback_opaque,
+                                 fw_callback, NULL, callback_opaque,
                                  data, rom->datasize, read_only);
     }
     return mr;