[Qemu-devel] [PATCH 3/3] loader: mark MR for resizeable blobs as extendable

["Michael S. Tsirkin" <mst@redhat.com>]

This makes migration from older QEMU versions
more robust.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/core/loader.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/hw/core/loader.c b/hw/core/loader.c
index ad6ec67..fc00a87 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -745,6 +745,13 @@ void *rom_add_blob_resizeable(const char *name, const void *blob,
 
         if (rom_file_has_mr) {
             data = rom_set_mr(rom, OBJECT(fw_cfg), devpath);
+            /* If there's padding at tail, blob is resizeable.
+             * Set flag to allow migration from older QEMU versions
+             * where this region could have been smaller.
+             */
+            if (max_len != len) {
+                memory_region_permit_extendable_migration(rom->mr);
+            }
         } else {
             data = rom->data;
         }
-- 
MST