It actually never worked with libvirt, as auto-generated names are
different on source and destination.

It's unsafe and useless to migrate by auto-generated node-names, so
let's forbid it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 migration/block-dirty-bitmap.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index e0e081ce60..f5744c35e6 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -285,6 +285,13 @@ static int add_bitmaps_to_list(BlockDriverState *bs, const char *bs_name)
         return -1;
     }
 
+    if (bs_name[0] == '#') {
+        error_report("Found bitmap '%s' in a node with auto-generated "
+                     "name: %s. It can't be migrated",
+                     bdrv_dirty_bitmap_name(bitmap), bs_name);
+        return -1;
+    }
+
     FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
         if (!bdrv_dirty_bitmap_name(bitmap)) {
             continue;
-- 
2.21.0

On 5/15/20 7:40 AM, Vladimir Sementsov-Ogievskiy wrote:
> It actually never worked with libvirt, as auto-generated names are
> different on source and destination.
> 
> It's unsafe and useless to migrate by auto-generated node-names, so
> let's forbid it.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Reviewed-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
> ---
>   migration/block-dirty-bitmap.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

> diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
> index e0e081ce60..f5744c35e6 100644
> --- a/migration/block-dirty-bitmap.c
> +++ b/migration/block-dirty-bitmap.c
> @@ -285,6 +285,13 @@ static int add_bitmaps_to_list(BlockDriverState *bs, const char *bs_name)
>           return -1;
>       }
>   
> +    if (bs_name[0] == '#') {
> +        error_report("Found bitmap '%s' in a node with auto-generated "
> +                     "name: %s. It can't be migrated",

Maybe compress to:

"Bitmap '%s' in auto-generated node '%s' can't be migrated"

> +                     bdrv_dirty_bitmap_name(bitmap), bs_name);
> +        return -1;
> +    }
> +
>       FOR_EACH_DIRTY_BITMAP(bs, bitmap) {
>           if (!bdrv_dirty_bitmap_name(bitmap)) {
>               continue;
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org