aboutsummaryrefslogtreecommitdiff
path: root/migration
diff options
context:
space:
mode:
authorStefan Reiter <s.reiter@proxmox.com>2020-10-21 16:44:56 +0200
committerEric Blake <eblake@redhat.com>2020-10-26 06:55:37 -0500
commited7b70c27b5c11ff4800e608d301cd7a36b81c5e (patch)
tree4785a7ba48aefa565a9a2585fe96c2457db1b517 /migration
parent4c5b97bfd0dd54dc27717ae8d1cd10e14eef1430 (diff)
migration/block-dirty-bitmap: fix larger granularity bitmaps
sectors_per_chunk is a 64 bit integer, but the calculation is done in 32 bits, leading to an overflow for coarse bitmap granularities. If that results in the value 0, it leads to a hang where no progress is made but send_bitmap_bits is constantly called with nr_sectors being 0. Signed-off-by: Stefan Reiter <s.reiter@proxmox.com> Message-Id: <20201021144456.1072-1-s.reiter@proxmox.com> Fixes: b35ebdf07 migration: add postcopy migration of dirty bitmaps Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Eric Blake <eblake@redhat.com> [eblake: Use correct type for 8ULL, use () to avoid overflow] Signed-off-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'migration')
-rw-r--r--migration/block-dirty-bitmap.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index 5bef793ac0..98921db772 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -562,8 +562,9 @@ static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs,
dbms->bitmap_alias = g_strdup(bitmap_alias);
dbms->bitmap = bitmap;
dbms->total_sectors = bdrv_nb_sectors(bs);
- dbms->sectors_per_chunk = CHUNK_SIZE * 8 *
- bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS;
+ dbms->sectors_per_chunk = CHUNK_SIZE * 8LLU *
+ (bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS);
+ assert(dbms->sectors_per_chunk != 0);
if (bdrv_dirty_bitmap_enabled(bitmap)) {
dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED;
}