The 'savevm' command hangs when -object iothread is used. See patches for details, but basically the vmstate read/write code didn't conform to the latest block layer locking rules.
Stefan Hajnoczi (3): block: count bdrv_co_rw_vmstate() requests block: use BDRV_POLL_WHILE() in bdrv_rw_vmstate() migration: avoid recursive AioContext locking in save_vmstate() block/io.c | 21 +++++++++++++-------- migration/savevm.c | 12 +++++++++++- 2 files changed, 24 insertions(+), 9 deletions(-) -- 2.9.3
