Hi,
Sorry for forgetting to cc maintainers.
I got this issue when doing live migration test, and simple steps to reproduce
are
master: qemu -enable-kvm -smp 1 -m 512 -drive file=/data1/src.img,if=virtio
\
-net none -monitor stdio -vnc 0:2
slave: qemu -enable-kvm -smp 1 -m 512 -dirve
file=/data2/dest.img,if=virtio \
-net none -monitor stdio -vnc 0:3 -incoming tcp:127.0.0.1:3333
\
when doing migration cmd "migrate -b tcp:127.0.0.1:3333" in master's monitor,
it throws out a segfault error.
After checking some code of block migration, I think there is something wrong
with the
setup sequence in block migration setup.
thanks
chai wen
On 05/27/2014 04:54 PM, chai wen wrote:
> If we want to track dirty blocks using dirty_maps on a BlockDriverState
> when doing live block-migration, its correspoding 'BlkMigDevState' should be
> add to block_mig_state.bmds_list firstly for subsequent processing.
> Otherwise set_dirty_tracking will do nothing on an empty list than allocating
> dirty_bitmaps for them.
>
> And what's the worse, bdrv_get_dirty_count will access the
> bmds->dirty_maps directly, there could be a segfault as the reasons
> above.
>
> Signed-off-by: chai wen <chaiw.f...@cn.fujitsu.com>
> ---
> block-migration.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/block-migration.c b/block-migration.c
> index 56951e0..43203aa 100644
> --- a/block-migration.c
> +++ b/block-migration.c
> @@ -626,6 +626,7 @@ static int block_save_setup(QEMUFile *f, void *opaque)
> block_mig_state.submitted, block_mig_state.transferred);
>
> qemu_mutex_lock_iothread();
> + init_blk_migration(f);
>
> /* start track dirty blocks */
> ret = set_dirty_tracking();
> @@ -635,7 +636,6 @@ static int block_save_setup(QEMUFile *f, void *opaque)
> return ret;
> }
>
> - init_blk_migration(f);
>
> qemu_mutex_unlock_iothread();
>
--
Regards
Chai Wen
