From d35ff5e6b3aa3a706b0aa3bcf11400fac945b67a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Tue, 4 Apr 2017 17:29:03 +0200 Subject: block: Ignore guest dev permissions during incoming migration Usually guest devices don't like other writers to the same image, so they use blk_set_perm() to prevent this from happening. In the migration phase before the VM is actually running, though, they don't have a problem with writes to the image. On the other hand, storage migration needs to be able to write to the image in this phase, so the restrictive blk_set_perm() call of qdev devices breaks it. This patch flags all BlockBackends with a qdev device as blk->disable_perm during incoming migration, which means that the requested permissions are stored in the BlockBackend, but not actually applied to its root node yet. Once migration has finished and the VM should be resumed, the permissions are applied. If they cannot be applied (e.g. because the NBD server used for block migration hasn't been shut down), resuming the VM fails. Signed-off-by: Kevin Wolf Tested-by: Kashyap Chamarthy --- include/block/block.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/block/block.h b/include/block/block.h index 5149260..3e09222 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -366,6 +366,8 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp); void bdrv_invalidate_cache_all(Error **errp); int bdrv_inactivate_all(void); +void blk_resume_after_migration(Error **errp); + /* Ensure contents are flushed to disk. */ int bdrv_flush(BlockDriverState *bs); int coroutine_fn bdrv_co_flush(BlockDriverState *bs); -- cgit v1.1