Re: [Qemu-devel] [PATCH v3 2/8] block: add basic backup support to block driver

[Dietmar Maurer]

> Hmm, right.  But do we need the bitmap at all?  We can just use
> bdrv_is_allocated like bdrv_co_do_readv does.

Does that works with a nbd driver? Or does that add another RPC call (slow 
down)?