Re: [Qemu-block] [RFC] QMP design: Fixing query-block and friends

[Alberto Garcia]

On Tue 27 Jun 2017 06:31:45 PM CEST, Kevin Wolf wrote:
> * Speaking of recursion: ImageInfo recursively includes information
>   about all images in the backing chain. This is what makes the output
>   of query-named-block-nodes so redundant. It is also inconsistent
>   because the runtime information (BlockInfo/BlockDeviceInfo) isn't
>   recursive.

I've also been told of cases where a query-block command on a VM with a
very large amount of images in all backing chains would slow down the
guest because of this recursion.

I haven't been able to reproduce this problem myself, but being able to
see only the devices seen by the guest (as opposed to the complete
graph) seems like a good idea.

Berto