Most qemu-img subcommands that have (optional) JSON output don’t describe the structure of their JSON output -- but having a fixed, well-known output structure kind of is the point of having JSON output at all. Therefore, patch 1 in this series makes every such command note which QAPI type their JSON output has in the qemu-img man page. (The exception to this is the map subcommand, which does not emit a QAPI-typed object. It already has a description of the structure of its output object, though.)
That should be enough to thoroughly explain the machine-readable output. But we can also do better for the human-readable output: qemu-img info emits quite a bit of information, and not all of it is self-explanatory. In patch 2, I’ve tried to provide some potentially missing explanation. Max Reitz (2): qemu-img.texi: Be specific about JSON object types qemu-img.texi: Describe human-readable info output qemu-img.texi | 52 ++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 49 insertions(+), 3 deletions(-) -- 2.21.0