Re: [Qemu-devel] [RFC] introduce a dynamic library to expose qemu block API

[Paolo Bonzini]

Il 09/07/2012 10:54, Wenchao Xia ha scritto:
> Following is my implementing plan draft:
>   1 introduce libqblock.so in sub directory in qemu.
>   2 write a nbd client in libqblock, similar to qemu nbd client. Then
> use it to talk with nbd server, by default is qemu-nbd, to get access
> to images. In this way, libqblock.so could be friendly LGPL licensed.

Did you actually assess the license situation of the block layer?
block.c and large parts of block/* are under a BSD license, for example.
 If the library only has to support raw files, it might do so using
synchronous I/O only.  This would remove a large body of GPL-licensed code.

>   3 still not got a good way to get additional info in (2)(3)(4),
> currently in my head is patch qemu-nbd to add an additional nbd command,
> "image-info", in which returns related info.

On the Linux kernel mailing list I would have no qualms labeling such
command as "crap".  However, since the social standards on qemu-devel
are a bit higher, I'll ask instead: what information would the command
provide beyond the size?

Paolo