Hi, Paolo and folks, qemu have good capabilities to access different virtual disks, I want to expose its block layer API to let 3rd party program linked in, such as management stack or block tools, to access images data directly.
Following is the objects: (1) API to write/read block device at offset. (2) Determine the image type,qcow2/qed/raw (3) Determine which blocks are allocated. (4) Determine backing file. 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. 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. What do you think about it? -- Best Regards Wenchao Xia mail:xiaw...@linux.vnet.ibm.com tel:86-010-82450803
