On 03/08/18 11:17, Daniel P. Berrangé wrote:
On Thu, Mar 08, 2018 at 08:52:45AM +0100, Gerd Hoffmann wrote:
Hi,
[*] Open question: Who, between QEMU and libvirt, should define the said firmware metadata format and file?
IMHO QEMU should be defining the format, because the file will contain info about certain QEMU features associated with the firmware (eg smm). Also there are potentially other non-libvirt mgmt apps that spawn QEMU which would like this info (eg libguestfs), so having libvirt define the format is inappropriate.
I'd suggest we just need something in docs/specs/firmware-metadata.rst for QEMU source tree.
Potentially QEMU could even use the metadata files itself for finding the default firmeware images, instead of compiling this info into its binaries. I wouldn't suggest we need todo that right away, but bear it in mind as a potential use case.
With qemu using this itself in mind it probably makes sense to specify this as qapi schema. That'll simplify parsing and using these files in qemu, and possibly simplifies things on the libvirt side too.
I was thinking of an 'ini' style format, similar to that used by systemd unit files, but a JSON format file is a nicer fit with QEMU & Libvirt if we describe it with qapi.
I've created an RFC-level "qapi/firmware.json" schema file, based on this discussion. It "builds", and the generated documentation looks acceptable, superficially speaking. Before I post "qapi/firmware.json" for getting comments, I'd like to write JSON text that (a) describes firmware that I use, and (b) conforms to the schema. IOW, I'd like to validate whether the schema is good enough for describing at least such firmware that I know. Is there a tool that generates example JSON objects from a given schema? I vaguely recall there used to be one. Otherwise, writing the examples manually looks arduous (and I wouldn't know how to verify them against the schema). Thanks! Laszlo