The object model in QEMU is from 2007-2011. Internally there isn't a lot of inheritance (it's pretty shallow), but yeah I guess "is-a" is what was in vogue at t

The object model in QEMU is from 2007-2011. Internally there isn't a lot of inheritance (it's pretty shallow), but yeah I guess "is-a" is what was in vogue at the time. However there is a reason to have the object model, and it was added because some things were getting out of hand. You had to write three parsers for everything you added: one for command line, one for the text-based command interface and one for the JSON API. And you had to do it once for each kind of "object" (device, network backend, disk backend, character device backend etc.). The object model is designed to let you write code just once for all three and to reuse the interface across object types.