While one can post-creation configure a vm to directly boot a local kernel file, its supported by virt-install and the install wizard only indirectly (through autodetected media or tree links). Seems to me using directly local or remote kernel+initrd combo file would be quite the straightforward way to boot installers or any kind or any other payload. Best illustrated I think by https://netboot.xyz i.e It would be nice to be able to give virt-manager/virt-install just https://boot.netboot.xyz/ipxe/netboot.xyz.lkrn as location and for it to figure out the rest.
Thanks for the suggestion. I've thought about adding this to virt-install, for a one time boot option. The main problem with doing this for permanent config is that qemu can only boot off a local kernel/initrd, so we would need to either download it every boot or download it once and save it somewhere which the user can do anyways. For the netboot case you _can_ point a VM at an HTTP hosted iso like https://boot.netboot.xyz/ipxe/netboot.xyz.iso and boot from that, although it'll consume their bandwidth for every boot so if it was a permanent set up it would still be nicer to download it locally and boot from that
There's support for 'install from kernel path or URL' in virt-install now. I don't think we will be adding it to virt-manager because it's a pretty advanced case. Duping this to another similar bug where I will update with details when the new virt-manager release is out *** This bug has been marked as a duplicate of bug 1677425 ***