virt-builder and other tools need a mechanism to specify the subsequent image blocksize (sectorsize)

[anon99]

I found reference to using uefi to boot VM's and also reference to --blocksize in virt-install,However I dont see a way of telling virt-builder to build for a 4k sector target. This also has the side effect that it must also specify uefi/ocmf as a boot scheme and also the use of a gpt instead of mbr. I think most distros faced with a 4K sector target disk will install using uefi/gpt but I don't see
a way to tell virt-builder to build a 4K target and how it needs to launch it using uefii. Unless there is a way of using qemu-img to build a 4k sector image followed by some way to induce virt-builder to deal with that and know that to boot it involves uefi. If this is referenced or documented somewhere I'd be happy to refer to that.