Okay this was a silly question. Here's what I should have asked.
Redox OS distributed me a .img.zst file. I believe this is a "finished" disk image, not install media.
After un-zst'ing, the .img cannot be opened by virt-manager.
qemu has distributed to me a program qemu-img. it has a "convert" function.
virt-manager doesn't want a .img. What *does* it want, for "import existing disk image"? The manpage here mentions "qcow" and "qcow2". Does that mean it wants a qcow?
@mcc is it a disk image or is it a CDRom image?
What flavor QEMU are you using? Proxmox? Or build-it-yourself?
What qemu wants is a qcow2 format... that's the qemu equivalent of a VMDK.
