Comment 10 for bug 1490611

It looks like the option is "force_size" rather than "force-size".

It also seems to be having the intended effect. I regenerate my nixos iso with various configurations:

qemu-master + jeffcody patches + force_size = 2147484160
qemu-master + jeffcody patches (no force_size) = 2147992064
qemu-stable: 2147992064
qemu-220: 2147484160

2147992064 - 512 = 2147991552 (2048.484375 MiB)
2147484160 - 512 = 2147483648 (exactly 2048 MiB)

It appears to be working. Thanks!

(Note, I only applied the non-test patches. I have them applied on master in a fork under my user on GitHub if someone else wants to test easily).