other: 0.939
device: 0.825
graphic: 0.751
performance: 0.723
semantic: 0.658
boot: 0.639
socket: 0.596
vnc: 0.538
permissions: 0.505
PID: 0.471
network: 0.421
files: 0.301
debug: 0.243
KVM: 0.231

Loading virtio-input-host-pci drivers before boot? To allow using passthrough devices in grub and other preboot menus?

Currently virtio-input devices cannot be used before the kernel loads.  This is not really a full bug but it would be much more useful if you can use the keyboard+mouse this way.

This can not be fixed on the QEMU side. If you want to have virtio-input support in seabios or grub for example, you've got to ask the seabios or grub project to add it.