qemu-system-x86_64 -S -machine pc-i440fx-1.7,accel=kvm,usb=on -nographic -monitor stdio -usb
QEMU 1.7.0 monitor - type 'help' for more information
(qemu) info usbhost
USB host devices not supported

駄目だなぁ。

>>634
自分はAsrock c2750D4I使ってます