device_del is broken for me in master: $ qemu-system-x86_64 -nodefaults -S -m 384 -vnc :0 -monitor stdio -usb QEMU 1.0.50 monitor - type 'help' for more information (qemu) device_add usb-mouse,id=foo (qemu) device_del foo Device 'foo' is in use
Same for any hot-pluggable device I tried, with and without -S. git-bisect fingers this patch, which went in as commit 1de81d28.
