qemu usb storage emulation -------------------------- QEMU has three devices for usb storage emulation. Number one emulates the classic bulk-only transport protocol which is used by 99% of the usb sticks on the market today and is called "usb-storage". Usage (hooking up to xhci, other host controllers work too): qemu ${other_vm_args} \ -drive if=none,id=stick,file=/path/to/file.img \ -device nec-usb-xhci,id=xhci \ -device usb-storage,bus=xhci.0,drive=stick Number two is the newer usb attached scsi transport. This one doesn't automagically create a scsi disk, so you have to explicitly attach one manually. Multiple logical units are supported. Here is an example with tree logical units: qemu ${other_vm_args} \ -drive if=none,id=uas-disk1,file=/path/to/file1.img \ -drive if=none,id=uas-disk2,file=/path/to/file2.img \ -drive if=none,id=uas-cdrom,media=cdrom,file=/path/to/image.iso \ -device nec-usb-xhci,id=xhci \ -device usb-uas,id=uas,bus=xhci.0 \ -device scsi-hd,bus=uas.0,scsi-id=0,lun=0,drive=uas-disk1 \ -device scsi-hd,bus=uas.0,scsi-id=0,lun=1,drive=uas-disk2 \ -device scsi-cd,bus=uas.0,scsi-id=0,lun=5,drive=uas-cdrom Number three emulates the classic bulk-only transport protocol too. It's called "usb-bot". It shares most code with "usb-storage", and the guest will not be able to see the difference. The qemu command line interface is simliar to usb-uas though, i.e. no automatic scsi disk creation. It also features support for up to 16 LUNs. The LUN numbers must be continuous, i.e. for three devices you must use 0+1+2. The 0+1+5 numbering from the "usb-uas" example isn't going to work with "usb-bot". enjoy, Gerd -- Gerd Hoffmann <kraxel@redhat.com>