On 3 December 2012 11:58, walimis <walimis...@gmail.com> wrote: > For example, xilinx_zynq has two EHCI controllers. If I specify a usb > device of type "usb-storage", the question is: which EHCI controller does the > usb device attach to? The answer is dependent. > > 1. If I use "usbdevice" and pass the host usb device, such as: > > $ qemu -usb -usbdevice host:xxxx:xxxx > > The device will attach to the first EHCI controller. > > 2. If I use "device" and "usb-storage", such as: > > $ qemu -usb -device usb-storage,drive=ud -drive id=ud,file=usbdisk.img,if=none > > The device will attach to the second EHCI controller.
This is a long standing bug which is caused by the legacy -usbdevice search looking through the list of usb buses in one direction, and the generic -device code looking through it in the other direction: http://lists.gnu.org/archive/html/qemu-devel/2011-06/msg00926.html > Qemu doesn't provide some properties, such as "bus", to specify which EHCI > controller the > usb device attach to. If we use "device" and "usb-storage", we never attach > the usb > device to the specified EHCI controller. -device certainly ought to let you specify a bus= property; you want to be able to specify the USB controller regardless of whether we sort out the ordering mess. If that doesn't work then we have a different bug. -- PMM
