USB 2.0 Quick Start
===================
-The QEMU EHCI Adapter does *not* support companion controllers. That
-implies there are two completely separate USB busses: One USB 1.1 bus
-driven by the UHCI controller and one USB 2.0 bus driven by the EHCI
-controller. Devices must be attached to the correct controller
-manually.
+The QEMU EHCI Adapter can be used with and without companion
+controllers. See below for the companion controller mode.
+
+When not running in companion controller mode there are two completely
+separate USB busses: One USB 1.1 bus driven by the UHCI controller and
+one USB 2.0 bus driven by the EHCI controller. Devices must be
+attached to the correct controller manually.
The '-usb' switch will make qemu create the UHCI controller as part of
-the PIIX3 chipset. The USB 1.1 bus will carry the name "usb.0".
+the PIIX3 chipset. The USB 1.1 bus will carry the name "usb-bus.0".
You can use the standard -device switch to add a EHCI controller to
your virtual machine. It is strongly recommended to specify an ID for
-drive if=none,id=usbstick,file=/path/to/image \
-usb \
-device usb-ehci,id=ehci \
- -device usb-tablet,bus=usb.0 \
+ -device usb-tablet,bus=usb-bus.0 \
-device usb-storage,bus=ehci.0,drive=usbstick
This attaches a usb tablet to the UHCI adapter and a usb mass storage
device to the EHCI adapter.
+Companion controller support
+----------------------------
+
+Companion controller support has been added recently. The operational
+model described above with two completely separate busses still works
+fine. Additionally the UHCI and OHCI controllers got the ability to
+attach to a usb bus created by EHCI as companion controllers. This is
+done by specifying the masterbus and firstport properties. masterbus
+specifies the bus name the controller should attach to. firstport
+specifies the first port the controller should attach to, which is
+needed as usually one ehci controller with six ports has three uhci
+companion controllers with two ports each.
+
+There is a config file in docs which will do all this for you, just
+try ...
+
+ qemu -readconfig docs/ich9-ehci-uhci.cfg
+
+... then use "bus=ehci.0" to assign your usb devices to that bus.
+
+
+xhci controller support
+-----------------------
+
+There is also xhci host controller support available. It got a lot
+less testing than ehci and there are a bunch of known limitations, so
+ehci may work better for you. On the other hand the xhci hardware
+design is much more virtualization-friendly, thus xhci emulation uses
+less resources (especially cpu). If you want to give xhci a try
+use this to add the host controller ...
+
+ qemu -device nec-usb-xhci,id=xhci
+
+... then use "bus=xhci.0" when assigning usb devices.
+
+
More USB tips & tricks
======================
Plugging a tablet into UHCI port 1 works like this:
- -device usb-tablet,bus=usb.0,port=1
+ -device usb-tablet,bus=usb-bus.0,port=1
Plugging a hub into UHCI port 2 works like this:
- -device usb-hub,bus=usb.0,port=2
+ -device usb-hub,bus=usb-bus.0,port=2
Plugging a virtual usb stick into port 4 of the hub just plugged works
this way:
- -device usb-storage,bus=usb.0,port=2.4,drive=...
+ -device usb-storage,bus=usb-bus.0,port=2.4,drive=...
You can do basically the same in the monitor using the device_add
command. If you want to unplug devices too you should specify some
unique id which you can use to refer to the device ...
- (qemu) device_add usb-tablet,bus=usb.0,port=1,id=my-tablet
+ (qemu) device_add usb-tablet,bus=usb-bus.0,port=1,id=my-tablet
(qemu) device_del my-tablet
... when unplugging it with device_del.
for 1.1 devices. Passing through any device plugged into that port
and also assign them to the correct bus can be done this way:
- qemu -M pc ${otheroptions} \
- -usb \
- -device usb-ehci,id=ehci \
- -device usb-host,bus=usb.0,hostbus=3,hostport=1 \
+ qemu -M pc ${otheroptions} \
+ -usb \
+ -device usb-ehci,id=ehci \
+ -device usb-host,bus=usb-bus.0,hostbus=3,hostport=1 \
-device usb-host,bus=ehci.0,hostbus=1,hostport=1
enjoy,
projects / qemu.git / blobdiff