1.. _pcsys_005fusb: 2 3USB emulation 4------------- 5 6QEMU can emulate a PCI UHCI, OHCI, EHCI or XHCI USB controller. You can 7plug virtual USB devices or real host USB devices (only works with 8certain host operating systems). QEMU will automatically create and 9connect virtual USB hubs as necessary to connect multiple USB devices. 10 11USB controllers 12~~~~~~~~~~~~~~~ 13 14XHCI controller support 15^^^^^^^^^^^^^^^^^^^^^^^ 16 17QEMU has XHCI host adapter support. The XHCI hardware design is much 18more virtualization-friendly when compared to EHCI and UHCI, thus XHCI 19emulation uses less resources (especially CPU). So if your guest 20supports XHCI (which should be the case for any operating system 21released around 2010 or later) we recommend using it: 22 23 qemu -device qemu-xhci 24 25XHCI supports USB 1.1, USB 2.0 and USB 3.0 devices, so this is the 26only controller you need. With only a single USB controller (and 27therefore only a single USB bus) present in the system there is no 28need to use the bus= parameter when adding USB devices. 29 30 31EHCI controller support 32^^^^^^^^^^^^^^^^^^^^^^^ 33 34The QEMU EHCI Adapter supports USB 2.0 devices. It can be used either 35standalone or with companion controllers (UHCI, OHCI) for USB 1.1 36devices. The companion controller setup is more convenient to use 37because it provides a single USB bus supporting both USB 2.0 and USB 381.1 devices. See next section for details. 39 40When running EHCI in standalone mode you can add UHCI or OHCI 41controllers for USB 1.1 devices too. Each controller creates its own 42bus though, so there are two completely separate USB buses: One USB 431.1 bus driven by the UHCI controller and one USB 2.0 bus driven by 44the EHCI controller. Devices must be attached to the correct 45controller manually. 46 47The easiest way to add a UHCI controller to a ``pc`` machine is the 48``-usb`` switch. QEMU will create the UHCI controller as function of 49the PIIX3 chipset. The USB 1.1 bus will carry the name ``usb-bus.0``. 50 51You can use the standard ``-device`` switch to add a EHCI controller to 52your virtual machine. It is strongly recommended to specify an ID for 53the controller so the USB 2.0 bus gets an individual name, for example 54``-device usb-ehci,id=ehci``. This will give you a USB 2.0 bus named 55``ehci.0``. 56 57When adding USB devices using the ``-device`` switch you can specify the 58bus they should be attached to. Here is a complete example: 59 60.. parsed-literal:: 61 62 |qemu_system| -M pc ${otheroptions} \\ 63 -drive if=none,id=usbstick,format=raw,file=/path/to/image \\ 64 -usb \\ 65 -device usb-ehci,id=ehci \\ 66 -device usb-tablet,bus=usb-bus.0 \\ 67 -device usb-storage,bus=ehci.0,drive=usbstick 68 69This attaches a USB tablet to the UHCI adapter and a USB mass storage 70device to the EHCI adapter. 71 72 73Companion controller support 74^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 75 76The UHCI and OHCI controllers can attach to a USB bus created by EHCI 77as companion controllers. This is done by specifying the ``masterbus`` 78and ``firstport`` properties. ``masterbus`` specifies the bus name the 79controller should attach to. ``firstport`` specifies the first port the 80controller should attach to, which is needed as usually one EHCI 81controller with six ports has three UHCI companion controllers with 82two ports each. 83 84There is a config file in docs which will do all this for 85you, which you can use like this: 86 87.. parsed-literal:: 88 89 |qemu_system| -readconfig docs/config/ich9-ehci-uhci.cfg 90 91Then use ``bus=ehci.0`` to assign your USB devices to that bus. 92 93Using the ``-usb`` switch for ``q35`` machines will create a similar 94USB controller configuration. 95 96 97.. _Connecting USB devices: 98 99Connecting USB devices 100~~~~~~~~~~~~~~~~~~~~~~ 101 102USB devices can be connected with the ``-device usb-...`` command line 103option or the ``device_add`` monitor command. Available devices are: 104 105``usb-mouse`` 106 Virtual Mouse. This will override the PS/2 mouse emulation when 107 activated. 108 109``usb-tablet`` 110 Pointer device that uses absolute coordinates (like a touchscreen). 111 This means QEMU is able to report the mouse position without having 112 to grab the mouse. Also overrides the PS/2 mouse emulation when 113 activated. 114 115``usb-storage,drive=drive_id`` 116 Mass storage device backed by drive_id (see the :ref:`disk images` 117 chapter in the System Emulation Users Guide). This is the classic 118 bulk-only transport protocol used by 99% of USB sticks. This 119 example shows it connected to an XHCI USB controller and with 120 a drive backed by a raw format disk image: 121 122 .. parsed-literal:: 123 124 |qemu_system| [...] \\ 125 -drive if=none,id=stick,format=raw,file=/path/to/file.img \\ 126 -device nec-usb-xhci,id=xhci \\ 127 -device usb-storage,bus=xhci.0,drive=stick 128 129``usb-uas`` 130 USB attached SCSI device. This does not create a SCSI disk, so 131 you need to explicitly create a ``scsi-hd`` or ``scsi-cd`` device 132 on the command line, as well as using the ``-drive`` option to 133 specify what those disks are backed by. One ``usb-uas`` device can 134 handle multiple logical units (disks). This example creates three 135 logical units: two disks and one cdrom drive: 136 137 .. parsed-literal:: 138 139 |qemu_system| [...] \\ 140 -drive if=none,id=uas-disk1,format=raw,file=/path/to/file1.img \\ 141 -drive if=none,id=uas-disk2,format=raw,file=/path/to/file2.img \\ 142 -drive if=none,id=uas-cdrom,media=cdrom,format=raw,file=/path/to/image.iso \\ 143 -device nec-usb-xhci,id=xhci \\ 144 -device usb-uas,id=uas,bus=xhci.0 \\ 145 -device scsi-hd,bus=uas.0,scsi-id=0,lun=0,drive=uas-disk1 \\ 146 -device scsi-hd,bus=uas.0,scsi-id=0,lun=1,drive=uas-disk2 \\ 147 -device scsi-cd,bus=uas.0,scsi-id=0,lun=5,drive=uas-cdrom 148 149``usb-bot`` 150 Bulk-only transport storage device. This presents the guest with the 151 same USB bulk-only transport protocol interface as ``usb-storage``, but 152 the QEMU command line option works like ``usb-uas`` and does not 153 automatically create SCSI disks for you. ``usb-bot`` supports up to 154 16 LUNs. Unlike ``usb-uas``, the LUN numbers must be continuous, 155 i.e. for three devices you must use 0+1+2. The 0+1+5 numbering from the 156 ``usb-uas`` example above won't work with ``usb-bot``. 157 158``usb-mtp,rootdir=dir`` 159 Media transfer protocol device, using dir as root of the file tree 160 that is presented to the guest. 161 162``usb-host,hostbus=bus,hostaddr=addr`` 163 Pass through the host device identified by bus and addr 164 165``usb-host,vendorid=vendor,productid=product`` 166 Pass through the host device identified by vendor and product ID 167 168``usb-wacom-tablet`` 169 Virtual Wacom PenPartner tablet. This device is similar to the 170 ``tablet`` above but it can be used with the tslib library because in 171 addition to touch coordinates it reports touch pressure. 172 173``usb-kbd`` 174 Standard USB keyboard. Will override the PS/2 keyboard (if present). 175 176``usb-serial,chardev=id`` 177 Serial converter. This emulates an FTDI FT232BM chip connected to 178 host character device id. 179 180``usb-braille,chardev=id`` 181 Braille device. This will use BrlAPI to display the braille output on 182 a real or fake device referenced by id. 183 184``usb-net[,netdev=id]`` 185 Network adapter that supports CDC ethernet and RNDIS protocols. id 186 specifies a netdev defined with ``-netdev …,id=id``. For instance, 187 user-mode networking can be used with 188 189 .. parsed-literal:: 190 191 |qemu_system| [...] -netdev user,id=net0 -device usb-net,netdev=net0 192 193``usb-ccid`` 194 Smartcard reader device 195 196``usb-audio`` 197 USB audio device 198 199``u2f-{emulated,passthru}`` 200 Universal Second Factor device 201 202``canokey`` 203 An Open-source Secure Key implementing FIDO2, OpenPGP, PIV and more. 204 For more information, see :ref:`canokey`. 205 206Physical port addressing 207^^^^^^^^^^^^^^^^^^^^^^^^ 208 209For all the above USB devices, by default QEMU will plug the device 210into the next available port on the specified USB bus, or onto 211some available USB bus if you didn't specify one explicitly. 212If you need to, you can also specify the physical port where 213the device will show up in the guest. This can be done using the 214``port`` property. UHCI has two root ports (1,2). EHCI has six root 215ports (1-6), and the emulated (1.1) USB hub has eight ports. 216 217Plugging a tablet into UHCI port 1 works like this:: 218 219 -device usb-tablet,bus=usb-bus.0,port=1 220 221Plugging a hub into UHCI port 2 works like this:: 222 223 -device usb-hub,bus=usb-bus.0,port=2 224 225Plugging a virtual USB stick into port 4 of the hub just plugged works 226this way:: 227 228 -device usb-storage,bus=usb-bus.0,port=2.4,drive=... 229 230In the monitor, the ``device_add` command also accepts a ``port`` 231property specification. If you want to unplug devices too you should 232specify some unique id which you can use to refer to the device. 233You can then use ``device_del`` to unplug the device later. 234For example:: 235 236 (qemu) device_add usb-tablet,bus=usb-bus.0,port=1,id=my-tablet 237 (qemu) device_del my-tablet 238 239Hotplugging USB storage 240~~~~~~~~~~~~~~~~~~~~~~~ 241 242The ``usb-bot`` and ``usb-uas`` devices can be hotplugged. In the hotplug 243case they are added with ``attached = false`` so the guest will not see 244the device until the ``attached`` property is explicitly set to true. 245That allows you to attach one or more scsi devices before making the 246device visible to the guest. The workflow looks like this: 247 248#. ``device-add usb-bot,id=foo`` 249#. ``device-add scsi-{hd,cd},bus=foo.0,lun=0`` 250#. optionally add more devices (luns 1 ... 15) 251#. ``scripts/qmp/qom-set foo.attached = true`` 252 253.. _host_005fusb_005fdevices: 254 255Using host USB devices on a Linux host 256~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 257 258WARNING: this is an experimental feature. QEMU will slow down when using 259it. USB devices requiring real time streaming (i.e. USB Video Cameras) 260are not supported yet. 261 2621. If you use an early Linux 2.4 kernel, verify that no Linux driver is 263 actually using the USB device. A simple way to do that is simply to 264 disable the corresponding kernel module by renaming it from 265 ``mydriver.o`` to ``mydriver.o.disabled``. 266 2672. Verify that ``/proc/bus/usb`` is working (most Linux distributions 268 should enable it by default). You should see something like that: 269 270 :: 271 272 ls /proc/bus/usb 273 001 devices drivers 274 2753. Since only root can access to the USB devices directly, you can 276 either launch QEMU as root or change the permissions of the USB 277 devices you want to use. For testing, the following suffices: 278 279 :: 280 281 chown -R myuid /proc/bus/usb 282 2834. Launch QEMU and do in the monitor: 284 285 :: 286 287 info usbhost 288 Device 1.2, speed 480 Mb/s 289 Class 00: USB device 1234:5678, USB DISK 290 291 You should see the list of the devices you can use (Never try to use 292 hubs, it won't work). 293 2945. Add the device in QEMU by using: 295 296 :: 297 298 device_add usb-host,vendorid=0x1234,productid=0x5678 299 300 Normally the guest OS should report that a new USB device is plugged. 301 You can use the option ``-device usb-host,...`` to do the same. 302 3036. Now you can try to use the host USB device in QEMU. 304 305When relaunching QEMU, you may have to unplug and plug again the USB 306device to make it work again (this is a bug). 307 308``usb-host`` properties for specifying the host device 309^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 310 311The example above uses the ``vendorid`` and ``productid`` to 312specify which host device to pass through, but this is not 313the only way to specify the host device. ``usb-host`` supports 314the following properties: 315 316``hostbus=<nr>`` 317 Specifies the bus number the device must be attached to 318``hostaddr=<nr>`` 319 Specifies the device address the device got assigned by the guest os 320``hostport=<str>`` 321 Specifies the physical port the device is attached to 322``vendorid=<hexnr>`` 323 Specifies the vendor ID of the device 324``productid=<hexnr>`` 325 Specifies the product ID of the device. 326 327In theory you can combine all these properties as you like. In 328practice only a few combinations are useful: 329 330- ``vendorid`` and ``productid`` -- match for a specific device, pass it to 331 the guest when it shows up somewhere in the host. 332 333- ``hostbus`` and ``hostport`` -- match for a specific physical port in the 334 host, any device which is plugged in there gets passed to the 335 guest. 336 337- ``hostbus`` and ``hostaddr`` -- most useful for ad-hoc pass through as the 338 hostaddr isn't stable. The next time you plug the device into the host it 339 will get a new hostaddr. 340 341Note that on the host USB 1.1 devices are handled by UHCI/OHCI and USB 3422.0 by EHCI. That means different USB devices plugged into the very 343same physical port on the host may show up on different host buses 344depending on the speed. Supposing that devices plugged into a given 345physical port appear as bus 1 + port 1 for 2.0 devices and bus 3 + port 1 346for 1.1 devices, you can pass through any device plugged into that port 347and also assign it to the correct USB bus in QEMU like this: 348 349.. parsed-literal:: 350 351 |qemu_system| -M pc [...] \\ 352 -usb \\ 353 -device usb-ehci,id=ehci \\ 354 -device usb-host,bus=usb-bus.0,hostbus=3,hostport=1 \\ 355 -device usb-host,bus=ehci.0,hostbus=1,hostport=1 356