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Diffstat (limited to 'docs/usb2.txt')
| -rw-r--r-- | docs/usb2.txt | 58 |
1 files changed, 0 insertions, 58 deletions
diff --git a/docs/usb2.txt b/docs/usb2.txt deleted file mode 100644 index 6a88d5314f..0000000000 --- a/docs/usb2.txt +++ /dev/null @@ -1,58 +0,0 @@ - -More USB tips & tricks -====================== - -Recently the USB pass through driver (also known as usb-host) and the -QEMU USB subsystem gained a few capabilities which are available only -via qdev properties, i,e. when using '-device'. - -USB pass through hints ----------------------- - -The usb-host driver has a bunch of properties to specify the device -which should be passed to the guest: - - hostbus=<nr> -- Specifies the bus number the device must be attached - to. - - hostaddr=<nr> -- Specifies the device address the device got - assigned by the guest os. - - hostport=<str> -- Specifies the physical port the device is attached - to. - - vendorid=<hexnr> -- Specifies the vendor ID of the device. - productid=<hexnr> -- Specifies the product ID of the device. - -In theory you can combine all these properties as you like. In -practice only a few combinations are useful: - - (1) vendorid+productid -- match for a specific device, pass it to - the guest when it shows up somewhere in the host. - - (2) hostbus+hostport -- match for a specific physical port in the - host, any device which is plugged in there gets passed to the - guest. - - (3) hostbus+hostaddr -- most useful for ad-hoc pass through as the - hostaddr isn't stable, the next time you plug in the device it - gets a new one ... - -Note that USB 1.1 devices are handled by UHCI/OHCI and USB 2.0 by -EHCI. That means a device plugged into the very same physical port -may show up on different buses depending on the speed. The port I'm -using for testing is bus 1 + port 1 for 2.0 devices and bus 3 + port 1 -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-bus.0,hostbus=3,hostport=1 \ - -device usb-host,bus=ehci.0,hostbus=1,hostport=1 - -enjoy, - Gerd - --- -Gerd Hoffmann <kraxel@redhat.com> |