[libvirt-users] Support for on-demand USB pass through

Jiri Denemark jdenemar at redhat.com
Wed Dec 12 13:12:48 UTC 2012


On Fri, Dec 07, 2012 at 11:25:49 +0100, Felicitus wrote:
> Hi,
> 
> I'm trying to use USB pass through with devices that are not present at
> the VM startup. However, when starting the machine, libvirt complains
> that the USB device doesn't exist. I was following the guide at [1], but
> this doesn't seem to work on Debian Wheezy.
> 
> Any hints how to achieve that?

With libvirt-1.0.0 or newer, you can use startupPolicy='optional' for that USB
device, as documented at http://www.libvirt.org/formatdomain.html#elementsUSB

However, such device would not be automatically connected when it becomes
available (which seems to be what you are after according to the guide you
posted). You'd need to shut the VM down and start it up again. It might be
possible to use USB redirection provided by SPICE
(http://www.libvirt.org/formatdomain.html#elementsRedir) for this but I'm not
sure about it, I've never used it.

Jirka




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