Re: [Xen-devel] [PATCH 2 of 2] xl: Accept a list for usbdevice in config file

[George Dunlap <George.Dunlap@xxxxxxxxxxxxx>]

On Wed, Nov 28, 2012 at 3:11 PM, Pasi Kärkkäinen <pasik@xxxxxx> wrote:

On Wed, Nov 28, 2012 at 12:16:06PM +0000, George Dunlap wrote:
> # HG changeset patch
> # User George Dunlap <george.dunlap@xxxxxxxxxxxxx>
> # Date 1354104851 0
> # Node ID e87d8fad28e00090591b65b2682dea9112f8830d
> # Parent  538d9ffbd71b41e8cf6d7da0ded9e0a0b07f3c0d
> xl: Accept a list for usbdevice in config file
>
> Allow the "usbdevice" key to accept a list of USB devices, and pass
> them in using the new usbdevice_list domain build element.
>
> For backwards compatibility, still accept singleton values.
>
> Also update the xl.cfg manpage, adding information about how to pass
> through host devices.
>
> Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
>
> diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
> --- a/docs/man/xl.cfg.pod.5
> +++ b/docs/man/xl.cfg.pod.5
> @@ -1103,15 +1103,22 @@ device.
>
>  Enables or disables a USB bus in the guest.
>

Should we add "HVM" there ?

I could make this say, "...in an HVM guest".  (I'll wait to see if I get other comments before re-sending the patch.)
 

> -=item B<usbdevice=DEVICE>
> +=item B<usbdevice=[ "DEVICE", "DEVICE", ...]>
>
> -Adds B<DEVICE> to the USB bus. The USB bus must also be enabled using
> -B<usb=1>. The most common use for this option is B<usbdevice=tablet>
> -which adds pointer device using absolute coordinates. Such devices
> -function better than relative coordinate devices (such as a standard
> -mouse) since many methods of exporting guest graphics (such as VNC)
> -work better in this mode. Note that this is independent of the actual
> -pointer device you are using on the host/client side.
> +Adds B<DEVICE>s to the emulated USB bus. The USB bus must also be
> +enabled using B<usb=1>. The most common use for this option is
> +B<usbdevice=['tablet']> which adds pointer device using absolute
> +coordinates. Such devices function better than relative coordinate
> +devices (such as a standard mouse) since many methods of exporting
> +guest graphics (such as VNC) work better in this mode. Note that this
> +is independent of the actual pointer device you are using on the
> +host/client side.
> +
> +Host devices can also be passed through in this way, by specifying
> +host:USBID, where USBID is of the form xxxx:yyyy.  The USBID can
> +typically be found by using lsusb or usb-devices.
> +
> +The form usbdevice=DEVICE is also accepted for backwards compatibility.
>

Should we mention the difference between qemu-traditional and qemu-upstream here?

qemu-traditional only supports USB 1.1 devices, while qemu-upstream offers USB 2.0 (and 3.0) emulation.
Is there currently a way to control to which virtual usb controller the host device gets added to?

See here for help how to configure that with qemu/kvm:
http://www.linux-kvm.com/content/qemu-kvm-11-adds-experimental-support-usb-30

I think this level of detail is probably too high for a man page -- this kind of thing should be on a wiki somewhere I think.

In general though, I think xl's approach to USB stuff is really simplistic.  It would be nice to have it be more fully-featured, but I'm not sure that's on anyone's priority list.

 -George

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel