<Hostdevice> parameters

[Andrés García]

Hi,

I want to set up wo virtual WinXP machines to act as licence managers
for a couple of CAD/CAM programs.

With the first one, everything went well, but when I got the second one
to work, the virtual machines got confused, as if they didn't know which
was their dongle.

I think it is because in their definition files there is something like:

...
    <hostdev mode='subsystem' type='usb'>
    <source>
    <vendor id='0x1234'/>
    <product id='0xbeef'/>
    </source>
    </hostdev>
    ...

The vendor and product ids are the same in both cases.

I saw in the docs that I can't change it to:

<hostdev mode='subsystem' type='sub'>
    <source>
    <address bus='0x06' slot='0x02' function='0x0'/>
    </source>
    </hostdev>

'bus' and 'slot' I can get with 'lsusb', but what does 'function' mean?

Thanks,
Andrés

[Andrés García]

> <hostdev mode='subsystem' type='sub'>
> <source>
> <address bus='0x06' slot='0x02' function='0x0'/>
> </source>
> </hostdev>
>
> 'bus' and 'slot' I can get with 'lsusb', but what does 'function' mean?

Looking it up in the libvirt sources, it appears to be used only for pci 
devices.

Andrés

[Daniel P. Berrange]

On Wed, Oct 07, 2009 at 01:17:06PM +0200, Andr?s Garc?a wrote:
> > <hostdev mode='subsystem' type='sub'>
> > <source>
> > <address bus='0x06' slot='0x02' function='0x0'/>
> > </source>
> > </hostdev>
> >
> > 'bus' and 'slot' I can get with 'lsusb', but what does 'function' mean?
>
> Looking it up in the libvirt sources, it appears to be used only for pci 
> devices.

For USB passthrough, you want

<hostdev mode='subsystem' type='usb'>
    <source>
      <address bus='0x01' device='0x02' />
    </source>
  </hostdev>

The bus/slot/domain/function  style is for PCI device addressing.

Daniel