Re: [Xen-users] usb passthrough

[chris <tknchris@xxxxxxxxx>]

How is usb passthrough performance wise with a HVM domain? Is this
something thats emulated? I'm curious how it would compare performance
wise to passthrough of a usb controller card.

- chris

On Fri, Feb 26, 2010 at 1:33 PM, Pasi Kärkkäinen <pasik@xxxxxx> wrote:
> On Fri, Feb 26, 2010 at 01:22:52PM -0500, chris wrote:
>> Pasi,
>>
>> I know, my understanding was that pvusb was simply for exposing usb
>> mass storage as a block device to the domain. I've never actually used
>> it but I believe you can do this with a hvm domain without anything
>> special. If anyone can actually confirm this it would be good to know
>> :)
>>
>
> There are two separate things:
>
> 1. the normal usb passthrough; this works for hvm guests without anything 
> special by specifying usb=1 and usbdevice = []
> 2. pvusb, which requires separate usbback driver in dom0, and xen+tools that 
> has pvusb support, and usbfront driver in the guest.
>
> -- Pasi
>
>> As far as his original question, he needs vt-d to passthrough any
>> physical device to a hvm domain.
>>
>> - chris
>>
>> On Fri, Feb 26, 2010 at 10:03 AM, Pasi Kärkkäinen <pasik@xxxxxx> wrote:
>> > On Fri, Feb 26, 2010 at 10:00:34AM -0500, chris wrote:
>> >> He said it was a HVM guest. I don't think you can passthrough to a hvm
>> >> domain anything except usb storage with pvusb, correct?
>> >>
>> >
>> > pvusb is different from the 'normal' usb=1 / usbdevice = [] stuff..
>> >
>> > I'm not totally sure what devices are supported with pvusb and with the 
>> > normal usb passthrough.
>> >
>> > -- Pasi
>> >
>> >> On Fri, Feb 26, 2010 at 9:49 AM, Pasi Kärkkäinen <pasik@xxxxxx> wrote:
>> >> > On Fri, Feb 26, 2010 at 09:49:38AM -0300, Sergio Charpinel Jr. wrote:
>> >> >> Hi,
>> >> >>
>> >> >> I want to use a webcam in a HVM guest, but my dom0 doesnt support VT-d
>> >> >> (just VT).
>> >> >>
>> >> >
>> >> > USB passthrough doesn't require VT-d, it's only required for PCI device
>> >> > passthrough to HVM guests.
>> >> >
>> >> >> I tried passing the parameters usb=1 and usbdevice = [ '..' ] and I
>> >> >> could see an usb device in domU. But it does not know which device is.
>> >> >>
>> >> >> Which are the possibilites to do that? I prefer to use hvm machines,
>> >> >> but if it is not possible, with PV machines it can work?
>> >> >>
>> >> >
>> >> > With PV guest you could passthrough the whole USB controller (the PCI 
>> >> > device)..
>> >> >
>> >> > -- Pasi
>> >> >
>> >> >
>> >> > _______________________________________________
>> >> > Xen-users mailing list
>> >> > Xen-users@xxxxxxxxxxxxxxxxxxx
>> >> > http://lists.xensource.com/xen-users
>> >> >
>> >
>

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