This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] Virtualization project idea

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Virtualization project idea
From: Dhananjay Goel <dhananjaygoel123@xxxxxxxxx>
Date: Fri, 27 Aug 2010 15:18:24 +0530
Cc: David Markey <admin@xxxxxxxxxxx>, James Harper <james.harper@xxxxxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Fri, 27 Aug 2010 02:49:18 -0700
Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:received:in-reply-to :references:from:date:message-id:subject:to:cc:content-type; bh=lLz2W8NA4jBsEpWsunaXpzZfbnMHv8jpcMSEFqD3ymQ=; b=tuU2jhMlpbiAm+XzyWvM4CltiJVh4Mxp6LYJeC3IOgLI6SgMIC+WFEF82ND9IrGjBv xh0ZPgAbJz1vEYQAeHJpfsfdY/Yho9Lwri7+QznQt3P3HmNUvg9pDpCj4hXSickKlW7r 8jdl6IajOud7PJi9CD6JCro5uZhGGNENhXqKA=
Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; b=hXdu9iFFkLvtfmPNx/ZvLsCbfsBsPEjLIQbzJ5DWdNeNEE7qC5wApsmGZSJ9QNgXkg hwUBsj/3cRjqidXMMEnd4pqbWHnhjYhrfKCWwzPhHwPm3Wb+BcKJDptk5KYgZyZAtQvL 7Q9mZiM7IVwvJMuQ6FbT3qrNTD1zIjmYTeAZQ=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C89D479E.2075B%keir.fraser@xxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <AANLkTik5oJE0GuFbdqpMGHb9oriRM9twTbPPiGH=O_t4@xxxxxxxxxxxxxx> <C89D479E.2075B%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Fri, Aug 27, 2010 at 3:14 PM, Keir Fraser <keir.fraser@xxxxxxxxxxxxx> wrote:
On 27/08/2010 10:25, "Dhananjay Goel" <dhananjaygoel123@xxxxxxxxx> wrote:

>  Would USB over IP not be helpful here?
> USB over IP is just another way of doing direct USB passthru,
> it doesn't really allow sharing the devices.
> --Consider a use case: You are using your mobile for browsing internet on PC.
> Your mobile device 
> acts a usb modem for the host machine. That can not be used in guest
> for internet connectivity simuntaneously. You need to connect/disconnect
> every time to access internet whereas it would have been seamless
> internet connectivity. 

You don't necessarily share network, disc, or mouse/keyboard at the USB
level. For network, as an example, the hardware device belongs to the host
which provides NATed or bridged networking to VMs. VMs see a virtual network
device rather than the underlying physical device. Similar principle applies
to other device classes -- VMs see a virtual device. If you want a VM to see
a property of a physical device that cannot be expressed in your virtual
device model, you pass that physical device through directly to that one VM.
If you want direct passthrough and some semblance of sharing between VMs...
that's harder to do.

I agree its difficult to do. But is it possible to do? Can we make such that USB devices are shared across VMs? Any suggestion of how it can be done? 

 -- Keir

Xen-devel mailing list