Re: [PATCH V7 6/7] xl: add usb-assignable-list command

[Ian Campbell <ian.campbell@citrix.com>]

On Wed, 2015-10-07 at 13:49 +0200, Juergen Gross wrote:
> On 10/07/2015 01:39 PM, Ian Campbell wrote:
> > On Wed, 2015-10-07 at 13:25 +0200, Juergen Gross wrote:
> > > > The "usb-assignable-list" that Chunyan has submitted will give you
> > > > a
> > > > list of all dom0 USB devices that have not yet been assigned to a
> > > > guest.
> > > >    It should be basically equivalent to "lsusb", except that it
> > > > filters
> > > > out devices which have already been assigned to VMs.
> > 
> > Right, that does sound like useful enough functionality to justify not
> > just
> > using lsusb.
> > 
> > > > In the e-mail you respond to, I was suggesting that
> > > > 
> > > > # xl usb-list --all
> > > > 
> > > > would show you usb devices attached to every VM, and also USB
> > > > devices
> > > > attached to no VM, and that
> > 
> > And would "xl usb-list" list all domain attached to every VM but not
> > the
> > unattached ones?
> > 
> > > > # xl usb-list --host
> > > > 
> > > > would show you only host usb devices not attached to any VM.
> > > > 
> > > > I think it's the second bit if functionality which Juergen is keen
> > > > be
> > > > available in some form or other.
> > > 
> > > Exactly.
> > 
> > I'm happy with this proposal too.
> > 
> > Is the distinction between --host and --all important to you? Assuming
> > unassigned devices are clearly indicated in the --all output (as they
> > should be).
> 
> Depends on how the output would look like.
> 
> In case it either isn't containing VMs without any attached USB device
> or the unassigned devices are listed at the end this would be okay. I
> just wouldn't want to have to scroll a lot in case of a host with 1000
> domains.

Makes sense.

> BTW: In case you don't have the --host option it would be nice to omit
> --all as well and just assume --all when no domain was specified (like
> xl list).

I think "xl usb-list" should list the devices attached to all domains, for
sure. I'm ambivalent about whether it also lists unattached devices (in
which case --all is unnecessary) or if --all is required to get those.

Ian.