From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: [PATCH V7 6/7] xl: add usb-assignable-list command Date: Wed, 7 Oct 2015 13:25:38 +0200 Message-ID: <56150132.1040305@suse.com> References: <1443147102-6471-1-git-send-email-cyliu@suse.com> <1443147102-6471-7-git-send-email-cyliu@suse.com> <5613FCE7.5080002@citrix.com> <1444207207.5302.269.camel@citrix.com> <1444216188.5302.333.camel@citrix.com> <5614FFF1.20304@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5614FFF1.20304@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: George Dunlap , Ian Campbell , George Dunlap Cc: Ian Jackson , Jim Fehlig , Wei Liu , Chunyan Liu , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 10/07/2015 01:20 PM, George Dunlap wrote: > On 07/10/15 12:09, Ian Campbell wrote: >> On Wed, 2015-10-07 at 11:10 +0100, George Dunlap wrote: >> >>>> So IMHO xl usb-assignable-list should behave like pci-assignable-list by >>>> default. >>> >>> I don't think that's really suitable. >> >> Then I'm terribly confused because I thought that is what you were >> initially advocating. > > I think in v3 I was trying to come up with a different name > (usb-available-list or something); but my main point was that it > *shouldn't* be named similarly but have different functionality. > > As I said, for this am I was ready to just let it slide; I just wanted > to make sure other people knew what was being let slide. :-) > >> >> [...] >> >>> For USB, there is no "assignable" stage -- "usb-attach" will take it >>> all the way from being assigned to a driver to being assigned to the >>> guest. (You can think of this as pci-attach with "seize=1" always.) >>> So making "usb-assignable-list" act like "pci-assignable-list" doesn't >>> actually make any sense. >> >> Thanks. Jeurgen has also explained this. >> >> Do you agree that adding a dummy usbback driver just for the purposes of >> adding this extra "assignable" state doesn't make sense? > > Yes, I agree. > >>>> Now, maybe it should also support some sort of --all or --full or --host >>>> option which lists everything, ideally with some indication as to whether >>>> they are attached to usbback or not and using syntax which can just be cut >>>> -and-pasted into a cfg file (without at least one of those it's just a >>>> pointless reimplementation of lsusb). >>>> >>>> However I think --all/full/host is an optional extra. >>> >>> Juergen suggested having "usb-list" have an --all option in the v3 >>> discussion. If like me you're concerned about confusing people, then >>> having --all and --host is probably the best option. >>> >>> Thoughts? >> >> If there is no assignable state in usb then I guess I don't really >> understand what usb-list-assignable would even be for, so I don't really >> understand why anyone is arguing what semantics it should have (my initial >> reply was predicated on this state existing and it therefore being useful >> to discuss how the command should behave). >> >> Given that doing something with usb-list seems most plausible _if_ we need >> some sort of thing like that at all. >> >> What would "usb-list --all" add over and above using lsusb? >> >> I take it that as things stand in patch #5: >> # xl usb-list >> will list the usb devices attached to and that: >> # xl usb-list >> will list the usb devices attached to every vm, is that >> correct? >> >> So the idea would then be to add some way of listing the devices not included in "xl usb-list", which are notionally attached to dom0, but via physical USB and not PV usb. > > 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. > > 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 > > # 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. BTW: I've explained that in another reply, but my mail client has chosen to send it via another account - I've no idea how that happened. So now my wife has some xen-devel history as well. ;-) Juergen