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 15:54:35 +0200 Message-ID: <5615241B.5@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> <56150132.1040305@suse.com> <1444217988.1410.15.camel@citrix.com> <561506C5.6050205@suse.com> <1444218902.1410.25.camel@citrix.com> <56150A6C.2080101@suse.com> <56151C3E.4000504@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56151C3E.4000504@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: Wei Liu , Jim Fehlig , Ian Jackson , Chunyan Liu , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 10/07/2015 03:21 PM, George Dunlap wrote: > On 07/10/15 13:05, Juergen Gross wrote: >> On 10/07/2015 01:55 PM, Ian Campbell wrote: >>> 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. >> >> I'd go for nuking the --all option. I suppose xl usb-list without >> specifying a domain will nearly always be used to see the unassigned >> devices and not "uuh, to which domain did I assign device x?". > > I don't know -- if you've assigned a device to one particular domain, > then it seems pretty likely that at some point in the future you might > want to say, "Wait, what devices do I have assigned where again?" > > I think > * people will expect "xl usb-list" to show all VMs but *not* all > unassigned host devices > * In this sort of a case, doing what people expect is probably more > important than doing what we think is probably more convenient for them. Hmm, technically all unassigned USB-devices are usable from Dom0. So why not list them there. "xl usb-list 0" would be the same then as "xl usb-list --host". "xl usb-list" would be the same as "xl usb-list --all". Just a thought - I'm fine with either variant. Juergen