Re: [Engine-devel] [libvirt]Supporting native USB in oVirt

From: "Hans de Goede" <hdegoede(a)redhat.com&gt; To: "Oved Ourfalli" <ovedo(a)redhat.com&gt; Cc: "engine-devel" <engine-devel(a)ovirt.org&gt;, libvirt-list(a)redhat.com Sent: Thursday, May 10, 2012 11:32:15 AM Subject: Re: [Engine-devel] [libvirt]Supporting native USB in oVirt Hi Oved, I think it will help if you can re-formulate things into a question for the libvirt developers. e.g. something along the lines of: "is it possible to add composite PCI devices to a vm while using automatic address assignment" ? Regards, Hans On 05/09/2012 03:46 PM, Oved Ourfalli wrote: > Hey, > > We are now working on adding the support for native USB devices on > oVirt, and we have some difficulties. > Please see the details/discussion below. > > Thank you for your help, > Oved > > ----- Forwarded Message ----- > From: "Itamar Heim&quot;&lt;iheim(a)redhat.com&gt; > To: "Michal Privoznik&quot;&lt;mprivozn(a)redhat.com&gt; > Cc: "Oved Ourfalli&quot;&lt;ovedo(a)redhat.com&gt;, "Dave > Allan&quot;&lt;dallan(a)redhat.com&gt;, "Jiri Denemark&quot;&lt;jdenemar(a)redhat.com&gt;, > "Igor Lvovsky&quot;&lt;ilvovsky(a)redhat.com&gt;, "Eli > Mesika&quot;&lt;emesika(a)redhat.com&gt;, "Hans de Goede&quot;&lt;hdegoede(a)redhat.com&gt;, > "Dan Kenigsberg&quot;&lt;danken(a)redhat.com&gt;, "Andrew > Cathrow&quot;&lt;acathrow(a)redhat.com&gt; > Sent: Wednesday, May 9, 2012 1:18:40 PM > Subject: Re: Supporting native USB in oVirt > > On 05/09/2012 01:12 PM, Michal Privoznik wrote: >> On 08.05.2012 09:19, Oved Ourfalli wrote: >>> Hi, >>> >>> We are now working on adding the support for native USB devices >>> on oVirt. >>> As far as we understand, in order to use it we need to pass the >>> following devices with the following restrictions (according to >>> the EHCI spec): >>> 1. EHCI USB controller - with the highest function number, #7. >>> >>> devices='{type:controller,device:usb,model:ich9-ehci1,address:{type:pci,domain:0x0000,bus:0x00,slot:0x04,function:0x7}}' >>> >>> 2. 3 UHCI USB controllers, on the same bus and PCI slot as the >>> EHCI controller. Set the multifunction bit to on, on the >>> controller with function #0. >>> >>> devices='{type:controller,device:usb,model:ich9-uhci1,master:{startport:0},address:{type:pci,domain:0x0000,bus:0x00,slot:0x04,function:0x0,multifunction:on}}' >>> devices='{type:controller,device:usb,model:ich9-uhci2,master:{startport:2},address:{type:pci,domain:0x0000,bus:0x00,slot:0x04,function:0x1}}' >>> devices='{type:controller,device:usb,model:ich9-uhci3,master:{startport:4},address:{type:pci,domain:0x0000,bus:0x00,slot:0x04,function:0x2}}' >>> >>> 3. USB redirect devices (according to the needed number of USB >>> slots, maximum 6) on the same bus, each one having a different >>> port. >>> >>> devices='{type:redir,device:spicevmc,bus:usb,address:{type:usb,bus:0,port:1}}' >>> devices='{type:redir,device:spicevmc,bus:usb,address:{type:usb,bus:0,port:2}}' >>> devices='{type:redir,device:spicevmc,bus:usb,address:{type:usb,bus:0,port:3}}' >>> devices='{type:redir,device:spicevmc,bus:usb,address:{type:usb,bus:0,port:4}}' >>> devices='{type:redir,device:spicevmc,bus:usb,address:{type:usb,bus:0,port:5}}' >>> devices='{type:redir,device:spicevmc,bus:usb,address:{type:usb,bus:0,port:6}}' >>> >>> 4. If we want more than 6 USB slots, we need to have 2 EHCI >>> controllers, and 6 UHCI controllers, that are consistent with >>> the restrictions above, on different bus. >>> (we need them to be on different bus, since the connection >>> between the redirect devices and the controllers is the bus). >>> >>> According to Hans (cc-ed), if we let libvirt pick its own >>> addresses, it will put each controller of the composite USB >>> controller device on its own pci slot, which is a violation of >>> the EHCI spec. >> >>> >>> The problem is that the oVirt engine is not aware of addresses. >>> They aren't managed by it. >>> They are chosen automatically by libvirt, returned to the engine, >>> and they saved in the engine database in order to provide the >>> ability to retain the same PCI addresses after VM restart. >>> >>> So, in order to support the EHCI spec, oVirt will have to be >>> aware of addresses, manage them (allocate them, check for >>> collisions, update on every libvirt change regarding that, >>> etc...). Obviously, it doesn't feel right, and in fact it is >>> also not feasible, to manage these addresses in the oVirt >>> domain. >>> >>> Is all the above correct, or are we missing something? >>> If so, can you address the issues above, and provide the ability >>> to manage these devices in libvirt? >> >> Let's have this conversation upstream (libvirt-list(a)redhat.com). >> Many >> developers are there so if there's anything libvirt can do, we >> should >> agree on concept there. > > -- > libvir-list mailing list > libvir-list(a)redhat.com > https://www.redhat.com/mailman/listinfo/libvir-list _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel