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

Rephrasing my question a bit, to make it more clear. We are now working on adding the support for native USB devices on oVirt. This requires adding composite PCI devices to a VM (details below), requiring specific set of restrictions on the addresses of these devices, and the connections between them. Is it possible to add such a composite set of devices to a VM while using automatic address assignment, as we do today on the other PCI devices?

More details below... Thank you, Oved ----- Original Message ----- > From: "Hans de Goede"<hdegoede(a)redhat.com> > To: "Oved Ourfalli"<ovedo(a)redhat.com> > Cc: "engine-devel"<engine-devel(a)ovirt.org>, 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"<iheim(a)redhat.com> >> To: "Michal Privoznik"<mprivozn(a)redhat.com> >> Cc: "Oved Ourfalli"<ovedo(a)redhat.com>, "Dave >> Allan"<dallan(a)redhat.com>, "Jiri Denemark"<jdenemar(a)redhat.com>, >> "Igor Lvovsky"<ilvovsky(a)redhat.com>, "Eli >> Mesika"<emesika(a)redhat.com>, "Hans de Goede"<hdegoede(a)redhat.com>, >> "Dan Kenigsberg"<danken(a)redhat.com>, "Andrew >> Cathrow"<acathrow(a)redhat.com> >> 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 >