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

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; To: "Hans de Goede" <hdegoede(a)redhat.com&gt; Cc: "Oved Ourfalli" <ovedo(a)redhat.com&gt;, "engine-devel" <engine-devel(a)ovirt.org&gt;, libvirt-list(a)redhat.com Sent: Thursday, May 10, 2012 4:05:11 PM Subject: Re: [Engine-devel] [libvirt]Supporting native USB in oVirt On Thu, May 10, 2012 at 02:12:42PM +0200, Hans de Goede wrote: > Hi, > > On 05/10/2012 01:39 PM, Oved Ourfalli wrote: > >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? > > To be clear, what the ovirt-engine people want to do (AFAIK), is > add an EHCI controller > with UHCI companion controllers to a vm, which would normally be > done in the xml file > like this: > > <controller type='usb' index='0' model='ich9-ehci1'> > <address type='pci' domain='0x0000' bus='0x00' slot='0x08' > function='0x7'/> > </controller> > <controller type='usb' index='0' model='ich9-uhci1'> > <master startport='0'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x08' > function='0x0' multifunction='on'/> > </controller> > <controller type='usb' index='0' model='ich9-uhci2'> > <master startport='2'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x08' > function='0x1'/> > </controller> > <controller type='usb' index='0' model='ich9-uhci3'> > <master startport='4'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x08' > function='0x2'/> > </controller> > > Without manually specifying the addresses, ie they want to be able > to write > something like: > > <controller type='usb' index='0' model='ich9-ehci1'> > </controller> > <controller type='usb' index='0' model='ich9-uhci1'> > <master startport='0'/> > </controller> > <controller type='usb' index='0' model='ich9-uhci2'> > <master startport='2'/> > </controller> > <controller type='usb' index='0' model='ich9-uhci3'> > <master startport='4'/> > </controller> > > Which currently does not work, and even if it would work > libvirt does not seem to know that all devices here should > share one pci slot using different functions of that slot > (and the EHCI controller must have the highest function) > > I can imagine a syntax like this: > > <controller type='usb' index='0' model='ich9-ehci1'> > </controller> > <controller type='usb' index='0' model='ich9-uhci1'> > <master id='usb' startport='0'/> > </controller> > <controller type='usb' index='0' model='ich9-uhci2'> > <master id='usb' startport='2'/> > </controller> > <controller type='usb' index='0' model='ich9-uhci3'> > <master id='usb' startport='4'/> > </controller> > > Where the id='usb' tells libvirt which master usb controller > the companions belong to, and that libvirt would then > automatically assign them all the same pci-slot, with different > function number, ensuring the EHCI device gets the highest > function nr. While I don't much fancy adding support for automatic assignment with the companion controllers, we could probably make it work, even without needing an extra 'id' attribute. We'd just have to special-case handling of model names uhci[1-3], and apply a first-match rule against ehci controller, if there were multiple

Daniel -- |: http://berrange.com -o- | http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- | http://virt-manager.org :| |: http://autobuild.org -o- | http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- | http://live.gnome.org/gtk-vnc :| _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel