Re: [libvirt] [PATCH 4/6] qemu: Implement startupPolicy for USB passed through devices

On Wed, Oct 10, 2012 at 16:39:06 +0100, Daniel P. Berrange wrote: > On Tue, Oct 09, 2012 at 02:13:25PM +0200, Jiri Denemark wrote: > > > > + virBufferAddLit(&buf, "usb-host"); > > + if (!dev->missing) { > > + virBufferAsprintf(&buf, ",hostbus=%d,hostaddr=%d", > > + dev->source.subsys.u.usb.bus, > > + dev->source.subsys.u.usb.device); > > + } > > + virBufferAsprintf(&buf, ",id=%s", dev->info->alias); > > I'm curious about this - it will result in > > -device usb-host,id=XXXXX > > shouldn't we actually just leave out the entire arg. I'm not sure > what QEMU would do with such a device specification. According to Gerd (and my testing) it's the desired command line. QEMU needs to know about the usb-host device during incoming migration to avoid aborting on unknown section in migration data. It's not necessary when starting a domain from scratch but it doesn't seem to cause any harm.