On Thu, Mar 12, 2015 at 09:46:44AM +0100, Frank Blaschka wrote: > On Wed, Mar 11, 2015 at 03:57:05PM +0100, Michael S. Tsirkin wrote: > > On Wed, Mar 11, 2015 at 03:38:44PM +0100, Frank Blaschka wrote: > > > I like Alex's idea because: > > > 1) It reflects pretty well the actual nature of the pci system in real > > > s390 hw > > > > why do you say this? does real hw has this > > one device per bridge limit? > > > Actually we don't know. HW does not expose this information. All we know is > each > pci function is completely separated. So it is a good assumption to have a > separate > bridge/bus for each pci function. By the way the Linux kernel for s390 makes > the > same assumption by creating a new pci domain for each function. You may want > to read the cover letter again to get more technical details on this.
I'm sorry, my question wasn't clear. I'll try to rephrase. Imagine that I'm using s390, and I add a pci to pci bridge: -device s390-pcihost,fid=17,uid=2217,id=mydev -device ne2k_pci,bus=mydev.0,addr=0 -device pci-bridge,chassis_nr=2,bus=bus=mydev.0,addr=0,id=newdev -device ne2k_pci,bus=newdev,addr=8 What happens with your scheme then? It seems reasonable to assume that this is a legal configuration on real hardware. -- MST