在 2012-12-26三的 15:38 +0800，Osier Yang写道： > On 2012年12月26日 09:00, liguang wrote: > > Now, it's unnecessary to arrange devices into multi-pci-bus, > > for example: > > <sound model='ac97'> > > <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> > > </sound> > > <video> > > <model type='cirrus' vram='9216' heads='1'/> > > <address type='pci' domain='0x0000' bus='0x1' slot='0x02' function='0x0'/> > > </video> > > libvirt will complain about "bus != 0", > > fortunately, qemu supports pci-to-pci bridge, > > if we want to use multi-pci-bus, we can define > > 2 pci bridge devices then attach 1 to the other > > as a subordinate pci-bus, so, 2 pci-buses appear. > > for example: > > <pci-bridge type='root'/> > > <pci-bridge type='subordinate'> > > <address type='pci-bridge' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> > > </pci-bridge> > > <sound model='ac97'> > > <address type='pci-bridge' domain='0x0000' bus='0x01' slot='0x02' function='0x0'/> > > </sound> > > <video> > > <model type='cirrus' vram='9216' heads='1'/> > > <address type='pci-bridge' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> > > </video> > > I think this is rather not workable, E.g. how to known the video device > attached to which pci bridge if there are multiple pci bridges? please bear in mind bus 0 is root bridge, bus 1 is subordinate bridge, and so forth, which was implemented in my patch 2/3 > And the > new address type "pci-bridge" looks bogus, as the address properties of > a pci bridge are exactly same with a normal pci device. > > From the qemu patch: > > -device pci-bridge,id=bridge1 \ > -netdev user,id=u \ > -device ne2k_pci,id=net2,bus=bridge1,netdev=u > > I think what we only need is to describe the relapship between pci > bridge and pci bridge (if it's supported, the two types "root" and > "subordinate" are not enough to describe the relatioship), also pci > device and pci bridge. relationship between pci-bus and devices are embedded, just like pci.0, e.g. <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> means a device sitting on bus pci.0 slot 4 then after my changes <address type='pci-bridge' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> would have the same mean relationship between pci-bridges are primary and secondary, (as far as I know qemu doesn’t support multi-pci-bridges at present) so root and subordinate attribute may be enough, every subordinate will attach to root bridge, and has its own slot. > > To describe the relationship between bridges, perhaps we will need > "parent" and "child" properties for <pcibridge> device. > > To describe the relatioship between a pci device and a pci bridge, > a property like "bridge" for general pci device should be enough. > In this case, another property for <pcibridge> is needed, to > indentify it, such as "id" or "name". only relationship is not enough, it's unsuitable for passing '-device pci-bridge' to qemu, so I define a new device and address type for pci-bridge in libvirt. > > Regards, > Osier > > -- regards! li guang -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list