在 2012-12-26三的 16:28 +0800，Osier Yang写道： > On 2012年12月26日 16:12, li guang wrote: > > 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 > > That doesn't answer the question. video attached to root bridge(bus 0), slot 2 sound attached to bus 1 , slot 1 > > > > >> 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, > > No, even it's not supported now, the proposed XML should be > designed compatible enough for future. Note that as long > as a new XML is added, it can't changed/removed for back-compact, > so when introducing new XMLs, you should consider the future. > > And on other hand, the introduced XML should be general > enough for all drivers, not only QEMU. > > Anyway, regardless of the current qemu implementation, I think > you should refer to the specification of PCI SGI, so that the > proposed XML could be compatible enough for the future. yes, I will, but any problem with the pci-bridge definition in XML? it's just a simple element. can you tell more details about problem of this new definition? > > > 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