On Wed, Jun 20, 2018 at 11:53:59AM +0200, Cornelia Huck wrote: > On Tue, 19 Jun 2018 23:32:06 +0300 > "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > > > On Tue, Jun 19, 2018 at 12:54:53PM +0200, Cornelia Huck wrote: > > > Sorry about dragging mainframes into this, but this will only work for > > > homogenous device coupling, not for heterogenous. Consider my vfio-pci > > > + virtio-net-ccw example again: The guest cannot find out that the two > > > belong together by checking some group ID, it has to either use the MAC > > > or some needs-to-be-architectured property. > > > > > > Alternatively, we could propose that mechanism as pci-only, which means > > > we can rely on mechanisms that won't necessarily work on non-pci > > > transports. (FWIW, I don't see a use case for using vfio-ccw to pass > > > through a network card anytime in the near future, due to the nature of > > > network cards currently in use on s390.) > > > > That's what it boils down to, yes. If there's need to have this for > > non-pci devices, then we should put it in config space. > > Cornelia, what do you think? > > > > I think the only really useful config on s390 is the vfio-pci network > card coupled with a virtio-net-ccw device: Using an s390 network card > via vfio-ccw is out due to the nature of the s390 network cards, and > virtio-ccw is the default transport (virtio-pci is not supported on any > enterprise distro AFAIK). > > For this, having a uuid in the config space could work (vfio-pci > devices have a config space by virtue of being pci devices, and > virtio-net-ccw devices have a config space by virtue of being virtio > devices -- ccw devices usually don't have that concept). OK so this calls for adding such a field generally (it's device agnostic right now). How would you suggest doing that? -- MST _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
