On Tue, 19 Jun 2018 23:32:06 +0300 "Michael S. Tsirkin" <m...@redhat.com> 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). _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
