On Thu, Jun 21, 2018 at 06:21:55PM -0700, Siwei Liu wrote: > On Thu, Jun 21, 2018 at 7:59 AM, Cornelia Huck <cohuck@xxxxxxxxxx> wrote: > > On Wed, 20 Jun 2018 22:48:58 +0300 > > "Michael S. Tsirkin" <mst@xxxxxxxxxx> wrote: > > > >> On Wed, Jun 20, 2018 at 06:06:19PM +0200, Cornelia Huck wrote: > >> > In any case, I'm not sure anymore why we'd want the extra uuid. > >> > >> It's mostly so we can have e.g. multiple devices with same MAC > >> (which some people seem to want in order to then use > >> then with different containers). > >> > >> But it is also handy for when you assign a PF, since then you > >> can't set the MAC. > >> > > > > OK, so what about the following: > > > > - introduce a new feature bit, VIRTIO_NET_F_STANDBY_UUID that indicates > > that we have a new uuid field in the virtio-net config space > > - in QEMU, add a property for virtio-net that allows to specify a uuid, > > offer VIRTIO_NET_F_STANDBY_UUID if set > > - when configuring, set the property to the group UUID of the vfio-pci > > device > > If feature negotiation fails on VIRTIO_NET_F_STANDBY_UUID, is it safe > to still expose UUID in the config space on virtio-pci? Yes but guest is not supposed to read it. > I'm not even sure if it's sane to expose group UUID on the PCI bridge > where the corresponding vfio-pci device attached to for a guest which > doesn't support the feature (legacy). > > -Siwei Yes but you won't add the primary behind such a bridge. > > > - in the guest, use the uuid from the virtio-net device's config space > > if applicable; else, fall back to matching by MAC as done today > > > > That should work for all virtio transports. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
