On Thu, Jun 21, 2018 at 7:59 AM, Cornelia Huck <coh...@redhat.com> wrote: > On Wed, 20 Jun 2018 22:48:58 +0300 > "Michael S. Tsirkin" <m...@redhat.com> 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? 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 > - 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.
