On Thu, Dec 28, 2017 at 10:53:54AM -0500, Jason Baron wrote: > > > On 12/27/2017 04:43 PM, David Miller wrote: > > From: Jason Baron <jbaron@xxxxxxxxxx> > > Date: Fri, 22 Dec 2017 16:54:01 -0500 > > > >> The ability to set speed and duplex for virtio_net in useful in various > >> scenarios as described here: > >> > >> 16032be virtio_net: add ethtool support for set and get of settings > >> > >> However, it would be nice to be able to set this from the hypervisor, > >> such that virtio_net doesn't require custom guest ethtool commands. > >> > >> Introduce a new feature flag, VIRTIO_NET_F_SPEED_DUPLEX, which allows > >> the hypervisor to export a linkspeed and duplex setting. The user can > >> subsequently overwrite it later if desired via: 'ethtool -s'. > >> > >> Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx> > >> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> > >> Cc: Jason Wang <jasowang@xxxxxxxxxx> > > > > Looks mostly fine to me but need some virtio_net reviewers on this one. > > > >> @@ -57,6 +57,8 @@ > >> * Steering */ > >> #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ > >> > >> +#define VIRTIO_NET_F_SPEED_DUPLEX 63 /* Host set linkspeed and duplex */ > >> + > > > > Why use a value so far away from the largest existing one? > > > > Just curious. > > > > So that came from a discussion with Michael about which bit to use for > this, and he suggested using 63: > > " > Transports started from bit 24 and are growing up. > So I would say devices should start from bit 63 and grow down. > " > > https://patchwork.ozlabs.org/patch/848814/#1826669 > > I will add a comment to explain it. Maybe in the commit log. I don't think we need it in the header. > Thanks, > > -Jason _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
