David Ahern
2021-Dec-18 20:53 UTC
[iproute2-next v2 4/4] vdpa: Enable user to set mtu of the vdpa device
On 12/17/21 1:08 AM, Parav Pandit wrote:> @@ -204,6 +217,8 @@ static void vdpa_opts_put(struct nlmsghdr *nlh, struct vdpa *vdpa) > if (opts->present & VDPA_OPT_VDEV_MAC) > mnl_attr_put(nlh, VDPA_ATTR_DEV_NET_CFG_MACADDR, > sizeof(opts->mac), opts->mac); > + if (opts->present & VDPA_OPT_VDEV_MTU) > + mnl_attr_put_u16(nlh, VDPA_ATTR_DEV_NET_CFG_MTU, opts->mtu);Why limit the MTU to a u16? Eric for example is working on "Big TCP" where IPv6 can work with Jumbograms where mtu can be > 64k. https://datatracker.ietf.org/doc/html/rfc2675
Michael S. Tsirkin
2021-Dec-18 22:07 UTC
[iproute2-next v2 4/4] vdpa: Enable user to set mtu of the vdpa device
On Sat, Dec 18, 2021 at 01:53:01PM -0700, David Ahern wrote:> On 12/17/21 1:08 AM, Parav Pandit wrote: > > @@ -204,6 +217,8 @@ static void vdpa_opts_put(struct nlmsghdr *nlh, struct vdpa *vdpa) > > if (opts->present & VDPA_OPT_VDEV_MAC) > > mnl_attr_put(nlh, VDPA_ATTR_DEV_NET_CFG_MACADDR, > > sizeof(opts->mac), opts->mac); > > + if (opts->present & VDPA_OPT_VDEV_MTU) > > + mnl_attr_put_u16(nlh, VDPA_ATTR_DEV_NET_CFG_MTU, opts->mtu); > > Why limit the MTU to a u16? Eric for example is working on "Big TCP" > where IPv6 can work with Jumbograms where mtu can be > 64k. > > https://datatracker.ietf.org/doc/html/rfc2675Well it's 16 bit at the virtio level, though we can extend that of course. Making it match for now removes need for validation. -- MST