Lorenzo Bianconi wrote:
> Enable the capability to receive jumbo frames even if the interface is
> running in XDP mode if the loaded program declare to properly support
> xdp multi-buff. At same time reject a xdp program not supporting xdp
> multi-buffer if the driver is running in xdp multi-buffer mode.
>
> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> ---
Allow me to enumerate the cases as a sanity check.
mb prog on driver w/out mb support:
The program will never receive a non-linear buffer so no
trouble here. If user tries to configure MTU >1500 an error
will be thrown by driver same as always.
!mb prog on driver w/out mb support.
This is the normal case, no change.
mb prog on driver with mb support.
Allowed and user may now set MTU >1500.
!mb prog on driver with mb support
Allowed and now driver must throw an error on MTU >1500
OK works for me. Thanks.
Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
> drivers/net/ethernet/marvell/mvneta.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index 332699960b53..98db3d03116a 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -3750,6 +3750,7 @@ static void mvneta_percpu_disable(void *arg)
> static int mvneta_change_mtu(struct net_device *dev, int mtu)
> {
> struct mvneta_port *pp = netdev_priv(dev);
> + struct bpf_prog *prog = pp->xdp_prog;
> int ret;
>
> if (!IS_ALIGNED(MVNETA_RX_PKT_SIZE(mtu), 8)) {
> @@ -3758,8 +3759,11 @@ static int mvneta_change_mtu(struct net_device *dev, int mtu)
> mtu = ALIGN(MVNETA_RX_PKT_SIZE(mtu), 8);
> }
>
> - if (pp->xdp_prog && mtu > MVNETA_MAX_RX_BUF_SIZE) {
> - netdev_info(dev, "Illegal MTU value %d for XDP mode\n", mtu);
> + if (prog && !prog->aux->xdp_mb && mtu > MVNETA_MAX_RX_BUF_SIZE) {
> + netdev_info(dev,
> + "Illegal MTU %d for XDP prog without multi-buf\n",
> + mtu);
> +
> return -EINVAL;
> }
>
> @@ -4428,8 +4432,9 @@ static int mvneta_xdp_setup(struct net_device *dev, struct bpf_prog *prog,
> struct mvneta_port *pp = netdev_priv(dev);
> struct bpf_prog *old_prog;
>
> - if (prog && dev->mtu > MVNETA_MAX_RX_BUF_SIZE) {
> - NL_SET_ERR_MSG_MOD(extack, "MTU too large for XDP");
> + if (prog && !prog->aux->xdp_mb && dev->mtu > MVNETA_MAX_RX_BUF_SIZE) {
> + NL_SET_ERR_MSG_MOD(extack,
> + "prog does not support XDP multi-buff");
> return -EOPNOTSUPP;
> }
>
> --
> 2.31.1
