Wednesday, September 5, 2018 7:42 PM, Stephen Hemminger:
> Subject: [dpdk-dev] [RFC] ethdev: add min/max MTU to device info
>
> This addresses the usability issue raised by OVS at DPDK Userspace summit.
> It adds general min/max mtu into device info. For compatiablity, and to save
> space, it fits in a hole in existing structure.
>
> The initial version sets max mtu to normal Ethernet, it is up to PMD to set
> larger value if it supports Jumbo frames.
>
> Fixing the drivers to use this is trivial and can be done by 18.11.
> Already have some of the patches done.
>
> Signed-off-by: Stephen Hemminger <step...@networkplumber.org>
Makes sense.
Acked-by: Shahaf Shuler <shah...@mellanox.com>
> ---
> lib/librte_ethdev/rte_ethdev.c | 7 +++++++ lib/librte_ethdev/rte_ethdev.h
> | 2 ++
> 2 files changed, 9 insertions(+)
>
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index 4c320250589a..df0c7536a7c4 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -2408,6 +2408,8 @@ rte_eth_dev_info_get(uint16_t port_id, struct
> rte_eth_dev_info *dev_info)
> dev_info->rx_desc_lim = lim;
> dev_info->tx_desc_lim = lim;
> dev_info->device = dev->device;
> + dev_info->min_mtu = ETHER_MIN_MTU;
> + dev_info->max_mtu = ETHER_MTU;
>
> RTE_FUNC_PTR_OR_RET(*dev->dev_ops->dev_infos_get);
> (*dev->dev_ops->dev_infos_get)(dev, dev_info); @@ -2471,12
> +2473,17 @@ int rte_eth_dev_set_mtu(uint16_t port_id, uint16_t mtu) {
> int ret;
> + struct rte_eth_dev_info dev_info;
> struct rte_eth_dev *dev;
>
> RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> dev = &rte_eth_devices[port_id];
> RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->mtu_set, -
> ENOTSUP);
>
> + rte_eth_dev_info_get(port_id, &dev_info);
> + if (mtu < dev_info.min_mtu || mtu > dev_info.max_mtu)
> + return -EINVAL;
> +
> ret = (*dev->dev_ops->mtu_set)(dev, mtu);
> if (!ret)
> dev->data->mtu = mtu;
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index 7070e9ab408f..5171a9083288 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -1015,6 +1015,8 @@ struct rte_eth_dev_info {
> const char *driver_name; /**< Device Driver name. */
> unsigned int if_index; /**< Index to bound host interface, or 0 if
> none.
> Use if_indextoname() to translate into an interface name. */
> + uint16_t min_mtu; /**< Minimum MTU allowed */
> + uint16_t max_mtu; /**< Maximum MTU allowed */
> const uint32_t *dev_flags; /**< Device flags */
> uint32_t min_rx_bufsize; /**< Minimum size of RX buffer. */
> uint32_t max_rx_pktlen; /**< Maximum configurable length of RX
> pkt. */
> --
> 2.17.1
