On 7/13/2021 1:47 PM, Andrew Rybchenko wrote:
> On 7/9/21 8:29 PM, Ferruh Yigit wrote:
>> There is a confusion on setting max Rx packet length, this patch aims to
>> clarify it.
>>
>> 'rte_eth_dev_configure()' API accepts max Rx packet size via
>> 'uint32_t max_rx_pkt_len' filed of the config struct 'struct
>> rte_eth_conf'.
>>
>> Also 'rte_eth_dev_set_mtu()' API can be used to set the MTU, and result
>> stored into '(struct rte_eth_dev)->data->mtu'.
>>
>> These two APIs are related but they work in a disconnected way, they
>> store the set values in different variables which makes hard to figure
>> out which one to use, also two different related method is confusing for
>> the users.
>>
>> Other issues causing confusion is:
>> * maximum transmission unit (MTU) is payload of the Ethernet frame. And
>> 'max_rx_pkt_len' is the size of the Ethernet frame. Difference is
>> Ethernet frame overhead, but this may be different from device to
>> device based on what device supports, like VLAN and QinQ.
>> * 'max_rx_pkt_len' is only valid when application requested jumbo frame,
>> which adds additional confusion and some APIs and PMDs already
>> discards this documented behavior.
>> * For the jumbo frame enabled case, 'max_rx_pkt_len' is an mandatory
>> field, this adds configuration complexity for application.
>>
>> As solution, both APIs gets MTU as parameter, and both saves the result
>> in same variable '(struct rte_eth_dev)->data->mtu'. For this
>> 'max_rx_pkt_len' updated as 'mtu', and it is always valid independent
>> from jumbo frame.
>>
>> For 'rte_eth_dev_configure()', 'dev->data->dev_conf.rxmode.mtu' is user
>> request and it should be used only within configure function and result
>> should be stored to '(struct rte_eth_dev)->data->mtu'. After that point
>> both application and PMD uses MTU from this variable.
>>
>> When application doesn't provide an MTU during 'rte_eth_dev_configure()'
>> default 'RTE_ETHER_MTU' value is used.
>>
>> As additional clarification, MTU is used to configure the device for
>> physical Rx/Tx limitation. Other related issue is size of the buffer to
>> store Rx packets, many PMDs use mbuf data buffer size as Rx buffer size.
>> And compares MTU against Rx buffer size to decide enabling scattered Rx
>> or not, if PMD supports it. If scattered Rx is not supported by device,
>> MTU bigger than Rx buffer size should fail.
>>
>
> Do I understand correctly that target is 21.11?
>
Yes, it is for 21.11, I should clarify it.
> Really huge work. Many thanks.
>
> See my notes below.
>
>> Signed-off-by: Ferruh Yigit <ferruh.yi...@intel.com>
>
> [snip]
>
>> diff --git a/app/test-eventdev/test_pipeline_common.c
>> b/app/test-eventdev/test_pipeline_common.c
>> index 6ee530d4cdc9..5fcea74b4d43 100644
>> --- a/app/test-eventdev/test_pipeline_common.c
>> +++ b/app/test-eventdev/test_pipeline_common.c
>> @@ -197,8 +197,9 @@ pipeline_ethdev_setup(struct evt_test *test, struct
>> evt_options *opt)
>> return -EINVAL;
>> }
>>
>> - port_conf.rxmode.max_rx_pkt_len = opt->max_pkt_sz;
>> - if (opt->max_pkt_sz > RTE_ETHER_MAX_LEN)
>> + port_conf.rxmode.mtu = opt->max_pkt_sz - RTE_ETHER_HDR_LEN -
>> + RTE_ETHER_CRC_LEN;
>
> Subtract requires overflow check. May max_pkt_size be 0 or just
> smaller that RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN?
>
There is a "opt->max_pkt_sz < RTE_ETHER_MIN_LEN" check above this, which ensures
it won't overflow.
>> + if (port_conf.rxmode.mtu > RTE_ETHER_MTU)
>> port_conf.rxmode.offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
>>
>> t->internal_port = 1;
>> diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
>> index 8468018cf35d..8bdc042f6e8e 100644
>> --- a/app/test-pmd/cmdline.c
>> +++ b/app/test-pmd/cmdline.c
>> @@ -1892,43 +1892,36 @@ cmd_config_max_pkt_len_parsed(void *parsed_result,
>> __rte_unused void *data)
>> {
>> struct cmd_config_max_pkt_len_result *res = parsed_result;
>> - uint32_t max_rx_pkt_len_backup = 0;
>> - portid_t pid;
>> + portid_t port_id;
>> int ret;
>>
>> + if (strcmp(res->name, "max-pkt-len")) {
>> + printf("Unknown parameter\n");
>> + return;
>> + }
>> +
>> if (!all_ports_stopped()) {
>> printf("Please stop all ports first\n");
>> return;
>> }
>>
>> - RTE_ETH_FOREACH_DEV(pid) {
>> - struct rte_port *port = &ports[pid];
>> -
>> - if (!strcmp(res->name, "max-pkt-len")) {
>> - if (res->value < RTE_ETHER_MIN_LEN) {
>> - printf("max-pkt-len can not be less than %d\n",
>> - RTE_ETHER_MIN_LEN);
>> - return;
>> - }
>> - if (res->value == port->dev_conf.rxmode.max_rx_pkt_len)
>> - return;
>> -
>> - ret = eth_dev_info_get_print_err(pid, &port->dev_info);
>> - if (ret != 0) {
>> - printf("rte_eth_dev_info_get() failed for port
>> %u\n",
>> - pid);
>> - return;
>> - }
>> + RTE_ETH_FOREACH_DEV(port_id) {
>> + struct rte_port *port = &ports[port_id];
>>
>> - max_rx_pkt_len_backup =
>> port->dev_conf.rxmode.max_rx_pkt_len;
>> + if (res->value < RTE_ETHER_MIN_LEN) {
>> + printf("max-pkt-len can not be less than %d\n",
>
> fprintf() to stderr, please.
> Here and in a number of places below.
>
Overall I agree, but not sure to have this change in this patch. The patch is
already complex, I am for keeping logging part same as before, what do you think
to update all usage later on its own patch?
>> + RTE_ETHER_MIN_LEN);
>> + return;
>> + }
>>
>> - port->dev_conf.rxmode.max_rx_pkt_len = res->value;
>> - if (update_jumbo_frame_offload(pid) != 0)
>> - port->dev_conf.rxmode.max_rx_pkt_len =
>> max_rx_pkt_len_backup;
>> - } else {
>> - printf("Unknown parameter\n");
>> + ret = eth_dev_info_get_print_err(port_id, &port->dev_info);
>> + if (ret != 0) {
>> + printf("rte_eth_dev_info_get() failed for port %u\n",
>> + port_id);
>> return;
>> }
>> +
>> + update_jumbo_frame_offload(port_id, res->value);
>> }
>>
>> init_port_config();
>> diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
>> index 04ae0feb5852..a87265d7638b 100644
>> --- a/app/test-pmd/config.c
>> +++ b/app/test-pmd/config.c
>
> [snip]
>
>> @@ -1155,20 +1154,17 @@ port_mtu_set(portid_t port_id, uint16_t mtu)
>> return;
>> }
>> diag = rte_eth_dev_set_mtu(port_id, mtu);
>> - if (diag)
>> + if (diag) {
>> printf("Set MTU failed. diag=%d\n", diag);
>> - else if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_JUMBO_FRAME) {
>> - /*
>> - * Ether overhead in driver is equal to the difference of
>> - * max_rx_pktlen and max_mtu in rte_eth_dev_info when the
>> - * device supports jumbo frame.
>> - */
>> - eth_overhead = dev_info.max_rx_pktlen - dev_info.max_mtu;
>> + return;
>> + }
>> +
>> + rte_port->dev_conf.rxmode.mtu = mtu;
>> +
>> + if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_JUMBO_FRAME) {
>> if (mtu > RTE_ETHER_MTU) {
>> rte_port->dev_conf.rxmode.offloads |=
>> DEV_RX_OFFLOAD_JUMBO_FRAME;
>> - rte_port->dev_conf.rxmode.max_rx_pkt_len =
>> - mtu + eth_overhead;
>> } else
>
> I guess curly brackets should be removed now.
>
ack
>> rte_port->dev_conf.rxmode.offloads &=
>> ~DEV_RX_OFFLOAD_JUMBO_FRAME;
>
> [snip]
>
>> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
>> index 1cdd3cdd12b6..2c79cae05664 100644
>> --- a/app/test-pmd/testpmd.c
>> +++ b/app/test-pmd/testpmd.c
>
> [snip]
>
>> @@ -1465,7 +1473,7 @@ init_config(void)
>> rte_exit(EXIT_FAILURE,
>> "rte_eth_dev_info_get() failed\n");
>>
>> - ret = update_jumbo_frame_offload(pid);
>> + ret = update_jumbo_frame_offload(pid, 0);
>> if (ret != 0)
>> printf("Updating jumbo frame offload failed for port
>> %u\n",
>> pid);
>> @@ -1512,14 +1520,19 @@ init_config(void)
>> */
>> if (port->dev_info.rx_desc_lim.nb_mtu_seg_max != UINT16_MAX &&
>> port->dev_info.rx_desc_lim.nb_mtu_seg_max != 0)
>> {
>> - data_size = rx_mode.max_rx_pkt_len /
>> - port->dev_info.rx_desc_lim.nb_mtu_seg_max;
>> + uint32_t eth_overhead =
>> get_eth_overhead(&port->dev_info);
>> + uint16_t mtu;
>>
>> - if ((data_size + RTE_PKTMBUF_HEADROOM) >
>> + if (rte_eth_dev_get_mtu(pid, &mtu) == 0) {
>> + data_size = mtu + eth_overhead /
>> +
>> port->dev_info.rx_desc_lim.nb_mtu_seg_max;
>> +
>> + if ((data_size + RTE_PKTMBUF_HEADROOM) >
>
> Unnecessary parenthesis.
>
This part already changed in upstream.
>> mbuf_data_size[0]) {
>> - mbuf_data_size[0] = data_size +
>> - RTE_PKTMBUF_HEADROOM;
>> - warning = 1;
>> + mbuf_data_size[0] = data_size +
>> + RTE_PKTMBUF_HEADROOM;
>> + warning = 1;
>> + }
>> }
>> }
>> }
>
> [snip]
>
>> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
>> index c515de3bf71d..0a8d29277aeb 100644
>> --- a/drivers/net/tap/rte_eth_tap.c
>> +++ b/drivers/net/tap/rte_eth_tap.c
>> @@ -1627,13 +1627,8 @@ tap_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
>> {
>> struct pmd_internals *pmd = dev->data->dev_private;
>> struct ifreq ifr = { .ifr_mtu = mtu };
>> - int err = 0;
>>
>> - err = tap_ioctl(pmd, SIOCSIFMTU, &ifr, 1, LOCAL_AND_REMOTE);
>> - if (!err)
>> - dev->data->mtu = mtu;
>> -
>> - return err;
>> + return tap_ioctl(pmd, SIOCSIFMTU, &ifr, 1, LOCAL_AND_REMOTE);
>
> The cleanup could be done separately before the patch, since
> it just makes the long patch longer and unrelated in fact,
> since assignment after callback is already done.
>
Yes, and agree it can be updated seperately, but I think change is related, not
sure about having too many commits. If you have strong opinion I can update it.
>> }
>>
>> static int
>
> [snip]
>
>> diff --git a/examples/ip_fragmentation/main.c
>> b/examples/ip_fragmentation/main.c
>> index 77a6a18d1914..f97287ce2243 100644
>> --- a/examples/ip_fragmentation/main.c
>> +++ b/examples/ip_fragmentation/main.c
>> @@ -146,7 +146,7 @@ struct lcore_queue_conf lcore_queue_conf[RTE_MAX_LCORE];
>>
>> static struct rte_eth_conf port_conf = {
>> .rxmode = {
>> - .max_rx_pkt_len = JUMBO_FRAME_MAX_SIZE,
>> + .mtu = JUMBO_FRAME_MAX_SIZE,
>
> Before the patch JUMBO_FRAME_MAX_SIZE inluded overhad, but
> after the patch it is used as it is does not include overhead.
>
> There a number of similiar cases in other apps.
>
ack, Huisong also highlighted it, I will update.
>> .split_hdr_size = 0,
>> .offloads = (DEV_RX_OFFLOAD_CHECKSUM |
>> DEV_RX_OFFLOAD_SCATTER |
>
> [snip]
>
>> diff --git a/examples/ip_pipeline/link.c b/examples/ip_pipeline/link.c
>> index 16bcffe356bc..8628db22f56b 100644
>> --- a/examples/ip_pipeline/link.c
>> +++ b/examples/ip_pipeline/link.c
>> @@ -46,7 +46,7 @@ static struct rte_eth_conf port_conf_default = {
>> .link_speeds = 0,
>> .rxmode = {
>> .mq_mode = ETH_MQ_RX_NONE,
>> - .max_rx_pkt_len = 9000, /* Jumbo frame max packet len */
>> + .mtu = 9000, /* Jumbo frame MTU */
>
> Strictly speaking 9000 included overhead before the patch and
> does not include overhead after the patch.
>
> There a number of similiar cases in other apps.
>
ack
>> .split_hdr_size = 0, /* Header split buffer size */
>> },
>> .rx_adv_conf = {
>
> [snip]
>
>> diff --git a/examples/l3fwd-acl/main.c b/examples/l3fwd-acl/main.c
>> index a1f457b564b6..913037d5f835 100644
>> --- a/examples/l3fwd-acl/main.c
>> +++ b/examples/l3fwd-acl/main.c
>
> [snip]
>
>> @@ -1833,12 +1832,12 @@ parse_args(int argc, char **argv)
>> print_usage(prgname);
>> return -1;
>> }
>> - port_conf.rxmode.max_rx_pkt_len = ret;
>> + port_conf.rxmode.mtu = ret - (RTE_ETHER_HDR_LEN
>> +
>> + RTE_ETHER_CRC_LEN);
>> }
>> - printf("set jumbo frame max packet length "
>> - "to %u\n",
>> - (unsigned int)
>> - port_conf.rxmode.max_rx_pkt_len);
>> + printf("set jumbo frame max packet length to %u\n",
>> + (unsigned int)port_conf.rxmode.mtu +
>> + RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN);
>
>
> I think that overhead should be obtainded from dev_info with
> fallback to value used above.
>
Right, but since at this stage it is hard to get the overhead for the
application, I wonder if we should change the applications to get the MTU as
paramter.
And overall this work makes it harder for application to use frame size, since
it brings 'rte_eth_dev_info_get()' API call requirement. Not sure how big a
problem is this, and if we can provide some help to applications, any suggestion
is welcome.
Specific to above sample app, it can be possible to record user parameter in a
temp var, and set the 'port_conf.rxmode.max_rx_pkt_len' when app has the
dev_info, I will update it.
> There are many similar cases in other apps.
>
ack
> [snip]
>
>> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
>> index c607eabb5b0c..3451125639f9 100644
>> --- a/lib/ethdev/rte_ethdev.c
>> +++ b/lib/ethdev/rte_ethdev.c
>> @@ -1249,15 +1249,15 @@ rte_eth_dev_tx_offload_name(uint64_t offload)
>>
>> static inline int
>> eth_dev_check_lro_pkt_size(uint16_t port_id, uint32_t config_size,
>> - uint32_t max_rx_pkt_len, uint32_t dev_info_size)
>> + uint32_t max_rx_pktlen, uint32_t dev_info_size)
>> {
>> int ret = 0;
>>
>> if (dev_info_size == 0) {
>> - if (config_size != max_rx_pkt_len) {
>> + if (config_size != max_rx_pktlen) {
>> RTE_ETHDEV_LOG(ERR, "Ethdev port_id=%d max_lro_pkt_size"
>> " %u != %u is not allowed\n",
>> - port_id, config_size, max_rx_pkt_len);
>> + port_id, config_size, max_rx_pktlen);
>
> This patch looks a bit unrelated and make the long patch
> even more longer. May be it is better to do the cleanup
> first (before the patch).
>
I also had same doubt, but it is somehow related.
Previously the variable name in the two struct was slightly different:
dev_info.max_rx_pktlen => max Rx packet lenght device capability
rxmode.max_rx_pkt_len => max Rx packet length configuration
This slight difference was bothering me :), since we are removing
'rxmode.max_rx_pkt_len' now, I though it is good opportunity to unifiy variabe
name to 'max_rx_pktlen'. After this patch only avp driver has 'max_rx_pkt_len'
usage (because of usage on its interface).
I am not sure if above change worth to have its own patch, another option is
discard this change, if you have strong opinion on it I can drop the changes.
>> ret = -EINVAL;
>> }
>> } else if (config_size > dev_info_size) {
>> @@ -1325,6 +1325,19 @@ eth_dev_validate_offloads(uint16_t port_id, uint64_t
>> req_offloads,
>> return ret;
>> }
>>
>> +static uint16_t
>> +eth_dev_get_overhead_len(uint32_t max_rx_pktlen, uint16_t max_mtu)
>> +{
>> + uint16_t overhead_len;
>> +
>> + if (max_mtu != UINT16_MAX && max_rx_pktlen > max_mtu)
>> + overhead_len = max_rx_pktlen - max_mtu;
>> + else
>> + overhead_len = RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN;
>> +
>> + return overhead_len;
>> +}
>> +
>> int
>> rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
>> const struct rte_eth_conf *dev_conf)
>> @@ -1332,6 +1345,7 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t
>> nb_rx_q, uint16_t nb_tx_q,
>> struct rte_eth_dev *dev;
>> struct rte_eth_dev_info dev_info;
>> struct rte_eth_conf orig_conf;
>> + uint32_t max_rx_pktlen;
>> uint16_t overhead_len;
>> int diag;
>> int ret;
>> @@ -1375,11 +1389,8 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t
>> nb_rx_q, uint16_t nb_tx_q,
>> goto rollback;
>>
>> /* Get the real Ethernet overhead length */
>> - if (dev_info.max_mtu != UINT16_MAX &&
>> - dev_info.max_rx_pktlen > dev_info.max_mtu)
>> - overhead_len = dev_info.max_rx_pktlen - dev_info.max_mtu;
>> - else
>> - overhead_len = RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN;
>> + overhead_len = eth_dev_get_overhead_len(dev_info.max_rx_pktlen,
>> + dev_info.max_mtu);
>>
>> /* If number of queues specified by application for both Rx and Tx is
>> * zero, use driver preferred values. This cannot be done individually
>> @@ -1448,49 +1459,45 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t
>> nb_rx_q, uint16_t nb_tx_q,
>> }
>>
>> /*
>> - * If jumbo frames are enabled, check that the maximum RX packet
>> - * length is supported by the configured device.
>> + * Check that the maximum RX packet length is supported by the
>> + * configured device.
>> */
>> - if (dev_conf->rxmode.offloads & DEV_RX_OFFLOAD_JUMBO_FRAME) {
>> - if (dev_conf->rxmode.max_rx_pkt_len > dev_info.max_rx_pktlen) {
>> - RTE_ETHDEV_LOG(ERR,
>> - "Ethdev port_id=%u max_rx_pkt_len %u > max
>> valid value %u\n",
>> - port_id, dev_conf->rxmode.max_rx_pkt_len,
>> - dev_info.max_rx_pktlen);
>> - ret = -EINVAL;
>> - goto rollback;
>> - } else if (dev_conf->rxmode.max_rx_pkt_len < RTE_ETHER_MIN_LEN)
>> {
>> - RTE_ETHDEV_LOG(ERR,
>> - "Ethdev port_id=%u max_rx_pkt_len %u < min
>> valid value %u\n",
>> - port_id, dev_conf->rxmode.max_rx_pkt_len,
>> - (unsigned int)RTE_ETHER_MIN_LEN);
>> - ret = -EINVAL;
>> - goto rollback;
>> - }
>> + if (dev_conf->rxmode.mtu == 0)
>> + dev->data->dev_conf.rxmode.mtu = RTE_ETHER_MTU;
>> + max_rx_pktlen = dev->data->dev_conf.rxmode.mtu + overhead_len;
>> + if (max_rx_pktlen > dev_info.max_rx_pktlen) {
>> + RTE_ETHDEV_LOG(ERR,
>> + "Ethdev port_id=%u max_rx_pktlen %u > max valid value
>> %u\n",
>> + port_id, max_rx_pktlen, dev_info.max_rx_pktlen);
>> + ret = -EINVAL;
>> + goto rollback;
>> + } else if (max_rx_pktlen < RTE_ETHER_MIN_LEN) {
>> + RTE_ETHDEV_LOG(ERR,
>> + "Ethdev port_id=%u max_rx_pktlen %u < min valid value
>> %u\n",
>> + port_id, max_rx_pktlen, RTE_ETHER_MIN_LEN);
>> + ret = -EINVAL;
>> + goto rollback;
>> + }
>>
>> - /* Scale the MTU size to adapt max_rx_pkt_len */
>> - dev->data->mtu = dev->data->dev_conf.rxmode.max_rx_pkt_len -
>> - overhead_len;
>> - } else {
>> - uint16_t pktlen = dev_conf->rxmode.max_rx_pkt_len;
>> - if (pktlen < RTE_ETHER_MIN_MTU + overhead_len ||
>> - pktlen > RTE_ETHER_MTU + overhead_len)
>> + if ((dev_conf->rxmode.offloads & DEV_RX_OFFLOAD_JUMBO_FRAME) == 0) {
>> + if (dev->data->dev_conf.rxmode.mtu < RTE_ETHER_MIN_MTU ||
>> + dev->data->dev_conf.rxmode.mtu > RTE_ETHER_MTU)
>> /* Use default value */
>> - dev->data->dev_conf.rxmode.max_rx_pkt_len =
>> - RTE_ETHER_MTU + overhead_len;
>> + dev->data->dev_conf.rxmode.mtu = RTE_ETHER_MTU;
>
> I don't understand it. It would be good to add comments to
> explain logic above.
>
This part will be updated in next patches, and I will extract the checks to a
common function, can you please check the final out output of next patch, if it
makes sense?
>> }
>>
>> + dev->data->mtu = dev->data->dev_conf.rxmode.mtu;
>> +
>> /*
>> * If LRO is enabled, check that the maximum aggregated packet
>> * size is supported by the configured device.
>> */
>> if (dev_conf->rxmode.offloads & DEV_RX_OFFLOAD_TCP_LRO) {
>> if (dev_conf->rxmode.max_lro_pkt_size == 0)
>> - dev->data->dev_conf.rxmode.max_lro_pkt_size =
>> - dev->data->dev_conf.rxmode.max_rx_pkt_len;
>> + dev->data->dev_conf.rxmode.max_lro_pkt_size =
>> max_rx_pktlen;
>> ret = eth_dev_check_lro_pkt_size(port_id,
>> dev->data->dev_conf.rxmode.max_lro_pkt_size,
>> - dev->data->dev_conf.rxmode.max_rx_pkt_len,
>> + max_rx_pktlen,
>> dev_info.max_lro_pkt_size);
>> if (ret != 0)
>> goto rollback;
>
> [snip]
>
>> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
>> index faf3bd901d75..9f288f98329c 100644
>> --- a/lib/ethdev/rte_ethdev.h
>> +++ b/lib/ethdev/rte_ethdev.h
>> @@ -410,7 +410,7 @@ enum rte_eth_tx_mq_mode {
>> struct rte_eth_rxmode {
>> /** The multi-queue packet distribution mode to be used, e.g. RSS. */
>> enum rte_eth_rx_mq_mode mq_mode;
>> - uint32_t max_rx_pkt_len; /**< Only used if JUMBO_FRAME enabled. */
>> + uint32_t mtu; /**< Requested MTU. */
>
> Maximum Transmit Unit looks a bit confusing in Rx mode
> structure.
>
True, but I think it is already used for Rx already as concept, I believe the
intention will be clear enough. Do you think will be more clear if we pick a
DPDK specific variable name?
>> /** Maximum allowed size of LRO aggregated packet. */
>> uint32_t max_lro_pkt_size;
>> uint16_t split_hdr_size; /**< hdr buf size (header_split enabled).*/
>
> [snip]
>
