On Fri, Nov 24, 2017 at 9:26 AM, Stokes, Ian <[email protected]> wrote:
>> Some PMD assumes that the RX buffers are already allocated when setting
>> the device MTU, because the RX buffer size depends on the MTU.
>> This worked until 67fe6d635193 added a call to rte_eth_dev_set_mtu() in
>> the init code, which would set the MTU before the RX buffer allocation,
>> triggering a segmentation fault with some PMD:
>>
>> Stack trace of thread 20680:
>> #0 0x0000559464396534 qede_set_mtu (ovs-vswitchd)
>> #1 0x0000559464323c41 rte_eth_dev_set_mtu (ovs-vswitchd)
>> #2 0x00005594645f5e85 dpdk_eth_dev_queue_setup (ovs-vswitchd)
>> #3 0x00005594645f8ae6 netdev_dpdk_reconfigure (ovs-vswitchd)
>> #4 0x000055946452225c reconfigure_datapath (ovs-vswitchd)
>> #5 0x0000559464522d07 do_add_port (ovs-vswitchd)
>> #6 0x0000559464522e8d dpif_netdev_port_add (ovs-vswitchd)
>> #7 0x0000559464528dde dpif_port_add (ovs-vswitchd)
>> #8 0x00005594644dc0e0 port_add (ovs-vswitchd)
>> #9 0x00005594644d2ab1 ofproto_port_add (ovs-vswitchd)
>> #10 0x00005594644c0a85 bridge_add_ports__ (ovs-vswitchd)
>> #11 0x00005594644c26e8 bridge_reconfigure (ovs-vswitchd)
>> #12 0x00005594644c5c49 bridge_run (ovs-vswitchd)
>> #13 0x00005594642d4155 main (ovs-vswitchd)
>> #14 0x00007f0e1444bc05 __libc_start_main (libc.so.6)
>> #15 0x00005594642d8328 _start (ovs-vswitchd)
>>
>> A possible solution could be to move the first call to
>> rte_eth_dev_set_mtu() just after the device start instead of
>> dpdk_eth_dev_queue_setup() which, by the way, set the MTU multiple times
>> as the call to rte_eth_dev_set_mtu() was in a loop.
>>
>> CC: Mark Kavanagh <[email protected]>
>> Fixes: 67fe6d635193 ("netdev-dpdk: use rte_eth_dev_set_mtu.")
>> Signed-off-by: Matteo Croce <[email protected]>
>> ---
>> lib/netdev-dpdk.c | 14 +++++++-------
>> 1 file changed, 7 insertions(+), 7 deletions(-)
>>
>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index
>> 76e79be25..229aa4a76 100644
>> --- a/lib/netdev-dpdk.c
>> +++ b/lib/netdev-dpdk.c
>> @@ -750,13 +750,6 @@ dpdk_eth_dev_queue_setup(struct netdev_dpdk *dev, int
>> n_rxq, int n_txq)
>> break;
>> }
>>
>> - diag = rte_eth_dev_set_mtu(dev->port_id, dev->mtu);
>> - if (diag) {
>> - VLOG_ERR("Interface %s MTU (%d) setup error: %s",
>> - dev->up.name, dev->mtu, rte_strerror(-diag));
>> - break;
>> - }
>> -
>> for (i = 0; i < n_txq; i++) {
>> diag = rte_eth_tx_queue_setup(dev->port_id, i, dev->txq_size,
>> dev->socket_id, NULL); @@ -
>> 849,6 +842,13 @@ dpdk_eth_dev_init(struct netdev_dpdk *dev)
>> return -diag;
>> }
>>
>> + diag = rte_eth_dev_set_mtu(dev->port_id, dev->mtu);
>> + if (diag) {
>> + VLOG_ERR("Interface %s MTU (%d) setup error: %s",
>> + dev->up.name, dev->mtu, rte_strerror(-diag));
>> + return -diag;
>> + }
>> +
>
> In my testing I didn't see any issues here, but would like to flag it to our
> MTU Guru (Mark K).
>
> Any opinion on this? From the API description it looks like it is ok?
>
>
>> rte_eth_promiscuous_enable(dev->port_id);
>> rte_eth_allmulticast_enable(dev->port_id);
>>
>> --
>> 2.13.6
>>
>> _______________________________________________
>> dev mailing list
>> [email protected]
>> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
The issue only arises with the qede PMD and 67fe6d635193
("netdev-dpdk: use rte_eth_dev_set_mtu.")
Regards,
--
Matteo Croce
per aspera ad upstream
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