We are missing some comments about this proposal. 24/04/2017 16:50, Andriy Berestovskyy: > Hey Thomas, > > On 21.04.2017 00:25, Thomas Monjalon wrote: > >> The hardware is different, there is not much we can do about it. > > > > We can return an error if the max_rx_pkt_len cannot be set in the NIC. > > Yes, we pass the value to the PMD, which might check the value and > return an error. > > >> Nevertheless, we can fix the false comment and have a default for the > >> jumbos, which is beneficial for the apps/examples. > > > > The examples are using a hardcoded value, so they need to be fixed > > anyway. > > We might change the hardcoded values to zeros once the patch is in. This > will make the examples a bit more clear. > > > > This ethdev patch is about a behaviour change of the API. > > The behaviour was not documented, so IMO it is not an issue. > > > > It is about considering 0 as a request for default value > > and return an error if a value cannot be set. > > Right. > > > > It will require more agreements and changes in the drivers > > for returning an error where appropriate. > > IMO the changes are transparent for the PMDs (please see below), but it > might affect some applications. Here is the change in API behaviour: > > Before the patch: > jumbo == 0, max_rx_pkt_len == 0, RESULT: max_rx_pkt_len = ETHER_MAX_LEN > jumbo == 0, max_rx_pkt_len == 10, RESULT: max_rx_pkt_len = ETHER_MAX_LEN > jumbo == 0, max_rx_pkt_len == 1200, RESULT: max_rx_pkt_len = 1200 > jumbo == 0, max_rx_pkt_len == 9K, RESULT: max_rx_pkt_len = ETHER_MAX_LEN > > jumbo == 1, max_rx_pkt_len == 0, RESULT: ERROR > jumbo == 1, max_rx_pkt_len == 10, RESULT: ERROR > jumbo == 1, max_rx_pkt_len == 1200, RESULT: max_rx_pkt_len = 1200 > jumbo == 1, max_rx_pkt_len == 9K, RESULT: ERROR or max_rx_pkt_len = 9K > jumbo == 1, max_rx_pkt_len == 90K, RESULT: ERROR > > > After the patch: > jumbo == 0, max_rx_pkt_len == 0, RESULT: max_rx_pkt_len = ETHER_MAX_LEN > jumbo == 0, max_rx_pkt_len == 10, RESULT: ERROR (changed) > jumbo == 0, max_rx_pkt_len == 1200, RESULT: max_rx_pkt_len = 1200 > jumbo == 0, max_rx_pkt_len == 9K, RESULT: ERROR (changed) > > jumbo == 1, max_rx_pkt_len == 0, RESULT: max_rx_pkt_len = dev_info() > jumbo == 1, max_rx_pkt_len == 10, RESULT: ERROR > jumbo == 1, max_rx_pkt_len == 1200, RESULT: max_rx_pkt_len = 1200 > jumbo == 1, max_rx_pkt_len == 9K, RESULT: ERROR or max_rx_pkt_len = 9K > jumbo == 1, max_rx_pkt_len == 90K, RESULT: ERROR > > Only the apps which requested too small or too big normal frames will be > affected. In most cases it will be rather an error in the app... > > > Also I have looked through all the PMDs to confirm they are not > affected. Here is the summary: > > af_packet > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = ETH_FRAME_LEN (1514) > > ark > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = ETH_FRAME_LEN (16K - 128) > > avp > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = avp->max_rx_pkt_len > rx_queue_setup() uses max_rx_pkt_len for scattering > > bnx2x > configure() uses max_rx_pkt_len to set internal mtu > info() returns max_rx_pktlen = BNX2X_MAX_RX_PKT_LEN (15872) > > bnxt > configure() uses max_rx_pkt_len to set internal mtu > info() returns max_rx_pktlen = BNXT_MAX_MTU + ETHER_HDR_LEN + > ETHER_CRC_LEN + VLAN_TAG_SIZE (9000 + 14 + 4 + 4) > > bonding > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = internals->candidate_max_rx_pktlen or > ETHER_MAX_JUMBO_FRAME_LEN (0x3F00) > > cxgbe > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = CXGBE_MAX_RX_PKTLEN (9000 + 14 + 4) > rx_queue_setup() checks max_rx_pkt_len boundaries > > dpaa2 > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = DPAA2_MAX_RX_PKT_LEN (10240) > > e1000 (em) > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = em_get_max_pktlen() (0x2412, 0x1000, > 1518, 0x3f00, depends on model) > > e1000 (igb) > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = 0x3fff > start() writes max_rx_pkt_len to HW for jumbo frames only > start() uses max_rx_pkt_len for scattering > > ena > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = adapter->max_mtu > start() checks max_rx_pkt_len boundaries > > enic > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = enic->max_mtu + 14 + 4 > > fm10k > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = FM10K_MAX_PKT_SIZE (15 * 1024) > start() uses max_rx_pkt_len for scattering > > i40e > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = I40E_FRAME_SIZE_MAX (9728) > rx_queue_config() checks max_rx_pkt_len boundaries > > ixgbe > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = 15872 (9728 for vf) > start() writes max_rx_pkt_len to HW for jumbo frames only > start() uses max_rx_pkt_len for scattering > > kni > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = UINT32_MAX > > liquidio > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = LIO_MAX_RX_PKTLEN (64K) > start() checks max_rx_pkt_len boundaries > > mlx4 > configure() uses max_rx_pkt_len for scattering > info() returns max_rx_pktlen = 65536 > > mlx5 > configure() uses max_rx_pkt_len for scattering > info() returns max_rx_pktlen = 65536 > > nfp > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = hw->mtu > > null > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = (uint32_t)-1 > > pcap > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = (uint32_t)-1 > > qede > configure() uses max_rx_pkt_len for scattering + internal data > info() returns max_rx_pktlen = ETH_TX_MAX_NON_LSO_PKT_LEN (9700 - 4 - 4 > - 12 - 8) > > ring > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = (uint32_t)-1 > > sfc > configure() uses max_rx_pkt_len to set internal data > info() returns max_rx_pktlen = EFX_MAC_PDU_MAX (9202 + 14 + 4 + 4 + 16) > > szedata2 > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = (uint32_t)-1 > > tap > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = ETHER_MAX_VLAN_FRAME_LEN (1518 + 4) > > thunderx > configure() uses max_rx_pkt_len for scattering + sets internal mtu > info() returns max_rx_pktlen = NIC_HW_MAX_FRS (9200) > > vhost > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = (uint32_t)-1 > > virtio > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = VIRTIO_MAX_RX_PKTLEN (9728U) > > vmxnet3 > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = 16384; > > xenvirt > configure() does not use max_rx_pkt_len > info() returns max_rx_pktlen = 2048 > > > Regards, > Andriy >
