The Netvsc PMD got broken on DPDK 19.08 by a bad patch in Mellanox driver. On a simple setup with SRIOV enabled and using netvsc PMD with the testpmd. It worked in 19.05 and does not work with current master.
The probe code gets stuck because netvsc PMD sends a request to host and never sees a response. # ./build/app/testpmd --log-level='pmd.net.netvsc.*:debug' -l 0-3 -n 4 -- --rxq=4 --txq=4 -i EAL: Detected 4 lcore(s) EAL: Detected 1 NUMA nodes EAL: Multi-process socket /var/run/dpdk/rte/mp_socket EAL: Probing VFIO support... EAL: WARNING: cpu flags constant_tsc=yes nonstop_tsc=no -> using unreliable clock cycles ! EAL: PCI device 935f:00:02.0 on NUMA socket 0 EAL: probe driver: 15b3:1014 net_mlx5 net_mlx5: can not get IB device "mlx5_0" ports number eth_hn_probe(): >> eth_hn_dev_init(): >> hn_nvs_init(): NVS version 0x60001, NDIS version 6.30 hn_nvs_conn_rxbuf(): connect rxbuff va=0x2200402000 gpad=0xe1e2d hn_nvs_conn_rxbuf(): receive buffer size 1728 count 18811 hn_nvs_conn_chim(): connect send buf va=0x2202302000 gpad=0xe1e2e hn_nvs_conn_chim(): send buffer 16777216 section size:6144, count:2730 (hung) The problem does not occur without SRIOV (or if MLX driver is not compiled in). Doing bisect the problem is caused by: commit 69c06d0e357ed0064b498d510d169603cf7308cd Author: Yongseok Koh <ys...@mellanox.com> Date: Thu May 2 02:07:54 2019 -0700 net/mlx: support IOVA VA mode Set RTE_PCI_DRV_IOVA_AS_VA to driver's drv_flags as device's IOMMU takes virtual address. Cc: sta...@dpdk.org Signed-off-by: Yongseok Koh <ys...@mellanox.com> Acked-by: Shahaf Shuler <shah...@mellanox.com> Please either revert or fix this patch ASAP.