Hello. I am having some trouble with getting various dpdk applications to work when using in a KVM VM. This happens with the 2nd port on a dual port adapter. What I have configured:
Haswell-ep host with KVM, 2 x i40e phys functions bound to vfio-pci, 2 functions assigned to KVM guest. In the guest, the i40 functions bound to uio_pci_generic, running testpmd with these options: --nb-cores=2 --nb-ports=2 --portmask=3 --interactive --auto-start. On another host directly connected to these adapters, I run pktgen on the 2 i40e ports. If I Tx on port1, I get packets back on port0. If I Tx on port0, no packets come back on port0. For some reason Tx simply does not happen on that second port. I have tried this test where there is no KVM, just using host, and it works as expected. I have also tried this test with ixgbe adapter in a KVM VM (I have both in same system), and it works as expected. I have also tried just using a bridge in the VM with i40e ports, with i40e module in use, and that also works as expected. So, I don't think this has anything to do with the adapters themselves, or cables, etc. Something is not working when using the KVM VM, I just don't know what it is. Here is xstats from testpmd: ###### NIC extended statistics for port 1 rx_packets: 134615456 tx_packets: 0 rx_bytes: 8615389184 tx_bytes: 0 tx_errors: 0 rx_missed_errors: 0 rx_crc_errors: 0 rx_bad_length_errors: 0 rx_errors: 0 alloc_rx_buff_failed: 0 fdir_match: 0 fdir_miss: 0 tx_flow_control_xon: 0 rx_flow_control_xon: 0 tx_flow_control_xoff: 0 rx_flow_control_xoff: 0 rx_queue_0_rx_packets: 0 rx_queue_0_rx_bytes: 0 tx_queue_0_tx_packets: 0 tx_queue_0_tx_bytes: 0 tx_queue_0_tx_errors: 0 I can't find any evidence of errors anywhere. It's just not doing Tx at all on that port. I have also tried using ptkgen in the VM, to manually send packets on that port, and again, no packets sent, but no errors either. Has anyone else tried 2 i40e ports in a KVM VM? Any ideas what could be going on here? Thanks, -Andrew
