Hello Patrick, You can use rte_net_get_ptype function directly if packet_type is RTE_PTYPE_UNKNOWN. Whether the packet_type value is set is PMD/NIC dependent. i40e does this at the hardware level, virtio does this in software with rte_net_get_ptype and only in the specific case.
Best regards, Oleksandr On Sun, Dec 8, 2024 at 12:49 AM Patrick Mahan <ma...@mahan.org> wrote: > Hello All, > > Specifics: > DPDK Version: dpdk-stable-18.11.11 > Linux Kernel: 4.19.87 > Intel 64-bit architecture > > I am working on a code to support our socket based processes that need to > run on > our DPDK-enabled platform. I am using the virtio_user exception path > mechanism > to support this and initial tests seem fine. > > However, I am seeing issues when we receive the packet from the virtio > port, that > the packet_type field is not set. > > In my code, I have setup my physical PMD (i40e) as etherdev 0 and etherdev > 1 and > have setup the virtual side with virtio as etherdev 2 and etherdev 3. > > I am pairing this as etherdev 0 (physical) to etherdev 2 (virtio_user0) and > etherdev 1 (physical) to etherdev 3 (virtio_user1). > > I am using the EAL function `rte_eal_hotplug_add()` as suggested in the > documentation. > > I have added code in my dispatch function to generate a syslog(3) to print > the > contents of the packet_type field in the received mbuf. > > I then generate traffic to etherdev 1 from connected host and I am seeing > the > following: > > The inbound packet log shows - > > Dec 7 21:24:45 2024 pmahan-dpdk pktdaemon-eal[27614]: CPU 2 TID > 1140607382984128: [pktdaemon.NOTICE]: > pkt_dpdk::switch_q_pkts()[2][1=>3][Q=0]: > mbuf packet type is 0x00000091 > > So etherdev 1 packet (physical) has packet_type of 0x91 which translates to > RTE_PTYPE_L2_ETHER > RTE_PTYPE_L3_IPV4_EXT_UNKNOWN > > Which has been my experience for receiving packets from the physical PMD. > However, now that I have added the virtio port, the return packet does not > seemed > to have this value set - > > Dec 7 21:24:45 2024 pmahan-dpdk pktdaemon-eal[27614]: CPU 2 TID > 1140607382984128: [pktdaemon.NOTICE]: > pkt_dpdk::switch_q_pkts()[2][3=>1][Q=0]: > mbuf packet type is 0x00000000 > > I have looked into virtio PMD code and see that there is a function to > fill in > the packet type called `virtio_rx_offload()` but it is only called if the > hardware associated with the virtual queue supports offloading and then > only if > the `virtio_net_hdr` has no flags or its `gso_type` is not GSO_NONE. > > If I ignore the flags and just inject the packets directly, everything > seems to > work, but I have internal code that needs to know the basic ethernet type > as well > as the L3 options and I was hoping to rely on the packet_type of the mbuf > instead > of having to do packet groveling. > > Is this an "as designed" or am I missing something in the configuration? > > Thanks for any pointers, > > Patrick >
