17. ThunderX NICVF Poll Mode Driver

17.4.1. Config File Options

The following options can be modified in the config file. Please note that enabling debugging options may affect system performance.

• CONFIG_RTE_LIBRTE_THUNDERX_NICVF_PMD (default n)

  By default it is enabled only for defconfig_arm64-thunderx-* config. Toggle compilation of the librte_pmd_thunderx_nicvf driver.

• CONFIG_RTE_LIBRTE_THUNDERX_NICVF_DEBUG_INIT (default n)

  Toggle display of initialization related messages.

• CONFIG_RTE_LIBRTE_THUNDERX_NICVF_DEBUG_RX (default n)

  Toggle display of receive fast path run-time message

• CONFIG_RTE_LIBRTE_THUNDERX_NICVF_DEBUG_TX (default n)

  Toggle display of transmit fast path run-time message

• CONFIG_RTE_LIBRTE_THUNDERX_NICVF_DEBUG_DRIVER (default n)

  Toggle display of generic debugging messages

• CONFIG_RTE_LIBRTE_THUNDERX_NICVF_DEBUG_MBOX (default n)

  Toggle display of PF mailbox related run-time check messages

17.4.2. Driver Compilation

To compile the ThunderX NICVF PMD for Linux arm64 gcc target, run the following “make” command:

cd <DPDK-source-directory>
make config T=arm64-thunderx-linuxapp-gcc install

17.5.1. Running testpmd

This section demonstrates how to launch testpmd with ThunderX NIC VF device managed by librte_pmd_thunderx_nicvf in the Linux operating system.

1. Load vfio-pci driver:

   modprobe vfio-pci
   

2. Enable VFIO-NOIOMMU mode (optional):

   echo 1 > /sys/module/vfio/parameters/enable_unsafe_noiommu_mode
   

   Note

   VFIO-NOIOMMU is required only when running in VM context and should not be enabled otherwise. See also SR-IOV: Prerequisites and sample Application Notes.

3. Bind the ThunderX NIC VF device to vfio-pci loaded in the previous step:

   Setup VFIO permissions for regular users and then bind to vfio-pci:

   ./tools/dpdk-devbind.py --bind vfio-pci 0002:01:00.2
   

4. Start testpmd with basic parameters:

   ./arm64-thunderx-linuxapp-gcc/app/testpmd -c 0xf -n 4 -w 0002:01:00.2 \
     -- -i --disable-hw-vlan-filter --crc-strip --no-flush-rx \
     --port-topology=loop
   

   Example output:

   ...
   
   PMD: rte_nicvf_pmd_init(): librte_pmd_thunderx nicvf version 1.0
   
   ...
   EAL:   probe driver: 177d:11 rte_nicvf_pmd
   EAL:   using IOMMU type 1 (Type 1)
   EAL:   PCI memory mapped at 0x3ffade50000
   EAL: Trying to map BAR 4 that contains the MSI-X table.
        Trying offsets: 0x40000000000:0x0000, 0x10000:0x1f0000
   EAL:   PCI memory mapped at 0x3ffadc60000
   PMD: nicvf_eth_dev_init(): nicvf: device (177d:11) 2:1:0:2
   PMD: nicvf_eth_dev_init(): node=0 vf=1 mode=tns-bypass sqs=false
        loopback_supported=true
   PMD: nicvf_eth_dev_init(): Port 0 (177d:11) mac=a6:c6:d9:17:78:01
   Interactive-mode selected
   Configuring Port 0 (socket 0)
   ...
   
   PMD: nicvf_dev_configure(): Configured ethdev port0 hwcap=0x0
   Port 0: A6:C6:D9:17:78:01
   Checking link statuses...
   Port 0 Link Up - speed 10000 Mbps - full-duplex
   Done
   testpmd>
   

17.5.2. SR-IOV: Prerequisites and sample Application Notes

Current ThunderX NIC PF/VF kernel modules maps each physical Ethernet port automatically to virtual function (VF) and presented them as PCIe-like SR-IOV device. This section provides instructions to configure SR-IOV with Linux OS.

1. Verify PF devices capabilities using lspci:

   lspci -vvv
   

   Example output:

   0002:01:00.0 Ethernet controller: Cavium Networks Device a01e (rev 01)
           ...
           Capabilities: [100 v1] Alternative Routing-ID Interpretation (ARI)
           ...
           Capabilities: [180 v1] Single Root I/O Virtualization (SR-IOV)
           ...
           Kernel driver in use: thunder-nic
           ...
   

   Note

   Unless thunder-nic driver is in use make sure your kernel config includes CONFIG_THUNDER_NIC_PF setting.

2. Verify VF devices capabilities and drivers using lspci:

   lspci -vvv
   

   Example output:

   0002:01:00.1 Ethernet controller: Cavium Networks Device 0011 (rev 01)
           ...
           Capabilities: [100 v1] Alternative Routing-ID Interpretation (ARI)
           ...
           Kernel driver in use: thunder-nicvf
           ...
   
   0002:01:00.2 Ethernet controller: Cavium Networks Device 0011 (rev 01)
           ...
           Capabilities: [100 v1] Alternative Routing-ID Interpretation (ARI)
           ...
           Kernel driver in use: thunder-nicvf
           ...
   

   Note

   Unless thunder-nicvf driver is in use make sure your kernel config includes CONFIG_THUNDER_NIC_VF setting.

3. Verify PF/VF bind using dpdk-devbind.py:

   ./tools/dpdk-devbind.py --status
   

   Example output:

   ...
   0002:01:00.0 'Device a01e' if= drv=thunder-nic unused=vfio-pci
   0002:01:00.1 'Device 0011' if=eth0 drv=thunder-nicvf unused=vfio-pci
   0002:01:00.2 'Device 0011' if=eth1 drv=thunder-nicvf unused=vfio-pci
   ...
   

4. Load vfio-pci driver:

   modprobe vfio-pci
   

5. Bind VF devices to vfio-pci using dpdk-devbind.py:

   ./tools/dpdk-devbind.py --bind vfio-pci 0002:01:00.1
   ./tools/dpdk-devbind.py --bind vfio-pci 0002:01:00.2
   

6. Verify VF bind using dpdk-devbind.py:

   ./tools/dpdk-devbind.py --status
   

   Example output:

   ...
   0002:01:00.1 'Device 0011' drv=vfio-pci unused=
   0002:01:00.2 'Device 0011' drv=vfio-pci unused=
   ...
   0002:01:00.0 'Device a01e' if= drv=thunder-nic unused=vfio-pci
   ...
   

7. Pass VF device to VM context (PCIe Passthrough):

   The VF devices may be passed through to the guest VM using qemu or virt-manager or virsh etc. librte_pmd_thunderx_nicvf or thunder-nicvf should be used to bind the VF devices in the guest VM in VFIO-NOIOMMU mode.

   Example qemu guest launch command:

   sudo qemu-system-aarch64 -name vm1 \
   -machine virt,gic_version=3,accel=kvm,usb=off \
   -cpu host -m 4096 \
   -smp 4,sockets=1,cores=8,threads=1 \
   -nographic -nodefaults \
   -kernel <kernel image> \
   -append "root=/dev/vda console=ttyAMA0 rw hugepagesz=512M hugepages=3" \
   -device vfio-pci,host=0002:01:00.1 \
   -drive file=<rootfs.ext3>,if=none,id=disk1,format=raw  \
   -device virtio-blk-device,scsi=off,drive=disk1,id=virtio-disk1,bootindex=1 \
   -netdev tap,id=net0,ifname=tap0,script=/etc/qemu-ifup_thunder \
   -device virtio-net-device,netdev=net0 \
   -serial stdio \
   -mem-path /dev/huge
   

8. Refer to section Running testpmd for instruction how to launch testpmd application.

17.6.1. CRC striping

The ThunderX SoC family NICs strip the CRC for every packets coming into the host interface. So, CRC will be stripped even when the rxmode.hw_strip_crc member is set to 0 in struct rte_eth_conf.

17.6.2. Maximum packet length

The ThunderX SoC family NICs support a maximum of a 9K jumbo frame. The value is fixed and cannot be changed. So, even when the rxmode.max_rx_pkt_len member of struct rte_eth_conf is set to a value lower than 9200, frames up to 9200 bytes can still reach the host interface.

17.6.3. Maximum packet segments

The ThunderX SoC family NICs support up to 12 segments per packet when working in scatter/gather mode. So, setting MTU will result with EINVAL when the frame size does not fit in the maximum number of segments.

17.6.4. Limited VFs

The ThunderX SoC family NICs has 128VFs and each VF has 8/8 queues for RX/TX respectively. Current driver implementation has one to one mapping between physical port and VF hence only limited VFs can be used.