Hi Tao, On 23/05/2016 14:39, DING, TAO wrote: > Hello dpdk dev, > > Do you know if the vfio_pci can be bind to network interface from within > RedHat virtual machine ? I read the doc that igb_uio should not be used ; it > is not stable. (http://people.redhat.com/~pmatilai/dpdk-guide/index.html) > however I cannot use vfio_pci driver from inside VM. > > Currently I am working on a project that migrating a network package capture > application into virtual machines so that it can be hosted on cloud. My > intent is using SR-IOR to ensure the data sending from physical NIC to vNIC > in line speed; using DPDK inside VM to read data from vNIC to get good > performance because the libpcap does not perform well inside VM. > > Following dpdk instruction, I was able to set up the SR-IOV and bind the > vfio_pci to virtual Function on the host. Once the VM starts, the Virtual > Functions bind to vfio-pci automatically on the host. . The following is the > output from host. > Option: 22 > > > Network devices using DPDK-compatible driver > ============================================ > 0000:04:10.4 'X540 Ethernet Controller Virtual Function' drv=vfio-pci unused= > 0000:04:10.6 'X540 Ethernet Controller Virtual Function' drv=vfio-pci unused= > 0000:04:11.4 'X540 Ethernet Controller Virtual Function' drv=vfio-pci unused= > 0000:04:11.6 'X540 Ethernet Controller Virtual Function' drv=vfio-pci unused= > > Network devices using kernel driver > =================================== > 0000:01:00.0 'NetXtreme BCM5720 Gigabit Ethernet PCIe' if=em1 drv=tg3 > unused=vfio-pci > 0000:01:00.1 'NetXtreme BCM5720 Gigabit Ethernet PCIe' if=em2 drv=tg3 > unused=vfio-pci > 0000:02:00.0 'NetXtreme BCM5720 Gigabit Ethernet PCIe' if=em3 drv=tg3 > unused=vfio-pci > 0000:02:00.1 'NetXtreme BCM5720 Gigabit Ethernet PCIe' if=em4 drv=tg3 > unused=vfio-pci > 0000:04:00.0 'Ethernet Controller 10-Gigabit X540-AT2' if=p3p1 drv=ixgbe > unused=vfio-pci *Active* > 0000:04:00.1 'Ethernet Controller 10-Gigabit X540-AT2' if=p3p2 drv=ixgbe > unused=vfio-pci > 0000:04:10.0 'X540 Ethernet Controller Virtual Function' if=p3p1_0 > drv=ixgbevf unused=vfio-pci > 0000:04:10.2 'X540 Ethernet Controller Virtual Function' if=p3p1_1 > drv=ixgbevf unused=vfio-pci > 0000:04:11.0 'X540 Ethernet Controller Virtual Function' if=p3p1_4 > drv=ixgbevf unused=vfio-pci > 0000:04:11.2 'X540 Ethernet Controller Virtual Function' if=p3p1_5 > drv=ixgbevf unused=vfio-pci > > I repeated the same set up within the VM which has 4 Virtual Functions > assigned to it, I could not successfully bind any of network devices to > vfio-pci. I followed different suggestion from the web , but no luck. > (however I was able to bind UIO driver to the network devices inside the VM) > One difference I noticed between VM and host is the outcome of IOMMU setting. > On the host, the /sys/kernel/iommu_groups/ is NOT empty , but on the VM , it > is empty. I rebooted VM several time. There's not luck.
AFAIK VFIO is not supported in a guest. https://lists.gnu.org/archive/html/qemu-devel/2015-11/msg04284.html So you are left with two options, VFIO no-IOMMU or igb_uio, none of them safe. If you have Linux kernel +4.5 and DPDK +16.04, you could use VFIO no-IOMMU inside the VM. Otherwise, you are left with igb_uio. IMHO the main difference is that igb_uio is an out-of-tree kernel module. Sergio
