[libvirt] About the vfio error when using SR-IOV

Mon Feb 22 15:23:16 UTC 2016

On 02/22/2016 04:29 AM, Xiao Ma (xima2) wrote:
> Hi, All
>
> I want to use the SR-IOV of intel 82576 NIC.
>
> I enabled IOMMU and VT-d and SR-IOV in BIOS.
> And enabled VT-d in kernel.
> The OS information is bellow:
> [root at host3 nova]# cat /etc/redhat-release
> CentOS Linux release 7.1.1503 (Core)
> [root at host3 nova]# uname -an
> Linux host3.localdomain 3.10.0-229.el7.x86_64 #1 SMP Fri Mar 6 11:36:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
> [root at host3 nova]# rpm -qa|grep qemu
> libvirt-daemon-driver-qemu-1.2.8-16.el7.x86_64
> qemu-kvm-1.5.3-86.el7.x86_64
> qemu-kvm-common-1.5.3-86.el7.x86_64
> ipxe-roms-qemu-20130517-6.gitc4bce43.el7.noarch
> qemu-img-1.5.3-86.el7.x86_64
> [root at host3 nova]# rpm -qa|grep libvirt
> libvirt-daemon-1.2.8-16.el7.x86_64
> libvirt-daemon-driver-nwfilter-1.2.8-16.el7.x86_64
> libvirt-python-1.2.8-7.el7.x86_64
> libvirt-daemon-driver-storage-1.2.8-16.el7.x86_64
> libvirt-daemon-driver-qemu-1.2.8-16.el7.x86_64
> libvirt-daemon-config-nwfilter-1.2.8-16.el7.x86_64
> libvirt-daemon-driver-secret-1.2.8-16.el7.x86_64
> libvirt-daemon-driver-interface-1.2.8-16.el7.x86_64
> libvirt-client-1.2.8-16.el7.x86_64
> libvirt-glib-0.1.7-3.el7.x86_64
> libvirt-daemon-driver-network-1.2.8-16.el7.x86_64
> libvirt-daemon-driver-nodedev-1.2.8-16.el7.x86_64
> libvirt-daemon-kvm-1.2.8-16.el7.x86_64
>
> And I can see the vf of the NIC after ‘ echo '7' > /sys/class/net/ens1f1/device/sriov_numvfs '
>
> [root at host3 VTS2.1-demo]# lspci |grep -i ethernet
> 08:00.0 Ethernet controller: QLogic Corp. 10GbE Converged Network Adapter (TCP/IP Networking) (rev 02)
> 08:00.1 Ethernet controller: QLogic Corp. 10GbE Converged Network Adapter (TCP/IP Networking) (rev 02)
> 0f:00.0 Ethernet controller: Intel Corporation 82576 Gigabit Network Connection (rev 01)
> 0f:00.1 Ethernet controller: Intel Corporation 82576 Gigabit Network Connection (rev 01)
> 10:10.1 Ethernet controller: Intel Corporation 82576 Virtual Function (rev 01)
> 10:10.3 Ethernet controller: Intel Corporation 82576 Virtual Function (rev 01)
> 10:10.5 Ethernet controller: Intel Corporation 82576 Virtual Function (rev 01)
> 10:10.7 Ethernet controller: Intel Corporation 82576 Virtual Function (rev 01)
> 10:11.1 Ethernet controller: Intel Corporation 82576 Virtual Function (rev 01)
> 10:11.3 Ethernet controller: Intel Corporation 82576 Virtual Function (rev 01)
> 10:11.5 Ethernet controller: Intel Corporation 82576 Virtual Function (rev 01)
>
>
> I configured the interface as bellow in XML:
>
>         <interface type="hostdev" managed="yes">
>         <mac address="fa:16:3e:f7:57:5f"/>
>         <source>
>             <address type="pci" domain="0x0000" bus="0x10" slot="0x10" function="0x3"/>
>         </source>
>         <vlan>
>             <tag id="1000"/>
>         </vlan>
>         </interface>
>
>
> But the error output when I boot one vm:
>
> [root at host3 VTS2.1-demo]# virsh create vtc.demo.xml
> error: Failed to create domain from vtc.demo.xml
> error: internal error: early end of file from monitor: possible problem:
> 2016-02-22T07:38:42.169035Z qemu-kvm: -device vfio-pci,host=10:10.3,id=hostdev0,bus=pci.0,addr=0x3: vfio: error, group 17 is not viable, please ensure all devices within the iommu_group are bound to their vfio bus driver.

One possible meaning is that vfio sees multiple devices in the same 
iommu group as the VF at 10:10.3 (in case there is some other possible 
cause, I'm Cc'ing Alex Williamson, the vfio author). You can check this 
by looking at the output of "virsh nodedev-dumpxml pci_0000_10_10_3" and 
look at the "iommuGroup" section - if there are multiple addresses 
listed there, then there are multiple devices in the same iommu group.

It could be that your particular chipset needs a "quirk" in the kernel 
to be told that the VFs really can be in separate iommu groups; without 
that quirk, all 14 VFs show up in the same iommu group, so the only way 
to assign one to a guest is to assign *all* of them to the same guest 
(or at least detach all of them from the VF driver and attach to 
vfio-pci, then only assign one of them to a guest while the others sit 
unused).

Since you're still running a 7.1 kernel, you may want to try updating to 
the latest available and see if that solves your problem.

If you have further questions, please include the output of "virsh 
nodedev-dumpxxml pci_0000_10_10_3" and full lspci output (among other 
things, that should tell us which chipset your machine uses).

> 2016-02-22T07:38:42.169215Z qemu-kvm: -device vfio-pci,host=10:10.3,id=hostdev0,bus=pci.0,addr=0x3: vfio: failed to get group 17
> 2016-02-22T07:38:42.169233Z qemu-kvm: -device vfio-pci,host=10:10.3,id=hostdev0,bus=pci.0,addr=0x3: Device initialization failed.
> 2016-02-22T07:38:42.169248Z qemu-kvm: -device vfio-pci,host=10:10.3,id=hostdev0,bus=pci.0,addr=0x3: Device 'vfio-pci' could not be initialized
>
>
> Could you please help to solve it?
>
> Looking forward for your reply.
>
> Thanks.
>
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