sr-iov support: /dev/vfio/vfio missing from /etc/libvirt/qemu.conf

[JuanJo Ciarlante]

/dev/vfio/vfio needs to be added to /etc/libvirt/qemu.conf,
else sr-iov VMs fail with:

* /var/log/nova/nova-compute.log

libvirtError: internal error: process exited while connecting to monitor:
qemu-system-x86_64: -device vfio-pci,host=81:1f.5,id=hostdev0,bus=pci.0,addr=0x4:
vfio: failed to open /dev/vfio/vfio: Operation not permitted

* /var/log/libvirt/qemu/instance-*.log:

qemu-system-x86_64: -device vfio-pci,host=81:1f.5,id=hostdev0,bus=pci.0,addr=0x4: vfio: failed to open /dev/vfio/vfio: Operation not permitted
qemu-system-x86_64: -device vfio-pci,host=81:1f.5,id=hostdev0,bus=pci.0,addr=0x4: vfio: failed to setup container for group 117
qemu-system-x86_64: -device vfio-pci,host=81:1f.5,id=hostdev0,bus=pci.0,addr=0x4: vfio: failed to get group 117
qemu-system-x86_64: -device vfio-pci,host=81:1f.5,id=hostdev0,bus=pci.0,addr=0x4: Device initialization failed

[Nobuto Murata (nobuto)]

I found this: https://review.openstack.org/#/c/334334/
> Patch Set 2: Workflow-1
> I'm not convinced this is the correct fix - this might be a bug in libvirt itself.

Is there a bug number linked with libvirt to track the issue?

[James Page (james-page)]

Nobuto

I'll tie this into the testing I'm doing for SR-IOV alongside the charm enablement work.

Its possible it might be a libvirt bug but we don't have a reliable reproducer atm.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/427799

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/427799
Committed: https://git.openstack.org/cgit/openstack/charm-nova-compute/commit/?id=ab33eeb2ee670ff869d1c629f40146dd184c585e
Submitter: Jenkins
Branch: master

commit ab33eeb2ee670ff869d1c629f40146dd184c585e
Author: James Page <email address hidden>
Date: Wed Feb 1 16:28:20 2017 +0000

    Add /dev/vfio/vfio to cgroup permissions

    Ensure that qemu instances can access /dev/vfio/vfio for connection
    to SR-IOV devices.

    Change-Id: Ib31e7a00eaf5a32e343a723de21866be2f0efc27
    Closes-Bug: 1628677