Container support for TSN: time sync stopped when nic is pci-passthrogh into container

[XuYizhou]

Brief Description
-----------------
There is conflict between applying PCI passthrough for TSN Nic to run TSN application in container workload with STX current support for PTP: STX run p4p4l and phc2sys in host and the system time can be used by container directly while after applying PCI-pt, ptp4l and phc2sys cannot run in host.

Severity
--------

Steps to Reproduce
------------------
# create pod for TSN application
kubectl -f apply tsn_pod.yaml

# get PID of tsn contanier
PID=sudo docker inspect -f '{{.State.Pid}}' $container_id

# create network namespace entry for host
sudo ln -sf /proc/$PID/ns/net "/var/run/netns/tsn_pod_from_k8s"

# move tsn_nic(enp2s0) to container namespace
sudo ip link set enp2s0 netns tsn_pod_from_k8s

# see the tsn nic from internal of container
kubectl exec -it tsn_pod bash
(tsn_pod_Internal):/ ip a
.....
.....
.....
98: enp2s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 00:1b:21:00:00:00 brd ff:ff:ff:ff:ff:ff
.....
.....

Expected Behavior
------------------
host can still sync with PTP grandmaster clock outside/ or serve as grandmaster clock

Actual Behavior
----------------
sync stopped

Reproducibility
---------------
100% reproducible

System Configuration
--------------------
AIO node

Branch/Pull Time/Commit
-----------------------
iso version:20190607T142331Z

Last Pass
---------
None

Timestamp/Logs
--------------
content of tsn_pod.yaml
''''
apiVersion: v1
kind: Pod
metadata:
  name: tsn-pod-priviledge
spec:
  containers:
  - name: tsn-pod
    image: ubuntu:19.04
    args:
    - sleep
    - "1000000"
    securityContext:
      privileged: true
''''
Test Activity
-------------
Other?
[Sanity, Feature Testing, Regression Testing, Developer Testing, Evaluation, Other - Please specify]

Story Page: https://storyboard.openstack.org/#!/story/2005516

[Brent Rowsell (brent-rowsell)]

Which NIC interface are you moving to the container ?
This is not the right way to expose a PCI device to a container. Please refer to sriov-cni/device plugin.

[XuYizhou (xyz4berserk)]

The nic i moved into container is just for ptp sync.it didn't have any other role to play in stalingX.
Is sriov the only way for pci-passthrough in stx? The nic i used (Intel I210) didn't support sriov.

[XuYizhou (xyz4berserk)]

Since it's related to TSN application enable for container workload, suggest to postpone in STX3.0 version.

[Brent Rowsell (brent-rowsell)]

You would configure the interface through sysinv as pci-passthrough. You can expose to the container using the same mechanism as sr-iov.

There is no bug here, if changes are required it would need to be done under a feature to support TSN within a container.