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Bug 1862726

Summary: ppc64le guest does not detect hotplugged network interface
Product: Red Hat Enterprise Linux 8 Reporter: Carlos Goncalves <cgoncalves>
Component: kernelAssignee: Virtualization Maintenance <virt-maint>
kernel sub component: KVM QA Contact: Yihuang Yu <yihyu>
Status: CLOSED NOTABUG Docs Contact:
Severity: high    
Priority: high CC: dgibson, jinzhao, juzhang, qzhang, virt-maint, yihyu
Version: 8.2Keywords: Triaged
Target Milestone: rcFlags: pm-rhel: mirror+
Target Release: 8.3   
Hardware: ppc64le   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2020-08-03 09:08:14 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Carlos Goncalves 2020-08-01 21:25:35 UTC 
ppc64le KVM (RHEL 8.2) does not detect hotplugged network interface. However, there is an RTAS event in the journal when it was hot-plugged.

Aug 01 20:52:07 amphora-e17ca7e5-913c-4d4e-9db2-70fe36055d72.novalocal kernel: RTAS: event: 1, Type: Hotplug Event, Severity: 1                                                                                                               
Aug 01 20:52:15 amphora-e17ca7e5-913c-4d4e-9db2-70fe36055d72.novalocal amphora-agent[913]: 2020-08-01 20:52:15.264 990 INFO octavia.amphorae.backends.agent.api_server.plug [-] Unable to find interface with MAC: fa:16:3e:78:dc:24, rescann$


[cgoncalves@ibm-p9wr-07 devstack]$ sudo virsh domiflist 1
 Interface        Type     Source   Model    MAC
----------------------------------------------------------------
 tap08c5bd61-49   bridge   br-int   virtio   fa:16:3e:18:be:89
 tapff281112-bc   bridge   br-int   virtio   fa:16:3e:78:dc:24       <-----------------


Upon rebooting the guest, the attached virtual network interface is recognized by the guest OS:

[cloud-user@amphora-e17ca7e5-913c-4d4e-9db2-70fe36055d72 ~]$ sudo ip netns exec amphora-haproxy ip a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc fq_codel state UP group default qlen 1000    <----------------
    link/ether fa:16:3e:78:dc:24 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.33/26 brd 10.0.0.63 scope global eth1
       valid_lft forever preferred_lft forever
    inet 10.0.0.11/26 brd 10.0.0.63 scope global secondary eth1:0
       valid_lft forever preferred_lft forever


[cloud-user@amphora-e17ca7e5-913c-4d4e-9db2-70fe36055d72 ~]$ rpm -qa | egrep 'kernel|systemd'
kernel-core-4.18.0-193.14.2.el8_2.ppc64le
systemd-239-30.el8_2.ppc64le
systemd-pam-239-30.el8_2.ppc64le
systemd-udev-239-30.el8_2.ppc64le
systemd-libs-239-30.el8_2.ppc64le
kernel-modules-4.18.0-193.14.2.el8_2.ppc64le
kernel-4.18.0-193.14.2.el8_2.ppc64le
rpm-plugin-systemd-inhibit-4.14.2-37.el8.ppc64le
Comment 1 David Gibson 2020-08-03 04:34:47 UTC 
Carlos,

Is your guest running rtas_errd, which is necessary to process hotplug events?
Comment 2 Carlos Goncalves 2020-08-03 09:08:14 UTC 
David, thanks for the prompt reply!

Indeed, rtas_errd was missing. I installed package ppc64-diag in our pp64le Red Hat OpenStack Octavia KVM image and now see systemd rtas_errd.service running and the hotplugged network interface visible to the guest.