Comment 0 for bug 1572347

On an amd64 system with a 1Gb NIC, I can examine /sys/class/net/<DEVICE> for various bits of data. In this case, we need link speed.

For example:

bladernr@galactica:~/Datacenters/Home$ cat /sys/class/net/enp2s0/speed
1000

However, on my z/VM instance of Xenial on s390, the reported speed is WAY below what it actually is:
hwe@hwe-zvm1:/sys/class/net/enc600$ cat speed
10

iperf confirms that this virtual device is actually functioning at 1Gb speeds. This is causing failures in the cert networking tests that probe for reported link speed and then compare that to reported maximum speed.

On a zKVM instance of Xenial, this is even worse as I am completely unable to examine /sys/class/net/<DEVICE>/speed at all:

hwe@s1lp9g003:~$ cat /sys/class/net/eth0/speed
cat: /sys/class/net/eth0/speed: Invalid argument
hwe@s1lp9g003:/sys/class/net/eth0$ ll
total 0
drwxr-xr-x 5 root root 0 Apr 19 20:02 ./
drwxr-xr-x 3 root root 0 Apr 19 20:02 ../
-r--r--r-- 1 root root 4096 Apr 19 20:02 addr_assign_type
-r--r--r-- 1 root root 4096 Apr 19 20:02 addr_len
-r--r--r-- 1 root root 4096 Apr 19 20:02 address
-r--r--r-- 1 root root 4096 Apr 19 20:02 broadcast
-rw-r--r-- 1 root root 4096 Apr 19 20:02 carrier
-r--r--r-- 1 root root 4096 Apr 19 20:02 carrier_changes
-r--r--r-- 1 root root 4096 Apr 19 20:02 dev_id
-r--r--r-- 1 root root 4096 Apr 19 20:02 dev_port
lrwxrwxrwx 1 root root 0 Apr 19 20:02 device -> ../../../virtio1/
-r--r--r-- 1 root root 4096 Apr 19 20:02 dormant
-r--r--r-- 1 root root 4096 Apr 19 20:02 duplex
-rw-r--r-- 1 root root 4096 Apr 19 20:02 flags
-rw-r--r-- 1 root root 4096 Apr 19 20:02 gro_flush_timeout
-rw-r--r-- 1 root root 4096 Apr 19 20:02 ifalias
-r--r--r-- 1 root root 4096 Apr 19 20:02 ifindex
-r--r--r-- 1 root root 4096 Apr 19 20:02 iflink
-r--r--r-- 1 root root 4096 Apr 19 20:02 link_mode
-rw-r--r-- 1 root root 4096 Apr 19 20:02 mtu
-r--r--r-- 1 root root 4096 Apr 19 20:02 name_assign_type
-rw-r--r-- 1 root root 4096 Apr 19 20:02 netdev_group
-r--r--r-- 1 root root 4096 Apr 19 20:02 operstate
-r--r--r-- 1 root root 4096 Apr 19 20:02 phys_port_id
-r--r--r-- 1 root root 4096 Apr 19 20:02 phys_port_name
-r--r--r-- 1 root root 4096 Apr 19 20:02 phys_switch_id
drwxr-xr-x 2 root root 0 Apr 19 20:02 power/
-rw-r--r-- 1 root root 4096 Apr 19 20:02 proto_down
drwxr-xr-x 4 root root 0 Apr 19 20:02 queues/
-r--r--r-- 1 root root 4096 Apr 19 20:02 speed
drwxr-xr-x 2 root root 0 Apr 19 20:02 statistics/
lrwxrwxrwx 1 root root 0 Apr 19 20:02 subsystem -> ../../../../../../../class/net/
-rw-r--r-- 1 root root 4096 Apr 19 20:02 tx_queue_len
-r--r--r-- 1 root root 4096 Apr 19 20:02 type
-rw-r--r-- 1 root root 4096 Apr 19 20:02 uevent
hwe@s1lp9g003:/sys/class/net/eth0$ sudo cat speed
cat: speed: Invalid argument
hwe@s1lp9g003:/sys/class/net/eth0$ sudo su
root@s1lp9g003:/sys/devices/css0/0.0.0001/0.0.0001/virtio1/net/eth0# cat speed
cat: speed: Invalid argument

So on zKVM even root is not able to view the current link speed.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-18-generic 4.4.0-18.34
ProcVersionSignature: Ubuntu 4.4.0-18.34-generic 4.4.6
Uname: Linux 4.4.0-18-generic s390x
AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 2: ls: cannot access '/dev/snd/': No such file or directory
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.1-0ubuntu2
Architecture: s390x
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Date: Tue Apr 19 22:58:52 2016
HibernationDevice: RESUME=UUID=7ddabd20-1d15-492c-bcd5-ec2dbb16b777
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lspci:

Lsusb: Error: command ['lsusb'] failed with exit code 1:
PciMultimedia:

ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: Error: [Errno 2] No such file or directory: '/proc/fb'
ProcKernelCmdLine: root=UUID=b732515f-dacf-4007-85af-a27b5bf48fdf crashkernel=196M BOOT_IMAGE=0
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-18-generic N/A
 linux-backports-modules-4.4.0-18-generic N/A
 linux-firmware 1.157
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)