So where does that 10Mb/s speed come from that ethtool is indicating? If the hypervisor is providing no indication of what the device is configured to provide, that's fine. BUT the kernel should not then be simply making stuff up to fill in data.
For example, this is on zKVM: Settings for eth0: Supported ports: [ ] Supported link modes: Not reported Supported pause frame use: No Supports auto-negotiation: No Advertised link modes: Not reported Advertised pause frame use: No Advertised auto-negotiation: No Speed: Unknown! Duplex: Unknown! (255) Port: Other PHYAD: 0 Transceiver: internal Auto-negotiation: off Cannot get wake-on-lan settings: Operation not permitted Link detected: yes Just like on z/VM, the virtio device has no idea what it is capable of nor what speed it is connected at. HOWEVER, it also doesn't lie about what speed it's connected at, it simply says "Unknown!" which is perfectly acceptable for these situations. This IS a valid kernel bug, as ethtool (and sysfs) are presenting patently false data. If the kernel doesn't know what speed it's connected at, that's perfectly find, I can live with that and even work with it. But flat out providing false data is wrong. On Mon, Feb 27, 2017 at 6:54 AM, Dimitri John Ledkov <[email protected]> wrote: > This is known issue/deficiency of the z/VM and the linux kernel. > > -- > You received this bug notification because you are subscribed to the bug > report. > https://bugs.launchpad.net/bugs/1667828 > > Title: > Network device on z/VM instance incorrectly reports line speed > > Status in linux-hwe package in Ubuntu: > Won't Fix > > Bug description: > Line speed is incorrectly reported on z/VM instances in /sys when > compared to what is claimed to be supported and advertised. > > for example, ethtool shows supported and advertised speeds of 1000Mb/s > but /sys is only indicating 10Mb/s. > > ubuntu@hwe0008:~$ ethtool enc600 > Settings for enc600: > Supported ports: [ TP ] > Supported link modes: 10baseT/Half 10baseT/Full > 100baseT/Half 100baseT/Full > 1000baseT/Half 1000baseT/Full > Supported pause frame use: No > Supports auto-negotiation: Yes > Advertised link modes: 10baseT/Half 10baseT/Full > 100baseT/Half 100baseT/Full > 1000baseT/Half 1000baseT/Full > Advertised pause frame use: No > Advertised auto-negotiation: Yes > Speed: 10Mb/s > Duplex: Full > Port: Twisted Pair > PHYAD: 0 > Transceiver: internal > Auto-negotiation: on > MDI-X: Unknown > Cannot get wake-on-lan settings: Operation not permitted > Link detected: yes > ubuntu@hwe0008:~$ cat /sys/class/net/enc600/speed > 10 > > I'm presuming this issue lies somewhere in the qeth driver: > P: /devices/qeth/0.0.0600/net/enc600 > E: DEVPATH=/devices/qeth/0.0.0600/net/enc600 > E: ID_NET_DRIVER=qeth_l2 > E: ID_NET_LINK_FILE=/lib/systemd/network/99-default.link > E: ID_NET_NAME=enc600 > E: ID_NET_NAME_MAC=enx02280b000004 > E: ID_NET_NAME_PATH=enc600 > E: ID_PATH=ccwgroup-0.0.0600 > E: ID_PATH_TAG=ccwgroup-0_0_0600 > E: IFINDEX=2 > E: INTERFACE=enc600 > E: SUBSYSTEM=net > E: SYSTEMD_ALIAS=/sys/subsystem/net/devices/enc600 > /sys/subsystem/net/devices/enc600 > E: TAGS=:systemd: > E: USEC_INITIALIZED=3784115 > > This is not an issue on my LPAR that uses the same drivers (but also > adds ctcm and zfcp, so maybe therein lies the difference in speed > reporting?) > > In any case, if the speeds cannot be correctly reported, they shouldn't be > reported at all. virtio handles this by setting speed to -1: > ubuntu@s1lp9g003:~$ cat /sys/class/net/eth0/speed > -1 > ubuntu@s1lp9g003:~$ ethtool eth0 > Settings for eth0: > Supported ports: [ ] > Supported link modes: Not reported > Supported pause frame use: No > Supports auto-negotiation: No > Advertised link modes: Not reported > Advertised pause frame use: No > Advertised auto-negotiation: No > Speed: Unknown! > Duplex: Unknown! (255) > Port: Other > PHYAD: 0 > Transceiver: internal > Auto-negotiation: off > Cannot get wake-on-lan settings: Operation not permitted > Link detected: yes > > That last example is a 1Gb/s interface on a z/KVM instance. > > ProblemType: Bug > DistroRelease: Ubuntu 16.04 > Package: linux-image-4.8.0-36-generic 4.8.0-36.36~16.04.1 > ProcVersionSignature: Ubuntu 4.8.0-36.36~16.04.1-generic 4.8.11 > Uname: Linux 4.8.0-36-generic s390x > ApportVersion: 2.20.1-0ubuntu2.5 > Architecture: s390x > Date: Fri Feb 24 17:08:59 2017 > ProcEnviron: > TERM=screen > PATH=(custom, no user) > XDG_RUNTIME_DIR=<set> > LANG=C > SHELL=/bin/bash > SourcePackage: linux-hwe > UpgradeStatus: No upgrade log present (probably fresh install) > > To manage notifications about this bug go to: > https://bugs.launchpad.net/ubuntu/+source/linux-hwe/+bug/1667828/+subscriptions > > Launchpad-Notification-Type: bug > Launchpad-Bug: distribution=ubuntu; sourcepackage=linux-hwe; component=main; > status=Won't Fix; importance=Undecided; assignee=None; > Launchpad-Bug-Tags: apport-bug s390x xenial > Launchpad-Bug-Information-Type: Public > Launchpad-Bug-Private: no > Launchpad-Bug-Security-Vulnerability: no > Launchpad-Bug-Commenters: bladernr xnox > Launchpad-Bug-Reporter: Jeff Lane (bladernr) > Launchpad-Bug-Modifier: Dimitri John Ledkov (xnox) > Launchpad-Message-Rationale: Subscriber > Launchpad-Message-For: bladernr -- "Entropy isn't what it used to be." Jeff Lane - Server Certification Lead, Warrior Poet, Biker, Lover of Pie Phone: 919-442-8649 Ubuntu Ham: W4KDH Freenode IRC: bladernr or bladernr_ gpg: 1024D/3A14B2DD 8C88 B076 0DD7 B404 1417 C466 4ABD 3635 3A14 B2DD -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1667828 Title: Network device on z/VM instance incorrectly reports line speed To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-hwe/+bug/1667828/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
