Ubuntu
linux package

s390x kernels are inconsistent for cloud stuff

Bug #1532886 reported by Dimitri John Ledkov
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Fix Released
Medium
Tim Gardner
Xenial
Fix Released
Medium
Tim Gardner

Bug Description

So to do virtual machine / cloudy stuff things in the kernel config, are not how one would expect them to be. Whilst investigating that I've went ahead to compare all our kernel configs.

amd64/config.common.amd64:CONFIG_VIRTIO_BLK=y
amd64/config.common.amd64:CONFIG_VIRTIO_NET=y
arm64/config.common.arm64:CONFIG_VIRTIO_BLK=y
arm64/config.common.arm64:CONFIG_VIRTIO_NET=y
armhf/config.common.armhf:CONFIG_VIRTIO_BLK=y
armhf/config.common.armhf:CONFIG_VIRTIO_NET=y
i386/config.common.i386:CONFIG_VIRTIO_BLK=y
i386/config.common.i386:CONFIG_VIRTIO_NET=y
powerpc/config.common.powerpc:CONFIG_VIRTIO_BLK=y
powerpc/config.common.powerpc:CONFIG_VIRTIO_NET=y
ppc64el/config.common.ppc64el:CONFIG_VIRTIO_BLK=y
ppc64el/config.common.ppc64el:CONFIG_VIRTIO_NET=y

but...
s390x/config.common.s390x:CONFIG_VIRTIO_BLK=m
s390x/config.common.s390x:CONFIG_VIRTIO_NET=m

It would make sense to set CONFIG_VIRTIO_BLK and _NET to "=y" on s390x.

Also:

amd64/config.common.amd64:CONFIG_KVM=m
arm64/config.common.arm64:CONFIG_KVM=y
armhf/config.common.armhf:CONFIG_KVM=y
i386/config.common.i386:CONFIG_KVM=m
powerpc/config.common.powerpc:CONFIG_KVM=y
ppc64el/config.common.ppc64el:CONFIG_KVM=y
s390x/config.common.s390x:CONFIG_KVM=m

Is a bit of mixed bag... x86+s390x have it as a module, yet arm*+powerpc* have it built in? Maybe all arches should be =y ?

another one:
Is there something special about ZLIB_DEFLATE on s390x?

amd64/config.common.amd64:CONFIG_ZLIB_DEFLATE=y
arm64/config.common.arm64:CONFIG_ZLIB_DEFLATE=y
armhf/config.common.armhf:CONFIG_ZLIB_DEFLATE=y
i386/config.common.i386:CONFIG_ZLIB_DEFLATE=y
powerpc/config.common.powerpc:CONFIG_ZLIB_DEFLATE=y
ppc64el/config.common.ppc64el:CONFIG_ZLIB_DEFLATE=y

s390x/config.common.s390x:CONFIG_ZLIB_DEFLATE=m

CVE References

Andy Whitcroft (apw)
Changed in linux (Ubuntu):
status: New → Confirmed
Revision history for this message
Tim Gardner (timg-tpi) wrote :

I'm not sure why CONFIG_ZLIB_DEFLATE is forced to =m for s390. Regardless, the whole lib directory is referenced in debian.master/control.d/generic.inclusion-list which gets zlib_deflate.ko into the linux-image-generic-*.deb package.

Changed in linux (Ubuntu Xenial):
assignee: nobody → Tim Gardner (timg-tpi)
status: Confirmed → Fix Committed
Revision history for this message
Dimitri John Ledkov (xnox) wrote :

I can confirm the proposed image works great for VIRTIO_BLK/_NET stuff. Thank you.

penalvch (penalvch)
Changed in linux (Ubuntu Xenial):
importance: Undecided → Medium
Revision history for this message
Dimitri John Ledkov (xnox) wrote :

I'm partially happy about this bug report now:

s390x/config.common.s390x:CONFIG_KVM=m

Is still a module rather than built-in on s390x. Unlike x86 there is only one implementation and it should be loaded by default. The trouble is, that it doesn't get autoloaded (and/or when libvirt-bin service tries to load it, it gets permission denied).

Please set CONFIG_KVM=y, as without that libvirt does not just work(tm)

Revision history for this message
Tim Gardner (timg-tpi) wrote :

Done. "UBUNTU: [Config] CONFIG_KVM=y for s390x"

Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package linux - 4.3.0-6.17

---------------
linux (4.3.0-6.17) xenial; urgency=low

  [ Tim Gardner ]

  * Release Tracking Bug
    - LP: #1532958

  [ Eric Dumazet ]

  * SAUCE: (noup) net: fix IP early demux races
    - LP: #1526946

  [ Guilherme G. Piccoli ]

  * SAUCE: powerpc/eeh: Validate arch in eeh_add_device_early()
    - LP: #1486180

  [ Hui Wang ]

  * [Config] CONFIG_I2C_DESIGNWARE_BAYTRAIL=y, CONFIG_IOSF_MBI=y
    - LP: #1527096

  [ Jann Horn ]

  * ptrace: being capable wrt a process requires mapped uids/gids
    - LP: #1527374

  [ Serge Hallyn ]

  * SAUCE: add a sysctl to disable unprivileged user namespace unsharing

  [ Tim Gardner ]

  * [Config] CONFIG_ZONE_DEVICE=y for amd64
  * [Config] CONFIG_VIRTIO_BLK=y, CONFIG_VIRTIO_NET=y for s390
    - LP: #1532886

  [ Upstream Kernel Changes ]

  * rhashtable: Fix walker list corruption
    - LP: #1526811
  * rhashtable: Kill harmless RCU warning in rhashtable_walk_init
    - LP: #1526811
  * ovl: fix permission checking for setattr
    - LP: #1528904
    - CVE-2015-8660

 -- Tim Gardner <email address hidden> Thu, 17 Dec 2015 05:34:47 -0700

Changed in linux (Ubuntu Xenial):
status: Fix Committed → Fix Released
To post a comment you must log in.
This report contains Public information  
Everyone can see this information.
Subscribing...

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.