ubuntu_blktrace_smoke_test failed with 4.4 / 4.15 kvm kernel

[Po-Hsu Lin]

The test failed with:
  FAILED (CONFIG_BLK_DEV_IO_TRACE=y in /boot/config-4.4.0-1019-kvm)
  FAILED (/sys/kernel/debug/tracing does not exist)

Steps to reproduce:
  Deploy the node with Xenial 4.4 kernel, install linux-kvm
  sudo apt-get install python-minimal
  git clone --depth=1 git://kernel.ubuntu.com/ubuntu/autotest-client-tests -b master-next
  git clone --depth=1 git://kernel.ubuntu.com/ubuntu/autotest
  rm -fr autotest/client/tests
  ln -sf ~/autotest-client-tests autotest/client/tests
  AUTOTEST_PATH=/home/ubuntu/autotest sudo -E autotest/client/autotest-local --verbose autotest/client/tests/ubuntu_blktrace_smoke_test/control

Output:
  https://pastebin.ubuntu.com/p/QY2dKcSybD/

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-1019-kvm 4.4.0-1019.24
ProcVersionSignature: User Name 4.4.0-1019.24-kvm 4.4.98
Uname: Linux 4.4.0-1019-kvm x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
Date: Mon Apr 2 16:07:26 2018
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-kvm
UpgradeStatus: No upgrade log present (probably fresh install)

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1760636

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Po-Hsu Lin (cypressyew)]

This issue can be reproduced in 4.15 KVM kernel as well.

[Po-Hsu Lin (cypressyew)]

This requires CONFIG_BLK_DEV_IO_TRACE to be enabled in the kernel.

However as this is for debugging purpose in some rare cases, we decided to disable this test for KVM kernel.

[Po-Hsu Lin (cypressyew)]

http://kernel.ubuntu.com/git/ubuntu/autotest-client-tests.git/commit/?id=3489bbe9fb8adbfe02973523953e4d1c591ec43d