kvm_stat : missing python dependency

[bugproxy]

After installing linux-tools-host, the included kvm_stat utility won't work:

root@ubuntu:~# kvm_stat
-bash: /usr/bin/kvm_stat: /usr/bin/python: bad interpreter: No such file or directory

Reason is that there is apparently no dependency on a python package from the linux-tools-host package.

[Frank Heimes (frank-heimes)]

A minimal Ubuntu 18.10 installation comes by default with python3 only:
$ ls /usr/bin/python*
/usr/bin/python3 /usr/bin/python3.6 /usr/bin/python3.6m /usr/bin/python3m

The 'shebang' in /usr/bin/kvm_stat points to /usr/bin/python:
$ grep \#\! /usr/bin/kvm_stat
#!/usr/bin/python
Which is usually python version 2.x.

kvm_stat should work with python 2 or 3.
Since python3 is the default and because python 2 is legacy, the shebang in kvm_stat should better point to python3.

As a workaround create a link or an alias
or install python-minimal (which is python2):
$ sudo apt install python-minimal
...
and 'sudo kvm_stat' will work again.

[Christian Ehrhardt  (paelzer)]

I agree that adding a dependency and pulling in python2 from the kernel seems very wrong.

Per https://www.python.org/dev/peps/pep-0394/#recommendation I think the right header would be
  #!/usr/bin/env python3

That would be a (trivial) upstream change to the kernel as code is held there.
Unless it is still important to keep it also py2 executable - is it?

Per last commits on that file Stefan Raspl <email address hidden> should be best to decide where the upstream code should go to.
Even if it is py2 it should use the "env" sheband btw, see above pep link.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-10-19 16:03 EDT-------
Uh, now that would be me :O
Two aspects:
kvm_stat would need commit 58f33cfe73076 "tools/kvm_stat: fix python3 issues" from the kernel tree, which came with 4.19. I believe it was pulled into the stable kernels, but upon checking it doesn't appear to be present in cosmic.
The other thing is that the kernel community is quite conservative when it comes to backwards compatibility. I'm not sure if a switch to a later python version would go down too well with that crowd...

[Dimitri John Ledkov (xnox)]

Given that python2 is effectively EOL soon, and python3 has been available since forever... the switch must happen. Including stable releases of kernel, imho.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-10-22 16:40 EDT-------
According to https://legacy.python.org/dev/peps/pep-0373/, end of life for Python 2.7 was moved to 2020 - that's still a wee bit!
Still, since kvm_stat should be Python 3 compatible by now, why not just go a head and try to convert to "#!/usr/bin/env python3" upstream? Are you folks up to submitting a respective patch upstream, or do you want me to...?

[Frank Heimes (frank-heimes)]

Hi Stefan, since you recently brought some changes to kvm_stats upstream (iirc), I think it would be good if you can push for the python 'shebang' change to pythong3, too.
The code itself already runs fine on python3.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-10-24 15:44 EDT-------
OK, patch postet, see https://marc.info/?l=kvm&m=154041011320484&w=2
Let's see what happens next...

[Frank Heimes (frank-heimes)]

Thx Stefan, yes - let's wait and see. Hope upstream will agree.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-11-16 08:42 EDT-------
No feedback from upstream at all, sent a ping on the mailing list.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-11-26 08:47 EDT-------
In discussions with upstream now.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-12-14 16:44 EDT-------
Patch is queued according to maintainer, should be part of 4.21.

[Frank Heimes (frank-heimes)]

Hi Stefan, that would be fantastic, since this is the target for disco ...

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2018-12-18 03:35 EDT-------
Changed target milestone to 19.04, due to inclusion within kernel 4.21.
@Can: Is this also required for 18.04 LTS?

[Frank Heimes (frank-heimes)]

Yes, once it landed in 19.04,
it should be changed in 18.10 and 18.04, too.
All these have python3 per default.

[bugproxy (bugproxy)]

------- Comment From <email address hidden> 2019-01-09 04:06 EDT-------
fixed in upstream kernel

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/tools/kvm/kvm_stat
/kvm_stat?id=09f70c3b70e7d9e209a820b54dda42502fa40711

author Stefan Raspl <email address hidden> 2018-10-24 21:41:34 +0200
committer Paolo Bonzini <email address hidden> 2018-11-27 12:53:44 +0100
commit 09f70c3b70e7d9e209a820b54dda42502fa40711 (patch)
tree c58cbc7296cb398b41914b76314f88e6a1571e43 /tools/kvm/kvm_stat/kvm_stat
parent 45c3af974ec6c22d7392e15eb5d755e3c0079bd1 (diff)
download linux-09f70c3b70e7d9e209a820b54dda42502fa40711.tar.gz
tools/kvm_stat: switch to python3

[Seth Forshee (sforshee)]

Applied to disco.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 4.19.0-12.13

---------------
linux (4.19.0-12.13) disco; urgency=medium

  * linux: 4.19.0-12.13 -proposed tracker (LP: #1813664)

  * kernel oops in bcache module (LP: #1793901)
    - SAUCE: bcache: never writeback a discard operation

  * Disco update: 4.19.18 upstream stable release (LP: #1813611)
    - ipv6: Consider sk_bound_dev_if when binding a socket to a v4 mapped address
    - mlxsw: spectrum: Disable lag port TX before removing it
    - mlxsw: spectrum_switchdev: Set PVID correctly during VLAN deletion
    - net: dsa: mv88x6xxx: mv88e6390 errata
    - net, skbuff: do not prefer skb allocation fails early
    - qmi_wwan: add MTU default to qmap network interface
    - ipv6: Take rcu_read_lock in __inet6_bind for mapped addresses
    - net: clear skb->tstamp in bridge forwarding path
    - netfilter: ipset: Allow matching on destination MAC address for mac and
      ipmac sets
    - gpio: pl061: Move irq_chip definition inside struct pl061
    - drm/amd/display: Guard against null stream_state in set_crc_source
    - drm/amdkfd: fix interrupt spin lock
    - ixgbe: allow IPsec Tx offload in VEPA mode
    - platform/x86: asus-wmi: Tell the EC the OS will handle the display off
      hotkey
    - e1000e: allow non-monotonic SYSTIM readings
    - usb: typec: tcpm: Do not disconnect link for self powered devices
    - selftests/bpf: enable (uncomment) all tests in test_libbpf.sh
    - of: overlay: add missing of_node_put() after add new node to changeset
    - writeback: don't decrement wb->refcnt if !wb->bdi
    - serial: set suppress_bind_attrs flag only if builtin
    - bpf: Allow narrow loads with offset > 0
    - ALSA: oxfw: add support for APOGEE duet FireWire
    - x86/mce: Fix -Wmissing-prototypes warnings
    - MIPS: SiByte: Enable swiotlb for SWARM, LittleSur and BigSur
    - crypto: ecc - regularize scalar for scalar multiplication
    - arm64: perf: set suppress_bind_attrs flag to true
    - drm/atomic-helper: Complete fake_commit->flip_done potentially earlier
    - clk: meson: meson8b: fix incorrect divider mapping in cpu_scale_table
    - samples: bpf: fix: error handling regarding kprobe_events
    - usb: gadget: udc: renesas_usb3: add a safety connection way for
      forced_b_device
    - fpga: altera-cvp: fix probing for multiple FPGAs on the bus
    - selinux: always allow mounting submounts
    - ASoC: pcm3168a: Don't disable pcm3168a when CONFIG_PM defined
    - scsi: qedi: Check for session online before getting iSCSI TLV data.
    - drm/amdgpu: Reorder uvd ring init before uvd resume
    - rxe: IB_WR_REG_MR does not capture MR's iova field
    - efi/libstub: Disable some warnings for x86{,_64}
    - jffs2: Fix use of uninitialized delayed_work, lockdep breakage
    - clk: imx: make mux parent strings const
    - pstore/ram: Do not treat empty buffers as valid
    - media: uvcvideo: Refactor teardown of uvc on USB disconnect
    - powerpc/xmon: Fix invocation inside lock region
    - powerpc/pseries/cpuidle: Fix preempt warning
    - media: firewire: Fix app_info parameter type in avc_ca{,_app}_info
    - ASoC: use dma_ops of parent device for acp_audio_dma
    - media: ve...

[Brad Figg (brad-figg)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-cosmic' to 'verification-done-cosmic'. If the problem still exists, change the tag 'verification-needed-cosmic' to 'verification-failed-cosmic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Frank Heimes (frank-heimes)]

Successfully verified after moving to latest kernel in proposed and installing corresponding linux-tools-host package - see attachment.
Adjusting tags accordingly ...

[Brad Figg (brad-figg)]

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-bionic' to 'verification-done-bionic'. If the problem still exists, change the tag 'verification-needed-bionic' to 'verification-failed-bionic'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Frank Heimes (frank-heimes)]

Successfully verified on bionic, too - see attachment.
Adjusting tags accordingly ...