Where to file this KVM/Qemu bug?

Where to file this KVM/Qemu bug?

[John W]

I have an issue where I cannot install or run Windows XP using KVM,
but it is fine under plain QEMU (with "-no-kvm").

Details here: https://stackoverflow.com/questions/57499661/libvirt-how-to-prevent-accel-kvm

I have found some similar-sounding cases, but they are from ~10 years ago.

Assuming this is a valid bug, I am trying to find the right place to file it.
Perhaps this is the right link?  https://www.linux-kvm.org/page/Bugs

If so, then the instructions there tell me "Even if you use kvm from a
distribution ... it is important to use the latest sources."

I am indeed using a distribution (Debian 10.0), but I'm not sure what
is meant by "use the latest sources". Does it mean an up-to-date
package for my distribution? Or is it suggesting I compile KVM myself
from source?

Thanks for any advice.
-John

Re: Where to file this KVM/Qemu bug?

[John Snow]

On 8/16/19 4:13 AM, John W wrote:
> I have an issue where I cannot install or run Windows XP using KVM,
> but it is fine under plain QEMU (with "-no-kvm").
> 
> Details here: https://stackoverflow.com/questions/57499661/libvirt-how-to-prevent-accel-kvm
> 
> I have found some similar-sounding cases, but they are from ~10 years ago.
> 
> Assuming this is a valid bug, I am trying to find the right place to file it.
> Perhaps this is the right link?  https://www.linux-kvm.org/page/Bugs
> 
> If so, then the instructions there tell me "Even if you use kvm from a
> distribution ... it is important to use the latest sources."
> 
> I am indeed using a distribution (Debian 10.0), but I'm not sure what
> is meant by "use the latest sources". Does it mean an up-to-date
> package for my distribution? Or is it suggesting I compile KVM myself
> from source?
> 
> Thanks for any advice.
> -John
> 

Generally, reporting bugs is nicest when you are using the "current
version." That can mean two things:

1: You may report bugs to your distribution; this lets you use the
latest version of KVM+QEMU+libvirt et al from your distro. I'm not sure
what that reporting process may look like for Debian, but there is a
Launchpad tracker that Ubuntu has for e.g. QEMU which allows you to file
bugs against the latest Ubuntu release.

This can be a bit slow; usually distributions want to know if there's a
problem on the very latest-and-greatest sources anyway, so:

2: You can skip the red tape and report bugs directly to the relevant
project, but they will often expect you to be using a version that's
newer than what your distribution packages; which does involve building
from source, usually.

It seems likely to me that this is a bug or misconfiguration in QEMU;
and QEMU also uses that same launchpad as an upstream bug tracker:
https://launchpad.net/qemu


I'd recommend that you:

- Download the 4.1.0 release tarball which came out just today, or clone
the git repo and checkout the 4.1 release tag, whichever you prefer.

- Grab build dependencies. A decent shortcut on debian is likely:
  > sudo apt-get build-dep qemu

- Build QEMU from source:
  > pushd src/qemu/
  > mkdir bin
  > pushd bin
  > ../configure --target-list="i386-softmmu"
  > make -j4

- Try to reproduce your problem using the newly built
src/qemu/bin/i386-softmmu/qemu-system-i386 binary.

If the bug reproduces:
- file a bug on the launchpad. Include linux kernel version, the exact
command line, and the version/edition of Windows you are trying to
install if you know it.

If it doesn't reproduce:
- we may have fixed the issue. It will likely be fixed when your
distribution releases a 4.1.0 package. There are steps you can take to
install your custom-built version of QEMU for use with libvirt/VMM in
the meantime.


Windows XP related bugs can be tricky because not everyone has easy
access to installation media for that operating system, and it has so
many versions that sometimes it's hard to get a reproducer. We might
need you to stick around and enable logging/tracing and relay some
information back to us.

Hope this answers your question, happy Friday and have a good weekend :)
--js