[Pkg-xen-devel] Bug#733865: Bug#733865: xen-utils-4.3: qemu-dm is not executable: No such file or directory

[Ian Campbell]

On Wed, 2014-01-01 at 09:52 -0600, Marc F. Clemente wrote:
> I have seen posts mentioning "traditional" and "upstream" qemu-dm.
> But it is not clear to me what the difference is between "traditional"
> and "upstream", or how to select either one.

This is explained in the xl.cfg(5) man page.
http://xenbits.xen.org/docs/unstable/man/xl.cfg.5.html

Briefly:

"traditional" is the historical Xen fork of Qemu (0.7 or 0.8 ish,
ancient), this was the default qemu used for HVM guests until Xen 4.4.

"upstream" is the upstream (i.e. qemu.org) version of Qemu which can be
used with Xen since 4.1 or 4.2 (I forget exactly) and became the default
in 4.4.

You can select a non-default model use by using the
"device_model_version" directive in your config.

In the context of Debian the Debian Xen maintainer has been trying to
move away from the traditional fork for several releases. Historically
the traditional qemu was shipped with the Xen utils in but in some
release (Wheezy? Maybe Squeeze?) it was removed and ended up packaged
separately as a separate xen-qemu-dm-4.0 package in order to keep things
working. In Jessie even that is gone. Luckily however the upstream qemu
package in Jessie already supports Xen so you should be able to simply
select that in your configuration.

So, things are a bit in flux right now but will be sorted by the time
Jessie is actually released. The fact that the Xen tools in 4.3 still
default to qemu-traditional which is not present is a bit unfortunate
but with Xen 4.4 due to be released in the next 4-6 weeks with a default
of qemu-upstream this will take care of itself sooner rather than later.
Xen 4.4 also includes support for compiling without qemu-traditional
support which will improve the error message should you try to use it
(either inadvertently as you have done here or deliberately).

> I don't know if there are missing files in the distibution.  Or if I
> am missing an important package.

xen-utils-4.3 recommends qemu-system-x86 which I think is the one you
want for qemu-upstream support and you seem to have it installed.

>   Or maybe I'm doing something wrong- and the documentation is
> inaccurate.
> 
> Is it possible to do HVM with Debian?

It should be, although as I say it may be in flux a bit.

Ian