Pkg xen devel - Jan 2014 - Bug#733865: Bug#733865: xen-utils-4.3: qemu-dm is not executable: No such file or directory

Package: xen-utils-4.3
Version: 4.3.0-3+b1
Severity: normal


When I try to create an HVW withDevian/xen, I run into trouble. It used to work,
maybe with xen 4.1, but it has never worked since.

Bug 688311 was filed, with the same exact problem.  That bug was somehow closed
and no resolution or explanation was provided.

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. 
My config file (snaptest.cfg) is nearly identical to the one provided by the
distribution in /etc/xen/xlexample.hvm.

I don't know if there are missing files in the distibution.  Or if I am
missing an important package.  Or maybe I'm doing something wrong- and the
documentation is inaccurate.

Is it possible to do HVM with Debian?

Thanks,

Marc

# xl create snaptest.cfg 
Parsing config from snaptest.cfg
xc: info: VIRTUAL MEMORY ARRANGEMENT:
  Loader:        0000000000100000->00000000001a0164
  Modules:       0000000000000000->0000000000000000
  TOTAL:         0000000000000000->00000000ff800000
  ENTRY ADDRESS: 0000000000100608
xc: info: PHYSICAL MEMORY ALLOCATION:
  4KB PAGES: 0x0000000000000200
  2MB PAGES: 0x00000000000005fb
  1GB PAGES: 0x0000000000000001
libxl: error: libxl_dm.c:1142:libxl__spawn_local_dm: device model
/usr/lib/xen-4.3/bin/qemu-dm is not executable: No such file or directory
libxl: error: libxl_dm.c:1275:device_model_spawn_outcome: (null): spawn failed
(rc=-3)
libxl: error: libxl_create.c:1075:domcreate_devmodel_started: device model did
not start: -3
libxl: error: libxl_dm.c:1300:libxl__destroy_device_model: could not find
device-model's pid for dom 2
libxl: error: libxl.c:1408:libxl__destroy_domid: libxl__destroy_device_model
failed for 2
Exit 3


# cat snaptest.cfg 
builder='hvm'
name = "example.hvm"
memory = 4096
vcpus = 2
disk = [ 'phy:/dev/vg0/snap,hda,w' ]
 


-- System Information:
Debian Release: jessie/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.12-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages xen-utils-4.3 depends on:
ii  e2fslibs          1.42.8-1
ii  libc6             2.17-97
ii  libncurses5       5.9+20130608-1
ii  libtinfo5         5.9+20130608-1
ii  libxen-4.3        4.3.0-3+b1
ii  libxenstore3.0    4.3.0-3+b1
ii  libyajl2          2.0.4-4
ii  python2.7         2.7.6-3
pn  python:any        <none>
ii  xen-utils-common  4.3.0-3

Versions of packages xen-utils-4.3 recommends:
ii  bridge-utils                                   1.5-7
ii  qemu-system-x86                                1.7.0+dfsg-2
ii  xen-hypervisor-4.3-amd64 [xen-hypervisor-4.3]  4.3.0-3+b1

xen-utils-4.3 suggests no packages.

-- no debconf information

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

On 01/02/2014 11:56 AM, Ian Campbell wrote:
> You can select a non-default model use by using the
> "device_model_version" directive in your config.
 From what I gather, for now, you MUST select a non-default model, using 
something like:

device_model_version="qemu-xen"
device_model_override="/usr/bin/qemu-system-x86_64"
> 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 "traditional" disappeared when Debian's xen went from 4.1 to
4.2.
> 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).
Is it, or will it be possible for me to build xen 4.3 or 4.4 WITH 
"traditional"?
>> Is it possible to do HVM with Debian?
>
> It should be, although as I say it may be in flux a bit.
My problem is that I was doing HVM with xen 4.1.  I had MS Windows XP, 7 
and 8 virtual machines.  I had VGA and PCI passthrough working just 
fine.  I tried using xen 4.2, but I was unable to do VGA passthrough. 
With 4.3, I can't even do PCI passthrough.  It says that my Intel 5500 
chipset is buggy (Intel errata #53), and disables IOMMU.  Maybe my 
chipset is buggy...  But it is rock-solid stable when I do HVMs with VGA 
passthrough using xen 4.1.

I wonder if anybody else shares my experience...

Comments or emails are welcome.

Thanks,

Marc