[Pkg-xen-devel] Bug#737613: Debian Bug 737613: Xen not loading dom0 on Jessie - FATAL error on running /etc/init.d/xen

[Ian Campbell]

Control: forcemerge 503287 737613

(making $subjet a bit more helpful this time too)

On Mon, Nov 24, 2014 at 05:28:59PM +0000, Ian Campbell wrote:
> Before investigating any further can either of you confirm whether
> this still happens with the version of Xen currently in Jessie, which
> is 4.4.1-3 (and the current kernel too). That was a major version
> bump, so it is worth confirming.

Actually nevermind this. Right after hitting send a bit more googling around
the issue took me to http://osdir.com/ml/general/2013-09/msg42718.html which
reminded me about https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=503287 and
checking the original report again it appears that you are indeed running
32-bit userspace on a 64-kernel on a 64-bit Xen. Unfortunately that combination
is not supported, quoting that first link:

  The Xen i386 userspace tools cannot run on a 64-bit kernel+hypervisor
  combo.
  
  The working combinations are:
  
  64 bit hyp, 64 bit dom0 kernel, 64 bit dom0 userspace.
  64 bit hyp, 32 bit dom0 kernel, 32 bit dom0 userspace.

The failure would be the same sort of invalid ioctl error as was observed.

Sorry for not spotting this sooner. Unfortunately this is unlikely to be fixed
within Debian (it's really an upstream thing).

Now that multiarch exists I think it ought to be possible to install the 64-bit
Xen toolstack on an otherwise 32-bit dom0 userspace, but I've not tried that
myself.

Sorry again for not figuring this out before.

I'm merging this bug with the existing wishlist bug, which is tagged wontfix
I'm afraid. It occurs to me today that /etc/init.d/xen could at least try and
detect this situation and warn about it instead of hanging.

Ian.